Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

Issuer	Date	Time CET	Quantity	Price (DKK)	Venue
GENMAB A/S	26-Mar-25	9:30:18 AM	70	1337.00	XCSE
GENMAB A/S	26-Mar-25	9:30:42 AM	42	1338.00	XCSE
GENMAB A/S	26-Mar-25	9:30:42 AM	67	1338.00	CEUX
GENMAB A/S	26-Mar-25	9:32:04 AM	56	1338.50	XCSE
GENMAB A/S	26-Mar-25	9:32:04 AM	68	1339.50	XCSE
GENMAB A/S	26-Mar-25	9:32:04 AM	1	1339.50	XCSE
GENMAB A/S	26-Mar-25	9:32:04 AM	4	1338.50	XCSE
GENMAB A/S	26-Mar-25	9:32:04 AM	24	1339.00	CEUX
GENMAB A/S	26-Mar-25	9:32:04 AM	39	1338.00	CEUX
GENMAB A/S	26-Mar-25	9:32:04 AM	63	1339.00	TQEX
GENMAB A/S	26-Mar-25	9:32:04 AM	68	1338.00	TQEX
GENMAB A/S	26-Mar-25	9:32:04 AM	64	1338.00	AQEU
GENMAB A/S	26-Mar-25	9:32:04 AM	71	1339.00	AQEU
GENMAB A/S	26-Mar-25	9:34:10 AM	30	1339.00	CEUX
GENMAB A/S	26-Mar-25	9:36:02 AM	18	1340.50	CEUX
GENMAB A/S	26-Mar-25	9:36:02 AM	37	1340.50	CEUX
GENMAB A/S	26-Mar-25	9:36:02 AM	32	1340.50	AQEU
GENMAB A/S	26-Mar-25	9:36:04 AM	72	1340.00	XCSE
GENMAB A/S	26-Mar-25	9:36:04 AM	7	1340.00	TQEX
GENMAB A/S	26-Mar-25	9:36:04 AM	16	1340.00	TQEX
GENMAB A/S	26-Mar-25	9:36:06 AM	26	1339.50	CEUX
GENMAB A/S	26-Mar-25	9:36:06 AM	12	1339.50	CEUX
GENMAB A/S	26-Mar-25	9:39:00 AM	23	1339.50	AQEU
GENMAB A/S	26-Mar-25	9:39:01 AM	23	1339.00	TQEX
GENMAB A/S	26-Mar-25	9:39:11 AM	15	1338.50	XCSE
GENMAB A/S	26-Mar-25	9:39:19 AM	54	1338.50	XCSE
GENMAB A/S	26-Mar-25	9:39:32 AM	22	1338.00	CEUX
GENMAB A/S	26-Mar-25	9:39:32 AM	3	1338.00	CEUX
GENMAB A/S	26-Mar-25	9:39:33 AM	75	1338.00	XCSE
GENMAB A/S	26-Mar-25	9:39:33 AM	53	1338.50	CEUX
GENMAB A/S	26-Mar-25	9:40:16 AM	39	1337.00	XCSE
GENMAB A/S	26-Mar-25	9:40:16 AM	3	1337.00	CEUX
GENMAB A/S	26-Mar-25	9:41:21 AM	72	1337.00	XCSE
GENMAB A/S	26-Mar-25	9:41:21 AM	34	1337.00	CEUX
GENMAB A/S	26-Mar-25	9:41:24 AM	33	1336.00	CEUX
GENMAB A/S	26-Mar-25	9:41:24 AM	14	1336.00	CEUX
GENMAB A/S	26-Mar-25	9:41:24 AM	23	1336.00	TQEX
GENMAB A/S	26-Mar-25	9:42:39 AM	73	1335.50	XCSE
GENMAB A/S	26-Mar-25	9:42:39 AM	48	1334.50	XCSE
GENMAB A/S	26-Mar-25	9:42:39 AM	27	1334.50	XCSE
GENMAB A/S	26-Mar-25	9:42:39 AM	44	1335.00	CEUX
GENMAB A/S	26-Mar-25	9:43:04 AM	71	1333.50	XCSE
GENMAB A/S	26-Mar-25	9:43:04 AM	64	1333.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	9:43:27 AM	71	1332.50	XCSE
GENMAB A/S	26-Mar-25	9:43:27 AM	49	1332.50	CEUX
GENMAB A/S	26-Mar-25	9:43:29 AM	1	1331.50	XCSE
GENMAB A/S	26-Mar-25	9:44:14 AM	8	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:44:14 AM	24	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:45:04 AM	71	1334.00	CEUX
GENMAB A/S	26-Mar-25	9:46:05 AM	73	1334.00	CEUX
GENMAB A/S	26-Mar-25	9:47:01 AM	23	1334.00	XCSE
GENMAB A/S	26-Mar-25	9:47:12 AM	12	1334.00	XCSE
GENMAB A/S	26-Mar-25	9:47:12 AM	11	1334.00	XCSE
GENMAB A/S	26-Mar-25	9:47:28 AM	20	1334.00	CEUX
GENMAB A/S	26-Mar-25	9:48:01 AM	23	1335.00	XCSE
GENMAB A/S	26-Mar-25	9:48:01 AM	4	1335.00	XCSE
GENMAB A/S	26-Mar-25	9:48:01 AM	74	1334.50	XCSE
GENMAB A/S	26-Mar-25	9:48:26 AM	2	1334.50	CEUX
GENMAB A/S	26-Mar-25	9:48:50 AM	12	1334.50	XCSE
GENMAB A/S	26-Mar-25	9:48:50 AM	58	1334.50	XCSE
GENMAB A/S	26-Mar-25	9:49:03 AM	73	1334.50	XCSE
GENMAB A/S	26-Mar-25	9:49:27 AM	29	1334.50	CEUX
GENMAB A/S	26-Mar-25	9:49:28 AM	52	1334.00	CEUX
GENMAB A/S	26-Mar-25	9:49:28 AM	23	1334.00	TQEX
GENMAB A/S	26-Mar-25	9:50:01 AM	1	1333.50	XCSE
GENMAB A/S	26-Mar-25	9:50:01 AM	69	1333.50	XCSE
GENMAB A/S	26-Mar-25	9:50:02 AM	18	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:50:02 AM	42	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:50:02 AM	21	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:50:02 AM	4	1332.50	XCSE
GENMAB A/S	26-Mar-25	9:50:02 AM	42	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:50:02 AM	27	1333.00	TQEX
GENMAB A/S	26-Mar-25	9:51:32 AM	42	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:51:32 AM	30	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:51:32 AM	14	1332.50	XCSE
GENMAB A/S	26-Mar-25	9:51:32 AM	11	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:51:32 AM	73	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:51:32 AM	23	1333.00	TQEX
GENMAB A/S	26-Mar-25	9:51:49 AM	27	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:51:54 AM	6	1332.50	XCSE
GENMAB A/S	26-Mar-25	9:52:06 AM	47	1332.50	XCSE
GENMAB A/S	26-Mar-25	9:52:41 AM	37	1332.00	XCSE
GENMAB A/S	26-Mar-25	9:52:41 AM	74	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:52:41 AM	5	1331.50	TQEX
GENMAB A/S	26-Mar-25	9:52:44 AM	9	1331.50	TQEX
GENMAB A/S	26-Mar-25	9:53:03 AM	2	1331.50	TQEX
GENMAB A/S	26-Mar-25	9:53:17 AM	11	1331.50	TQEX
GENMAB A/S	26-Mar-25	9:54:27 AM	16	1332.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	9:54:29 AM	1	1332.50	CEUX
GENMAB A/S	26-Mar-25	9:54:46 AM	42	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:54:46 AM	12	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:54:46 AM	30	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:54:46 AM	7	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:54:46 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:54:48 AM	9	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:54:48 AM	1	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:54:48 AM	31	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:54:48 AM	28	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:54:48 AM	18	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:55:15 AM	36	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:55:26 AM	2	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:56:05 AM	72	1332.00	XCSE
GENMAB A/S	26-Mar-25	9:56:05 AM	72	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:56:05 AM	29	1332.00	TQEX
GENMAB A/S	26-Mar-25	9:56:26 AM	1	1332.50	CEUX
GENMAB A/S	26-Mar-25	9:56:27 AM	1	1332.50	CEUX
GENMAB A/S	26-Mar-25	9:56:41 AM	23	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:56:41 AM	9	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:56:41 AM	6	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:56:41 AM	17	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:56:41 AM	8	1333.00	CEUX
GENMAB A/S	26-Mar-25	9:56:44 AM	58	1332.50	CEUX
GENMAB A/S	26-Mar-25	9:56:54 AM	50	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:54 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:54 AM	8	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:54 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:54 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:54 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:54 AM	33	1333.00	TQEX
GENMAB A/S	26-Mar-25	9:56:55 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:55 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	53	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	21	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	60	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:57 AM	12	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:58 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:58 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:58 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:58 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:59 AM	11	1333.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	9:56:59 AM	72	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:59 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:59 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:56:59 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	75	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:00 AM	44	1333.00	TQEX
GENMAB A/S	26-Mar-25	9:57:01 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:01 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:01 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:01 AM	74	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:02 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:02 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:02 AM	3	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:02 AM	20	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:04 AM	13	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:04 AM	9	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:04 AM	1	1333.00	XCSE
GENMAB A/S	26-Mar-25	9:57:07 AM	15	1332.50	CEUX
GENMAB A/S	26-Mar-25	9:57:28 AM	73	1332.00	XCSE
GENMAB A/S	26-Mar-25	9:57:28 AM	24	1332.00	TQEX
GENMAB A/S	26-Mar-25	9:57:54 AM	2	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:58:26 AM	5	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:59:14 AM	36	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:59:14 AM	27	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:59:34 AM	26	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:59:34 AM	7	1332.00	CEUX
GENMAB A/S	26-Mar-25	9:59:40 AM	25	1331.00	XCSE
GENMAB A/S	26-Mar-25	9:59:40 AM	71	1331.50	CEUX
GENMAB A/S	26-Mar-25	9:59:43 AM	47	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:00:04 AM	20	1330.50	CEUX
GENMAB A/S	26-Mar-25	10:00:04 AM	14	1330.50	CEUX
GENMAB A/S	26-Mar-25	10:00:04 AM	35	1330.50	CEUX
GENMAB A/S	26-Mar-25	10:00:04 AM	10	1330.50	TQEX
GENMAB A/S	26-Mar-25	10:00:04 AM	18	1330.50	TQEX
GENMAB A/S	26-Mar-25	10:00:06 AM	2	1330.50	TQEX
GENMAB A/S	26-Mar-25	10:00:18 AM	71	1329.50	XCSE
GENMAB A/S	26-Mar-25	10:01:22 AM	39	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:01:23 AM	42	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:01:23 AM	8	1331.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	10:01:23 AM	8	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:02:00 AM	4	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:02:00 AM	42	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:02:11 AM	23	1331.00	XCSE
GENMAB A/S	26-Mar-25	10:02:34 AM	72	1330.50	XCSE
GENMAB A/S	26-Mar-25	10:02:34 AM	71	1330.50	CEUX
GENMAB A/S	26-Mar-25	10:02:34 AM	33	1330.50	TQEX
GENMAB A/S	26-Mar-25	10:02:55 AM	43	1329.50	CEUX
GENMAB A/S	26-Mar-25	10:02:55 AM	28	1329.50	CEUX
GENMAB A/S	26-Mar-25	10:02:58 AM	10	1329.50	XCSE
GENMAB A/S	26-Mar-25	10:02:58 AM	59	1329.50	XCSE
GENMAB A/S	26-Mar-25	10:02:58 AM	23	1329.50	TQEX
GENMAB A/S	26-Mar-25	10:03:45 AM	34	1329.00	XCSE
GENMAB A/S	26-Mar-25	10:03:45 AM	8	1329.00	XCSE
GENMAB A/S	26-Mar-25	10:03:45 AM	28	1329.00	XCSE
GENMAB A/S	26-Mar-25	10:03:45 AM	24	1328.50	CEUX
GENMAB A/S	26-Mar-25	10:03:45 AM	50	1328.50	CEUX
GENMAB A/S	26-Mar-25	10:04:21 AM	66	1328.50	CEUX
GENMAB A/S	26-Mar-25	10:04:46 AM	71	1328.00	XCSE
GENMAB A/S	26-Mar-25	10:04:50 AM	23	1328.00	XCSE
GENMAB A/S	26-Mar-25	10:04:50 AM	42	1328.00	XCSE
GENMAB A/S	26-Mar-25	10:04:50 AM	4	1328.00	XCSE
GENMAB A/S	26-Mar-25	10:04:50 AM	25	1328.00	XCSE
GENMAB A/S	26-Mar-25	10:05:29 AM	70	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:29 AM	21	1330.00	CEUX
GENMAB A/S	26-Mar-25	10:05:29 AM	18	1330.00	AQEU
GENMAB A/S	26-Mar-25	10:05:30 AM	58	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	39	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	11	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	12	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	42	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	1	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	12	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	13	1330.00	XCSE
GENMAB A/S	26-Mar-25	10:05:30 AM	51	1330.00	CEUX
GENMAB A/S	26-Mar-25	10:05:30 AM	25	1330.00	TQEX
GENMAB A/S	26-Mar-25	10:05:30 AM	7	1330.00	AQEU
GENMAB A/S	26-Mar-25	10:05:53 AM	75	1329.00	XCSE
GENMAB A/S	26-Mar-25	10:05:53 AM	74	1329.00	CEUX
GENMAB A/S	26-Mar-25	10:05:53 AM	23	1329.00	AQEU
GENMAB A/S	26-Mar-25	10:11:06 AM	13	1331.50	XCSE
GENMAB A/S	26-Mar-25	10:11:12 AM	25	1331.50	XCSE
GENMAB A/S	26-Mar-25	10:11:57 AM	13	1331.50	XCSE
GENMAB A/S	26-Mar-25	10:11:57 AM	10	1331.50	XCSE
GENMAB A/S	26-Mar-25	10:11:57 AM	37	1331.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	10:11:57 AM	42	1331.50	XCSE
GENMAB A/S	26-Mar-25	10:12:51 AM	73	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:12:56 AM	15	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:12:56 AM	12	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:12:56 AM	19	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:12:56 AM	69	1333.00	CEUX
GENMAB A/S	26-Mar-25	10:13:21 AM	5	1333.50	CEUX
GENMAB A/S	26-Mar-25	10:13:21 AM	68	1333.50	CEUX
GENMAB A/S	26-Mar-25	10:13:22 AM	10	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:13:22 AM	7	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:14:23 AM	27	1334.00	TQEX
GENMAB A/S	26-Mar-25	10:14:23 AM	1	1334.00	TQEX
GENMAB A/S	26-Mar-25	10:14:26 AM	3	1334.00	XCSE
GENMAB A/S	26-Mar-25	10:14:32 AM	6	1333.50	XCSE
GENMAB A/S	26-Mar-25	10:16:02 AM	10	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:02 AM	42	1334.00	XCSE
GENMAB A/S	26-Mar-25	10:16:02 AM	42	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:02 AM	75	1334.50	CEUX
GENMAB A/S	26-Mar-25	10:16:02 AM	23	1334.00	TQEX
GENMAB A/S	26-Mar-25	10:16:02 AM	39	1334.00	AQEU
GENMAB A/S	26-Mar-25	10:16:03 AM	30	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:03 AM	42	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:09 AM	42	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:09 AM	30	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:09 AM	70	1334.50	CEUX
GENMAB A/S	26-Mar-25	10:16:27 AM	30	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:27 AM	42	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:27 AM	58	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:27 AM	6	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:47 AM	42	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:47 AM	10	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:16:48 AM	27	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:17:03 AM	37	1334.00	AQEU
GENMAB A/S	26-Mar-25	10:17:29 AM	11	1335.00	TQEX
GENMAB A/S	26-Mar-25	10:17:44 AM	16	1335.00	TQEX
GENMAB A/S	26-Mar-25	10:18:06 AM	73	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:18:06 AM	72	1334.50	CEUX
GENMAB A/S	26-Mar-25	10:18:06 AM	23	1334.50	AQEU
GENMAB A/S	26-Mar-25	10:18:55 AM	23	1334.00	XCSE
GENMAB A/S	26-Mar-25	10:20:26 AM	42	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:20:26 AM	1	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:20:26 AM	2	1334.50	XCSE
GENMAB A/S	26-Mar-25	10:21:14 AM	25	1336.00	CEUX
GENMAB A/S	26-Mar-25	10:22:04 AM	73	1336.00	XCSE
GENMAB A/S	26-Mar-25	10:22:04 AM	48	1336.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	10:22:04 AM	23	1336.00	TQEX
GENMAB A/S	26-Mar-25	10:22:04 AM	23	1336.00	AQEU
GENMAB A/S	26-Mar-25	10:22:54 AM	42	1336.00	XCSE
GENMAB A/S	26-Mar-25	10:22:54 AM	11	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:54 AM	41	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:55 AM	12	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:55 AM	1	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:55 AM	58	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:55 AM	12	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:55 AM	11	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:22:57 AM	73	1337.00	XCSE
GENMAB A/S	26-Mar-25	10:22:57 AM	20	1337.00	XCSE
GENMAB A/S	26-Mar-25	10:22:57 AM	35	1337.00	XCSE
GENMAB A/S	26-Mar-25	10:22:59 AM	24	1337.00	AQEU
GENMAB A/S	26-Mar-25	10:23:06 AM	60	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:23:06 AM	15	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:23:06 AM	25	1336.50	CEUX
GENMAB A/S	26-Mar-25	10:23:06 AM	47	1336.50	CEUX
GENMAB A/S	26-Mar-25	10:23:06 AM	9	1336.50	TQEX
GENMAB A/S	26-Mar-25	10:23:06 AM	33	1336.50	TQEX
GENMAB A/S	26-Mar-25	10:23:57 AM	69	1336.50	CEUX
GENMAB A/S	26-Mar-25	10:25:08 AM	11	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:25:08 AM	10	1336.50	XCSE
GENMAB A/S	26-Mar-25	10:25:21 AM	71	1336.00	XCSE
GENMAB A/S	26-Mar-25	10:25:21 AM	69	1335.50	CEUX
GENMAB A/S	26-Mar-25	10:25:21 AM	27	1336.00	AQEU
GENMAB A/S	26-Mar-25	10:25:23 AM	1	1336.00	AQEU
GENMAB A/S	26-Mar-25	10:25:28 AM	73	1335.00	XCSE
GENMAB A/S	26-Mar-25	10:25:28 AM	1	1336.00	AQEU
GENMAB A/S	26-Mar-25	10:26:45 AM	23	1337.00	AQEU
GENMAB A/S	26-Mar-25	10:27:10 AM	10	1337.50	XCSE
GENMAB A/S	26-Mar-25	10:27:10 AM	42	1337.50	XCSE
GENMAB A/S	26-Mar-25	10:27:10 AM	12	1337.50	XCSE
GENMAB A/S	26-Mar-25	10:27:46 AM	74	1338.50	CEUX
GENMAB A/S	26-Mar-25	10:29:07 AM	10	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:29:07 AM	30	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:29:07 AM	27	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:29:07 AM	3	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:29:07 AM	23	1338.50	AQEU
GENMAB A/S	26-Mar-25	10:30:35 AM	69	1339.50	XCSE
GENMAB A/S	26-Mar-25	10:30:35 AM	44	1339.50	CEUX
GENMAB A/S	26-Mar-25	10:30:35 AM	28	1339.50	CEUX
GENMAB A/S	26-Mar-25	10:31:01 AM	4	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:01 AM	30	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:01 AM	72	1338.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	10:31:01 AM	18	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:01 AM	42	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:01 AM	58	1338.50	CEUX
GENMAB A/S	26-Mar-25	10:31:01 AM	41	1338.50	TQEX
GENMAB A/S	26-Mar-25	10:31:01 AM	32	1339.00	AQEU
GENMAB A/S	26-Mar-25	10:31:06 AM	18	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:06 AM	10	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:06 AM	35	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:31:26 AM	2	1338.50	XCSE
GENMAB A/S	26-Mar-25	10:32:32 AM	73	1339.50	XCSE
GENMAB A/S	26-Mar-25	10:32:32 AM	30	1339.50	XCSE
GENMAB A/S	26-Mar-25	10:32:32 AM	19	1339.50	XCSE
GENMAB A/S	26-Mar-25	10:32:32 AM	1	1339.50	XCSE
GENMAB A/S	26-Mar-25	10:32:32 AM	29	1339.50	CEUX
GENMAB A/S	26-Mar-25	10:32:32 AM	18	1339.50	CEUX
GENMAB A/S	26-Mar-25	10:32:32 AM	3	1339.50	CEUX
GENMAB A/S	26-Mar-25	10:33:11 AM	12	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:33:11 AM	2	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:33:23 AM	25	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:34:20 AM	71	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:34:20 AM	38	1340.00	CEUX
GENMAB A/S	26-Mar-25	10:34:20 AM	20	1340.00	CEUX
GENMAB A/S	26-Mar-25	10:35:03 AM	1	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:35:03 AM	1	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:36:14 AM	11	1340.50	XCSE
GENMAB A/S	26-Mar-25	10:36:14 AM	26	1340.50	XCSE
GENMAB A/S	26-Mar-25	10:36:14 AM	36	1340.50	XCSE
GENMAB A/S	26-Mar-25	10:36:14 AM	3	1340.50	XCSE
GENMAB A/S	26-Mar-25	10:36:14 AM	11	1340.50	XCSE
GENMAB A/S	26-Mar-25	10:37:11 AM	70	1340.00	XCSE
GENMAB A/S	26-Mar-25	10:37:11 AM	69	1340.00	CEUX
GENMAB A/S	26-Mar-25	10:38:01 AM	37	1339.50	AQEU
GENMAB A/S	26-Mar-25	10:38:01 AM	1	1339.50	AQEU
GENMAB A/S	26-Mar-25	10:38:21 AM	74	1339.50	XCSE
GENMAB A/S	26-Mar-25	10:41:26 AM	2	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:42:17 AM	71	1340.50	XCSE
GENMAB A/S	26-Mar-25	10:42:52 AM	71	1342.00	XCSE
GENMAB A/S	26-Mar-25	10:43:04 AM	10	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:04 AM	69	1341.50	CEUX
GENMAB A/S	26-Mar-25	10:43:04 AM	23	1341.50	TQEX
GENMAB A/S	26-Mar-25	10:43:04 AM	26	1341.50	AQEU
GENMAB A/S	26-Mar-25	10:43:11 AM	39	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	25	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	25	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	45	1341.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	10:43:11 AM	3	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	42	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	10	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	42	1341.00	XCSE
GENMAB A/S	26-Mar-25	10:43:11 AM	71	1340.50	CEUX
GENMAB A/S	26-Mar-25	10:43:11 AM	31	1340.50	TQEX
GENMAB A/S	26-Mar-25	10:43:11 AM	24	1340.50	AQEU
GENMAB A/S	26-Mar-25	10:43:59 AM	37	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:59 AM	23	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:59 AM	42	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:59 AM	26	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:59 AM	12	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:59 AM	11	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:43:59 AM	8	1341.50	XCSE
GENMAB A/S	26-Mar-25	10:44:50 AM	75	1342.00	CEUX
GENMAB A/S	26-Mar-25	10:45:28 AM	25	1342.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	19	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	11	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	11	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	23	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:31 AM	11	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:41 AM	13	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:41 AM	22	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:45:56 AM	35	1343.50	XCSE
GENMAB A/S	26-Mar-25	10:45:56 AM	26	1343.50	XCSE
GENMAB A/S	26-Mar-25	10:46:22 AM	71	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:46:22 AM	71	1343.00	CEUX
GENMAB A/S	26-Mar-25	10:46:22 AM	32	1343.00	TQEX
GENMAB A/S	26-Mar-25	10:46:22 AM	24	1343.00	AQEU
GENMAB A/S	26-Mar-25	10:46:23 AM	71	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:46:23 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:49:43 AM	26	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:49:43 AM	25	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:49:43 AM	36	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:16 AM	72	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:16 AM	32	1343.00	CEUX
GENMAB A/S	26-Mar-25	10:51:16 AM	71	1343.00	CEUX
GENMAB A/S	26-Mar-25	10:51:16 AM	25	1343.00	TQEX
GENMAB A/S	26-Mar-25	10:51:16 AM	27	1343.00	AQEU
GENMAB A/S	26-Mar-25	10:51:44 AM	23	1342.50	TQEX
GENMAB A/S	26-Mar-25	10:51:47 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:47 AM	36	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:47 AM	14	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	10:51:47 AM	19	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:47 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:47 AM	2	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:47 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:55 AM	3	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:55 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:55 AM	42	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:55 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:51:55 AM	27	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:52:24 AM	44	1342.00	XCSE
GENMAB A/S	26-Mar-25	10:52:24 AM	21	1342.00	CEUX
GENMAB A/S	26-Mar-25	10:52:24 AM	49	1342.00	CEUX
GENMAB A/S	26-Mar-25	10:52:24 AM	25	1342.00	AQEU
GENMAB A/S	26-Mar-25	10:54:10 AM	2	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:10 AM	27	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:10 AM	42	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:10 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:10 AM	4	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:10 AM	9	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:45 AM	19	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:45 AM	17	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:45 AM	2	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:45 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:45 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:54:56 AM	72	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:55:58 AM	4	1343.00	CEUX
GENMAB A/S	26-Mar-25	10:55:58 AM	1	1343.00	TQEX
GENMAB A/S	26-Mar-25	10:56:02 AM	23	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:56:02 AM	14	1343.00	XCSE
GENMAB A/S	26-Mar-25	10:56:02 AM	37	1343.00	CEUX
GENMAB A/S	26-Mar-25	10:56:02 AM	34	1343.00	CEUX
GENMAB A/S	26-Mar-25	10:56:02 AM	22	1343.00	TQEX
GENMAB A/S	26-Mar-25	10:57:00 AM	23	1342.50	AQEU
GENMAB A/S	26-Mar-25	10:57:25 AM	2	1342.50	XCSE
GENMAB A/S	26-Mar-25	10:58:13 AM	72	1342.00	XCSE
GENMAB A/S	26-Mar-25	10:58:13 AM	25	1342.00	CEUX
GENMAB A/S	26-Mar-25	10:58:13 AM	49	1342.00	CEUX
GENMAB A/S	26-Mar-25	10:58:43 AM	12	1342.00	XCSE
GENMAB A/S	26-Mar-25	10:58:43 AM	23	1342.00	XCSE
GENMAB A/S	26-Mar-25	10:59:26 AM	28	1342.00	XCSE
GENMAB A/S	26-Mar-25	11:00:01 AM	19	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:01 AM	23	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:01 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:01 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:01 AM	42	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:00:01 AM	33	1342.50	TQEX
GENMAB A/S	26-Mar-25	11:00:02 AM	15	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:02 AM	11	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:02 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:02 AM	13	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:02 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:02 AM	42	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:26 AM	1	1342.50	CEUX
GENMAB A/S	26-Mar-25	11:00:45 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:45 AM	13	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:45 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:45 AM	65	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:45 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:45 AM	4	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:00:45 AM	75	1343.00	CEUX
GENMAB A/S	26-Mar-25	11:02:26 AM	11	1343.00	CEUX
GENMAB A/S	26-Mar-25	11:02:27 AM	47	1342.00	XCSE
GENMAB A/S	26-Mar-25	11:02:27 AM	7	1342.00	XCSE
GENMAB A/S	26-Mar-25	11:02:27 AM	3	1342.00	CEUX
GENMAB A/S	26-Mar-25	11:03:26 AM	12	1342.50	XCSE
GENMAB A/S	26-Mar-25	11:03:26 AM	2	1342.50	XCSE
GENMAB A/S	26-Mar-25	11:03:26 AM	25	1342.50	CEUX
GENMAB A/S	26-Mar-25	11:03:27 AM	1	1342.50	CEUX
GENMAB A/S	26-Mar-25	11:03:35 AM	23	1342.50	TQEX
GENMAB A/S	26-Mar-25	11:03:35 AM	3	1342.50	TQEX
GENMAB A/S	26-Mar-25	11:03:39 AM	15	1342.00	XCSE
GENMAB A/S	26-Mar-25	11:03:39 AM	4	1342.00	CEUX
GENMAB A/S	26-Mar-25	11:03:40 AM	10	1342.00	CEUX
GENMAB A/S	26-Mar-25	11:04:26 AM	1	1342.50	CEUX
GENMAB A/S	26-Mar-25	11:04:52 AM	75	1342.50	XCSE
GENMAB A/S	26-Mar-25	11:04:59 AM	28	1342.50	XCSE
GENMAB A/S	26-Mar-25	11:04:59 AM	40	1342.50	XCSE
GENMAB A/S	26-Mar-25	11:04:59 AM	12	1342.50	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	1	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	18	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	12	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	2	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	10	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:40 AM	18	1343.00	CEUX
GENMAB A/S	26-Mar-25	11:05:41 AM	38	1343.00	XCSE
GENMAB A/S	26-Mar-25	11:05:41 AM	21	1343.00	CEUX
GENMAB A/S	26-Mar-25	11:05:44 AM	11	1343.00	CEUX
GENMAB A/S	26-Mar-25	11:05:50 AM	36	1343.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:06:04 AM	21	1343.00	CEUX
GENMAB A/S	26-Mar-25	11:06:37 AM	2	1344.50	XCSE
GENMAB A/S	26-Mar-25	11:06:42 AM	3	1344.50	TQEX
GENMAB A/S	26-Mar-25	11:06:42 AM	7	1344.50	TQEX
GENMAB A/S	26-Mar-25	11:06:42 AM	34	1344.50	TQEX
GENMAB A/S	26-Mar-25	11:08:26 AM	4	1345.00	CEUX
GENMAB A/S	26-Mar-25	11:08:44 AM	14	1346.50	AQEU
GENMAB A/S	26-Mar-25	11:08:48 AM	1	1346.50	AQEU
GENMAB A/S	26-Mar-25	11:08:48 AM	1	1346.50	AQEU
GENMAB A/S	26-Mar-25	11:08:51 AM	13	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:08:51 AM	35	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:08:51 AM	35	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:08:51 AM	59	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:09:12 AM	26	1346.50	AQEU
GENMAB A/S	26-Mar-25	11:09:25 AM	2	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:09:25 AM	1	1346.50	CEUX
GENMAB A/S	26-Mar-25	11:09:26 AM	2	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:09:26 AM	15	1346.50	CEUX
GENMAB A/S	26-Mar-25	11:10:25 AM	5	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:10:25 AM	11	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:10:25 AM	5	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:10:25 AM	23	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:10:37 AM	4	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:10:37 AM	5	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:11:03 AM	1	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:11:20 AM	22	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:11:20 AM	25	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:11:20 AM	2	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:12:55 AM	53	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:55 AM	41	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:56 AM	78	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:56 AM	10	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:56 AM	16	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:57 AM	9	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:58 AM	12	1347.50	XCSE
GENMAB A/S	26-Mar-25	11:12:58 AM	26	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:12:58 AM	26	1347.50	XCSE
GENMAB A/S	26-Mar-25	11:12:58 AM	36	1347.50	CEUX
GENMAB A/S	26-Mar-25	11:12:58 AM	23	1347.50	AQEU
GENMAB A/S	26-Mar-25	11:12:59 AM	24	1347.50	XCSE
GENMAB A/S	26-Mar-25	11:12:59 AM	12	1347.50	XCSE
GENMAB A/S	26-Mar-25	11:12:59 AM	10	1347.50	XCSE
GENMAB A/S	26-Mar-25	11:12:59 AM	22	1347.50	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	32	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	10	1347.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:13:05 AM	10	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	31	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	11	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	32	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	42	1347.00	XCSE
GENMAB A/S	26-Mar-25	11:13:05 AM	5	1347.50	CEUX
GENMAB A/S	26-Mar-25	11:13:05 AM	36	1347.50	CEUX
GENMAB A/S	26-Mar-25	11:13:05 AM	4	1347.50	CEUX
GENMAB A/S	26-Mar-25	11:13:05 AM	7	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:13:05 AM	62	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:13:05 AM	37	1347.00	TQEX
GENMAB A/S	26-Mar-25	11:13:05 AM	2	1347.00	TQEX
GENMAB A/S	26-Mar-25	11:13:07 AM	4	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:13:07 AM	11	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:13:07 AM	4	1347.00	CEUX
GENMAB A/S	26-Mar-25	11:14:23 AM	26	1346.50	CEUX
GENMAB A/S	26-Mar-25	11:14:23 AM	39	1346.50	CEUX
GENMAB A/S	26-Mar-25	11:14:45 AM	12	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:14:45 AM	2	1346.50	XCSE
GENMAB A/S	26-Mar-25	11:16:26 AM	1	1346.50	CEUX
GENMAB A/S	26-Mar-25	11:18:27 AM	71	1348.00	XCSE
GENMAB A/S	26-Mar-25	11:18:27 AM	42	1348.50	XCSE
GENMAB A/S	26-Mar-25	11:18:27 AM	12	1348.50	XCSE
GENMAB A/S	26-Mar-25	11:18:27 AM	7	1348.50	XCSE
GENMAB A/S	26-Mar-25	11:18:27 AM	10	1348.50	XCSE
GENMAB A/S	26-Mar-25	11:18:27 AM	5	1348.50	CEUX
GENMAB A/S	26-Mar-25	11:18:27 AM	12	1348.00	CEUX
GENMAB A/S	26-Mar-25	11:18:27 AM	4	1348.50	CEUX
GENMAB A/S	26-Mar-25	11:18:27 AM	63	1348.00	CEUX
GENMAB A/S	26-Mar-25	11:18:38 AM	4	1349.00	XCSE
GENMAB A/S	26-Mar-25	11:19:00 AM	61	1348.50	XCSE
GENMAB A/S	26-Mar-25	11:19:54 AM	10	1349.50	CEUX
GENMAB A/S	26-Mar-25	11:19:54 AM	64	1349.50	CEUX
GENMAB A/S	26-Mar-25	11:19:54 AM	2	1349.50	CEUX
GENMAB A/S	26-Mar-25	11:19:54 AM	1	1349.50	CEUX
GENMAB A/S	26-Mar-25	11:19:54 AM	17	1349.50	CEUX
GENMAB A/S	26-Mar-25	11:19:58 AM	13	1350.50	CEUX
GENMAB A/S	26-Mar-25	11:19:58 AM	8	1350.50	CEUX
GENMAB A/S	26-Mar-25	11:20:01 AM	71	1350.50	XCSE
GENMAB A/S	26-Mar-25	11:21:30 AM	42	1351.00	XCSE
GENMAB A/S	26-Mar-25	11:21:30 AM	23	1351.00	CEUX
GENMAB A/S	26-Mar-25	11:21:30 AM	8	1351.00	CEUX
GENMAB A/S	26-Mar-25	11:22:34 AM	9	1351.50	CEUX
GENMAB A/S	26-Mar-25	11:22:34 AM	16	1351.50	CEUX
GENMAB A/S	26-Mar-25	11:22:34 AM	30	1351.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:22:34 AM	1	1351.50	CEUX
GENMAB A/S	26-Mar-25	11:23:36 AM	35	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:36 AM	42	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:36 AM	8	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:36 AM	9	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	11	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	10	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	15	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	2	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	42	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	10	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:37 AM	12	1352.00	CEUX
GENMAB A/S	26-Mar-25	11:23:38 AM	17	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:38 AM	14	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:39 AM	12	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:39 AM	16	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:40 AM	9	1352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:40 AM	16	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:40 AM	17	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:41 AM	10	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:41 AM	11	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:42 AM	15	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:42 AM	7	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:23:42 AM	24	1,352.00	TQEX
GENMAB A/S	26-Mar-25	11:24:25 AM	36	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:24:26 AM	13	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:24:26 AM	1	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:24:26 AM	1	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:24:41 AM	36	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:25:00 AM	32	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:25:53 AM	11	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:25:53 AM	43	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:25:53 AM	1	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:25:53 AM	27	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:25:54 AM	71	1,351.00	XCSE
GENMAB A/S	26-Mar-25	11:26:00 AM	20	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:26:00 AM	17	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:26:25 AM	42	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:26:25 AM	10	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:26:26 AM	2	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:26:31 AM	11	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:26:38 AM	15	1,352.50	XCSE
GENMAB A/S	26-Mar-25	11:26:38 AM	35	1,352.50	XCSE
GENMAB A/S	26-Mar-25	11:26:38 AM	27	1,352.50	XCSE
GENMAB A/S	26-Mar-25	11:26:38 AM	2	1,352.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:26:46 AM	36	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:26:47 AM	5	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:26:54 AM	5	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:26:54 AM	5	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:26:54 AM	12	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:27:15 AM	23	1,352.00	XCSE
GENMAB A/S	26-Mar-25	11:27:27 AM	70	1,351.00	XCSE
GENMAB A/S	26-Mar-25	11:27:27 AM	74	1,349.50	XCSE
GENMAB A/S	26-Mar-25	11:27:27 AM	70	1,351.00	CEUX
GENMAB A/S	26-Mar-25	11:27:27 AM	29	1,351.00	TQEX
GENMAB A/S	26-Mar-25	11:27:27 AM	24	1,351.00	AQEU
GENMAB A/S	26-Mar-25	11:27:31 AM	23	1,351.00	TQEX
GENMAB A/S	26-Mar-25	11:28:25 AM	72	1,350.50	XCSE
GENMAB A/S	26-Mar-25	11:28:40 AM	9	1,348.50	XCSE
GENMAB A/S	26-Mar-25	11:28:40 AM	69	1,349.50	XCSE
GENMAB A/S	26-Mar-25	11:28:40 AM	69	1,350.00	CEUX
GENMAB A/S	26-Mar-25	11:28:40 AM	28	1,350.00	TQEX
GENMAB A/S	26-Mar-25	11:28:40 AM	23	1,350.00	AQEU
GENMAB A/S	26-Mar-25	11:29:11 AM	67	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:29:11 AM	67	1,349.00	XCSE
GENMAB A/S	26-Mar-25	11:29:11 AM	1	1,348.50	CEUX
GENMAB A/S	26-Mar-25	11:29:11 AM	71	1,348.50	CEUX
GENMAB A/S	26-Mar-25	11:29:15 AM	74	1,347.50	CEUX
GENMAB A/S	26-Mar-25	11:29:15 AM	26	1,348.00	AQEU
GENMAB A/S	26-Mar-25	11:29:56 AM	75	1,347.00	XCSE
GENMAB A/S	26-Mar-25	11:30:36 AM	49	1,348.00	CEUX
GENMAB A/S	26-Mar-25	11:32:07 AM	22	1,348.00	CEUX
GENMAB A/S	26-Mar-25	11:34:05 AM	3	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:34:05 AM	37	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:34:05 AM	4	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:34:35 AM	1	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:34:35 AM	12	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:34:45 AM	12	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:34:55 AM	12	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:37:25 AM	53	1,348.50	XCSE
GENMAB A/S	26-Mar-25	11:37:25 AM	18	1,348.50	XCSE
GENMAB A/S	26-Mar-25	11:37:25 AM	2	1,348.00	XCSE
GENMAB A/S	26-Mar-25	11:37:25 AM	18	1,348.50	CEUX
GENMAB A/S	26-Mar-25	11:37:25 AM	22	1,348.50	CEUX
GENMAB A/S	26-Mar-25	11:37:25 AM	34	1,348.50	CEUX
GENMAB A/S	26-Mar-25	11:39:05 AM	17	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:39:05 AM	40	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:39:05 AM	37	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:39:19 AM	1	1,351.00	CEUX
GENMAB A/S	26-Mar-25	11:39:19 AM	10	1,351.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:39:19 AM	58	1,351.00	CEUX
GENMAB A/S	26-Mar-25	11:39:24 AM	46	1,351.00	XCSE
GENMAB A/S	26-Mar-25	11:39:34 AM	7	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:39:35 AM	10	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:39:35 AM	18	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:40:41 AM	12	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:40:41 AM	3	1,351.50	XCSE
GENMAB A/S	26-Mar-25	11:42:25 AM	33	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:42:25 AM	16	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:42:25 AM	1	1,352.00	CEUX
GENMAB A/S	26-Mar-25	11:42:45 AM	59	1,354.50	XCSE
GENMAB A/S	26-Mar-25	11:42:45 AM	35	1,354.50	XCSE
GENMAB A/S	26-Mar-25	11:42:46 AM	47	1,354.50	XCSE
GENMAB A/S	26-Mar-25	11:43:10 AM	13	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:43:45 AM	5	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:43:45 AM	13	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:43:45 AM	5	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:44:14 AM	69	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:14 AM	25	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:14 AM	1	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:44:15 AM	48	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:15 AM	16	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:15 AM	78	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:15 AM	21	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:15 AM	25	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:15 AM	4	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:44:15 AM	4	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:44:15 AM	2	1,355.50	CEUX
GENMAB A/S	26-Mar-25	11:44:15 AM	43	1,355.00	TQEX
GENMAB A/S	26-Mar-25	11:44:16 AM	23	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:34 AM	23	1,355.00	CEUX
GENMAB A/S	26-Mar-25	11:44:35 AM	21	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:35 AM	2	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:55 AM	7	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:44:55 AM	25	1,355.00	XCSE
GENMAB A/S	26-Mar-25	11:45:13 AM	59	1,354.50	XCSE
GENMAB A/S	26-Mar-25	11:45:13 AM	13	1,354.50	XCSE
GENMAB A/S	26-Mar-25	11:45:13 AM	17	1,354.50	CEUX
GENMAB A/S	26-Mar-25	11:45:13 AM	56	1,354.50	CEUX
GENMAB A/S	26-Mar-25	11:45:13 AM	30	1,354.00	TQEX
GENMAB A/S	26-Mar-25	11:45:13 AM	32	1,354.50	AQEU
GENMAB A/S	26-Mar-25	11:45:19 AM	23	1,353.50	XCSE
GENMAB A/S	26-Mar-25	11:45:22 AM	51	1,353.50	XCSE
GENMAB A/S	26-Mar-25	11:45:22 AM	74	1,353.50	CEUX
GENMAB A/S	26-Mar-25	11:45:22 AM	4	1,354.00	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:45:22 AM	32	1,353.50	AQEU
GENMAB A/S	26-Mar-25	11:48:38 AM	7	1,354.00	XCSE
GENMAB A/S	26-Mar-25	11:49:43 AM	4	1,354.50	CEUX
GENMAB A/S	26-Mar-25	11:50:14 AM	32	1,354.50	CEUX
GENMAB A/S	26-Mar-25	11:51:29 AM	3	1,356.50	CEUX
GENMAB A/S	26-Mar-25	11:51:48 AM	2	1,357.00	XCSE
GENMAB A/S	26-Mar-25	11:51:48 AM	50	1,357.00	XCSE
GENMAB A/S	26-Mar-25	11:51:48 AM	29	1,357.00	XCSE
GENMAB A/S	26-Mar-25	11:51:48 AM	72	1,356.50	CEUX
GENMAB A/S	26-Mar-25	11:51:48 AM	26	1,356.50	TQEX
GENMAB A/S	26-Mar-25	11:51:51 AM	70	1,357.00	CEUX
GENMAB A/S	26-Mar-25	11:51:51 AM	29	1,357.00	TQEX
GENMAB A/S	26-Mar-25	11:52:05 AM	15	1,357.50	XCSE
GENMAB A/S	26-Mar-25	11:52:05 AM	7	1,357.50	XCSE
GENMAB A/S	26-Mar-25	11:53:44 AM	75	1,359.00	CEUX
GENMAB A/S	26-Mar-25	11:53:45 AM	29	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:53:50 AM	50	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:53:53 AM	50	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:53:58 AM	54	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:53:58 AM	18	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:53:58 AM	23	1,359.50	TQEX
GENMAB A/S	26-Mar-25	11:54:04 AM	11	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:04 AM	10	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:04 AM	42	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:04 AM	10	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:07 AM	50	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:17 AM	70	1,361.00	CEUX
GENMAB A/S	26-Mar-25	11:54:21 AM	62	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:25 AM	37	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:55 AM	7	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:54:55 AM	2	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:55:25 AM	1	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:55:25 AM	24	1,361.00	XCSE
GENMAB A/S	26-Mar-25	11:55:43 AM	24	1,361.50	XCSE
GENMAB A/S	26-Mar-25	11:55:43 AM	18	1,361.50	XCSE
GENMAB A/S	26-Mar-25	11:55:43 AM	23	1,361.50	XCSE
GENMAB A/S	26-Mar-25	11:55:43 AM	21	1,361.50	XCSE
GENMAB A/S	26-Mar-25	11:55:58 AM	70	1,360.50	XCSE
GENMAB A/S	26-Mar-25	11:55:58 AM	1	1,360.50	XCSE
GENMAB A/S	26-Mar-25	11:55:58 AM	55	1,360.50	AQEU
GENMAB A/S	26-Mar-25	11:57:30 AM	75	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:57:30 AM	69	1,360.00	CEUX
GENMAB A/S	26-Mar-25	11:57:30 AM	23	1,360.50	TQEX
GENMAB A/S	26-Mar-25	11:57:30 AM	50	1,359.50	AQEU
GENMAB A/S	26-Mar-25	11:57:30 AM	56	1,360.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	11:59:25 AM	11	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:59:25 AM	10	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:59:26 AM	1	1,359.50	XCSE
GENMAB A/S	26-Mar-25	11:59:35 AM	18	1,360.00	XCSE
GENMAB A/S	26-Mar-25	11:59:35 AM	22	1,360.00	XCSE
GENMAB A/S	26-Mar-25	11:59:35 AM	10	1,360.00	XCSE
GENMAB A/S	26-Mar-25	11:59:35 AM	10	1,360.00	XCSE
GENMAB A/S	26-Mar-25	12:01:26 PM	1	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:02:02 PM	12	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:02:26 PM	2	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:02:26 PM	1	1,363.00	CEUX
GENMAB A/S	26-Mar-25	12:03:26 PM	1	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:03:26 PM	2	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:03:27 PM	4	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:03:27 PM	2	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:03:45 PM	42	1,362.50	TQEX
GENMAB A/S	26-Mar-25	12:03:58 PM	10	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:03:58 PM	12	1,362.50	CEUX
GENMAB A/S	26-Mar-25	12:03:58 PM	4	1,362.50	CEUX
GENMAB A/S	26-Mar-25	12:04:26 PM	1	1,362.50	CEUX
GENMAB A/S	26-Mar-25	12:04:27 PM	11	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:04:27 PM	10	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:04:27 PM	31	1,362.50	CEUX
GENMAB A/S	26-Mar-25	12:05:25 PM	1	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:05:25 PM	1	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:05:25 PM	1	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:05:25 PM	1	1,362.50	CEUX
GENMAB A/S	26-Mar-25	12:05:26 PM	4	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:06:25 PM	1	1,362.50	XCSE
GENMAB A/S	26-Mar-25	12:06:34 PM	1	1,363.00	CEUX
GENMAB A/S	26-Mar-25	12:06:34 PM	18	1,363.00	CEUX
GENMAB A/S	26-Mar-25	12:06:40 PM	12	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:06:40 PM	22	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:06:40 PM	36	1,363.00	CEUX
GENMAB A/S	26-Mar-25	12:06:40 PM	24	1,363.00	CEUX
GENMAB A/S	26-Mar-25	12:06:40 PM	26	1,362.50	TQEX
GENMAB A/S	26-Mar-25	12:07:09 PM	12	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:09 PM	35	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:09 PM	17	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:09 PM	30	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:09 PM	5	1,363.00	CEUX
GENMAB A/S	26-Mar-25	12:07:10 PM	34	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:10 PM	39	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:10 PM	12	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:10 PM	11	1,363.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	12:07:10 PM	10	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:10 PM	10	1,363.00	XCSE
GENMAB A/S	26-Mar-25	12:07:18 PM	70	1,364.00	CEUX
GENMAB A/S	26-Mar-25	12:07:19 PM	30	1,364.50	XCSE
GENMAB A/S	26-Mar-25	12:07:19 PM	71	1,364.50	CEUX
GENMAB A/S	26-Mar-25	12:07:21 PM	70	1,364.00	CEUX
GENMAB A/S	26-Mar-25	12:08:52 PM	71	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:08:52 PM	69	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:08:52 PM	73	1,370.00	AQEU
GENMAB A/S	26-Mar-25	12:08:53 PM	33	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:08:53 PM	50	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:08:54 PM	18	1,370.50	XCSE
GENMAB A/S	26-Mar-25	12:08:54 PM	1	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:09:01 PM	69	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:09:01 PM	72	1,371.00	CEUX
GENMAB A/S	26-Mar-25	12:09:01 PM	74	1,370.50	AQEU
GENMAB A/S	26-Mar-25	12:09:02 PM	75	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:09:02 PM	74	1,370.00	CEUX
GENMAB A/S	26-Mar-25	12:09:04 PM	13	1,369.00	XCSE
GENMAB A/S	26-Mar-25	12:09:04 PM	69	1,369.50	AQEU
GENMAB A/S	26-Mar-25	12:09:06 PM	60	1,369.00	XCSE
GENMAB A/S	26-Mar-25	12:09:06 PM	74	1,369.00	CEUX
GENMAB A/S	26-Mar-25	12:09:06 PM	1	1,369.00	CEUX
GENMAB A/S	26-Mar-25	12:13:05 PM	10	1,372.00	XCSE
GENMAB A/S	26-Mar-25	12:13:49 PM	11	1,372.00	XCSE
GENMAB A/S	26-Mar-25	12:13:52 PM	11	1,372.00	XCSE
GENMAB A/S	26-Mar-25	12:13:52 PM	11	1,372.00	XCSE
GENMAB A/S	26-Mar-25	12:13:52 PM	28	1,371.50	AQEU
GENMAB A/S	26-Mar-25	12:13:59 PM	17	1,372.00	XCSE
GENMAB A/S	26-Mar-25	12:14:07 PM	74	1,372.00	XCSE
GENMAB A/S	26-Mar-25	12:14:07 PM	62	1,372.00	CEUX
GENMAB A/S	26-Mar-25	12:14:07 PM	23	1,372.00	TQEX
GENMAB A/S	26-Mar-25	12:14:27 PM	70	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:14:27 PM	24	1,370.50	CEUX
GENMAB A/S	26-Mar-25	12:14:27 PM	45	1,370.50	AQEU
GENMAB A/S	26-Mar-25	12:14:27 PM	17	1,371.50	AQEU
GENMAB A/S	26-Mar-25	12:15:25 PM	69	1,369.50	XCSE
GENMAB A/S	26-Mar-25	12:15:25 PM	28	1,369.50	CEUX
GENMAB A/S	26-Mar-25	12:17:25 PM	3	1,371.50	XCSE
GENMAB A/S	26-Mar-25	12:17:25 PM	2	1,371.50	XCSE
GENMAB A/S	26-Mar-25	12:17:25 PM	2	1,371.50	XCSE
GENMAB A/S	26-Mar-25	12:17:26 PM	38	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:17:26 PM	37	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:17:26 PM	39	1,371.00	CEUX
GENMAB A/S	26-Mar-25	12:17:26 PM	25	1,370.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	12:18:04 PM	14	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:18:04 PM	59	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:18:04 PM	20	1,370.00	CEUX
GENMAB A/S	26-Mar-25	12:18:04 PM	18	1,370.00	CEUX
GENMAB A/S	26-Mar-25	12:18:04 PM	41	1,369.50	AQEU
GENMAB A/S	26-Mar-25	12:18:07 PM	6	1,369.00	XCSE
GENMAB A/S	26-Mar-25	12:18:07 PM	68	1,369.00	XCSE
GENMAB A/S	26-Mar-25	12:18:11 PM	44	1,368.50	CEUX
GENMAB A/S	26-Mar-25	12:18:11 PM	26	1,368.50	TQEX
GENMAB A/S	26-Mar-25	12:21:00 PM	23	1,370.00	AQEU
GENMAB A/S	26-Mar-25	12:21:25 PM	2	1,369.50	XCSE
GENMAB A/S	26-Mar-25	12:21:25 PM	70	1,369.50	XCSE
GENMAB A/S	26-Mar-25	12:21:25 PM	14	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:21:25 PM	2	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:21:25 PM	7	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:21:25 PM	46	1,369.50	CEUX
GENMAB A/S	26-Mar-25	12:21:51 PM	1	1,368.50	XCSE
GENMAB A/S	26-Mar-25	12:21:51 PM	4	1,368.50	CEUX
GENMAB A/S	26-Mar-25	12:25:25 PM	23	1,369.00	TQEX
GENMAB A/S	26-Mar-25	12:25:26 PM	2	1,369.50	XCSE
GENMAB A/S	26-Mar-25	12:25:26 PM	1	1,369.50	XCSE
GENMAB A/S	26-Mar-25	12:27:26 PM	75	1,370.00	XCSE
GENMAB A/S	26-Mar-25	12:27:26 PM	23	1,370.00	AQEU
GENMAB A/S	26-Mar-25	12:28:07 PM	6	1,370.50	XCSE
GENMAB A/S	26-Mar-25	12:28:07 PM	11	1,370.50	XCSE
GENMAB A/S	26-Mar-25	12:28:26 PM	1	1,370.50	XCSE
GENMAB A/S	26-Mar-25	12:29:53 PM	3	1,370.00	AQEU
GENMAB A/S	26-Mar-25	12:30:08 PM	1	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	30	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	30	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	1	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	11	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	27	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	10	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	2	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	43	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:08 PM	10	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	11	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	12	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	12	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	34	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	12	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	30	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:09 PM	30	1,371.00	XCSE
GENMAB A/S	26-Mar-25	12:30:22 PM	73	1,369.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	12:30:22 PM	75	1,369.50	CEUX
GENMAB A/S	26-Mar-25	12:30:22 PM	41	1,369.50	TQEX
GENMAB A/S	26-Mar-25	12:30:45 PM	72	1,368.50	XCSE
GENMAB A/S	26-Mar-25	12:30:45 PM	38	1,368.50	CEUX
GENMAB A/S	26-Mar-25	12:30:47 PM	74	1,367.50	XCSE
GENMAB A/S	26-Mar-25	12:30:47 PM	40	1,367.50	CEUX
GENMAB A/S	26-Mar-25	12:30:55 PM	75	1,366.50	XCSE
GENMAB A/S	26-Mar-25	12:30:55 PM	73	1,366.50	CEUX
GENMAB A/S	26-Mar-25	12:30:57 PM	70	1,365.50	XCSE
GENMAB A/S	26-Mar-25	12:30:57 PM	75	1,365.50	CEUX
GENMAB A/S	26-Mar-25	12:31:29 PM	20	1,364.00	XCSE
GENMAB A/S	26-Mar-25	12:31:29 PM	35	1,365.00	XCSE
GENMAB A/S	26-Mar-25	12:31:29 PM	14	1,364.50	CEUX
GENMAB A/S	26-Mar-25	12:31:29 PM	35	1,364.50	CEUX
GENMAB A/S	26-Mar-25	12:36:45 PM	1	1,366.00	XCSE
GENMAB A/S	26-Mar-25	12:36:45 PM	11	1,366.00	XCSE
GENMAB A/S	26-Mar-25	12:36:45 PM	1	1,366.00	XCSE
GENMAB A/S	26-Mar-25	12:37:20 PM	23	1,365.00	XCSE
GENMAB A/S	26-Mar-25	12:37:20 PM	23	1,365.50	CEUX
GENMAB A/S	26-Mar-25	12:37:20 PM	40	1,365.00	TQEX
GENMAB A/S	26-Mar-25	12:37:20 PM	26	1,365.50	AQEU
GENMAB A/S	26-Mar-25	12:38:17 PM	24	1,365.00	AQEU
GENMAB A/S	26-Mar-25	12:38:37 PM	10	1,365.00	XCSE
GENMAB A/S	26-Mar-25	12:38:37 PM	30	1,365.00	XCSE
GENMAB A/S	26-Mar-25	12:38:37 PM	42	1,365.00	XCSE
GENMAB A/S	26-Mar-25	12:38:37 PM	12	1,365.00	XCSE
GENMAB A/S	26-Mar-25	12:38:37 PM	27	1,364.50	CEUX
GENMAB A/S	26-Mar-25	12:38:37 PM	14	1,364.50	CEUX
GENMAB A/S	26-Mar-25	12:39:10 PM	3	1,365.50	XCSE
GENMAB A/S	26-Mar-25	12:39:14 PM	1	1365.50	XCSE
GENMAB A/S	26-Mar-25	12:40:26 PM	63	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:40:26 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:40:35 PM	2	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:40:35 PM	94	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:41:16 PM	74	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:41:21 PM	52	1364.00	XCSE
GENMAB A/S	26-Mar-25	12:41:21 PM	58	1364.00	CEUX
GENMAB A/S	26-Mar-25	12:41:21 PM	40	1364.00	TQEX
GENMAB A/S	26-Mar-25	12:41:21 PM	27	1364.00	AQEU
GENMAB A/S	26-Mar-25	12:43:51 PM	23	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:43:51 PM	75	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:43:51 PM	74	1365.00	CEUX
GENMAB A/S	26-Mar-25	12:45:47 PM	47	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:45:47 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:45:47 PM	1	1367.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	12:45:47 PM	26	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:45:47 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	42	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	8	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	71	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	19	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	2	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	12:47:15 PM	69	1366.00	CEUX
GENMAB A/S	26-Mar-25	12:47:15 PM	42	1365.50	AQEU
GENMAB A/S	26-Mar-25	12:48:26 PM	74	1366.50	CEUX
GENMAB A/S	26-Mar-25	12:48:27 PM	20	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:48:27 PM	49	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:48:42 PM	6	1365.50	TQEX
GENMAB A/S	26-Mar-25	12:49:35 PM	73	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:52:26 PM	42	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:52:26 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:52:26 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:52:26 PM	19	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:53:23 PM	71	1366.00	CEUX
GENMAB A/S	26-Mar-25	12:53:26 PM	1	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	2	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	75	1365.50	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	21	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	42	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	37	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	13	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	42	1365.50	XCSE
GENMAB A/S	26-Mar-25	12:54:25 PM	67	1365.00	CEUX
GENMAB A/S	26-Mar-25	12:54:25 PM	30	1365.50	TQEX
GENMAB A/S	26-Mar-25	12:54:25 PM	41	1365.50	AQEU
GENMAB A/S	26-Mar-25	12:55:40 PM	44	1365.00	XCSE
GENMAB A/S	26-Mar-25	12:58:47 PM	23	1365.50	TQEX
GENMAB A/S	26-Mar-25	12:59:10 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:59:10 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:59:10 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	12:59:37 PM	71	1366.00	XCSE
GENMAB A/S	26-Mar-25	1:00:14 PM	4	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:00:14 PM	1	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:00:14 PM	42	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:00:14 PM	70	1366.00	CEUX
GENMAB A/S	26-Mar-25	1:00:14 PM	41	1366.50	TQEX
GENMAB A/S	26-Mar-25	1:01:14 PM	74	1368.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	1:01:14 PM	73	1368.00	CEUX
GENMAB A/S	26-Mar-25	1:02:24 PM	42	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:02:26 PM	27	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:02:57 PM	69	1368.00	CEUX
GENMAB A/S	26-Mar-25	1:03:24 PM	21	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:03:24 PM	30	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:03:24 PM	15	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:03:24 PM	28	1367.50	AQEU
GENMAB A/S	26-Mar-25	1:03:26 PM	72	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:03:26 PM	1	1367.00	CEUX
GENMAB A/S	26-Mar-25	1:03:26 PM	70	1367.00	CEUX
GENMAB A/S	26-Mar-25	1:04:06 PM	6	1366.00	XCSE
GENMAB A/S	26-Mar-25	1:04:06 PM	69	1366.00	XCSE
GENMAB A/S	26-Mar-25	1:04:06 PM	72	1366.00	CEUX
GENMAB A/S	26-Mar-25	1:04:08 PM	71	1365.50	XCSE
GENMAB A/S	26-Mar-25	1:08:53 PM	25	1369.50	XCSE
GENMAB A/S	26-Mar-25	1:08:53 PM	10	1369.50	XCSE
GENMAB A/S	26-Mar-25	1:08:56 PM	72	1369.50	CEUX
GENMAB A/S	26-Mar-25	1:09:58 PM	34	1370.50	XCSE
GENMAB A/S	26-Mar-25	1:09:58 PM	42	1370.50	XCSE
GENMAB A/S	26-Mar-25	1:09:58 PM	18	1370.50	XCSE
GENMAB A/S	26-Mar-25	1:10:00 PM	75	1370.00	XCSE
GENMAB A/S	26-Mar-25	1:10:00 PM	36	1369.50	CEUX
GENMAB A/S	26-Mar-25	1:10:00 PM	23	1370.00	TQEX
GENMAB A/S	26-Mar-25	1:10:00 PM	25	1370.00	AQEU
GENMAB A/S	26-Mar-25	1:10:01 PM	75	1369.00	XCSE
GENMAB A/S	26-Mar-25	1:10:03 PM	9	1369.00	AQEU
GENMAB A/S	26-Mar-25	1:10:03 PM	18	1369.00	AQEU
GENMAB A/S	26-Mar-25	1:10:35 PM	35	1368.50	CEUX
GENMAB A/S	26-Mar-25	1:10:35 PM	34	1368.50	CEUX
GENMAB A/S	26-Mar-25	1:10:45 PM	74	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:11:14 PM	69	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:11:18 PM	66	1371.50	XCSE
GENMAB A/S	26-Mar-25	1:11:18 PM	48	1372.00	CEUX
GENMAB A/S	26-Mar-25	1:11:21 PM	23	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:12:10 PM	51	1373.50	XCSE
GENMAB A/S	26-Mar-25	1:12:10 PM	28	1373.00	CEUX
GENMAB A/S	26-Mar-25	1:12:24 PM	43	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:12:24 PM	29	1372.00	CEUX
GENMAB A/S	26-Mar-25	1:12:27 PM	50	1371.50	XCSE
GENMAB A/S	26-Mar-25	1:12:27 PM	44	1371.00	CEUX
GENMAB A/S	26-Mar-25	1:12:32 PM	25	1371.50	XCSE
GENMAB A/S	26-Mar-25	1:12:54 PM	41	1370.50	CEUX
GENMAB A/S	26-Mar-25	1:15:58 PM	5	1371.50	CEUX
GENMAB A/S	26-Mar-25	1:15:58 PM	18	1371.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	1:16:13 PM	27	1372.50	TQEX
GENMAB A/S	26-Mar-25	1:19:25 PM	3	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:19:25 PM	4	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:19:48 PM	30	1373.00	XCSE
GENMAB A/S	26-Mar-25	1:19:48 PM	17	1373.00	XCSE
GENMAB A/S	26-Mar-25	1:20:25 PM	1	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:20:25 PM	1	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:20:25 PM	10	1372.50	XCSE
GENMAB A/S	26-Mar-25	1:20:42 PM	2	1373.50	XCSE
GENMAB A/S	26-Mar-25	1:20:42 PM	15	1373.50	XCSE
GENMAB A/S	26-Mar-25	1:21:06 PM	12	1373.50	XCSE
GENMAB A/S	26-Mar-25	1:21:06 PM	10	1373.50	XCSE
GENMAB A/S	26-Mar-25	1:21:55 PM	73	1373.00	XCSE
GENMAB A/S	26-Mar-25	1:21:55 PM	42	1373.00	XCSE
GENMAB A/S	26-Mar-25	1:21:55 PM	17	1373.00	XCSE
GENMAB A/S	26-Mar-25	1:21:55 PM	35	1373.00	XCSE
GENMAB A/S	26-Mar-25	1:21:55 PM	61	1373.00	CEUX
GENMAB A/S	26-Mar-25	1:21:55 PM	28	1373.00	AQEU
GENMAB A/S	26-Mar-25	1:21:56 PM	69	1372.00	XCSE
GENMAB A/S	26-Mar-25	1:21:56 PM	20	1372.00	CEUX
GENMAB A/S	26-Mar-25	1:21:56 PM	3	1372.00	CEUX
GENMAB A/S	26-Mar-25	1:21:56 PM	23	1372.00	TQEX
GENMAB A/S	26-Mar-25	1:21:56 PM	26	1372.00	AQEU
GENMAB A/S	26-Mar-25	1:22:15 PM	70	1372.00	XCSE
GENMAB A/S	26-Mar-25	1:22:15 PM	26	1372.00	TQEX
GENMAB A/S	26-Mar-25	1:23:25 PM	49	1372.50	CEUX
GENMAB A/S	26-Mar-25	1:24:24 PM	71	1372.00	XCSE
GENMAB A/S	26-Mar-25	1:25:41 PM	23	1372.00	AQEU
GENMAB A/S	26-Mar-25	1:26:18 PM	73	1372.00	XCSE
GENMAB A/S	26-Mar-25	1:26:35 PM	9	1371.50	CEUX
GENMAB A/S	26-Mar-25	1:26:37 PM	38	1371.50	CEUX
GENMAB A/S	26-Mar-25	1:26:49 PM	60	1371.00	XCSE
GENMAB A/S	26-Mar-25	1:26:49 PM	43	1371.00	TQEX
GENMAB A/S	26-Mar-25	1:26:50 PM	75	1370.00	XCSE
GENMAB A/S	26-Mar-25	1:26:50 PM	24	1370.50	CEUX
GENMAB A/S	26-Mar-25	1:29:19 PM	9	1370.00	AQEU
GENMAB A/S	26-Mar-25	1:29:27 PM	8	1369.50	XCSE
GENMAB A/S	26-Mar-25	1:29:31 PM	1	1369.50	XCSE
GENMAB A/S	26-Mar-25	1:30:02 PM	5	1369.50	XCSE
GENMAB A/S	26-Mar-25	1:30:02 PM	9	1369.50	XCSE
GENMAB A/S	26-Mar-25	1:30:25 PM	52	1369.00	CEUX
GENMAB A/S	26-Mar-25	1:30:27 PM	75	1368.50	XCSE
GENMAB A/S	26-Mar-25	1:30:30 PM	2	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:30:31 PM	10	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:30:59 PM	19	1367.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	1:31:07 PM	27	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:31:15 PM	44	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:31:15 PM	27	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:32:30 PM	70	1366.00	XCSE
GENMAB A/S	26-Mar-25	1:32:30 PM	71	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:32:30 PM	46	1366.00	CEUX
GENMAB A/S	26-Mar-25	1:32:30 PM	24	1367.00	AQEU
GENMAB A/S	26-Mar-25	1:33:04 PM	75	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:33:04 PM	57	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:34:45 PM	75	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:34:45 PM	58	1366.50	CEUX
GENMAB A/S	26-Mar-25	1:35:38 PM	72	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:35:38 PM	23	1367.00	AQEU
GENMAB A/S	26-Mar-25	1:37:27 PM	23	1366.50	CEUX
GENMAB A/S	26-Mar-25	1:39:26 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:39:26 PM	71	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:39:26 PM	59	1367.00	CEUX
GENMAB A/S	26-Mar-25	1:39:26 PM	24	1367.50	TQEX
GENMAB A/S	26-Mar-25	1:39:26 PM	24	1367.50	AQEU
GENMAB A/S	26-Mar-25	1:39:30 PM	70	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:40:21 PM	73	1365.50	XCSE
GENMAB A/S	26-Mar-25	1:40:21 PM	1	1365.50	CEUX
GENMAB A/S	26-Mar-25	1:40:21 PM	43	1365.50	CEUX
GENMAB A/S	26-Mar-25	1:40:31 PM	57	1365.50	CEUX
GENMAB A/S	26-Mar-25	1:41:00 PM	69	1365.00	XCSE
GENMAB A/S	26-Mar-25	1:41:00 PM	25	1365.00	TQEX
GENMAB A/S	26-Mar-25	1:41:08 PM	72	1364.00	XCSE
GENMAB A/S	26-Mar-25	1:41:08 PM	4	1364.00	CEUX
GENMAB A/S	26-Mar-25	1:41:08 PM	29	1364.00	CEUX
GENMAB A/S	26-Mar-25	1:41:40 PM	14	1363.00	XCSE
GENMAB A/S	26-Mar-25	1:42:28 PM	41	1363.50	AQEU
GENMAB A/S	26-Mar-25	1:43:08 PM	35	1363.50	CEUX
GENMAB A/S	26-Mar-25	1:44:48 PM	50	1367.00	CEUX
GENMAB A/S	26-Mar-25	1:44:48 PM	26	1367.50	TQEX
GENMAB A/S	26-Mar-25	1:44:49 PM	74	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:44:49 PM	35	1367.00	CEUX
GENMAB A/S	26-Mar-25	1:44:49 PM	56	1366.00	CEUX
GENMAB A/S	26-Mar-25	1:44:54 PM	75	1365.00	XCSE
GENMAB A/S	26-Mar-25	1:46:26 PM	26	1365.00	CEUX
GENMAB A/S	26-Mar-25	1:46:41 PM	74	1365.00	XCSE
GENMAB A/S	26-Mar-25	1:48:35 PM	34	1366.00	CEUX
GENMAB A/S	26-Mar-25	1:48:41 PM	2	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:48:41 PM	8	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:49:03 PM	30	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:50:23 PM	75	1368.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	1:50:23 PM	28	1368.00	CEUX
GENMAB A/S	26-Mar-25	1:50:23 PM	42	1368.00	TQEX
GENMAB A/S	26-Mar-25	1:50:23 PM	41	1368.00	AQEU
GENMAB A/S	26-Mar-25	1:50:25 PM	19	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:50:25 PM	25	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:50:25 PM	2	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:50:25 PM	1	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:50:25 PM	74	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:50:25 PM	23	1368.00	CEUX
GENMAB A/S	26-Mar-25	1:51:25 PM	11	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:51:25 PM	2	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:51:25 PM	12	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:51:25 PM	2	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:51:25 PM	2	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:51:34 PM	29	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:52:05 PM	17	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:52:05 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:52:05 PM	30	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:52:05 PM	8	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:52:05 PM	4	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:52:55 PM	2	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:52:57 PM	18	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:53:11 PM	6	1366.50	CEUX
GENMAB A/S	26-Mar-25	1:53:15 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:53:15 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:53:15 PM	2	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:53:37 PM	18	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:54:03 PM	1	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:54:15 PM	1	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:54:15 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:54:15 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:54:15 PM	18	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:54:15 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:54:15 PM	18	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:54:55 PM	14	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:54:55 PM	18	1367.00	XCSE
GENMAB A/S	26-Mar-25	1:55:28 PM	5	1369.00	XCSE
GENMAB A/S	26-Mar-25	1:55:28 PM	72	1369.00	XCSE
GENMAB A/S	26-Mar-25	1:55:28 PM	18	1369.00	XCSE
GENMAB A/S	26-Mar-25	1:55:28 PM	40	1369.50	CEUX
GENMAB A/S	26-Mar-25	1:55:28 PM	12	1369.50	CEUX
GENMAB A/S	26-Mar-25	1:55:28 PM	22	1369.00	TQEX
GENMAB A/S	26-Mar-25	1:55:42 PM	48	1368.50	CEUX
GENMAB A/S	26-Mar-25	1:56:55 PM	73	1368.50	XCSE
GENMAB A/S	26-Mar-25	1:56:55 PM	18	1368.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	1:56:55 PM	1	1368.50	XCSE
GENMAB A/S	26-Mar-25	1:56:55 PM	4	1368.50	XCSE
GENMAB A/S	26-Mar-25	1:56:55 PM	40	1368.00	AQEU
GENMAB A/S	26-Mar-25	1:57:31 PM	55	1367.50	CEUX
GENMAB A/S	26-Mar-25	1:58:25 PM	8	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:58:25 PM	3	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:58:25 PM	3	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:25 PM	15	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:25 PM	2	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:25 PM	39	1368.00	CEUX
GENMAB A/S	26-Mar-25	1:59:26 PM	12	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:26 PM	11	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:26 PM	17	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:26 PM	18	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:26 PM	3	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:26 PM	4	1368.00	XCSE
GENMAB A/S	26-Mar-25	1:59:47 PM	70	1367.50	XCSE
GENMAB A/S	26-Mar-25	1:59:47 PM	44	1367.00	CEUX
GENMAB A/S	26-Mar-25	1:59:47 PM	39	1367.50	TQEX
GENMAB A/S	26-Mar-25	1:59:49 PM	49	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:59:49 PM	23	1366.50	XCSE
GENMAB A/S	26-Mar-25	1:59:49 PM	25	1366.00	CEUX
GENMAB A/S	26-Mar-25	2:00:32 PM	75	1366.00	XCSE
GENMAB A/S	26-Mar-25	2:00:32 PM	30	1366.00	CEUX
GENMAB A/S	26-Mar-25	2:01:36 PM	71	1366.00	XCSE
GENMAB A/S	26-Mar-25	2:03:52 PM	30	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:03:52 PM	40	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:04:34 PM	23	1365.00	CEUX
GENMAB A/S	26-Mar-25	2:06:32 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:32 PM	12	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:32 PM	8	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:32 PM	13	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:32 PM	16	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:32 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:33 PM	23	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:06:44 PM	48	1364.00	XCSE
GENMAB A/S	26-Mar-25	2:06:44 PM	6	1364.00	XCSE
GENMAB A/S	26-Mar-25	2:06:44 PM	37	1364.50	XCSE
GENMAB A/S	26-Mar-25	2:06:44 PM	8	1364.00	XCSE
GENMAB A/S	26-Mar-25	2:06:44 PM	7	1364.00	XCSE
GENMAB A/S	26-Mar-25	2:06:44 PM	15	1364.00	CEUX
GENMAB A/S	26-Mar-25	2:06:44 PM	10	1364.00	CEUX
GENMAB A/S	26-Mar-25	2:06:49 PM	36	1363.50	TQEX
GENMAB A/S	26-Mar-25	2:06:49 PM	5	1363.50	TQEX
GENMAB A/S	26-Mar-25	2:06:49 PM	39	1363.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:07:26 PM	74	1363.00	XCSE
GENMAB A/S	26-Mar-25	2:08:34 PM	71	1363.00	XCSE
GENMAB A/S	26-Mar-25	2:08:34 PM	23	1363.00	CEUX
GENMAB A/S	26-Mar-25	2:09:50 PM	72	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:10:25 PM	75	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:11:09 PM	75	1364.00	XCSE
GENMAB A/S	26-Mar-25	2:11:17 PM	41	1363.50	AQEU
GENMAB A/S	26-Mar-25	2:11:18 PM	72	1362.50	XCSE
GENMAB A/S	26-Mar-25	2:11:18 PM	72	1363.00	CEUX
GENMAB A/S	26-Mar-25	2:11:18 PM	20	1363.00	TQEX
GENMAB A/S	26-Mar-25	2:11:18 PM	19	1363.00	TQEX
GENMAB A/S	26-Mar-25	2:12:34 PM	39	1361.50	CEUX
GENMAB A/S	26-Mar-25	2:13:25 PM	42	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:13:25 PM	4	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:13:25 PM	10	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:13:25 PM	12	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:13:25 PM	71	1361.00	XCSE
GENMAB A/S	26-Mar-25	2:13:25 PM	26	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:13:33 PM	69	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:13:33 PM	62	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:15:12 PM	69	1362.50	XCSE
GENMAB A/S	26-Mar-25	2:15:12 PM	40	1362.50	CEUX
GENMAB A/S	26-Mar-25	2:15:16 PM	2	1362.50	CEUX
GENMAB A/S	26-Mar-25	2:15:16 PM	13	1362.50	CEUX
GENMAB A/S	26-Mar-25	2:16:57 PM	69	1362.50	XCSE
GENMAB A/S	26-Mar-25	2:16:57 PM	40	1363.00	AQEU
GENMAB A/S	26-Mar-25	2:17:27 PM	72	1366.00	XCSE
GENMAB A/S	26-Mar-25	2:17:27 PM	6	1366.00	CEUX
GENMAB A/S	26-Mar-25	2:17:27 PM	75	1366.00	CEUX
GENMAB A/S	26-Mar-25	2:17:27 PM	47	1366.00	CEUX
GENMAB A/S	26-Mar-25	2:17:27 PM	41	1366.00	TQEX
GENMAB A/S	26-Mar-25	2:17:41 PM	6	1365.50	CEUX
GENMAB A/S	26-Mar-25	2:17:41 PM	21	1365.50	CEUX
GENMAB A/S	26-Mar-25	2:17:44 PM	74	1365.00	XCSE
GENMAB A/S	26-Mar-25	2:17:54 PM	71	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:18:25 PM	72	1364.00	XCSE
GENMAB A/S	26-Mar-25	2:19:09 PM	73	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:19:09 PM	38	1363.50	CEUX
GENMAB A/S	26-Mar-25	2:19:09 PM	2	1363.50	CEUX
GENMAB A/S	26-Mar-25	2:19:49 PM	23	1363.00	CEUX
GENMAB A/S	26-Mar-25	2:19:59 PM	74	1364.50	XCSE
GENMAB A/S	26-Mar-25	2:20:00 PM	16	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:20:14 PM	59	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:21:29 PM	73	1362.50	XCSE
GENMAB A/S	26-Mar-25	2:21:29 PM	23	1362.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:21:53 PM	75	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:21:53 PM	30	1363.50	CEUX
GENMAB A/S	26-Mar-25	2:22:19 PM	10	1364.00	CEUX
GENMAB A/S	26-Mar-25	2:22:19 PM	18	1364.00	CEUX
GENMAB A/S	26-Mar-25	2:22:19 PM	30	1364.00	TQEX
GENMAB A/S	26-Mar-25	2:22:54 PM	68	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:23:25 PM	42	1363.50	AQEU
GENMAB A/S	26-Mar-25	2:23:52 PM	72	1362.50	XCSE
GENMAB A/S	26-Mar-25	2:23:52 PM	32	1362.50	CEUX
GENMAB A/S	26-Mar-25	2:24:40 PM	70	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:25:12 PM	1	1362.00	CEUX
GENMAB A/S	26-Mar-25	2:25:12 PM	27	1362.00	CEUX
GENMAB A/S	26-Mar-25	2:25:15 PM	8	1362.00	CEUX
GENMAB A/S	26-Mar-25	2:25:41 PM	65	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:25:41 PM	9	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:25:41 PM	43	1362.00	CEUX
GENMAB A/S	26-Mar-25	2:26:18 PM	75	1361.00	XCSE
GENMAB A/S	26-Mar-25	2:26:18 PM	71	1362.00	XCSE
GENMAB A/S	26-Mar-25	2:26:18 PM	23	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:26:18 PM	36	1362.00	CEUX
GENMAB A/S	26-Mar-25	2:26:18 PM	9	1360.50	TQEX
GENMAB A/S	26-Mar-25	2:26:18 PM	29	1361.50	TQEX
GENMAB A/S	26-Mar-25	2:26:19 PM	60	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:26:30 PM	25	1360.50	XCSE
GENMAB A/S	26-Mar-25	2:26:30 PM	30	1360.50	CEUX
GENMAB A/S	26-Mar-25	2:27:30 PM	70	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:27:30 PM	31	1363.50	CEUX
GENMAB A/S	26-Mar-25	2:27:55 PM	5	1364.50	XCSE
GENMAB A/S	26-Mar-25	2:27:55 PM	66	1364.50	XCSE
GENMAB A/S	26-Mar-25	2:27:55 PM	21	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:27:55 PM	10	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:27:55 PM	31	1364.50	AQEU
GENMAB A/S	26-Mar-25	2:29:33 PM	71	1364.50	XCSE
GENMAB A/S	26-Mar-25	2:29:33 PM	5	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:29:33 PM	2	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:29:33 PM	34	1364.50	CEUX
GENMAB A/S	26-Mar-25	2:29:52 PM	15	1364.00	AQEU
GENMAB A/S	26-Mar-25	2:29:52 PM	9	1364.00	AQEU
GENMAB A/S	26-Mar-25	2:30:00 PM	1	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:30:00 PM	15	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:30:00 PM	55	1363.50	XCSE
GENMAB A/S	26-Mar-25	2:30:00 PM	25	1363.50	CEUX
GENMAB A/S	26-Mar-25	2:30:02 PM	23	1363.00	TQEX
GENMAB A/S	26-Mar-25	2:30:10 PM	19	1362.50	XCSE
GENMAB A/S	26-Mar-25	2:30:10 PM	53	1362.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:30:10 PM	14	1362.50	CEUX
GENMAB A/S	26-Mar-25	2:30:10 PM	9	1362.50	CEUX
GENMAB A/S	26-Mar-25	2:30:11 PM	72	1361.00	XCSE
GENMAB A/S	26-Mar-25	2:30:11 PM	44	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:30:11 PM	6	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:30:12 PM	23	1359.50	XCSE
GENMAB A/S	26-Mar-25	2:30:12 PM	50	1359.50	XCSE
GENMAB A/S	26-Mar-25	2:30:12 PM	43	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:30:13 PM	52	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:30:41 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:30:41 PM	22	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:30:41 PM	34	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:30:41 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:30:42 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	2:30:42 PM	3	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:30:42 PM	8	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:30:42 PM	12	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:30:47 PM	10	1362.00	TQEX
GENMAB A/S	26-Mar-25	2:30:48 PM	15	1362.00	TQEX
GENMAB A/S	26-Mar-25	2:30:48 PM	3	1362.00	AQEU
GENMAB A/S	26-Mar-25	2:30:48 PM	21	1362.00	AQEU
GENMAB A/S	26-Mar-25	2:31:10 PM	57	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:31:10 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:31:10 PM	35	1361.50	CEUX
GENMAB A/S	26-Mar-25	2:31:13 PM	18	1360.50	XCSE
GENMAB A/S	26-Mar-25	2:31:13 PM	33	1360.50	CEUX
GENMAB A/S	26-Mar-25	2:31:18 PM	48	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:31:18 PM	25	1359.50	CEUX
GENMAB A/S	26-Mar-25	2:31:18 PM	34	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:31:19 PM	42	1358.00	XCSE
GENMAB A/S	26-Mar-25	2:31:31 PM	31	1358.00	XCSE
GENMAB A/S	26-Mar-25	2:31:31 PM	3	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:31:31 PM	7	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:31:31 PM	60	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:31:31 PM	1	1356.00	XCSE
GENMAB A/S	26-Mar-25	2:31:31 PM	33	1357.00	CEUX
GENMAB A/S	26-Mar-25	2:31:31 PM	12	1357.00	AQEU
GENMAB A/S	26-Mar-25	2:31:35 PM	26	1358.50	TQEX
GENMAB A/S	26-Mar-25	2:32:10 PM	22	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:32:10 PM	17	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:32:10 PM	68	1356.00	XCSE
GENMAB A/S	26-Mar-25	2:32:10 PM	62	1358.00	XCSE
GENMAB A/S	26-Mar-25	2:32:10 PM	24	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:32:10 PM	30	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:32:10 PM	29	1357.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:33:01 PM	23	1358.00	TQEX
GENMAB A/S	26-Mar-25	2:33:14 PM	74	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:33:27 PM	17	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:33:27 PM	10	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:33:27 PM	72	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:33:27 PM	21	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:33:27 PM	25	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:33:27 PM	23	1357.50	TQEX
GENMAB A/S	26-Mar-25	2:33:27 PM	23	1358.00	AQEU
GENMAB A/S	26-Mar-25	2:34:25 PM	74	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:34:25 PM	22	1355.00	XCSE
GENMAB A/S	26-Mar-25	2:34:25 PM	10	1356.00	XCSE
GENMAB A/S	26-Mar-25	2:34:25 PM	20	1356.00	XCSE
GENMAB A/S	26-Mar-25	2:34:25 PM	50	1355.00	XCSE
GENMAB A/S	26-Mar-25	2:34:25 PM	11	1355.50	XCSE
GENMAB A/S	26-Mar-25	2:34:25 PM	33	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	1	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	4	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	2	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	2	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	1	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	1	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	16	1355.00	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	20	1355.00	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	2	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	1	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:25 PM	11	1355.50	TQEX
GENMAB A/S	26-Mar-25	2:34:25 PM	24	1355.50	AQEU
GENMAB A/S	26-Mar-25	2:34:25 PM	14	1355.50	AQEU
GENMAB A/S	26-Mar-25	2:34:26 PM	39	1355.50	XCSE
GENMAB A/S	26-Mar-25	2:34:27 PM	23	1355.50	XCSE
GENMAB A/S	26-Mar-25	2:34:27 PM	59	1355.50	CEUX
GENMAB A/S	26-Mar-25	2:34:57 PM	20	1355.00	XCSE
GENMAB A/S	26-Mar-25	2:34:57 PM	30	1355.00	XCSE
GENMAB A/S	26-Mar-25	2:34:57 PM	10	1355.00	XCSE
GENMAB A/S	26-Mar-25	2:34:57 PM	12	1355.00	XCSE
GENMAB A/S	26-Mar-25	2:34:59 PM	12	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:34:59 PM	10	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:34:59 PM	20	1354.00	CEUX
GENMAB A/S	26-Mar-25	2:34:59 PM	6	1354.00	CEUX
GENMAB A/S	26-Mar-25	2:35:00 PM	20	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:35:30 PM	32	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:35:31 PM	42	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:35:31 PM	20	1353.50	XCSE
GENMAB A/S	26-Mar-25	2:35:31 PM	20	1354.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:35:31 PM	45	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:35:31 PM	30	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:35:31 PM	49	1354.00	CEUX
GENMAB A/S	26-Mar-25	2:35:31 PM	29	1354.00	TQEX
GENMAB A/S	26-Mar-25	2:35:31 PM	23	1354.00	AQEU
GENMAB A/S	26-Mar-25	2:35:41 PM	11	1354.50	XCSE
GENMAB A/S	26-Mar-25	2:35:41 PM	3	1354.50	XCSE
GENMAB A/S	26-Mar-25	2:35:41 PM	42	1354.50	XCSE
GENMAB A/S	26-Mar-25	2:35:41 PM	12	1354.50	XCSE
GENMAB A/S	26-Mar-25	2:35:41 PM	21	1354.50	XCSE
GENMAB A/S	26-Mar-25	2:35:41 PM	2	1354.50	XCSE
GENMAB A/S	26-Mar-25	2:36:21 PM	30	1353.00	XCSE
GENMAB A/S	26-Mar-25	2:36:21 PM	75	1354.00	XCSE
GENMAB A/S	26-Mar-25	2:36:21 PM	45	1353.00	XCSE
GENMAB A/S	26-Mar-25	2:36:21 PM	71	1352.50	CEUX
GENMAB A/S	26-Mar-25	2:36:21 PM	69	1353.50	CEUX
GENMAB A/S	26-Mar-25	2:36:21 PM	24	1352.50	TQEX
GENMAB A/S	26-Mar-25	2:36:27 PM	57	1353.00	CEUX
GENMAB A/S	26-Mar-25	2:36:30 PM	71	1352.50	XCSE
GENMAB A/S	26-Mar-25	2:36:31 PM	73	1352.00	CEUX
GENMAB A/S	26-Mar-25	2:36:43 PM	71	1351.50	XCSE
GENMAB A/S	26-Mar-25	2:37:04 PM	69	1353.50	XCSE
GENMAB A/S	26-Mar-25	2:37:13 PM	23	1353.50	AQEU
GENMAB A/S	26-Mar-25	2:37:44 PM	1	1353.00	CEUX
GENMAB A/S	26-Mar-25	2:37:44 PM	23	1353.00	CEUX
GENMAB A/S	26-Mar-25	2:37:48 PM	72	1352.50	XCSE
GENMAB A/S	26-Mar-25	2:37:48 PM	8	1352.00	CEUX
GENMAB A/S	26-Mar-25	2:37:48 PM	15	1352.00	CEUX
GENMAB A/S	26-Mar-25	2:37:48 PM	25	1352.00	TQEX
GENMAB A/S	26-Mar-25	2:38:53 PM	16	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:38:53 PM	2	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:01 PM	42	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:01 PM	10	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:01 PM	30	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:01 PM	23	1357.50	AQEU
GENMAB A/S	26-Mar-25	2:39:02 PM	17	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:02 PM	10	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:02 PM	9	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:02 PM	11	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:02 PM	69	1357.00	CEUX
GENMAB A/S	26-Mar-25	2:39:14 PM	69	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:39:15 PM	10	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:39:15 PM	14	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:39:15 PM	48	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:39:15 PM	43	1357.00	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:39:21 PM	2	1356.00	CEUX
GENMAB A/S	26-Mar-25	2:39:22 PM	71	1356.00	CEUX
GENMAB A/S	26-Mar-25	2:39:32 PM	11	1355.50	XCSE
GENMAB A/S	26-Mar-25	2:39:59 PM	9	1357.00	AQEU
GENMAB A/S	26-Mar-25	2:40:03 PM	10	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:40:15 PM	10	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:40:31 PM	9	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:40:35 PM	11	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:40:44 PM	72	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:40:44 PM	75	1358.00	CEUX
GENMAB A/S	26-Mar-25	2:41:05 PM	38	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:41:05 PM	4	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:41:05 PM	11	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:41:05 PM	19	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:41:05 PM	22	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:41:33 PM	42	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:41:33 PM	2	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:41:51 PM	72	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:41:51 PM	9	1359.50	CEUX
GENMAB A/S	26-Mar-25	2:41:51 PM	54	1359.50	CEUX
GENMAB A/S	26-Mar-25	2:41:51 PM	30	1359.50	AQEU
GENMAB A/S	26-Mar-25	2:41:52 PM	7	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:41:54 PM	9	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:41:54 PM	16	1358.50	TQEX
GENMAB A/S	26-Mar-25	2:42:23 PM	4	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:42:23 PM	2	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:42:23 PM	63	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:42:23 PM	15	1359.00	AQEU
GENMAB A/S	26-Mar-25	2:42:27 PM	15	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:42:27 PM	24	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:43:11 PM	3	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:43:11 PM	11	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:43:25 PM	44	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:43:25 PM	50	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:43:25 PM	57	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:43:26 PM	19	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:43:26 PM	75	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:43:56 PM	10	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:44:04 PM	10	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:44:04 PM	10	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:44:04 PM	37	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:44:27 PM	23	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:44:27 PM	31	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:44:27 PM	10	1358.00	XCSE
GENMAB A/S	26-Mar-25	2:44:27 PM	42	1358.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:44:27 PM	11	1358.00	XCSE
GENMAB A/S	26-Mar-25	2:44:27 PM	44	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:44:27 PM	10	1358.00	CEUX
GENMAB A/S	26-Mar-25	2:44:27 PM	17	1358.00	CEUX
GENMAB A/S	26-Mar-25	2:44:27 PM	23	1358.50	TQEX
GENMAB A/S	26-Mar-25	2:44:27 PM	26	1359.00	AQEU
GENMAB A/S	26-Mar-25	2:45:13 PM	12	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:13 PM	3	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:45:13 PM	4	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:45:13 PM	56	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:45:13 PM	11	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:13 PM	16	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:13 PM	10	1358.50	XCSE
GENMAB A/S	26-Mar-25	2:45:26 PM	3	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:26 PM	10	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:26 PM	10	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:45 PM	42	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:45 PM	10	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:45 PM	3	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:45 PM	23	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:45 PM	16	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:45:49 PM	5	1358.50	TQEX
GENMAB A/S	26-Mar-25	2:47:06 PM	10	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:47:06 PM	42	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:47:06 PM	11	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:47:06 PM	68	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:48:12 PM	74	1359.50	XCSE
GENMAB A/S	26-Mar-25	2:48:12 PM	24	1359.50	TQEX
GENMAB A/S	26-Mar-25	2:48:12 PM	35	1359.50	AQEU
GENMAB A/S	26-Mar-25	2:48:24 PM	2	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:48:24 PM	9	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:48:24 PM	5	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:48:24 PM	2	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:48:24 PM	4	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:49:27 PM	69	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:49:51 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:49:51 PM	19	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:49:51 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:50:04 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:50:41 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:50:41 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:50:45 PM	8	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:52:26 PM	1	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:53:28 PM	65	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:53:28 PM	7	1361.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:53:28 PM	36	1361.50	CEUX
GENMAB A/S	26-Mar-25	2:53:46 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:53:46 PM	9	1361.50	CEUX
GENMAB A/S	26-Mar-25	2:53:51 PM	69	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:53:52 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:53:52 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:07 PM	14	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:07 PM	28	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	71	1360.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	24	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	1	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	72	1359.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	28	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	2:54:26 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:54:26 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:54:26 PM	75	1359.00	CEUX
GENMAB A/S	26-Mar-25	2:54:26 PM	14	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:54:26 PM	58	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:54:26 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	2:54:26 PM	10	1360.00	TQEX
GENMAB A/S	26-Mar-25	2:54:26 PM	16	1360.00	TQEX
GENMAB A/S	26-Mar-25	2:54:26 PM	24	1361.00	TQEX
GENMAB A/S	26-Mar-25	2:54:26 PM	28	1360.50	AQEU
GENMAB A/S	26-Mar-25	2:55:21 PM	1	1359.50	CEUX
GENMAB A/S	26-Mar-25	2:55:40 PM	24	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:55:40 PM	7	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:55:40 PM	3	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:55:40 PM	2	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:55:40 PM	10	1360.00	CEUX
GENMAB A/S	26-Mar-25	2:55:48 PM	17	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:55:59 PM	42	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:55:59 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:55:59 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:56:00 PM	1	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:56:00 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:56:00 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:56:13 PM	72	1361.00	XCSE
GENMAB A/S	26-Mar-25	2:56:13 PM	9	1361.00	AQEU
GENMAB A/S	26-Mar-25	2:56:13 PM	26	1361.00	AQEU
GENMAB A/S	26-Mar-25	2:56:16 PM	74	1360.00	XCSE
GENMAB A/S	26-Mar-25	2:56:16 PM	10	1359.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:56:16 PM	32	1360.50	CEUX
GENMAB A/S	26-Mar-25	2:56:16 PM	11	1360.50	CEUX
GENMAB A/S	26-Mar-25	2:56:16 PM	30	1360.50	CEUX
GENMAB A/S	26-Mar-25	2:56:16 PM	70	1359.50	CEUX
GENMAB A/S	26-Mar-25	2:56:16 PM	34	1360.50	CEUX
GENMAB A/S	26-Mar-25	2:56:16 PM	36	1361.00	TQEX
GENMAB A/S	26-Mar-25	2:56:16 PM	4	1359.50	TQEX
GENMAB A/S	26-Mar-25	2:56:16 PM	8	1358.50	TQEX
GENMAB A/S	26-Mar-25	2:56:16 PM	10	1359.50	TQEX
GENMAB A/S	26-Mar-25	2:56:16 PM	10	1359.50	TQEX
GENMAB A/S	26-Mar-25	2:56:16 PM	7	1359.50	TQEX
GENMAB A/S	26-Mar-25	2:56:16 PM	35	1360.00	AQEU
GENMAB A/S	26-Mar-25	2:56:21 PM	63	1359.00	XCSE
GENMAB A/S	26-Mar-25	2:56:25 PM	20	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:56:25 PM	8	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:56:25 PM	20	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:56:25 PM	10	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:56:25 PM	2	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:56:25 PM	15	1358.50	CEUX
GENMAB A/S	26-Mar-25	2:56:37 PM	47	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:56:37 PM	22	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:56:37 PM	6	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:56:37 PM	14	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:56:37 PM	40	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:56:37 PM	11	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:56:37 PM	7	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:56:37 PM	3	1357.50	CEUX
GENMAB A/S	26-Mar-25	2:56:45 PM	6	1356.00	CEUX
GENMAB A/S	26-Mar-25	2:56:50 PM	7	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:56:50 PM	20	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:56:50 PM	32	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:56:50 PM	10	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:56:50 PM	30	1356.00	CEUX
GENMAB A/S	26-Mar-25	2:57:10 PM	23	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:57:10 PM	17	1357.00	CEUX
GENMAB A/S	26-Mar-25	2:57:10 PM	18	1357.00	CEUX
GENMAB A/S	26-Mar-25	2:57:10 PM	25	1357.00	AQEU
GENMAB A/S	26-Mar-25	2:57:13 PM	19	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:57:13 PM	42	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:57:13 PM	49	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:57:13 PM	14	1356.00	CEUX
GENMAB A/S	26-Mar-25	2:57:18 PM	42	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:57:18 PM	6	1356.00	XCSE
GENMAB A/S	26-Mar-25	2:57:18 PM	19	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:57:18 PM	19	1356.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	2:57:56 PM	67	1356.00	XCSE
GENMAB A/S	26-Mar-25	2:58:20 PM	4	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:58:20 PM	1	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:58:28 PM	20	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:58:28 PM	27	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:58:28 PM	10	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:58:30 PM	10	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:58:31 PM	12	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:58:31 PM	42	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:58:31 PM	33	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:58:31 PM	29	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:58:31 PM	8	1356.50	XCSE
GENMAB A/S	26-Mar-25	2:58:31 PM	11	1357.00	XCSE
GENMAB A/S	26-Mar-25	2:58:31 PM	8	1356.50	CEUX
GENMAB A/S	26-Mar-25	2:58:31 PM	23	1356.50	TQEX
GENMAB A/S	26-Mar-25	2:58:58 PM	31	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:58:58 PM	11	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:58:58 PM	42	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:58:58 PM	10	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:58:59 PM	10	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:58:59 PM	12	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:00 PM	42	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:00 PM	11	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:00 PM	42	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:00 PM	11	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:00 PM	12	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:00 PM	12	1357.50	XCSE
GENMAB A/S	26-Mar-25	2:59:01 PM	8	1356.50	XCSE
GENMAB A/S	26-Mar-25	3:00:00 PM	75	1357.50	XCSE
GENMAB A/S	26-Mar-25	3:00:00 PM	10	1357.00	CEUX
GENMAB A/S	26-Mar-25	3:01:16 PM	25	1358.50	XCSE
GENMAB A/S	26-Mar-25	3:01:16 PM	10	1358.00	CEUX
GENMAB A/S	26-Mar-25	3:01:16 PM	10	1358.00	CEUX
GENMAB A/S	26-Mar-25	3:01:16 PM	20	1358.00	CEUX
GENMAB A/S	26-Mar-25	3:02:31 PM	74	1360.00	CEUX
GENMAB A/S	26-Mar-25	3:02:31 PM	23	1360.00	TQEX
GENMAB A/S	26-Mar-25	3:02:31 PM	34	1360.00	AQEU
GENMAB A/S	26-Mar-25	3:03:00 PM	4	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:03:00 PM	70	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:03:35 PM	74	1361.00	CEUX
GENMAB A/S	26-Mar-25	3:04:12 PM	9	1361.00	TQEX
GENMAB A/S	26-Mar-25	3:04:12 PM	8	1361.00	AQEU
GENMAB A/S	26-Mar-25	3:05:30 PM	3	1361.00	AQEU
GENMAB A/S	26-Mar-25	3:06:03 PM	2	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:06:34 PM	4	1361.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:07:41 PM	1	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:07:41 PM	10	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:07:54 PM	39	1362.00	TQEX
GENMAB A/S	26-Mar-25	3:07:54 PM	41	1362.00	AQEU
GENMAB A/S	26-Mar-25	3:07:55 PM	2	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:08:23 PM	7	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:08:23 PM	3	1362.00	TQEX
GENMAB A/S	26-Mar-25	3:08:23 PM	20	1362.00	TQEX
GENMAB A/S	26-Mar-25	3:08:58 PM	10	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:08:59 PM	10	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:09:01 PM	38	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:09:01 PM	1	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:09:01 PM	7	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:09:15 PM	6	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:09:49 PM	35	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:10:05 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	66	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	15	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	27	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	71	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	71	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:10:05 PM	36	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:10:05 PM	69	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:10:05 PM	1	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:10:05 PM	7	1360.00	TQEX
GENMAB A/S	26-Mar-25	3:10:05 PM	26	1361.00	TQEX
GENMAB A/S	26-Mar-25	3:10:05 PM	15	1362.00	TQEX
GENMAB A/S	26-Mar-25	3:10:05 PM	12	1362.00	TQEX
GENMAB A/S	26-Mar-25	3:10:05 PM	31	1362.00	AQEU
GENMAB A/S	26-Mar-25	3:10:05 PM	19	1361.00	AQEU
GENMAB A/S	26-Mar-25	3:10:08 PM	28	1360.50	CEUX
GENMAB A/S	26-Mar-25	3:10:28 PM	7	1360.00	CEUX
GENMAB A/S	26-Mar-25	3:10:31 PM	20	1360.00	CEUX
GENMAB A/S	26-Mar-25	3:10:53 PM	2	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:11:23 PM	70	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:11:37 PM	10	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:11:37 PM	18	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:11:37 PM	11	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:11:37 PM	72	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:11:37 PM	42	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:11:44 PM	42	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:11:44 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:11:44 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:11:45 PM	11	1362.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:11:45 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:11:45 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:11:45 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:11:45 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:12:12 PM	20	1362.00	AQEU
GENMAB A/S	26-Mar-25	3:12:17 PM	24	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:12:17 PM	24	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:12:17 PM	6	1362.00	AQEU
GENMAB A/S	26-Mar-25	3:12:30 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:12:30 PM	42	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:12:30 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:12:30 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:12:31 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:12:31 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:13:15 PM	2	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:50 PM	21	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:13:50 PM	1	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:13:50 PM	20	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:13:50 PM	32	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:13:58 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	30	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	42	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	12	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	12	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	70	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:13:58 PM	28	1362.50	TQEX
GENMAB A/S	26-Mar-25	3:13:59 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:59 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:59 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:13:59 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:14:01 PM	12	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:15:10 PM	73	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:15:26 PM	4	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:15:26 PM	3	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:15:26 PM	74	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:15:26 PM	24	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:15:26 PM	27	1364.00	AQEU
GENMAB A/S	26-Mar-25	3:17:03 PM	71	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:18:23 PM	42	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:18:23 PM	2	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:18:23 PM	10	1364.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:18:23 PM	11	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:18:23 PM	33	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:18:23 PM	73	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:18:23 PM	2	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:18:23 PM	25	1364.00	TQEX
GENMAB A/S	26-Mar-25	3:18:23 PM	8	1364.00	AQEU
GENMAB A/S	26-Mar-25	3:18:23 PM	15	1364.00	AQEU
GENMAB A/S	26-Mar-25	3:18:58 PM	5	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:18:59 PM	23	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:19:03 PM	36	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:19:05 PM	23	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:19:09 PM	22	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:19:26 PM	1	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:19:46 PM	12	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:19:46 PM	10	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:19:46 PM	13	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:19:53 PM	11	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:19:53 PM	2	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:20:02 PM	60	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:20:02 PM	14	1364.00	TQEX
GENMAB A/S	26-Mar-25	3:20:02 PM	17	1364.00	TQEX
GENMAB A/S	26-Mar-25	3:20:02 PM	33	1364.00	AQEU
GENMAB A/S	26-Mar-25	3:20:47 PM	26	1364.00	AQEU
GENMAB A/S	26-Mar-25	3:21:07 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	69	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	42	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	69	1363.50	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	2	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	22	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:21:07 PM	36	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	4	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	3	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	32	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	68	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	4	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	25	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	2	1362.00	CEUX
GENMAB A/S	26-Mar-25	3:21:07 PM	9	1363.00	TQEX
GENMAB A/S	26-Mar-25	3:21:07 PM	16	1363.00	TQEX
GENMAB A/S	26-Mar-25	3:21:29 PM	10	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:21:44 PM	4	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:22:00 PM	24	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:22:00 PM	23	1363.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:22:00 PM	10	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:22:00 PM	25	1363.00	AQEU
GENMAB A/S	26-Mar-25	3:22:33 PM	31	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:22:33 PM	69	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:22:33 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:22:33 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:23:02 PM	12	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:24:03 PM	69	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:24:13 PM	23	1363.50	TQEX
GENMAB A/S	26-Mar-25	3:25:26 PM	3	1363.50	XCSE
GENMAB A/S	26-Mar-25	3:25:26 PM	9	1363.50	XCSE
GENMAB A/S	26-Mar-25	3:25:26 PM	1	1363.50	XCSE
GENMAB A/S	26-Mar-25	3:25:26 PM	8	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:25:26 PM	15	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	30	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	42	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	1	1363.50	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	12	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	72	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	33	1363.50	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:37 PM	1	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	10	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	4	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	10	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	2	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	10	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	20	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:25:37 PM	4	1363.50	CEUX
GENMAB A/S	26-Mar-25	3:25:42 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:42 PM	12	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:42 PM	30	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:42 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:42 PM	11	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:42 PM	10	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:25:42 PM	22	1362.50	CEUX
GENMAB A/S	26-Mar-25	3:26:17 PM	30	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	72	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	42	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	33	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	36	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	11	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	11	1362.00	XCSE
GENMAB A/S	26-Mar-25	3:26:17 PM	65	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:26:17 PM	6	1361.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:26:17 PM	25	1362.50	TQEX
GENMAB A/S	26-Mar-25	3:26:17 PM	44	1362.50	AQEU
GENMAB A/S	26-Mar-25	3:28:25 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:25 PM	4	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:28:31 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	38	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	7	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:37 PM	15	1361.00	TQEX
GENMAB A/S	26-Mar-25	3:28:37 PM	1	1361.00	TQEX
GENMAB A/S	26-Mar-25	3:28:37 PM	10	1361.00	TQEX
GENMAB A/S	26-Mar-25	3:28:38 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:38 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:38 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:38 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:38 PM	30	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:39 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:28:44 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:03 PM	12	1361.00	CEUX
GENMAB A/S	26-Mar-25	3:29:03 PM	15	1361.00	CEUX
GENMAB A/S	26-Mar-25	3:29:20 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:20 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:20 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:20 PM	24	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:20 PM	16	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:20 PM	38	1361.00	CEUX
GENMAB A/S	26-Mar-25	3:29:20 PM	6	1361.00	CEUX
GENMAB A/S	26-Mar-25	3:29:21 PM	40	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	40	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	40	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	4	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:21 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:29:23 PM	71	1360.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:29:35 PM	1	1360.50	AQEU
GENMAB A/S	26-Mar-25	3:29:47 PM	2	1361.50	CEUX
GENMAB A/S	26-Mar-25	3:30:05 PM	17	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:30:05 PM	71	1359.50	XCSE
GENMAB A/S	26-Mar-25	3:30:05 PM	69	1361.50	XCSE
GENMAB A/S	26-Mar-25	3:30:05 PM	28	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:30:05 PM	30	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:30:05 PM	72	1360.00	CEUX
GENMAB A/S	26-Mar-25	3:30:05 PM	17	1359.50	CEUX
GENMAB A/S	26-Mar-25	3:30:05 PM	50	1359.50	CEUX
GENMAB A/S	26-Mar-25	3:30:05 PM	75	1361.00	CEUX
GENMAB A/S	26-Mar-25	3:30:05 PM	7	1359.50	CEUX
GENMAB A/S	26-Mar-25	3:30:05 PM	23	1361.00	TQEX
GENMAB A/S	26-Mar-25	3:30:05 PM	3	1359.50	TQEX
GENMAB A/S	26-Mar-25	3:30:05 PM	31	1361.50	AQEU
GENMAB A/S	26-Mar-25	3:31:40 PM	18	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:01 PM	4	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:01 PM	18	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:01 PM	30	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:01 PM	42	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:01 PM	1	1360.00	XCSE
GENMAB A/S	26-Mar-25	3:32:01 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	3:32:01 PM	23	1360.50	TQEX
GENMAB A/S	26-Mar-25	3:32:01 PM	1	1360.50	AQEU
GENMAB A/S	26-Mar-25	3:32:01 PM	27	1360.50	AQEU
GENMAB A/S	26-Mar-25	3:32:02 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	42	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	26	1360.50	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	32	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	6	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	42	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:02 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:04 PM	18	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:04 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:04 PM	42	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:04 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:04 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:11 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:11 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:11 PM	42	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:11 PM	17	1361.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:32:11 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:26 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:26 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:26 PM	21	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:32:26 PM	25	1361.00	XCSE
GENMAB A/S	26-Mar-25	3:34:27 PM	73	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:34:27 PM	70	1363.00	CEUX
GENMAB A/S	26-Mar-25	3:34:56 PM	70	1363.00	XCSE
GENMAB A/S	26-Mar-25	3:36:25 PM	2	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:36:26 PM	2	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:36:27 PM	3	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:36:52 PM	6	1364.00	AQEU
GENMAB A/S	26-Mar-25	3:37:11 PM	36	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:38:20 PM	42	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:38:20 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:38:20 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:38:20 PM	13	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:38:20 PM	29	1366.00	TQEX
GENMAB A/S	26-Mar-25	3:38:20 PM	14	1365.00	TQEX
GENMAB A/S	26-Mar-25	3:39:37 PM	74	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:39:49 PM	13	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:39:49 PM	3	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:40:00 PM	35	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:40:00 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:40:00 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:40:00 PM	50	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:40:00 PM	20	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:40:00 PM	9	1365.00	TQEX
GENMAB A/S	26-Mar-25	3:40:00 PM	24	1366.00	TQEX
GENMAB A/S	26-Mar-25	3:40:00 PM	36	1366.00	AQEU
GENMAB A/S	26-Mar-25	3:40:29 PM	10	1365.00	AQEU
GENMAB A/S	26-Mar-25	3:41:26 PM	8	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:41:57 PM	2	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:41:57 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:41:57 PM	4	1365.50	CEUX
GENMAB A/S	26-Mar-25	3:42:25 PM	1	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:25 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:25 PM	2	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:25 PM	1	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:27 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:27 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:27 PM	2	1365.50	CEUX
GENMAB A/S	26-Mar-25	3:42:28 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:42:28 PM	5	1365.50	CEUX
GENMAB A/S	26-Mar-25	3:42:37 PM	94	1365.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:43:26 PM	2	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:44:26 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:44:26 PM	36	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:44:27 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:44:27 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:44:27 PM	2	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:44:27 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:44:27 PM	4	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:44:27 PM	4	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	42	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:44:49 PM	12	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:44:49 PM	72	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:44:49 PM	29	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:44:49 PM	69	1364.00	XCSE
GENMAB A/S	26-Mar-25	3:44:49 PM	11	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:44:49 PM	7	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	5	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	8	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	6	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	2	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	7	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	8	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	18	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	15	1365.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	5	1364.50	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	2	1364.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	59	1365.00	CEUX
GENMAB A/S	26-Mar-25	3:44:49 PM	9	1364.00	TQEX
GENMAB A/S	26-Mar-25	3:44:49 PM	7	1364.00	TQEX
GENMAB A/S	26-Mar-25	3:44:49 PM	23	1364.00	TQEX
GENMAB A/S	26-Mar-25	3:44:49 PM	25	1365.50	TQEX
GENMAB A/S	26-Mar-25	3:44:49 PM	13	1365.00	AQEU
GENMAB A/S	26-Mar-25	3:44:50 PM	20	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:44:51 PM	50	1364.50	XCSE
GENMAB A/S	26-Mar-25	3:45:20 PM	3	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:45:20 PM	55	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:45:20 PM	17	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:45:20 PM	36	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:45:20 PM	37	1366.00	AQEU
GENMAB A/S	26-Mar-25	3:46:08 PM	72	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:46:08 PM	34	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:46:08 PM	40	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:46:20 PM	72	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:46:20 PM	71	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:46:20 PM	24	1367.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:46:27 PM	9	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:46:58 PM	8	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:46:58 PM	14	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:46:58 PM	42	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:46:58 PM	30	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:46:58 PM	75	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:46:58 PM	36	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:46:58 PM	20	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:46:58 PM	36	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:46:58 PM	4	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:46:58 PM	50	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:46:58 PM	17	1367.00	AQEU
GENMAB A/S	26-Mar-25	3:46:58 PM	6	1367.00	AQEU
GENMAB A/S	26-Mar-25	3:46:59 PM	42	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:46:59 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:46:59 PM	22	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:46:59 PM	4	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:46:59 PM	5	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:47:25 PM	2	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:47:25 PM	3	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:47:25 PM	3	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:05 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:05 PM	11	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:48:05 PM	40	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:05 PM	10	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:48:05 PM	2	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:48:05 PM	10	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:48:05 PM	45	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:05 PM	24	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:05 PM	40	1367.00	TQEX
GENMAB A/S	26-Mar-25	3:48:05 PM	13	1367.00	AQEU
GENMAB A/S	26-Mar-25	3:48:05 PM	10	1367.00	AQEU
GENMAB A/S	26-Mar-25	3:48:11 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:11 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:11 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:11 PM	4	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:11 PM	36	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:11 PM	5	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:14 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:14 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:14 PM	4	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:14 PM	36	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:14 PM	4	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:48:23 PM	3	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:23 PM	7	1367.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:48:23 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:23 PM	42	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:23 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:24 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:24 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:24 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:24 PM	7	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:24 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:25 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:26 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:26 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:26 PM	41	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:26 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:26 PM	4	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:26 PM	5	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:27 PM	12	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:28 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:28 PM	42	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:28 PM	1	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:28 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:29 PM	70	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:48:29 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:29 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:29 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:48:29 PM	8	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:48:29 PM	36	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:29 PM	25	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:29 PM	4	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:29 PM	63	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:48:29 PM	5	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:48:29 PM	12	1366.00	AQEU
GENMAB A/S	26-Mar-25	3:48:29 PM	11	1366.00	AQEU
GENMAB A/S	26-Mar-25	3:49:26 PM	2	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:49:38 PM	27	1366.00	AQEU
GENMAB A/S	26-Mar-25	3:49:40 PM	29	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:49:40 PM	25	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:49:44 PM	12	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:49:44 PM	12	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:49:44 PM	10	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:49:44 PM	10	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:49:44 PM	1	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:50:14 PM	2	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	21	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	16	1365.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:50:50 PM	2	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	55	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	5	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	59	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	34	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	42	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	45	1365.00	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	3:50:50 PM	65	1365.00	CEUX
GENMAB A/S	26-Mar-25	3:50:50 PM	5	1365.00	CEUX
GENMAB A/S	26-Mar-25	3:50:50 PM	24	1364.50	AQEU
GENMAB A/S	26-Mar-25	3:51:52 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:51:52 PM	2	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:51:52 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:51:52 PM	41	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:04 PM	42	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:04 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:04 PM	42	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:04 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:04 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:05 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:05 PM	12	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:05 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:05 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:07 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:07 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:08 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:08 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:14 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:14 PM	42	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:14 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:15 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:15 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:21 PM	12	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:21 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:24 PM	4	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:52:49 PM	12	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:53:32 PM	74	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:53:32 PM	9	1366.50	TQEX
GENMAB A/S	26-Mar-25	3:53:32 PM	23	1366.50	TQEX
GENMAB A/S	26-Mar-25	3:53:32 PM	43	1366.50	AQEU
GENMAB A/S	26-Mar-25	3:53:59 PM	36	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:06 PM	9	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:06 PM	94	1367.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:54:06 PM	34	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:06 PM	9	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:06 PM	42	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:07 PM	94	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:07 PM	94	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:07 PM	94	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:08 PM	38	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:08 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:08 PM	11	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:08 PM	14	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:08 PM	94	1367.00	XCSE
GENMAB A/S	26-Mar-25	3:54:08 PM	36	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:08 PM	5	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:08 PM	23	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:09 PM	4	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:09 PM	4	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:14 PM	8	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:14 PM	65	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:14 PM	10	1366.50	XCSE
GENMAB A/S	26-Mar-25	3:54:14 PM	36	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:14 PM	2	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:54:26 PM	4	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:26 PM	30	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:54:26 PM	23	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:55:26 PM	10	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:55:30 PM	36	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:55:40 PM	22	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:55:45 PM	66	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:56:03 PM	13	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:56:13 PM	32	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:56:14 PM	4	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:56:14 PM	5	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:56:21 PM	2	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:56:21 PM	71	1366.00	CEUX
GENMAB A/S	26-Mar-25	3:56:25 PM	2	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:25 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:25 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:25 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:26 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:26 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:27 PM	20	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:27 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:27 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:27 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:27 PM	12	1366.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	3:56:34 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:34 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:56:34 PM	1	1366.00	XCSE
GENMAB A/S	26-Mar-25	3:58:05 PM	12	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:58:05 PM	8	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:58:05 PM	10	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:58:05 PM	12	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:58:06 PM	10	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:58:09 PM	59	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:58:34 PM	45	1367.00	CEUX
GENMAB A/S	26-Mar-25	3:59:12 PM	34	1366.50	CEUX
GENMAB A/S	26-Mar-25	3:59:59 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:59:59 PM	49	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:59:59 PM	11	1367.50	XCSE
GENMAB A/S	26-Mar-25	3:59:59 PM	9	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:59:59 PM	24	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:59:59 PM	27	1367.50	CEUX
GENMAB A/S	26-Mar-25	3:59:59 PM	6	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:00:00 PM	10	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:00 PM	10	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:03 PM	65	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:03 PM	2	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:03 PM	16	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:00:03 PM	58	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:00:04 PM	30	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:05 PM	1	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:05 PM	1	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:00:09 PM	18	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:01:00 PM	71	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:01:01 PM	65	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:01:01 PM	12	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:01:01 PM	17	1368.50	AQEU
GENMAB A/S	26-Mar-25	4:01:01 PM	13	1368.50	AQEU
GENMAB A/S	26-Mar-25	4:01:25 PM	32	1368.50	CEUX
GENMAB A/S	26-Mar-25	4:01:26 PM	23	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:01:28 PM	12	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:01:28 PM	10	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:01:28 PM	9	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:01 PM	2	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:01 PM	24	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:01 PM	39	1369.00	CEUX
GENMAB A/S	26-Mar-25	4:02:01 PM	34	1369.00	CEUX
GENMAB A/S	26-Mar-25	4:02:01 PM	41	1369.00	TQEX
GENMAB A/S	26-Mar-25	4:02:01 PM	34	1369.00	AQEU
GENMAB A/S	26-Mar-25	4:02:12 PM	30	1369.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:02:12 PM	41	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:02:12 PM	39	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:12 PM	25	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:12 PM	34	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:02:34 PM	58	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:34 PM	10	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:34 PM	26	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:34 PM	23	1368.50	CEUX
GENMAB A/S	26-Mar-25	4:02:36 PM	11	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:02:36 PM	12	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:03:13 PM	26	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:03:13 PM	12	1369.00	XCSE
GENMAB A/S	26-Mar-25	4:03:13 PM	72	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:03:26 PM	29	1368.50	CEUX
GENMAB A/S	26-Mar-25	4:03:27 PM	2	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:03:41 PM	50	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:03:41 PM	22	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:03:41 PM	50	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:03:41 PM	1	1368.00	CEUX
GENMAB A/S	26-Mar-25	4:03:41 PM	73	1368.00	CEUX
GENMAB A/S	26-Mar-25	4:03:41 PM	15	1368.00	TQEX
GENMAB A/S	26-Mar-25	4:03:41 PM	21	1368.00	TQEX
GENMAB A/S	26-Mar-25	4:03:41 PM	30	1368.00	AQEU
GENMAB A/S	26-Mar-25	4:03:56 PM	1	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:03:56 PM	69	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:03:56 PM	22	1367.00	TQEX
GENMAB A/S	26-Mar-25	4:03:56 PM	33	1367.50	AQEU
GENMAB A/S	26-Mar-25	4:03:57 PM	9	1367.00	TQEX
GENMAB A/S	26-Mar-25	4:04:05 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:05 PM	64	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:05 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:05 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:06 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:06 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:06 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:06 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:06 PM	1	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:04:06 PM	1	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:04:07 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:07 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:07 PM	75	1366.50	XCSE
GENMAB A/S	26-Mar-25	4:04:07 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:07 PM	2	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:07 PM	10	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:07 PM	10	1367.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:04:07 PM	34	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:04:08 PM	25	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	34	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	30	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	13	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	25	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:08 PM	15	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:09 PM	52	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:09 PM	12	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:09 PM	19	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:09 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:15 PM	7	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:15 PM	65	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:15 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:15 PM	11	1367.00	XCSE
GENMAB A/S	26-Mar-25	4:04:22 PM	1	1365.50	CEUX
GENMAB A/S	26-Mar-25	4:04:22 PM	35	1366.00	TQEX
GENMAB A/S	26-Mar-25	4:05:26 PM	10	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:05:26 PM	49	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:06:21 PM	34	1368.00	AQEU
GENMAB A/S	26-Mar-25	4:06:26 PM	24	1368.00	CEUX
GENMAB A/S	26-Mar-25	4:06:26 PM	30	1368.00	CEUX
GENMAB A/S	26-Mar-25	4:06:48 PM	10	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:06:48 PM	2	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:06:48 PM	11	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:06:48 PM	37	1368.50	XCSE
GENMAB A/S	26-Mar-25	4:07:03 PM	47	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:07:03 PM	25	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:07:03 PM	42	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:07:03 PM	27	1367.50	TQEX
GENMAB A/S	26-Mar-25	4:07:03 PM	15	1367.50	TQEX
GENMAB A/S	26-Mar-25	4:07:25 PM	4	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:08:13 PM	2	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:08:13 PM	23	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:08:15 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:08:15 PM	2	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:08:15 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:08:15 PM	36	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:08:20 PM	3	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:08:29 PM	23	1367.50	AQEU
GENMAB A/S	26-Mar-25	4:08:31 PM	11	1367.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:08:31 PM	12	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:08:31 PM	36	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:08:31 PM	4	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:09:26 PM	74	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:09:26 PM	2	1367.50	XCSE
GENMAB A/S	26-Mar-25	4:09:26 PM	75	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:09:26 PM	52	1367.50	CEUX
GENMAB A/S	26-Mar-25	4:09:26 PM	27	1367.50	TQEX
GENMAB A/S	26-Mar-25	4:10:24 PM	1	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:10:25 PM	1	1366.50	XCSE
GENMAB A/S	26-Mar-25	4:10:30 PM	1	1367.00	TQEX
GENMAB A/S	26-Mar-25	4:10:30 PM	6	1367.00	TQEX
GENMAB A/S	26-Mar-25	4:10:30 PM	27	1367.00	TQEX
GENMAB A/S	26-Mar-25	4:10:47 PM	36	1367.00	CEUX
GENMAB A/S	26-Mar-25	4:10:47 PM	29	1367.00	CEUX
GENMAB A/S	26-Mar-25	4:10:47 PM	40	1367.00	AQEU
GENMAB A/S	26-Mar-25	4:10:51 PM	1	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:10:56 PM	34	1366.50	XCSE
GENMAB A/S	26-Mar-25	4:10:56 PM	8	1366.50	XCSE
GENMAB A/S	26-Mar-25	4:10:56 PM	26	1366.50	XCSE
GENMAB A/S	26-Mar-25	4:10:56 PM	9	1366.50	CEUX
GENMAB A/S	26-Mar-25	4:11:37 PM	54	1365.50	CEUX
GENMAB A/S	26-Mar-25	4:11:37 PM	11	1365.50	CEUX
GENMAB A/S	26-Mar-25	4:11:38 PM	3	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:11:38 PM	25	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:11:38 PM	7	1365.50	CEUX
GENMAB A/S	26-Mar-25	4:12:12 PM	1	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	50	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	8	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	48	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	6	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:12 PM	44	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	1	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	48	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	3	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	9	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	10	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	12	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	3	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:13 PM	9	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:15 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:15 PM	10	1366.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:12:18 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:18 PM	11	1366.00	XCSE
GENMAB A/S	26-Mar-25	4:12:18 PM	2	1366.00	CEUX
GENMAB A/S	26-Mar-25	4:12:18 PM	12	1366.00	CEUX
GENMAB A/S	26-Mar-25	4:12:18 PM	33	1366.00	CEUX
GENMAB A/S	26-Mar-25	4:12:18 PM	6	1366.00	CEUX
GENMAB A/S	26-Mar-25	4:13:05 PM	41	1365.50	CEUX
GENMAB A/S	26-Mar-25	4:13:05 PM	34	1365.50	CEUX
GENMAB A/S	26-Mar-25	4:13:11 PM	24	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:11 PM	22	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:11 PM	48	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	1	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	5	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:12 PM	30	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:13 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:13 PM	3	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:13 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	3	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:14 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:16 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:16 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:16 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:16 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:18 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:19 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:22 PM	75	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:22 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:22 PM	32	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:22 PM	50	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:23 PM	34	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:23 PM	31	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:23 PM	23	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:23 PM	18	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:23 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:13:23 PM	10	1365.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:13:23 PM	36	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	1	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	42	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	35	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	13	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	23	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	35	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	11	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:26 PM	12	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:27 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:27 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:35 PM	2	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:35 PM	17	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:13:44 PM	27	1365.00	CEUX
GENMAB A/S	26-Mar-25	4:13:44 PM	20	1365.00	CEUX
GENMAB A/S	26-Mar-25	4:13:45 PM	10	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:14:26 PM	2	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:14:26 PM	29	1365.00	CEUX
GENMAB A/S	26-Mar-25	4:14:31 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:14:31 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:14:33 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:14:33 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:01 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:01 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:03 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:03 PM	2	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:03 PM	7	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:04 PM	9	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:11 PM	1	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:11 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:12 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:12 PM	48	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:12 PM	11	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:16 PM	10	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:16 PM	48	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:19 PM	12	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:23 PM	23	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:24 PM	1	1365.50	XCSE
GENMAB A/S	26-Mar-25	4:15:24 PM	20	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:15:24 PM	51	1365.00	XCSE
GENMAB A/S	26-Mar-25	4:15:24 PM	73	1365.00	CEUX
GENMAB A/S	26-Mar-25	4:15:24 PM	1	1365.00	AQEU
GENMAB A/S	26-Mar-25	4:15:24 PM	7	1365.00	AQEU
GENMAB A/S	26-Mar-25	4:15:25 PM	8	1364.00	XCSE
GENMAB A/S	26-Mar-25	4:15:25 PM	10	1364.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:15:25 PM	10	1364.00	CEUX
GENMAB A/S	26-Mar-25	4:15:25 PM	2	1364.00	CEUX
GENMAB A/S	26-Mar-25	4:15:25 PM	6	1365.00	AQEU
GENMAB A/S	26-Mar-25	4:15:25 PM	9	1365.00	AQEU
GENMAB A/S	26-Mar-25	4:16:10 PM	61	1364.00	XCSE
GENMAB A/S	26-Mar-25	4:16:10 PM	10	1364.50	XCSE
GENMAB A/S	26-Mar-25	4:16:10 PM	50	1364.00	CEUX
GENMAB A/S	26-Mar-25	4:16:10 PM	34	1364.00	TQEX
GENMAB A/S	26-Mar-25	4:16:10 PM	10	1364.50	AQEU
GENMAB A/S	26-Mar-25	4:16:14 PM	7	1364.50	AQEU
GENMAB A/S	26-Mar-25	4:16:26 PM	5	1364.00	CEUX
GENMAB A/S	26-Mar-25	4:16:39 PM	73	1364.00	XCSE
GENMAB A/S	26-Mar-25	4:16:39 PM	37	1364.00	CEUX
GENMAB A/S	26-Mar-25	4:16:39 PM	34	1364.00	CEUX
GENMAB A/S	26-Mar-25	4:16:39 PM	26	1364.00	TQEX
GENMAB A/S	26-Mar-25	4:16:55 PM	48	1364.00	XCSE
GENMAB A/S	26-Mar-25	4:16:55 PM	11	1364.00	XCSE
GENMAB A/S	26-Mar-25	4:17:12 PM	71	1363.00	XCSE
GENMAB A/S	26-Mar-25	4:17:12 PM	68	1363.50	CEUX
GENMAB A/S	26-Mar-25	4:17:12 PM	25	1362.50	CEUX
GENMAB A/S	26-Mar-25	4:17:12 PM	31	1362.50	CEUX
GENMAB A/S	26-Mar-25	4:17:12 PM	7	1362.50	CEUX
GENMAB A/S	26-Mar-25	4:17:12 PM	10	1362.50	CEUX
GENMAB A/S	26-Mar-25	4:17:12 PM	41	1363.50	AQEU
GENMAB A/S	26-Mar-25	4:17:24 PM	27	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:17:24 PM	32	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:17:24 PM	8	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:17:24 PM	2	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:17:30 PM	2	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:17:30 PM	26	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:17:30 PM	10	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:17:30 PM	26	1362.00	TQEX
GENMAB A/S	26-Mar-25	4:18:05 PM	33	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:18:05 PM	47	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	16	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	27	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	20	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	39	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	12	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	14	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	50	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	2	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	8	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:18:25 PM	69	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:18:25 PM	28	1360.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:18:26 PM	23	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:18:26 PM	24	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:19:33 PM	25	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:19:52 PM	9	1359.50	CEUX
GENMAB A/S	26-Mar-25	4:19:52 PM	14	1359.50	CEUX
GENMAB A/S	26-Mar-25	4:20:05 PM	48	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:20:05 PM	3	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:20:05 PM	43	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:20:35 PM	2	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:20:35 PM	48	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:20:35 PM	8	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:20:50 PM	1	1359.00	XCSE
GENMAB A/S	26-Mar-25	4:21:25 PM	3	1359.50	AQEU
GENMAB A/S	26-Mar-25	4:21:30 PM	7	1359.50	AQEU
GENMAB A/S	26-Mar-25	4:22:16 PM	41	1360.50	TQEX
GENMAB A/S	26-Mar-25	4:22:40 PM	71	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:22:40 PM	72	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:22:41 PM	26	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:22:41 PM	48	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:22:55 PM	36	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:22:55 PM	36	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:22:55 PM	10	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:22:56 PM	50	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:23:11 PM	4	1360.50	TQEX
GENMAB A/S	26-Mar-25	4:23:55 PM	23	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:23:55 PM	10	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:23:56 PM	2	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:23:56 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:23:56 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:24:32 PM	9	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:24:32 PM	85	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:24:38 PM	5	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:24:57 PM	74	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:24:57 PM	36	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:24:57 PM	27	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:24:57 PM	1	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:24:57 PM	1	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:24:57 PM	27	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:25:04 PM	7	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:25:04 PM	17	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:25:09 PM	48	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:25:09 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:25:09 PM	32	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:25:09 PM	73	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:25:09 PM	10	1361.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:25:09 PM	15	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:25:39 PM	14	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:25:39 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:25:40 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:26:25 PM	7	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:26:25 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:26:25 PM	35	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:26:25 PM	32	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:27:21 PM	72	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:27:32 PM	10	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:27:34 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	28	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	48	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	8	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	3	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	16	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	50	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	1	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:27:34 PM	50	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:27:34 PM	21	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:27:34 PM	72	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:27:34 PM	2	1360.00	TQEX
GENMAB A/S	26-Mar-25	4:27:34 PM	4	1360.00	TQEX
GENMAB A/S	26-Mar-25	4:27:34 PM	23	1360.00	TQEX
GENMAB A/S	26-Mar-25	4:27:34 PM	2	1360.00	TQEX
GENMAB A/S	26-Mar-25	4:27:34 PM	13	1360.00	TQEX
GENMAB A/S	26-Mar-25	4:27:34 PM	27	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:27:58 PM	30	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:27:58 PM	43	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:27:58 PM	8	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:28:00 PM	7	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:28:00 PM	19	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:28:26 PM	44	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:28:32 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	10	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	39	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	10	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	24	1359.00	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	12	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	48	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	12	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	12	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	45	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:04 PM	39	1359.50	CEUX
GENMAB A/S	26-Mar-25	4:29:04 PM	1	1358.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:29:05 PM	16	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:05 PM	12	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:05 PM	45	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:05 PM	9	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:05 PM	12	1359.50	XCSE
GENMAB A/S	26-Mar-25	4:29:07 PM	18	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:29:07 PM	53	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:29:26 PM	2	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:30:06 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:06 PM	6	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:06 PM	2	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:06 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:06 PM	14	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:06 PM	48	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	8	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	2	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	36	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	1	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	50	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	34	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	1	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	1	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	40	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	8	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:07 PM	38	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:30:08 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:30:08 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:30:08 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	37	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	35	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	2	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:23 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:25 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:25 PM	11	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:35 PM	11	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:35 PM	12	1360.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:30:45 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:45 PM	11	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:30:45 PM	36	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:30:59 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:30:59 PM	70	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:31:05 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:31:05 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:31:05 PM	25	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:31:05 PM	48	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:31:08 PM	25	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:31:11 PM	16	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:31:37 PM	15	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:31:44 PM	1	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:31:44 PM	5	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:32:24 PM	38	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:32:24 PM	1	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:32:25 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:33:23 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:23 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:23 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:23 PM	46	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:23 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:23 PM	34	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:23 PM	4	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:24 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:24 PM	23	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:24 PM	48	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:24 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:25 PM	48	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:33:25 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:34:08 PM	9	1362.00	TQEX
GENMAB A/S	26-Mar-25	4:34:08 PM	25	1362.00	TQEX
GENMAB A/S	26-Mar-25	4:34:14 PM	32	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:34:14 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:34:14 PM	34	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:36:16 PM	75	1362.50	CEUX
GENMAB A/S	26-Mar-25	4:36:16 PM	28	1362.50	TQEX
GENMAB A/S	26-Mar-25	4:36:16 PM	33	1362.50	AQEU
GENMAB A/S	26-Mar-25	4:36:26 PM	22	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:26 PM	1	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:26 PM	48	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:26 PM	23	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:27 PM	23	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:27 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:27 PM	12	1362.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:36:27 PM	48	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:29 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:29 PM	16	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:29 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:31 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:31 PM	13	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:31 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:32 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:32 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:32 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:32 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	35	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	48	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	7	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	30	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:36 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	31	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	41	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	40	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	3	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:37 PM	30	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:38 PM	45	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:38 PM	11	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:38 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:36:38 PM	26	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:37:05 PM	12	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:37:05 PM	9	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:37:05 PM	10	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:37:05 PM	30	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:37:05 PM	26	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:37:18 PM	2	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:37:18 PM	10	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:37:18 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:37:25 PM	10	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:37:26 PM	22	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:37:27 PM	53	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:37:27 PM	28	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:37:27 PM	28	1362.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:38:12 PM	30	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:38:26 PM	2	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:38:26 PM	43	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:38:29 PM	22	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:38:54 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:38:54 PM	9	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:39:09 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:39:18 PM	12	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:39:24 PM	11	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:39:24 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:39:25 PM	74	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:39:25 PM	75	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:39:26 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:39:26 PM	27	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:39:26 PM	38	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:39:26 PM	11	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:40:27 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:40:27 PM	7	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:40:27 PM	23	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:40:27 PM	42	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:40:27 PM	3	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:40:27 PM	39	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:40:27 PM	38	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:40:27 PM	27	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:40:28 PM	25	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:40:28 PM	49	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:41:11 PM	1	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:11 PM	27	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:22 PM	17	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:41:25 PM	22	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:41:25 PM	26	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:41:35 PM	48	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	47	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	1	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	25	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:35 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:36 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:36 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:36 PM	48	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:36 PM	11	1361.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:41:36 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:37 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:37 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:40 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:40 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:41 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:42 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:42 PM	24	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:42 PM	48	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:42 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:44 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:41:57 PM	39	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:42:25 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:42:35 PM	20	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:43:26 PM	41	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:43:26 PM	2	1362.00	XCSE
GENMAB A/S	26-Mar-25	4:43:26 PM	19	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:44:27 PM	7	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:44:29 PM	18	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:44:44 PM	9	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:45:04 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:45:04 PM	12	1362.00	TQEX
GENMAB A/S	26-Mar-25	4:45:19 PM	26	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:46:35 PM	28	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:46:35 PM	46	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:46:35 PM	1	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:46:35 PM	70	1362.50	XCSE
GENMAB A/S	26-Mar-25	4:46:35 PM	72	1362.50	CEUX
GENMAB A/S	26-Mar-25	4:46:35 PM	38	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:46:35 PM	3	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	12	1362.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	8	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	15	1362.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	6	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	23	1362.50	TQEX
GENMAB A/S	26-Mar-25	4:46:35 PM	2	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:46:35 PM	22	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:46:36 PM	2	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:46:38 PM	29	1362.00	CEUX
GENMAB A/S	26-Mar-25	4:47:16 PM	46	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:47:36 PM	2	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:47:36 PM	12	1362.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:47:36 PM	2	1362.00	AQEU
GENMAB A/S	26-Mar-25	4:47:40 PM	4	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:47:40 PM	5	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:47:41 PM	23	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:47:41 PM	28	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:47:41 PM	5	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:47:41 PM	5	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:48:04 PM	33	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:04 PM	38	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:48:04 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:04 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:04 PM	12	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:04 PM	2	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:04 PM	2	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:05 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:05 PM	8	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:09 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:09 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:09 PM	11	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:09 PM	2	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:09 PM	2	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:27 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:27 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:27 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:27 PM	21	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:27 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:27 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:27 PM	12	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:27 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:27 PM	7	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:27 PM	2	1361.50	TQEX
GENMAB A/S	26-Mar-25	4:48:27 PM	2	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:27 PM	2	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:27 PM	11	1361.50	AQEU
GENMAB A/S	26-Mar-25	4:48:29 PM	12	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:29 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:36 PM	5	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:48:37 PM	4	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:48:43 PM	2	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:43 PM	10	1361.50	XCSE
GENMAB A/S	26-Mar-25	4:48:43 PM	4	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:48:43 PM	92	1361.50	CEUX
GENMAB A/S	26-Mar-25	4:48:43 PM	9	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:48:43 PM	16	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:48:44 PM	9	1361.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:48:44 PM	42	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	34	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	48	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	6	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	39	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	29	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	4	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	5	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:48:44 PM	38	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:44 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:44 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:44 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:44 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	10	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	2	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	12	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	38	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:45 PM	12	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:48:46 PM	41	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:49:05 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:49:05 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:49:05 PM	38	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:49:11 PM	61	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:49:11 PM	8	1360.50	TQEX
GENMAB A/S	26-Mar-25	4:49:11 PM	25	1360.50	TQEX
GENMAB A/S	26-Mar-25	4:49:25 PM	57	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:49:40 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:49:40 PM	11	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:49:41 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:49:41 PM	10	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:50:01 PM	10	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:01 PM	5	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:01 PM	5	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:01 PM	2	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:50:01 PM	2	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:50:02 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:02 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:11 PM	4	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:11 PM	1	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:11 PM	3	1360.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:50:11 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:11 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:11 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:11 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:11 PM	9	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:11 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:12 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:12 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:12 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:12 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:12 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:12 PM	9	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:12 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:12 PM	5	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:13 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:15 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:15 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:17 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:17 PM	39	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:18 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:18 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:19 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:19 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:19 PM	39	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:20 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:20 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:20 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:20 PM	4	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:20 PM	5	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:21 PM	2	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:50:22 PM	10	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:22 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:22 PM	11	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:23 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:23 PM	12	1360.00	XCSE
GENMAB A/S	26-Mar-25	4:50:23 PM	10	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:23 PM	5	1360.00	CEUX
GENMAB A/S	26-Mar-25	4:50:23 PM	8	1360.00	TQEX
GENMAB A/S	26-Mar-25	4:50:23 PM	12	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:50:23 PM	7	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:50:23 PM	2	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:50:23 PM	2	1360.00	AQEU
GENMAB A/S	26-Mar-25	4:51:03 PM	62	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:51:03 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:51:07 PM	74	1361.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:51:24 PM	27	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:51:25 PM	55	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:51:41 PM	70	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:51:41 PM	71	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:51:41 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:51:41 PM	29	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:52:00 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	3	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	23	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	48	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	6	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	2	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:00 PM	11	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:52:00 PM	12	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:52:03 PM	9	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:06 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:06 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:06 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:52:06 PM	2	1361.00	AQEU
GENMAB A/S	26-Mar-25	4:52:13 PM	4	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:52:13 PM	2	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:52:27 PM	26	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:53:11 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:11 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:11 PM	3	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:11 PM	48	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:11 PM	94	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:11 PM	3	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:11 PM	6	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:12 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:12 PM	10	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:12 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:12 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:12 PM	48	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:42 PM	10	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:53:55 PM	22	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:53:57 PM	12	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:53:57 PM	24	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:53:57 PM	11	1360.50	XCSE
GENMAB A/S	26-Mar-25	4:53:57 PM	5	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:53:57 PM	5	1360.50	CEUX
GENMAB A/S	26-Mar-25	4:53:57 PM	2	1360.50	TQEX
GENMAB A/S	26-Mar-25	4:53:57 PM	20	1360.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	26-Mar-25	4:53:57 PM	2	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:53:58 PM	12	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:58 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:58 PM	11	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:53:58 PM	35	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:53:58 PM	5	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:53:58 PM	4	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:53:58 PM	15	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:53:58 PM	4	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:54:05 PM	75	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:54:05 PM	75	1361.00	CEUX
GENMAB A/S	26-Mar-25	4:54:10 PM	42	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:54:10 PM	33	1361.00	TQEX
GENMAB A/S	26-Mar-25	4:54:29 PM	10	1360.50	AQEU
GENMAB A/S	26-Mar-25	4:54:32 PM	75	1361.00	XCSE
GENMAB A/S	26-Mar-25	4:54:37 PM	25	1361.50	CEUX
GENMAB A/S	27-Mar-25	9:42:33 AM	49	1344.50	XCSE
GENMAB A/S	27-Mar-25	9:43:04 AM	69	1345.00	TQEX
GENMAB A/S	27-Mar-25	9:43:31 AM	24	1344.50	XCSE
GENMAB A/S	27-Mar-25	9:43:32 AM	70	1344.00	TQEX
GENMAB A/S	27-Mar-25	9:43:36 AM	70	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:43:36 AM	64	1343.50	CEUX
GENMAB A/S	27-Mar-25	9:43:36 AM	65	1343.50	AQEU
GENMAB A/S	27-Mar-25	9:44:02 AM	3	1344.50	XCSE
GENMAB A/S	27-Mar-25	9:44:02 AM	18	1344.50	XCSE
GENMAB A/S	27-Mar-25	9:44:02 AM	11	1344.50	XCSE
GENMAB A/S	27-Mar-25	9:44:02 AM	23	1344.50	CEUX
GENMAB A/S	27-Mar-25	9:44:02 AM	22	1344.50	TQEX
GENMAB A/S	27-Mar-25	9:44:02 AM	24	1344.50	AQEU
GENMAB A/S	27-Mar-25	9:44:39 AM	8	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:45:08 AM	16	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:45:08 AM	51	1343.50	CEUX
GENMAB A/S	27-Mar-25	9:45:08 AM	14	1343.50	TQEX
GENMAB A/S	27-Mar-25	9:45:08 AM	45	1343.50	AQEU
GENMAB A/S	27-Mar-25	9:45:32 AM	31	1342.50	XCSE
GENMAB A/S	27-Mar-25	9:45:32 AM	75	1342.50	AQEU
GENMAB A/S	27-Mar-25	9:45:51 AM	28	1342.00	CEUX
GENMAB A/S	27-Mar-25	9:45:51 AM	44	1342.00	CEUX
GENMAB A/S	27-Mar-25	9:48:05 AM	2	1342.00	CEUX
GENMAB A/S	27-Mar-25	9:49:12 AM	12	1343.00	CEUX
GENMAB A/S	27-Mar-25	9:49:20 AM	46	1343.00	CEUX
GENMAB A/S	27-Mar-25	9:51:12 AM	57	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:51:12 AM	20	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:52:29 AM	75	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:52:29 AM	35	1343.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	9:53:16 AM	74	1343.50	XCSE
GENMAB A/S	27-Mar-25	9:53:16 AM	11	1343.00	CEUX
GENMAB A/S	27-Mar-25	9:53:16 AM	18	1343.00	CEUX
GENMAB A/S	27-Mar-25	9:54:42 AM	46	1343.00	CEUX
GENMAB A/S	27-Mar-25	9:55:22 AM	10	1343.00	CEUX
GENMAB A/S	27-Mar-25	9:59:07 AM	32	1345.50	CEUX
GENMAB A/S	27-Mar-25	9:59:56 AM	44	1345.00	CEUX
GENMAB A/S	27-Mar-25	9:59:56 AM	29	1345.00	CEUX
GENMAB A/S	27-Mar-25	10:01:04 AM	73	1344.50	XCSE
GENMAB A/S	27-Mar-25	10:01:04 AM	1	1344.00	CEUX
GENMAB A/S	27-Mar-25	10:04:06 AM	13	1344.50	CEUX
GENMAB A/S	27-Mar-25	10:05:26 AM	74	1344.00	CEUX
GENMAB A/S	27-Mar-25	10:06:35 AM	1	1345.50	CEUX
GENMAB A/S	27-Mar-25	10:07:01 AM	66	1345.50	XCSE
GENMAB A/S	27-Mar-25	10:07:01 AM	9	1345.50	XCSE
GENMAB A/S	27-Mar-25	10:09:29 AM	33	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:29 AM	2	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:29 AM	43	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:29 AM	9	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:29 AM	9	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:41 AM	17	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:41 AM	16	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:41 AM	57	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:09:41 AM	8	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:10:00 AM	26	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:10:00 AM	12	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:10:00 AM	6	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:10:01 AM	10	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:10:45 AM	72	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:10:45 AM	73	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:12:02 AM	15	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:12:02 AM	3	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:12:02 AM	75	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:12:03 AM	16	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:12:10 AM	10	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:12:10 AM	4	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:12:10 AM	9	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:12:10 AM	10	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:12:13 AM	15	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:14:00 AM	16	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:14:00 AM	15	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:14:00 AM	38	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:14:00 AM	4	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:14:00 AM	21	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:14:00 AM	36	1347.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	10:15:01 AM	51	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:01 AM	36	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:01 AM	72	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:01 AM	11	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:01 AM	6	1346.00	CEUX
GENMAB A/S	27-Mar-25	10:15:01 AM	36	1346.50	CEUX
GENMAB A/S	27-Mar-25	10:15:01 AM	71	1346.00	CEUX
GENMAB A/S	27-Mar-25	10:15:02 AM	30	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:02 AM	11	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:02 AM	49	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:02 AM	8	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:15:04 AM	15	1346.00	XCSE
GENMAB A/S	27-Mar-25	10:15:04 AM	7	1346.00	XCSE
GENMAB A/S	27-Mar-25	10:15:10 AM	19	1345.50	XCSE
GENMAB A/S	27-Mar-25	10:15:10 AM	59	1345.50	XCSE
GENMAB A/S	27-Mar-25	10:15:10 AM	20	1345.50	CEUX
GENMAB A/S	27-Mar-25	10:15:19 AM	36	1345.50	CEUX
GENMAB A/S	27-Mar-25	10:17:03 AM	7	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:20:08 AM	15	1347.00	TQEX
GENMAB A/S	27-Mar-25	10:20:28 AM	7	1347.00	TQEX
GENMAB A/S	27-Mar-25	10:21:45 AM	11	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:21:45 AM	5	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:21:45 AM	9	1347.00	XCSE
GENMAB A/S	27-Mar-25	10:21:45 AM	36	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:21:45 AM	5	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:21:46 AM	13	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:21:46 AM	30	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:21:46 AM	20	1347.00	CEUX
GENMAB A/S	27-Mar-25	10:22:53 AM	73	1346.50	XCSE
GENMAB A/S	27-Mar-25	10:22:53 AM	6	1346.50	CEUX
GENMAB A/S	27-Mar-25	10:24:43 AM	5	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:24:43 AM	5	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:24:43 AM	18	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:24:43 AM	5	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:25:04 AM	11	1347.50	CEUX
GENMAB A/S	27-Mar-25	10:27:16 AM	19	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:27:16 AM	12	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:27:16 AM	33	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:27:16 AM	1	1349.50	CEUX
GENMAB A/S	27-Mar-25	10:27:16 AM	12	1349.50	CEUX
GENMAB A/S	27-Mar-25	10:29:47 AM	98	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:29:47 AM	46	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:29:47 AM	39	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:29:47 AM	13	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:29:47 AM	7	1350.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	10:29:47 AM	12	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:30:18 AM	37	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:30:18 AM	4	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:30:18 AM	43	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:30:18 AM	9	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:30:18 AM	43	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:30:18 AM	18	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:30:18 AM	36	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:31:53 AM	11	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:31:53 AM	3	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:31:53 AM	9	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:32:03 AM	3	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:32:24 AM	10	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:32:24 AM	4	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:32:24 AM	6	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:32:28 AM	26	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:32:28 AM	11	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:33:06 AM	34	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:34:10 AM	3	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:34:10 AM	21	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:34:10 AM	3	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:34:11 AM	28	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:34:12 AM	77	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:34:12 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:34:12 AM	57	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:34:12 AM	10	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:34:12 AM	42	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:34:13 AM	22	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:34:13 AM	16	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:34:21 AM	15	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:35:03 AM	11	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:35:07 AM	28	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:35:24 AM	16	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:35:26 AM	36	1351.50	TQEX
GENMAB A/S	27-Mar-25	10:35:27 AM	64	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:35:27 AM	10	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:38:23 AM	72	1350.50	XCSE
GENMAB A/S	27-Mar-25	10:38:23 AM	72	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:38:23 AM	31	1350.50	CEUX
GENMAB A/S	27-Mar-25	10:38:23 AM	1	1350.50	CEUX
GENMAB A/S	27-Mar-25	10:38:23 AM	36	1350.50	CEUX
GENMAB A/S	27-Mar-25	10:38:23 AM	37	1350.50	TQEX
GENMAB A/S	27-Mar-25	10:38:25 AM	54	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:38:25 AM	19	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:38:25 AM	25	1350.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	10:38:25 AM	4	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:38:25 AM	5	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:38:25 AM	12	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:38:25 AM	4	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:38:25 AM	23	1349.50	TQEX
GENMAB A/S	27-Mar-25	10:38:52 AM	10	1349.50	XCSE
GENMAB A/S	27-Mar-25	10:41:39 AM	29	1350.00	TQEX
GENMAB A/S	27-Mar-25	10:42:14 AM	75	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:42:14 AM	28	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:42:14 AM	46	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:42:14 AM	25	1350.00	AQEU
GENMAB A/S	27-Mar-25	10:42:16 AM	10	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:42:16 AM	15	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:42:16 AM	13	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:42:16 AM	19	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:42:18 AM	1	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:42:24 AM	12	1350.00	CEUX
GENMAB A/S	27-Mar-25	10:45:19 AM	8	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:45:59 AM	66	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:45:59 AM	13	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:45:59 AM	48	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:45:59 AM	4	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	72	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	5	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	30	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	5	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	34	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	39	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:45:59 AM	31	1351.00	TQEX
GENMAB A/S	27-Mar-25	10:45:59 AM	22	1351.00	AQEU
GENMAB A/S	27-Mar-25	10:46:00 AM	36	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:00 AM	5	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:00 AM	4	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:00 AM	4	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:01 AM	31	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:01 AM	31	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:06 AM	22	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	12	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	5	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	4	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	5	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	14	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	17	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:07 AM	2	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:09 AM	3	1351.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	10:46:14 AM	13	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:46:42 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:46:42 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:46:42 AM	10	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:46:42 AM	5	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:46:42 AM	4	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:46:42 AM	4	1352.00	CEUX
GENMAB A/S	27-Mar-25	10:49:33 AM	50	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:50:21 AM	30	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:50:21 AM	19	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:50:21 AM	13	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:40 AM	18	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:40 AM	2	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:41 AM	25	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:43 AM	15	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:44 AM	22	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:45 AM	4	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:51:48 AM	14	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:55:17 AM	76	1351.00	XCSE
GENMAB A/S	27-Mar-25	10:55:17 AM	77	1350.00	XCSE
GENMAB A/S	27-Mar-25	10:55:17 AM	77	1351.00	CEUX
GENMAB A/S	27-Mar-25	10:55:17 AM	30	1350.00	TQEX
GENMAB A/S	27-Mar-25	10:55:17 AM	23	1351.00	TQEX
GENMAB A/S	27-Mar-25	10:55:40 AM	50	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:55:40 AM	5	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:55:40 AM	73	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:55:40 AM	18	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:55:40 AM	25	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:55:40 AM	19	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:56:11 AM	22	1352.00	AQEU
GENMAB A/S	27-Mar-25	10:56:12 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	10	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	20	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	50	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	20	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	10	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:12 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	78	1351.50	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	8	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	43	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	26	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	5	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	8	1352.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	10:56:26 AM	8	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:26 AM	15	1351.50	CEUX
GENMAB A/S	27-Mar-25	10:56:27 AM	10	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:27 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:56:27 AM	9	1352.00	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	3	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	30	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	6	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	2	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	11	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:00 AM	3	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	43	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	2	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:01 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:02 AM	43	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:02 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:02 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	10:58:04 AM	14	1352.50	CEUX
GENMAB A/S	27-Mar-25	10:58:04 AM	5	1352.50	CEUX
GENMAB A/S	27-Mar-25	10:58:04 AM	10	1352.50	CEUX
GENMAB A/S	27-Mar-25	10:59:52 AM	15	1352.50	CEUX
GENMAB A/S	27-Mar-25	10:59:53 AM	14	1352.50	CEUX
GENMAB A/S	27-Mar-25	10:59:55 AM	2	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:00:13 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:00:13 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:00:13 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:00:21 AM	10	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:01:06 AM	11	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:01:51 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:01:51 AM	11	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:01:57 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:14 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:14 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:14 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:14 AM	5	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:15 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:15 AM	10	1352.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:02:15 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:36 AM	11	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:50 AM	45	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:50 AM	5	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:51 AM	45	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:51 AM	45	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:51 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:02:51 AM	5	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:51 AM	4	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:51 AM	4	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:51 AM	5	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:51 AM	4	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:02:56 AM	54	1352.00	XCSE
GENMAB A/S	27-Mar-25	11:02:56 AM	44	1352.00	XCSE
GENMAB A/S	27-Mar-25	11:02:56 AM	7	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:02:56 AM	73	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:02:56 AM	29	1352.00	TQEX
GENMAB A/S	27-Mar-25	11:03:27 AM	39	1352.00	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	2	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	29	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	2	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:38 AM	36	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:39 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:39 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:39 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:39 AM	3	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:40 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:40 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:40 AM	8	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:43 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:44 AM	4	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:44 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:44 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:46 AM	9	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:46 AM	10	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:04:46 AM	3	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:05:42 AM	30	1352.00	TQEX
GENMAB A/S	27-Mar-25	11:05:45 AM	41	1352.00	XCSE
GENMAB A/S	27-Mar-25	11:05:45 AM	17	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:05:45 AM	23	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:05:45 AM	26	1352.00	AQEU
GENMAB A/S	27-Mar-25	11:07:10 AM	5	1352.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:07:10 AM	72	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:10 AM	5	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:10 AM	4	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:10 AM	32	1352.00	TQEX
GENMAB A/S	27-Mar-25	11:07:11 AM	32	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:11 AM	29	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:11 AM	19	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:13 AM	36	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:07:13 AM	22	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:09:53 AM	24	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:53 AM	4	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:53 AM	11	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:53 AM	5	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:53 AM	11	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:53 AM	13	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:55 AM	30	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:09:55 AM	10	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:09:55 AM	9	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:09:55 AM	10	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:09:55 AM	8	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:09:55 AM	8	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	7	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	32	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	10	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	10	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	10	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	11	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	9	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	3	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	8	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	17	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	43	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	6	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:56 AM	30	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:09:58 AM	40	1353.00	XCSE
GENMAB A/S	27-Mar-25	11:09:58 AM	74	1352.50	XCSE
GENMAB A/S	27-Mar-25	11:09:58 AM	20	1352.50	CEUX
GENMAB A/S	27-Mar-25	11:09:58 AM	74	1353.00	CEUX
GENMAB A/S	27-Mar-25	11:09:58 AM	22	1353.00	TQEX
GENMAB A/S	27-Mar-25	11:10:14 AM	75	1351.50	XCSE
GENMAB A/S	27-Mar-25	11:10:14 AM	73	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:10:14 AM	78	1351.00	CEUX
GENMAB A/S	27-Mar-25	11:10:14 AM	24	1351.00	TQEX
GENMAB A/S	27-Mar-25	11:10:14 AM	26	1352.00	TQEX
GENMAB A/S	27-Mar-25	11:10:14 AM	24	1352.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:10:42 AM	38	1350.50	XCSE
GENMAB A/S	27-Mar-25	11:10:42 AM	73	1350.50	XCSE
GENMAB A/S	27-Mar-25	11:12:17 AM	2	1352.00	AQEU
GENMAB A/S	27-Mar-25	11:13:07 AM	37	1351.50	XCSE
GENMAB A/S	27-Mar-25	11:13:16 AM	38	1351.50	XCSE
GENMAB A/S	27-Mar-25	11:13:16 AM	75	1351.50	CEUX
GENMAB A/S	27-Mar-25	11:13:16 AM	36	1352.00	CEUX
GENMAB A/S	27-Mar-25	11:13:16 AM	32	1352.00	AQEU
GENMAB A/S	27-Mar-25	11:13:34 AM	26	1351.00	TQEX
GENMAB A/S	27-Mar-25	11:13:35 AM	14	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:13:35 AM	33	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:13:35 AM	8	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:13:35 AM	43	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:13:35 AM	37	1350.50	CEUX
GENMAB A/S	27-Mar-25	11:13:35 AM	36	1350.50	CEUX
GENMAB A/S	27-Mar-25	11:15:11 AM	76	1350.50	XCSE
GENMAB A/S	27-Mar-25	11:15:11 AM	11	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:11 AM	57	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:11 AM	30	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:11 AM	1	1350.50	CEUX
GENMAB A/S	27-Mar-25	11:15:12 AM	10	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:12 AM	23	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:12 AM	8	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:12 AM	10	1351.00	XCSE
GENMAB A/S	27-Mar-25	11:15:19 AM	75	1350.50	XCSE
GENMAB A/S	27-Mar-25	11:15:26 AM	43	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:15:26 AM	77	1357.00	XCSE
GENMAB A/S	27-Mar-25	11:15:26 AM	23	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:15:26 AM	11	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:15:26 AM	76	1356.00	CEUX
GENMAB A/S	27-Mar-25	11:15:31 AM	43	1356.00	XCSE
GENMAB A/S	27-Mar-25	11:15:31 AM	22	1356.00	XCSE
GENMAB A/S	27-Mar-25	11:15:31 AM	33	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:15:31 AM	36	1356.50	CEUX
GENMAB A/S	27-Mar-25	11:15:41 AM	20	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:15:41 AM	74	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:15:41 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:15:41 AM	22	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:15:41 AM	76	1355.50	TQEX
GENMAB A/S	27-Mar-25	11:15:41 AM	74	1355.50	AQEU
GENMAB A/S	27-Mar-25	11:16:06 AM	74	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:16:06 AM	12	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:16:06 AM	71	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:16:06 AM	36	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:16:06 AM	73	1355.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:16:06 AM	68	1354.50	TQEX
GENMAB A/S	27-Mar-25	11:16:06 AM	71	1354.50	AQEU
GENMAB A/S	27-Mar-25	11:16:07 AM	36	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:16:48 AM	19	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:16:48 AM	28	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:16:48 AM	26	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:16:48 AM	2	1354.50	TQEX
GENMAB A/S	27-Mar-25	11:16:51 AM	16	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:16:51 AM	8	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:17:57 AM	27	1354.00	AQEU
GENMAB A/S	27-Mar-25	11:18:00 AM	30	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:18:00 AM	17	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:18:00 AM	36	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:18:00 AM	22	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:18:00 AM	18	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:18:00 AM	63	1354.00	TQEX
GENMAB A/S	27-Mar-25	11:18:00 AM	28	1354.00	AQEU
GENMAB A/S	27-Mar-25	11:18:00 AM	14	1354.00	AQEU
GENMAB A/S	27-Mar-25	11:18:02 AM	31	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:18:04 AM	36	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:18:10 AM	24	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:18:13 AM	58	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:18:13 AM	30	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:18:13 AM	17	1353.50	CEUX
GENMAB A/S	27-Mar-25	11:18:13 AM	60	1353.50	CEUX
GENMAB A/S	27-Mar-25	11:18:52 AM	41	1353.00	AQEU
GENMAB A/S	27-Mar-25	11:20:00 AM	11	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:00 AM	87	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:01 AM	11	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:01 AM	2	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:01 AM	1	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:01 AM	3	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:01 AM	1	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:09 AM	46	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:09 AM	23	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:09 AM	7	1353.50	CEUX
GENMAB A/S	27-Mar-25	11:20:09 AM	14	1353.50	CEUX
GENMAB A/S	27-Mar-25	11:20:09 AM	15	1353.50	CEUX
GENMAB A/S	27-Mar-25	11:20:14 AM	17	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:38 AM	3	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:38 AM	19	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:20:38 AM	3	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:21:42 AM	2	1353.50	XCSE
GENMAB A/S	27-Mar-25	11:22:12 AM	12	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:22:12 AM	12	1354.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:22:12 AM	24	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:22:12 AM	9	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:24:07 AM	17	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:24:10 AM	18	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:24:11 AM	30	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:24:11 AM	30	1354.00	XCSE
GENMAB A/S	27-Mar-25	11:24:11 AM	40	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:24:11 AM	2	1354.00	CEUX
GENMAB A/S	27-Mar-25	11:25:16 AM	32	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:16 AM	15	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:16 AM	15	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:16 AM	5	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:16 AM	31	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	25	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	8	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	1	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	8	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	8	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	48	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	14	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	43	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	3	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:17 AM	3	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:25:28 AM	20	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:33 AM	25	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:33 AM	38	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:33 AM	30	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:34 AM	30	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:34 AM	10	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:34 AM	8	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:34 AM	10	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:34 AM	30	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:35 AM	30	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:35 AM	8	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:25:36 AM	4	1354.50	XCSE
GENMAB A/S	27-Mar-25	11:28:06 AM	6	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:06 AM	25	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:06 AM	10	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:06 AM	9	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:06 AM	19	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:06 AM	8	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:06 AM	10	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:28:27 AM	4	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:28:27 AM	15	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:28:27 AM	22	1355.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:28:27 AM	6	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:28:27 AM	8	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:28:28 AM	32	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:29:16 AM	74	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:29:16 AM	60	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:29:16 AM	14	1355.00	AQEU
GENMAB A/S	27-Mar-25	11:29:17 AM	23	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:29:17 AM	44	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:29:17 AM	32	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:29:17 AM	35	1355.00	AQEU
GENMAB A/S	27-Mar-25	11:29:36 AM	22	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:29:36 AM	30	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:29:36 AM	21	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:29:36 AM	77	1354.50	CEUX
GENMAB A/S	27-Mar-25	11:33:32 AM	15	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:33:32 AM	4	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:33:32 AM	23	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:33:32 AM	9	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:33:32 AM	10	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:33:36 AM	14	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:33:54 AM	23	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:33:58 AM	17	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:33:58 AM	3	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:35:53 AM	30	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	74	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	6	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	68	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	4	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	26	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	24	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:35:53 AM	36	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:35:54 AM	23	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:36:13 AM	7	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:36:13 AM	47	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:36:13 AM	21	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:36:13 AM	75	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:36:13 AM	15	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:36:13 AM	24	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:36:36 AM	3	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:36:44 AM	2	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	30	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	34	1355.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:37:17 AM	30	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	73	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	8	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:17 AM	38	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:18 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:30 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:30 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:30 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:30 AM	3	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:30 AM	8	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:32 AM	8	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:32 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:32 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:33 AM	8	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:38 AM	19	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:39 AM	2	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:41 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:41 AM	8	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:41 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:43 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:37:45 AM	46	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:39:58 AM	36	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:39:58 AM	25	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:40:00 AM	30	1355.00	AQEU
GENMAB A/S	27-Mar-25	11:40:28 AM	13	1355.00	AQEU
GENMAB A/S	27-Mar-25	11:43:11 AM	25	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:43:11 AM	44	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:43:11 AM	36	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:11 AM	11	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:11 AM	14	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:11 AM	30	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:43:11 AM	4	1355.00	AQEU
GENMAB A/S	27-Mar-25	11:43:51 AM	30	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:43:51 AM	43	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:43:51 AM	39	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:43:51 AM	17	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:51 AM	22	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:51 AM	14	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:51 AM	24	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:43:52 AM	3	1355.00	CEUX
GENMAB A/S	27-Mar-25	11:44:02 AM	50	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:44:03 AM	27	1355.00	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	8	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	27	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	13	1355.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:44:53 AM	27	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	9	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	27	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	19	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	4	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:53 AM	28	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:44:53 AM	21	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:44:53 AM	4	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:44:57 AM	2	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:57 AM	93	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:44:58 AM	2	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:45:06 AM	45	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:45:06 AM	3	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:45:06 AM	28	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:45:07 AM	20	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:45:07 AM	62	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:45:29 AM	1	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:45:29 AM	12	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:45:29 AM	5	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:45:59 AM	15	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:45:59 AM	36	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:45:59 AM	3	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:46:31 AM	17	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:46:31 AM	10	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:46:31 AM	23	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:46:37 AM	10	1356.00	XCSE
GENMAB A/S	27-Mar-25	11:46:37 AM	9	1356.00	XCSE
GENMAB A/S	27-Mar-25	11:46:38 AM	8	1356.00	XCSE
GENMAB A/S	27-Mar-25	11:47:07 AM	78	1356.00	XCSE
GENMAB A/S	27-Mar-25	11:48:09 AM	4	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:48:09 AM	43	1355.50	XCSE
GENMAB A/S	27-Mar-25	11:48:09 AM	36	1356.00	CEUX
GENMAB A/S	27-Mar-25	11:48:09 AM	5	1356.00	CEUX
GENMAB A/S	27-Mar-25	11:48:09 AM	77	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:48:09 AM	20	1355.50	CEUX
GENMAB A/S	27-Mar-25	11:48:09 AM	25	1355.00	TQEX
GENMAB A/S	27-Mar-25	11:49:37 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	43	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	9	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	9	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	9	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	9	1356.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:49:37 AM	43	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:37 AM	28	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	10	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	10	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	12	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	10	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:38 AM	41	1356.00	AQEU
GENMAB A/S	27-Mar-25	11:49:40 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:40 AM	9	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:40 AM	8	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:45 AM	9	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:45 AM	13	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:49:48 AM	10	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:50:43 AM	10	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:50:43 AM	1	1356.50	XCSE
GENMAB A/S	27-Mar-25	11:51:24 AM	96	1357.00	XCSE
GENMAB A/S	27-Mar-25	11:51:24 AM	2	1357.00	XCSE
GENMAB A/S	27-Mar-25	11:51:27 AM	3	1357.50	XCSE
GENMAB A/S	27-Mar-25	11:51:27 AM	18	1357.50	XCSE
GENMAB A/S	27-Mar-25	11:52:04 AM	7	1357.50	CEUX
GENMAB A/S	27-Mar-25	11:52:30 AM	2	1358.00	XCSE
GENMAB A/S	27-Mar-25	11:52:30 AM	50	1358.00	XCSE
GENMAB A/S	27-Mar-25	11:52:36 AM	2	1358.00	XCSE
GENMAB A/S	27-Mar-25	11:52:51 AM	3	1358.00	XCSE
GENMAB A/S	27-Mar-25	11:53:02 AM	3	1358.00	XCSE
GENMAB A/S	27-Mar-25	11:53:03 AM	13	1358.00	CEUX
GENMAB A/S	27-Mar-25	11:53:03 AM	15	1358.00	CEUX
GENMAB A/S	27-Mar-25	11:53:31 AM	3	1358.50	CEUX
GENMAB A/S	27-Mar-25	11:53:51 AM	12	1358.50	CEUX
GENMAB A/S	27-Mar-25	11:55:09 AM	73	1358.50	XCSE
GENMAB A/S	27-Mar-25	11:55:09 AM	32	1358.50	CEUX
GENMAB A/S	27-Mar-25	11:55:09 AM	43	1358.50	CEUX
GENMAB A/S	27-Mar-25	11:55:09 AM	34	1358.50	CEUX
GENMAB A/S	27-Mar-25	11:55:42 AM	9	1360.50	XCSE
GENMAB A/S	27-Mar-25	11:55:42 AM	8	1360.50	XCSE
GENMAB A/S	27-Mar-25	11:55:42 AM	10	1360.50	XCSE
GENMAB A/S	27-Mar-25	11:55:42 AM	72	1360.50	CEUX
GENMAB A/S	27-Mar-25	11:55:43 AM	75	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:43 AM	78	1360.00	TQEX
GENMAB A/S	27-Mar-25	11:55:43 AM	44	1360.00	AQEU
GENMAB A/S	27-Mar-25	11:55:45 AM	70	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:45 AM	15	1360.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:55:45 AM	13	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	7	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	11	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	10	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	25	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	36	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	10	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:46 AM	11	1359.50	CEUX
GENMAB A/S	27-Mar-25	11:55:47 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:47 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:47 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:47 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:47 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:47 AM	10	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:48 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:51 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	4	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	43	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	24	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:58 AM	66	1359.50	CEUX
GENMAB A/S	27-Mar-25	11:55:59 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:59 AM	10	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:59 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:59 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:59 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:55:59 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:56:00 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:56:00 AM	9	1360.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:56:00 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:56:01 AM	10	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:56:01 AM	9	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:56:01 AM	8	1360.00	XCSE
GENMAB A/S	27-Mar-25	11:56:56 AM	29	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:56:56 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:56:56 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:56:56 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:56:56 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:57:11 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:57:44 AM	2	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:57:51 AM	3	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	7	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	2	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	45	1360.50	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:06 AM	34	1360.50	CEUX
GENMAB A/S	27-Mar-25	11:58:06 AM	43	1360.50	CEUX
GENMAB A/S	27-Mar-25	11:58:07 AM	30	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	39	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	30	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	31	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	29	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:07 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	42	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	30	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	17	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:08 AM	30	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	8	1361.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:58:09 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	14	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	27	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	16	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	26	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:09 AM	9	1360.50	CEUX
GENMAB A/S	27-Mar-25	11:58:09 AM	68	1360.50	CEUX
GENMAB A/S	27-Mar-25	11:58:09 AM	11	1360.00	AQEU
GENMAB A/S	27-Mar-25	11:58:10 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:10 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:10 AM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:10 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:10 AM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:10 AM	26	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:10 AM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:13 AM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:13 AM	23	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:18 AM	23	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:19 AM	2	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	2	1361.00	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	25	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:22 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	14	1361.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	11:58:23 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:23 AM	1	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:24 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:24 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:58:27 AM	71	1361.00	TQEX
GENMAB A/S	27-Mar-25	11:58:27 AM	54	1361.00	AQEU
GENMAB A/S	27-Mar-25	11:59:47 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	33	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	31	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	16	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	13	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	7	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:47 AM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:48 AM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	11:59:48 AM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:00:13 PM	22	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:00:13 PM	43	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:00:24 PM	76	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:00:24 PM	24	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:00:24 PM	78	1361.50	CEUX
GENMAB A/S	27-Mar-25	12:00:43 PM	2	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:00:51 PM	3	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:17 PM	69	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:17 PM	31	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:18 PM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:18 PM	39	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:18 PM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:18 PM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:18 PM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:18 PM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:19 PM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:19 PM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:19 PM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:19 PM	10	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:20 PM	39	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:20 PM	39	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:20 PM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:20 PM	8	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:20 PM	9	1361.50	XCSE
GENMAB A/S	27-Mar-25	12:01:20 PM	9	1361.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	12:01:20 PM	42	1361.00	AQEU
GENMAB A/S	27-Mar-25	12:01:28 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:01:28 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:01:36 PM	28	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:01:36 PM	5	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:02:06 PM	37	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:02:06 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:02:18 PM	54	1360.50	CEUX
GENMAB A/S	27-Mar-25	12:02:58 PM	78	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:02:58 PM	72	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:02:58 PM	60	1363.00	TQEX
GENMAB A/S	27-Mar-25	12:02:58 PM	39	1363.00	AQEU
GENMAB A/S	27-Mar-25	12:03:21 PM	75	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:03:21 PM	32	1363.50	CEUX
GENMAB A/S	27-Mar-25	12:03:23 PM	48	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:03:23 PM	33	1363.00	TQEX
GENMAB A/S	27-Mar-25	12:03:23 PM	18	1363.00	AQEU
GENMAB A/S	27-Mar-25	12:04:34 PM	10	1363.00	AQEU
GENMAB A/S	27-Mar-25	12:09:49 PM	62	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:09:50 PM	30	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:10:05 PM	14	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	33	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	34	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	15	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	13	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	43	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	16	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:20 PM	17	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:21 PM	9	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:21 PM	33	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:21 PM	98	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:21 PM	8	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:10:21 PM	8	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:11:06 PM	4	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:11:06 PM	12	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:11:06 PM	4	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:11:06 PM	8	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:11:06 PM	9	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:11:33 PM	74	1362.00	XCSE
GENMAB A/S	27-Mar-25	12:11:33 PM	72	1362.00	CEUX
GENMAB A/S	27-Mar-25	12:11:33 PM	58	1362.00	TQEX
GENMAB A/S	27-Mar-25	12:11:33 PM	12	1362.00	AQEU
GENMAB A/S	27-Mar-25	12:11:33 PM	3	1362.00	AQEU
GENMAB A/S	27-Mar-25	12:11:33 PM	21	1362.00	AQEU
GENMAB A/S	27-Mar-25	12:11:42 PM	47	1361.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	12:11:42 PM	25	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:11:42 PM	22	1361.00	CEUX
GENMAB A/S	27-Mar-25	12:11:42 PM	30	1361.00	AQEU
GENMAB A/S	27-Mar-25	12:12:01 PM	33	1360.50	TQEX
GENMAB A/S	27-Mar-25	12:12:07 PM	27	1360.00	CEUX
GENMAB A/S	27-Mar-25	12:12:07 PM	15	1360.00	AQEU
GENMAB A/S	27-Mar-25	12:12:09 PM	9	1360.00	AQEU
GENMAB A/S	27-Mar-25	12:13:56 PM	4	1360.00	XCSE
GENMAB A/S	27-Mar-25	12:13:56 PM	23	1360.00	XCSE
GENMAB A/S	27-Mar-25	12:14:12 PM	74	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:14:12 PM	70	1359.50	CEUX
GENMAB A/S	27-Mar-25	12:14:12 PM	6	1359.50	CEUX
GENMAB A/S	27-Mar-25	12:14:12 PM	28	1359.50	TQEX
GENMAB A/S	27-Mar-25	12:15:40 PM	22	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:15:46 PM	9	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:15:46 PM	10	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:15:46 PM	9	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:16:45 PM	43	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:16:45 PM	6	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:17:40 PM	8	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:17:40 PM	2	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:17:46 PM	26	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:17:47 PM	3	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:18:08 PM	75	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:18:08 PM	8	1359.50	TQEX
GENMAB A/S	27-Mar-25	12:18:15 PM	76	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:18:15 PM	72	1358.50	CEUX
GENMAB A/S	27-Mar-25	12:18:15 PM	24	1358.50	AQEU
GENMAB A/S	27-Mar-25	12:18:15 PM	3	1358.50	AQEU
GENMAB A/S	27-Mar-25	12:19:27 PM	50	1357.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	9	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	43	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	15	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	2	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	10	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	13	1358.50	XCSE
GENMAB A/S	27-Mar-25	12:23:19 PM	7	1358.50	AQEU
GENMAB A/S	27-Mar-25	12:23:24 PM	75	1359.00	XCSE
GENMAB A/S	27-Mar-25	12:27:25 PM	43	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:27:25 PM	9	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:27:26 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:27:26 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:27:26 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:27:26 PM	1	1359.50	XCSE
GENMAB A/S	27-Mar-25	12:27:27 PM	72	1360.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	12:27:27 PM	5	1361.00	CEUX
GENMAB A/S	27-Mar-25	12:27:27 PM	73	1360.50	CEUX
GENMAB A/S	27-Mar-25	12:27:27 PM	5	1361.00	CEUX
GENMAB A/S	27-Mar-25	12:27:27 PM	36	1361.00	CEUX
GENMAB A/S	27-Mar-25	12:27:27 PM	4	1361.00	CEUX
GENMAB A/S	27-Mar-25	12:27:27 PM	31	1360.50	TQEX
GENMAB A/S	27-Mar-25	12:30:24 PM	28	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:24 PM	12	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:24 PM	6	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:25 PM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:25 PM	14	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:25 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:25 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:26 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:26 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:26 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:27 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:29 PM	2	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:29 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:29 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:31 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:32 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:32 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:32 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:32 PM	2	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:33 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:33 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:41 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:41 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:43 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:30:43 PM	9	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:31:17 PM	14	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:32:35 PM	43	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:32:35 PM	10	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:32:37 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:32:37 PM	13	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:32:41 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:32:42 PM	8	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:34:36 PM	20	1361.00	XCSE
GENMAB A/S	27-Mar-25	12:35:49 PM	76	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:49 PM	36	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:49 PM	72	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:49 PM	26	1363.00	TQEX
GENMAB A/S	27-Mar-25	12:35:49 PM	8	1363.00	TQEX
GENMAB A/S	27-Mar-25	12:35:49 PM	24	1363.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	12:35:50 PM	41	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:50 PM	19	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:50 PM	38	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:50 PM	78	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	23	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:51 PM	19	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:51 PM	43	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:35:51 PM	5	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	12	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	4	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	5	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	5	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	36	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:35:51 PM	25	1362.50	TQEX
GENMAB A/S	27-Mar-25	12:35:53 PM	21	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:36:05 PM	13	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:36:16 PM	44	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:36:16 PM	8	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:36:19 PM	15	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:39:27 PM	76	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:39:27 PM	73	1363.00	CEUX
GENMAB A/S	27-Mar-25	12:41:48 PM	73	1362.00	XCSE
GENMAB A/S	27-Mar-25	12:41:48 PM	43	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:41:48 PM	77	1362.00	CEUX
GENMAB A/S	27-Mar-25	12:41:48 PM	40	1362.50	CEUX
GENMAB A/S	27-Mar-25	12:41:48 PM	23	1362.50	TQEX
GENMAB A/S	27-Mar-25	12:41:48 PM	22	1362.50	AQEU
GENMAB A/S	27-Mar-25	12:43:08 PM	28	1362.50	CEUX
GENMAB A/S	27-Mar-25	12:43:08 PM	10	1362.50	CEUX
GENMAB A/S	27-Mar-25	12:43:08 PM	13	1362.50	CEUX
GENMAB A/S	27-Mar-25	12:43:16 PM	10	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:43:16 PM	43	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:43:16 PM	77	1362.00	CEUX
GENMAB A/S	27-Mar-25	12:43:23 PM	72	1362.50	CEUX
GENMAB A/S	27-Mar-25	12:43:35 PM	78	1362.00	XCSE
GENMAB A/S	27-Mar-25	12:44:10 PM	24	1361.50	TQEX
GENMAB A/S	27-Mar-25	12:44:10 PM	22	1361.50	AQEU
GENMAB A/S	27-Mar-25	12:44:53 PM	8	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:44:53 PM	9	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:44:53 PM	20	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:44:53 PM	9	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:44:54 PM	14	1363.00	XCSE
GENMAB A/S	27-Mar-25	12:45:02 PM	24	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:02 PM	8	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:02 PM	43	1365.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	12:45:02 PM	17	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:02 PM	46	1365.00	CEUX
GENMAB A/S	27-Mar-25	12:45:02 PM	28	1365.00	CEUX
GENMAB A/S	27-Mar-25	12:45:02 PM	26	1365.50	AQEU
GENMAB A/S	27-Mar-25	12:45:03 PM	41	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:15 PM	63	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:15 PM	20	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:15 PM	76	1365.00	XCSE
GENMAB A/S	27-Mar-25	12:45:15 PM	15	1365.50	XCSE
GENMAB A/S	27-Mar-25	12:45:15 PM	68	1365.50	CEUX
GENMAB A/S	27-Mar-25	12:45:15 PM	22	1365.50	TQEX
GENMAB A/S	27-Mar-25	12:45:15 PM	34	1365.50	AQEU
GENMAB A/S	27-Mar-25	12:47:02 PM	22	1364.50	TQEX
GENMAB A/S	27-Mar-25	12:47:06 PM	3	1364.50	XCSE
GENMAB A/S	27-Mar-25	12:48:18 PM	73	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:48:18 PM	76	1366.00	CEUX
GENMAB A/S	27-Mar-25	12:48:18 PM	23	1366.00	AQEU
GENMAB A/S	27-Mar-25	12:48:22 PM	33	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:50:00 PM	1	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:01 PM	21	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:13 PM	2	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:14 PM	2	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:17 PM	2	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:21 PM	9	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:21 PM	9	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:21 PM	4	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:50:27 PM	2	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:53:43 PM	15	1368.50	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	15	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	27	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	77	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	41	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	75	1368.50	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	10	1366.00	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	73	1367.00	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	98	1368.50	XCSE
GENMAB A/S	27-Mar-25	12:55:17 PM	46	1366.00	CEUX
GENMAB A/S	27-Mar-25	12:55:17 PM	76	1368.00	CEUX
GENMAB A/S	27-Mar-25	12:55:17 PM	78	1367.00	CEUX
GENMAB A/S	27-Mar-25	12:55:17 PM	1	1368.00	CEUX
GENMAB A/S	27-Mar-25	12:55:17 PM	29	1367.50	TQEX
GENMAB A/S	27-Mar-25	12:55:17 PM	22	1366.50	TQEX
GENMAB A/S	27-Mar-25	12:55:17 PM	23	1368.00	AQEU
GENMAB A/S	27-Mar-25	12:55:17 PM	22	1367.00	AQEU
GENMAB A/S	27-Mar-25	12:55:17 PM	23	1366.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	12:55:18 PM	11	1365.50	AQEU
GENMAB A/S	27-Mar-25	12:55:21 PM	28	1365.50	AQEU
GENMAB A/S	27-Mar-25	12:55:33 PM	76	1364.50	XCSE
GENMAB A/S	27-Mar-25	12:55:33 PM	9	1364.50	CEUX
GENMAB A/S	27-Mar-25	12:55:33 PM	67	1364.50	CEUX
GENMAB A/S	27-Mar-25	12:55:43 PM	78	1363.50	CEUX
GENMAB A/S	27-Mar-25	12:55:44 PM	19	1363.50	XCSE
GENMAB A/S	27-Mar-25	12:55:44 PM	55	1363.50	XCSE
GENMAB A/S	27-Mar-25	12:55:44 PM	15	1364.00	AQEU
GENMAB A/S	27-Mar-25	12:55:44 PM	9	1364.00	AQEU
GENMAB A/S	27-Mar-25	12:55:51 PM	45	1362.50	CEUX
GENMAB A/S	27-Mar-25	12:55:53 PM	76	1362.50	XCSE
GENMAB A/S	27-Mar-25	12:57:14 PM	27	1363.00	TQEX
GENMAB A/S	27-Mar-25	12:59:36 PM	48	1363.50	XCSE
GENMAB A/S	27-Mar-25	12:59:36 PM	29	1363.50	XCSE
GENMAB A/S	27-Mar-25	1:00:00 PM	48	1363.50	CEUX
GENMAB A/S	27-Mar-25	1:00:26 PM	48	1364.00	XCSE
GENMAB A/S	27-Mar-25	1:00:26 PM	8	1364.00	XCSE
GENMAB A/S	27-Mar-25	1:00:26 PM	13	1364.00	XCSE
GENMAB A/S	27-Mar-25	1:00:51 PM	39	1363.50	CEUX
GENMAB A/S	27-Mar-25	1:04:20 PM	56	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:20 PM	17	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:20 PM	69	1367.50	CEUX
GENMAB A/S	27-Mar-25	1:04:20 PM	40	1367.50	AQEU
GENMAB A/S	27-Mar-25	1:04:21 PM	9	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:21 PM	12	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:21 PM	8	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:21 PM	24	1367.00	TQEX
GENMAB A/S	27-Mar-25	1:04:24 PM	62	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:24 PM	22	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:04:29 PM	36	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:04:56 PM	27	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:04:56 PM	5	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:04:56 PM	21	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:04:56 PM	25	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:04:56 PM	8	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:04:56 PM	9	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:06:18 PM	24	1367.00	TQEX
GENMAB A/S	27-Mar-25	1:06:29 PM	34	1367.00	AQEU
GENMAB A/S	27-Mar-25	1:08:07 PM	22	1367.00	TQEX
GENMAB A/S	27-Mar-25	1:08:42 PM	40	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:08:42 PM	18	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:08:42 PM	24	1367.00	AQEU
GENMAB A/S	27-Mar-25	1:08:43 PM	42	1367.00	XCSE
GENMAB A/S	27-Mar-25	1:08:56 PM	26	1367.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	1:09:09 PM	10	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:09 PM	19	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:09 PM	7	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:09 PM	9	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:09 PM	37	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:09 PM	8	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:09 PM	8	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:09:17 PM	26	1366.50	XCSE
GENMAB A/S	27-Mar-25	1:09:17 PM	50	1366.50	XCSE
GENMAB A/S	27-Mar-25	1:09:18 PM	58	1366.50	CEUX
GENMAB A/S	27-Mar-25	1:09:43 PM	2	1365.50	XCSE
GENMAB A/S	27-Mar-25	1:09:43 PM	73	1365.50	XCSE
GENMAB A/S	27-Mar-25	1:09:48 PM	36	1365.00	CEUX
GENMAB A/S	27-Mar-25	1:11:31 PM	75	1367.00	CEUX
GENMAB A/S	27-Mar-25	1:12:13 PM	40	1367.50	TQEX
GENMAB A/S	27-Mar-25	1:12:18 PM	17	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:12:18 PM	8	1367.50	XCSE
GENMAB A/S	27-Mar-25	1:12:19 PM	25	1367.00	CEUX
GENMAB A/S	27-Mar-25	1:12:19 PM	3	1367.00	CEUX
GENMAB A/S	27-Mar-25	1:12:25 PM	1	1367.00	AQEU
GENMAB A/S	27-Mar-25	1:13:10 PM	34	1368.00	CEUX
GENMAB A/S	27-Mar-25	1:13:26 PM	16	1368.00	XCSE
GENMAB A/S	27-Mar-25	1:13:29 PM	6	1368.00	XCSE
GENMAB A/S	27-Mar-25	1:13:30 PM	26	1368.00	CEUX
GENMAB A/S	27-Mar-25	1:14:23 PM	27	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:14:23 PM	2	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:14:23 PM	35	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:14:24 PM	8	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:14:24 PM	8	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:14:24 PM	11	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:14:25 PM	74	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:15:05 PM	74	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:15:08 PM	74	1372.50	CEUX
GENMAB A/S	27-Mar-25	1:15:32 PM	77	1372.00	XCSE
GENMAB A/S	27-Mar-25	1:15:54 PM	72	1371.00	XCSE
GENMAB A/S	27-Mar-25	1:15:54 PM	56	1371.50	CEUX
GENMAB A/S	27-Mar-25	1:19:02 PM	14	1371.50	CEUX
GENMAB A/S	27-Mar-25	1:19:18 PM	14	1371.50	CEUX
GENMAB A/S	27-Mar-25	1:19:37 PM	6	1371.50	CEUX
GENMAB A/S	27-Mar-25	1:19:39 PM	10	1371.50	XCSE
GENMAB A/S	27-Mar-25	1:19:39 PM	33	1371.50	XCSE
GENMAB A/S	27-Mar-25	1:19:39 PM	10	1371.50	XCSE
GENMAB A/S	27-Mar-25	1:19:39 PM	10	1371.50	XCSE
GENMAB A/S	27-Mar-25	1:20:39 PM	14	1371.50	XCSE
GENMAB A/S	27-Mar-25	1:20:39 PM	11	1371.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	1:20:39 PM	50	1371.50	XCSE
GENMAB A/S	27-Mar-25	1:20:39 PM	23	1371.50	TQEX
GENMAB A/S	27-Mar-25	1:21:15 PM	18	1372.50	CEUX
GENMAB A/S	27-Mar-25	1:21:15 PM	57	1372.50	CEUX
GENMAB A/S	27-Mar-25	1:23:06 PM	19	1373.50	XCSE
GENMAB A/S	27-Mar-25	1:23:06 PM	14	1373.50	XCSE
GENMAB A/S	27-Mar-25	1:23:10 PM	44	1373.50	XCSE
GENMAB A/S	27-Mar-25	1:23:10 PM	20	1373.50	XCSE
GENMAB A/S	27-Mar-25	1:23:10 PM	34	1373.50	XCSE
GENMAB A/S	27-Mar-25	1:23:10 PM	76	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:23:10 PM	64	1373.00	CEUX
GENMAB A/S	27-Mar-25	1:23:10 PM	42	1373.00	TQEX
GENMAB A/S	27-Mar-25	1:24:27 PM	4	1372.00	XCSE
GENMAB A/S	27-Mar-25	1:24:35 PM	4	1372.00	XCSE
GENMAB A/S	27-Mar-25	1:25:35 PM	38	1372.00	XCSE
GENMAB A/S	27-Mar-25	1:25:35 PM	68	1372.00	XCSE
GENMAB A/S	27-Mar-25	1:25:35 PM	60	1372.00	XCSE
GENMAB A/S	27-Mar-25	1:26:00 PM	14	1371.50	CEUX
GENMAB A/S	27-Mar-25	1:26:56 PM	43	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:26:56 PM	3	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:26:56 PM	15	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:26:56 PM	9	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:26:56 PM	2	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:26:56 PM	2	1372.50	XCSE
GENMAB A/S	27-Mar-25	1:26:56 PM	24	1373.00	XCSE
GENMAB A/S	27-Mar-25	1:28:09 PM	42	1375.50	CEUX
GENMAB A/S	27-Mar-25	1:28:09 PM	34	1375.50	CEUX
GENMAB A/S	27-Mar-25	1:28:09 PM	42	1375.50	TQEX
GENMAB A/S	27-Mar-25	1:29:38 PM	36	1375.00	XCSE
GENMAB A/S	27-Mar-25	1:29:38 PM	30	1375.00	XCSE
GENMAB A/S	27-Mar-25	1:29:38 PM	72	1375.00	XCSE
GENMAB A/S	27-Mar-25	1:29:38 PM	22	1375.00	AQEU
GENMAB A/S	27-Mar-25	1:30:31 PM	19	1375.50	XCSE
GENMAB A/S	27-Mar-25	1:30:31 PM	11	1375.50	XCSE
GENMAB A/S	27-Mar-25	1:30:31 PM	22	1375.50	XCSE
GENMAB A/S	27-Mar-25	1:30:31 PM	46	1375.50	XCSE
GENMAB A/S	27-Mar-25	1:33:07 PM	73	1376.00	XCSE
GENMAB A/S	27-Mar-25	1:33:07 PM	26	1376.00	AQEU
GENMAB A/S	27-Mar-25	1:34:14 PM	47	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:34:14 PM	51	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:34:15 PM	41	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:37:15 PM	35	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:37:15 PM	42	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:37:15 PM	21	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:37:15 PM	72	1376.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	1:37:15 PM	32	1376.00	CEUX
GENMAB A/S	27-Mar-25	1:37:15 PM	31	1376.50	AQEU
GENMAB A/S	27-Mar-25	1:37:17 PM	9	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:37:17 PM	10	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:37:17 PM	8	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:37:17 PM	32	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:37:17 PM	18	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:37:17 PM	17	1377.00	XCSE
GENMAB A/S	27-Mar-25	1:37:37 PM	23	1378.00	CEUX
GENMAB A/S	27-Mar-25	1:41:27 PM	26	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:27 PM	8	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:27 PM	10	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:27 PM	11	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:27 PM	18	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:27 PM	14	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:27 PM	7	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:41:32 PM	31	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:41:32 PM	40	1378.00	TQEX
GENMAB A/S	27-Mar-25	1:41:42 PM	15	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	15	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	11	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	8	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	26	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	9	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	46	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	10	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	20	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	74	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:42 PM	4	1378.00	CEUX
GENMAB A/S	27-Mar-25	1:41:42 PM	72	1377.50	CEUX
GENMAB A/S	27-Mar-25	1:41:42 PM	3	1377.50	CEUX
GENMAB A/S	27-Mar-25	1:41:42 PM	23	1377.00	TQEX
GENMAB A/S	27-Mar-25	1:41:42 PM	22	1377.50	AQEU
GENMAB A/S	27-Mar-25	1:41:52 PM	8	1377.50	XCSE
GENMAB A/S	27-Mar-25	1:41:56 PM	5	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:41:57 PM	12	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:42:16 PM	45	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:42:16 PM	17	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:42:19 PM	20	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:42:19 PM	14	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:42:30 PM	3	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:44:24 PM	10	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:44:24 PM	8	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:44:24 PM	69	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:44:24 PM	9	1378.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	1:44:24 PM	73	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:44:24 PM	22	1378.50	AQEU
GENMAB A/S	27-Mar-25	1:44:25 PM	29	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:44:25 PM	21	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:44:25 PM	9	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:44:25 PM	30	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:44:25 PM	9	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:45:06 PM	14	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:45:06 PM	43	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:45:06 PM	12	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:45:06 PM	10	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:49:06 PM	26	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:49:07 PM	43	1379.00	CEUX
GENMAB A/S	27-Mar-25	1:50:00 PM	12	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	33	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	9	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	10	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	9	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	9	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	1	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	6	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	8	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:00 PM	9	1379.50	XCSE
GENMAB A/S	27-Mar-25	1:50:02 PM	49	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:50:02 PM	76	1379.00	XCSE
GENMAB A/S	27-Mar-25	1:50:02 PM	1	1379.00	CEUX
GENMAB A/S	27-Mar-25	1:50:02 PM	30	1379.00	CEUX
GENMAB A/S	27-Mar-25	1:50:02 PM	40	1379.00	CEUX
GENMAB A/S	27-Mar-25	1:50:02 PM	34	1379.00	CEUX
GENMAB A/S	27-Mar-25	1:50:44 PM	12	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:50:44 PM	19	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:50:46 PM	18	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:50:46 PM	30	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:50:46 PM	15	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:50:46 PM	23	1378.50	TQEX
GENMAB A/S	27-Mar-25	1:50:46 PM	24	1378.50	AQEU
GENMAB A/S	27-Mar-25	1:50:47 PM	44	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:50:47 PM	8	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:50:49 PM	28	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:50:49 PM	44	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:51:01 PM	78	1379.50	CEUX
GENMAB A/S	27-Mar-25	1:51:01 PM	32	1379.50	TQEX
GENMAB A/S	27-Mar-25	1:51:01 PM	7	1379.50	AQEU
GENMAB A/S	27-Mar-25	1:51:01 PM	15	1379.50	AQEU
GENMAB A/S	27-Mar-25	1:51:34 PM	17	1378.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	1:51:34 PM	44	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:51:34 PM	12	1378.50	XCSE
GENMAB A/S	27-Mar-25	1:51:34 PM	69	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:51:34 PM	8	1378.50	CEUX
GENMAB A/S	27-Mar-25	1:51:34 PM	22	1378.50	AQEU
GENMAB A/S	27-Mar-25	1:52:46 PM	22	1377.50	CEUX
GENMAB A/S	27-Mar-25	1:52:46 PM	54	1377.50	CEUX
GENMAB A/S	27-Mar-25	1:53:16 PM	8	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:53:16 PM	9	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:53:16 PM	14	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:53:16 PM	10	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:53:16 PM	13	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:06 PM	9	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:06 PM	32	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:06 PM	6	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:06 PM	9	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:06 PM	8	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:56 PM	9	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:56 PM	6	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:56 PM	10	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:54:56 PM	10	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:55:59 PM	78	1378.00	XCSE
GENMAB A/S	27-Mar-25	1:55:59 PM	73	1377.50	CEUX
GENMAB A/S	27-Mar-25	1:55:59 PM	25	1378.00	TQEX
GENMAB A/S	27-Mar-25	1:55:59 PM	22	1378.00	AQEU
GENMAB A/S	27-Mar-25	1:56:12 PM	72	1377.00	XCSE
GENMAB A/S	27-Mar-25	1:58:48 PM	43	1377.00	XCSE
GENMAB A/S	27-Mar-25	1:58:48 PM	55	1377.00	XCSE
GENMAB A/S	27-Mar-25	1:58:49 PM	48	1377.00	XCSE
GENMAB A/S	27-Mar-25	1:59:14 PM	28	1376.50	AQEU
GENMAB A/S	27-Mar-25	1:59:26 PM	41	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:59:26 PM	32	1376.50	XCSE
GENMAB A/S	27-Mar-25	1:59:43 PM	72	1376.00	CEUX
GENMAB A/S	27-Mar-25	2:00:31 PM	27	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:00:31 PM	73	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:00:57 PM	74	1376.00	CEUX
GENMAB A/S	27-Mar-25	2:01:28 PM	10	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:01:28 PM	78	1376.50	CEUX
GENMAB A/S	27-Mar-25	2:01:28 PM	9	1376.50	TQEX
GENMAB A/S	27-Mar-25	2:01:28 PM	14	1376.50	TQEX
GENMAB A/S	27-Mar-25	2:01:38 PM	2	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:01:57 PM	39	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:04:58 PM	27	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:04:58 PM	23	1376.00	AQEU
GENMAB A/S	27-Mar-25	2:05:19 PM	39	1375.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:05:19 PM	10	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:05:19 PM	73	1375.50	CEUX
GENMAB A/S	27-Mar-25	2:05:19 PM	22	1375.50	TQEX
GENMAB A/S	27-Mar-25	2:06:06 PM	10	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	9	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	9	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	7	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	8	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	10	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	20	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	9	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	10	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	13	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	11	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	10	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	10	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:06 PM	8	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:23 PM	8	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:23 PM	20	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:06:23 PM	3	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	44	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	8	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	11	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	9	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	9	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	30	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:25 PM	17	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:46 PM	7	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:46 PM	10	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:46 PM	10	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:07:46 PM	3	1375.00	XCSE
GENMAB A/S	27-Mar-25	2:08:12 PM	24	1374.50	XCSE
GENMAB A/S	27-Mar-25	2:08:12 PM	51	1374.50	XCSE
GENMAB A/S	27-Mar-25	2:08:12 PM	15	1374.50	AQEU
GENMAB A/S	27-Mar-25	2:09:39 PM	30	1374.50	XCSE
GENMAB A/S	27-Mar-25	2:09:39 PM	9	1374.50	XCSE
GENMAB A/S	27-Mar-25	2:09:39 PM	17	1374.50	XCSE
GENMAB A/S	27-Mar-25	2:09:39 PM	58	1374.50	CEUX
GENMAB A/S	27-Mar-25	2:09:39 PM	14	1374.50	CEUX
GENMAB A/S	27-Mar-25	2:09:39 PM	8	1374.50	AQEU
GENMAB A/S	27-Mar-25	2:09:41 PM	23	1374.00	TQEX
GENMAB A/S	27-Mar-25	2:11:06 PM	12	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:11:15 PM	61	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:11:38 PM	30	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:11:38 PM	43	1374.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:11:38 PM	8	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:11:38 PM	17	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:11:38 PM	44	1374.00	CEUX
GENMAB A/S	27-Mar-25	2:11:38 PM	34	1374.00	CEUX
GENMAB A/S	27-Mar-25	2:11:38 PM	30	1373.50	TQEX
GENMAB A/S	27-Mar-25	2:11:38 PM	24	1373.50	AQEU
GENMAB A/S	27-Mar-25	2:12:16 PM	9	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:12:16 PM	12	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:12:16 PM	9	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:12:16 PM	10	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:12:16 PM	13	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:12:16 PM	10	1374.00	XCSE
GENMAB A/S	27-Mar-25	2:12:46 PM	24	1373.00	XCSE
GENMAB A/S	27-Mar-25	2:13:18 PM	49	1373.00	XCSE
GENMAB A/S	27-Mar-25	2:14:25 PM	41	1373.00	XCSE
GENMAB A/S	27-Mar-25	2:14:25 PM	10	1373.00	XCSE
GENMAB A/S	27-Mar-25	2:14:25 PM	8	1373.00	XCSE
GENMAB A/S	27-Mar-25	2:14:25 PM	10	1373.00	XCSE
GENMAB A/S	27-Mar-25	2:14:25 PM	49	1373.00	CEUX
GENMAB A/S	27-Mar-25	2:14:25 PM	32	1373.50	CEUX
GENMAB A/S	27-Mar-25	2:14:36 PM	7	1372.50	XCSE
GENMAB A/S	27-Mar-25	2:14:36 PM	7	1372.50	XCSE
GENMAB A/S	27-Mar-25	2:14:36 PM	12	1372.50	XCSE
GENMAB A/S	27-Mar-25	2:14:36 PM	4	1372.50	XCSE
GENMAB A/S	27-Mar-25	2:14:36 PM	10	1372.50	XCSE
GENMAB A/S	27-Mar-25	2:14:41 PM	19	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:14:41 PM	54	1375.50	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	13	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	3	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	43	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	7	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	9	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	15	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	2	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	8	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	12	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	6	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	4	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:10 PM	9	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:16 PM	13	1376.00	XCSE
GENMAB A/S	27-Mar-25	2:17:25 PM	22	1377.00	CEUX
GENMAB A/S	27-Mar-25	2:17:30 PM	12	1377.00	XCSE
GENMAB A/S	27-Mar-25	2:17:31 PM	73	1377.50	XCSE
GENMAB A/S	27-Mar-25	2:17:31 PM	5	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:18:09 PM	73	1377.00	CEUX

100

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:18:09 PM	22	1377.00	TQEX
GENMAB A/S	27-Mar-25	2:21:23 PM	72	1376.50	XCSE
GENMAB A/S	27-Mar-25	2:21:24 PM	5	1376.50	CEUX
GENMAB A/S	27-Mar-25	2:21:24 PM	36	1376.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	5	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	5	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	5	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	30	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	9	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	1	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:31 PM	5	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:32 PM	12	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:46 PM	62	1377.50	XCSE
GENMAB A/S	27-Mar-25	2:22:46 PM	31	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:49 PM	62	1377.50	XCSE
GENMAB A/S	27-Mar-25	2:22:49 PM	31	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:22:51 PM	15	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:23:12 PM	5	1377.00	CEUX
GENMAB A/S	27-Mar-25	2:23:29 PM	98	1377.00	XCSE
GENMAB A/S	27-Mar-25	2:23:29 PM	69	1377.00	CEUX
GENMAB A/S	27-Mar-25	2:23:29 PM	42	1377.00	TQEX
GENMAB A/S	27-Mar-25	2:23:29 PM	10	1376.50	AQEU
GENMAB A/S	27-Mar-25	2:23:30 PM	98	1377.00	XCSE
GENMAB A/S	27-Mar-25	2:24:48 PM	4	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:24:49 PM	73	1377.00	CEUX
GENMAB A/S	27-Mar-25	2:24:49 PM	25	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:24:49 PM	4	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:24:49 PM	5	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:24:49 PM	4	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:25:20 PM	10	1378.00	CEUX
GENMAB A/S	27-Mar-25	2:25:41 PM	10	1378.50	XCSE
GENMAB A/S	27-Mar-25	2:25:41 PM	8	1378.50	XCSE
GENMAB A/S	27-Mar-25	2:25:41 PM	7	1378.50	XCSE
GENMAB A/S	27-Mar-25	2:25:41 PM	12	1378.50	XCSE
GENMAB A/S	27-Mar-25	2:26:19 PM	23	1380.50	XCSE
GENMAB A/S	27-Mar-25	2:26:19 PM	62	1380.50	XCSE
GENMAB A/S	27-Mar-25	2:26:19 PM	32	1380.50	CEUX
GENMAB A/S	27-Mar-25	2:26:20 PM	44	1380.50	XCSE
GENMAB A/S	27-Mar-25	2:26:41 PM	12	1381.00	CEUX
GENMAB A/S	27-Mar-25	2:26:41 PM	7	1381.00	CEUX
GENMAB A/S	27-Mar-25	2:26:59 PM	15	1381.00	CEUX
GENMAB A/S	27-Mar-25	2:27:14 PM	10	1381.00	CEUX
GENMAB A/S	27-Mar-25	2:27:23 PM	30	1380.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	17	1381.50	XCSE

101

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:27:26 PM	17	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	1	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	9	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	42	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	7	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	4	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:26 PM	12	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:36 PM	17	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:36 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:36 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:36 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:36 PM	7	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:37 PM	2	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:37 PM	12	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:27:42 PM	4	1381.50	CEUX
GENMAB A/S	27-Mar-25	2:27:50 PM	73	1381.00	CEUX
GENMAB A/S	27-Mar-25	2:28:20 PM	30	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:28:21 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:28:21 PM	12	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:28:21 PM	9	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:28:21 PM	8	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:28:30 PM	8	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:28:30 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:29:02 PM	98	1381.00	XCSE
GENMAB A/S	27-Mar-25	2:29:02 PM	74	1379.50	XCSE
GENMAB A/S	27-Mar-25	2:29:02 PM	76	1378.50	XCSE
GENMAB A/S	27-Mar-25	2:29:02 PM	76	1380.50	XCSE
GENMAB A/S	27-Mar-25	2:29:02 PM	77	1381.00	CEUX
GENMAB A/S	27-Mar-25	2:29:02 PM	34	1379.00	CEUX
GENMAB A/S	27-Mar-25	2:29:02 PM	41	1379.00	CEUX
GENMAB A/S	27-Mar-25	2:29:02 PM	72	1380.00	CEUX
GENMAB A/S	27-Mar-25	2:29:02 PM	29	1379.50	TQEX
GENMAB A/S	27-Mar-25	2:29:02 PM	38	1380.50	TQEX
GENMAB A/S	27-Mar-25	2:29:02 PM	32	1378.50	TQEX
GENMAB A/S	27-Mar-25	2:29:02 PM	23	1378.50	AQEU
GENMAB A/S	27-Mar-25	2:29:03 PM	22	1377.50	XCSE
GENMAB A/S	27-Mar-25	2:29:03 PM	50	1377.50	XCSE
GENMAB A/S	27-Mar-25	2:29:03 PM	71	1377.50	CEUX
GENMAB A/S	27-Mar-25	2:29:36 PM	10	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:36 PM	12	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:36 PM	12	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:46 PM	8	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:46 PM	37	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:46 PM	15	1379.00	XCSE

102

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:29:46 PM	11	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:46 PM	8	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:46 PM	8	1379.00	XCSE
GENMAB A/S	27-Mar-25	2:29:48 PM	5	1378.50	CEUX
GENMAB A/S	27-Mar-25	2:30:05 PM	28	1379.50	CEUX
GENMAB A/S	27-Mar-25	2:31:09 PM	1	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:31:09 PM	19	1382.50	CEUX
GENMAB A/S	27-Mar-25	2:31:09 PM	57	1382.50	CEUX
GENMAB A/S	27-Mar-25	2:31:09 PM	26	1382.50	TQEX
GENMAB A/S	27-Mar-25	2:31:15 PM	13	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:31:15 PM	10	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:31:15 PM	22	1381.50	TQEX
GENMAB A/S	27-Mar-25	2:31:21 PM	29	1381.50	XCSE
GENMAB A/S	27-Mar-25	2:31:35 PM	15	1382.50	XCSE
GENMAB A/S	27-Mar-25	2:31:35 PM	1	1382.50	XCSE
GENMAB A/S	27-Mar-25	2:31:35 PM	38	1382.50	XCSE
GENMAB A/S	27-Mar-25	2:31:35 PM	20	1382.50	XCSE
GENMAB A/S	27-Mar-25	2:31:45 PM	30	1382.50	CEUX
GENMAB A/S	27-Mar-25	2:31:48 PM	8	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:31:48 PM	12	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:31:48 PM	9	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:31:50 PM	10	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:31:51 PM	7	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:31:54 PM	13	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:32:01 PM	14	1383.00	XCSE
GENMAB A/S	27-Mar-25	2:32:52 PM	56	1384.50	CEUX
GENMAB A/S	27-Mar-25	2:32:52 PM	29	1385.00	TQEX
GENMAB A/S	27-Mar-25	2:32:53 PM	34	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:33:26 PM	73	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:33:26 PM	24	1386.00	TQEX
GENMAB A/S	27-Mar-25	2:34:21 PM	49	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:34:21 PM	2	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:34:21 PM	11	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:34:21 PM	24	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:34:21 PM	4	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:34:21 PM	10	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:34:21 PM	74	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:34:21 PM	23	1386.00	TQEX
GENMAB A/S	27-Mar-25	2:34:28 PM	12	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:34:28 PM	33	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:34:29 PM	42	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:34:44 PM	33	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:35:24 PM	31	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:35:24 PM	8	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:35:25 PM	8	1386.00	CEUX

103

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:35:27 PM	10	1385.00	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	5	1385.00	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	67	1385.00	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	14	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	39	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	4	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	31	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:35:27 PM	4	1385.50	CEUX
GENMAB A/S	27-Mar-25	2:35:27 PM	8	1385.00	TQEX
GENMAB A/S	27-Mar-25	2:35:27 PM	11	1385.00	TQEX
GENMAB A/S	27-Mar-25	2:35:27 PM	3	1385.00	TQEX
GENMAB A/S	27-Mar-25	2:35:27 PM	14	1385.50	AQEU
GENMAB A/S	27-Mar-25	2:35:27 PM	26	1385.50	AQEU
GENMAB A/S	27-Mar-25	2:35:57 PM	19	1384.50	CEUX
GENMAB A/S	27-Mar-25	2:35:57 PM	36	1384.50	CEUX
GENMAB A/S	27-Mar-25	2:36:05 PM	42	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:36:05 PM	56	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:36:07 PM	21	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:36:38 PM	19	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:36:39 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:39 PM	17	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:39 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:39 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:52 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:52 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:52 PM	11	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:52 PM	36	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:36:52 PM	5	1387.00	CEUX
GENMAB A/S	27-Mar-25	2:36:52 PM	5	1387.00	CEUX
GENMAB A/S	27-Mar-25	2:36:52 PM	56	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:36:55 PM	20	1386.50	AQEU
GENMAB A/S	27-Mar-25	2:36:55 PM	2	1386.50	AQEU
GENMAB A/S	27-Mar-25	2:37:01 PM	74	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:37:01 PM	85	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:37:01 PM	24	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:37:01 PM	5	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:01 PM	73	1385.50	CEUX
GENMAB A/S	27-Mar-25	2:37:01 PM	12	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:01 PM	9	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:01 PM	25	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:01 PM	33	1385.50	TQEX
GENMAB A/S	27-Mar-25	2:37:30 PM	8	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:33 PM	28	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:33 PM	25	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:37:33 PM	40	1386.00	CEUX

104

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:38:01 PM	32	1385.50	TQEX
GENMAB A/S	27-Mar-25	2:38:12 PM	14	1387.00	CEUX
GENMAB A/S	27-Mar-25	2:39:14 PM	14	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	55	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	55	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	36	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	7	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	40	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	55	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	3	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:14 PM	29	1388.00	XCSE
GENMAB A/S	27-Mar-25	2:39:20 PM	59	1387.00	CEUX
GENMAB A/S	27-Mar-25	2:39:21 PM	44	1387.50	XCSE
GENMAB A/S	27-Mar-25	2:39:49 PM	23	1387.00	TQEX
GENMAB A/S	27-Mar-25	2:39:49 PM	32	1387.00	AQEU
GENMAB A/S	27-Mar-25	2:40:01 PM	73	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:40:01 PM	11	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:01 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:01 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:01 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:01 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	30	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	20	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	11	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	26	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:02 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	20	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	11	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	13	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:03 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:04 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:04 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:04 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:05 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:05 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:05 PM	10	1387.00	XCSE

105

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:40:05 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:05 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:06 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:06 PM	22	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:06 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:06 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:07 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	49	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	17	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:08 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:10 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:10 PM	7	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:10 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:12 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	6	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	30	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	43	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	1	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	10	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	11	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:40:13 PM	16	1387.00	CEUX
GENMAB A/S	27-Mar-25	2:40:13 PM	74	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:40:13 PM	15	1387.00	CEUX
GENMAB A/S	27-Mar-25	2:40:13 PM	31	1386.00	TQEX
GENMAB A/S	27-Mar-25	2:40:14 PM	25	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:40:14 PM	40	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:41:05 PM	73	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:41:12 PM	15	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:41:12 PM	13	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:41:12 PM	19	1386.00	XCSE

106

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:41:12 PM	24	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:41:25 PM	28	1385.50	AQEU
GENMAB A/S	27-Mar-25	2:42:15 PM	19	1385.50	CEUX
GENMAB A/S	27-Mar-25	2:42:15 PM	23	1386.00	TQEX
GENMAB A/S	27-Mar-25	2:42:15 PM	13	1386.00	AQEU
GENMAB A/S	27-Mar-25	2:42:16 PM	9	1386.00	AQEU
GENMAB A/S	27-Mar-25	2:42:30 PM	68	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:42:30 PM	10	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:42:30 PM	72	1385.50	CEUX
GENMAB A/S	27-Mar-25	2:42:30 PM	36	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:35 PM	4	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:35 PM	11	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:35 PM	5	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:40 PM	8	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:43 PM	4	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:43 PM	22	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:43 PM	18	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:43 PM	5	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:43 PM	25	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:45 PM	10	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	19	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	22	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	10	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	11	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	9	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	15	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:42:52 PM	41	1386.00	TQEX
GENMAB A/S	27-Mar-25	2:42:59 PM	77	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:42:59 PM	41	1386.00	AQEU
GENMAB A/S	27-Mar-25	2:43:00 PM	13	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:43:00 PM	11	1385.00	XCSE
GENMAB A/S	27-Mar-25	2:43:00 PM	32	1385.00	XCSE
GENMAB A/S	27-Mar-25	2:43:00 PM	24	1385.00	CEUX
GENMAB A/S	27-Mar-25	2:43:05 PM	1	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:43:05 PM	23	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:43:05 PM	42	1384.50	CEUX
GENMAB A/S	27-Mar-25	2:43:11 PM	10	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:43:12 PM	29	1384.50	XCSE
GENMAB A/S	27-Mar-25	2:43:12 PM	30	1384.50	CEUX
GENMAB A/S	27-Mar-25	2:43:27 PM	1	1384.50	CEUX
GENMAB A/S	27-Mar-25	2:44:21 PM	10	1384.00	XCSE
GENMAB A/S	27-Mar-25	2:44:21 PM	30	1384.00	XCSE
GENMAB A/S	27-Mar-25	2:44:21 PM	15	1384.00	CEUX
GENMAB A/S	27-Mar-25	2:44:21 PM	22	1384.00	AQEU
GENMAB A/S	27-Mar-25	2:44:22 PM	20	1384.00	CEUX

107

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:44:22 PM	2	1384.00	CEUX
GENMAB A/S	27-Mar-25	2:44:26 PM	9	1383.50	XCSE
GENMAB A/S	27-Mar-25	2:44:26 PM	9	1383.50	XCSE
GENMAB A/S	27-Mar-25	2:44:26 PM	10	1383.50	XCSE
GENMAB A/S	27-Mar-25	2:44:26 PM	10	1383.50	XCSE
GENMAB A/S	27-Mar-25	2:45:11 PM	74	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:45:11 PM	15	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:45:11 PM	22	1386.00	TQEX
GENMAB A/S	27-Mar-25	2:45:11 PM	24	1386.00	AQEU
GENMAB A/S	27-Mar-25	2:45:20 PM	10	1385.50	XCSE
GENMAB A/S	27-Mar-25	2:45:21 PM	3	1385.50	CEUX
GENMAB A/S	27-Mar-25	2:45:23 PM	4	1385.50	CEUX
GENMAB A/S	27-Mar-25	2:45:33 PM	78	1386.00	CEUX
GENMAB A/S	27-Mar-25	2:45:43 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:43 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:43 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:43 PM	13	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:43 PM	20	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:43 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:43 PM	19	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:45:43 PM	58	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:45:45 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	20	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:45 PM	20	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:46 PM	2	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:45:46 PM	1	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:45:47 PM	11	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:47 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:48 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:48 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:48 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:48 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:48 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:51 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:51 PM	19	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:51 PM	1	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:45:52 PM	14	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:52 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:52 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:52 PM	10	1387.00	XCSE

108

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:45:52 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:52 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:52 PM	10	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:52 PM	9	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:53 PM	8	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:45:56 PM	7	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:46:01 PM	13	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:46:07 PM	75	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:46:07 PM	22	1387.00	TQEX
GENMAB A/S	27-Mar-25	2:46:07 PM	25	1387.00	AQEU
GENMAB A/S	27-Mar-25	2:46:15 PM	21	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:15 PM	20	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:15 PM	8	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:19 PM	14	1387.00	AQEU
GENMAB A/S	27-Mar-25	2:46:20 PM	74	1387.00	XCSE
GENMAB A/S	27-Mar-25	2:46:26 PM	20	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:46:26 PM	30	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:46:26 PM	10	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:26 PM	1	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:26 PM	14	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:26 PM	10	1387.00	AQEU
GENMAB A/S	27-Mar-25	2:46:30 PM	24	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:46:41 PM	4	1386.00	XCSE
GENMAB A/S	27-Mar-25	2:46:52 PM	74	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:46:52 PM	74	1386.50	CEUX
GENMAB A/S	27-Mar-25	2:46:52 PM	28	1386.00	AQEU
GENMAB A/S	27-Mar-25	2:47:43 PM	74	1386.50	XCSE
GENMAB A/S	27-Mar-25	2:47:59 PM	19	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:03 PM	17	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:06 PM	12	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:09 PM	2	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:11 PM	1	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:11 PM	1	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:11 PM	1	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:11 PM	1	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:15 PM	22	1388.00	CEUX
GENMAB A/S	27-Mar-25	2:48:21 PM	15	1388.00	TQEX
GENMAB A/S	27-Mar-25	2:48:54 PM	72	1389.00	XCSE
GENMAB A/S	27-Mar-25	2:48:54 PM	9	1389.00	XCSE
GENMAB A/S	27-Mar-25	2:48:54 PM	14	1389.00	XCSE
GENMAB A/S	27-Mar-25	2:48:54 PM	3	1389.00	XCSE
GENMAB A/S	27-Mar-25	2:49:24 PM	9	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:49:24 PM	20	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:49:24 PM	10	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:49:24 PM	8	1390.00	XCSE

109

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:49:25 PM	42	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:49:41 PM	20	1389.50	XCSE
GENMAB A/S	27-Mar-25	2:49:41 PM	18	1389.50	CEUX
GENMAB A/S	27-Mar-25	2:49:41 PM	5	1389.50	CEUX
GENMAB A/S	27-Mar-25	2:49:41 PM	45	1389.50	CEUX
GENMAB A/S	27-Mar-25	2:49:41 PM	5	1389.50	CEUX
GENMAB A/S	27-Mar-25	2:49:41 PM	22	1389.50	TQEX
GENMAB A/S	27-Mar-25	2:49:41 PM	22	1389.50	AQEU
GENMAB A/S	27-Mar-25	2:50:27 PM	56	1390.50	XCSE
GENMAB A/S	27-Mar-25	2:50:27 PM	3	1390.50	XCSE
GENMAB A/S	27-Mar-25	2:50:30 PM	68	1391.00	XCSE
GENMAB A/S	27-Mar-25	2:50:32 PM	7	1391.00	XCSE
GENMAB A/S	27-Mar-25	2:50:32 PM	4	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:50:32 PM	1	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:50:32 PM	1	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:50:32 PM	12	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:50:32 PM	25	1391.00	TQEX
GENMAB A/S	27-Mar-25	2:50:46 PM	56	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:50:46 PM	19	1390.50	AQEU
GENMAB A/S	27-Mar-25	2:50:48 PM	60	1390.50	XCSE
GENMAB A/S	27-Mar-25	2:50:48 PM	3	1390.50	AQEU
GENMAB A/S	27-Mar-25	2:51:23 PM	31	1392.00	XCSE
GENMAB A/S	27-Mar-25	2:51:23 PM	46	1392.00	XCSE
GENMAB A/S	27-Mar-25	2:51:23 PM	10	1391.50	CEUX
GENMAB A/S	27-Mar-25	2:51:23 PM	10	1391.50	CEUX
GENMAB A/S	27-Mar-25	2:51:23 PM	2	1391.50	CEUX
GENMAB A/S	27-Mar-25	2:51:23 PM	8	1391.50	CEUX
GENMAB A/S	27-Mar-25	2:51:24 PM	53	1392.00	XCSE
GENMAB A/S	27-Mar-25	2:51:24 PM	27	1392.00	XCSE
GENMAB A/S	27-Mar-25	2:51:31 PM	6	1391.00	XCSE
GENMAB A/S	27-Mar-25	2:51:31 PM	44	1391.50	CEUX
GENMAB A/S	27-Mar-25	2:51:31 PM	26	1391.50	AQEU
GENMAB A/S	27-Mar-25	2:51:34 PM	2	1391.50	AQEU
GENMAB A/S	27-Mar-25	2:51:35 PM	52	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:51:35 PM	21	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:51:35 PM	71	1391.00	XCSE
GENMAB A/S	27-Mar-25	2:51:35 PM	41	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:51:35 PM	31	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:51:35 PM	4	1390.50	AQEU
GENMAB A/S	27-Mar-25	2:51:35 PM	18	1390.50	AQEU
GENMAB A/S	27-Mar-25	2:51:46 PM	10	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:51:59 PM	77	1390.00	XCSE
GENMAB A/S	27-Mar-25	2:51:59 PM	59	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:51:59 PM	6	1390.50	CEUX
GENMAB A/S	27-Mar-25	2:51:59 PM	6	1390.50	TQEX

110

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:51:59 PM	17	1390.50	TQEX
GENMAB A/S	27-Mar-25	2:51:59 PM	2	1390.00	AQEU
GENMAB A/S	27-Mar-25	2:51:59 PM	2	1390.00	AQEU
GENMAB A/S	27-Mar-25	2:52:29 PM	24	1390.00	AQEU
GENMAB A/S	27-Mar-25	2:52:54 PM	2	1392.00	CEUX
GENMAB A/S	27-Mar-25	2:52:54 PM	8	1392.00	CEUX
GENMAB A/S	27-Mar-25	2:53:26 PM	8	1394.00	XCSE
GENMAB A/S	27-Mar-25	2:53:31 PM	74	1393.50	XCSE
GENMAB A/S	27-Mar-25	2:53:50 PM	73	1392.50	XCSE
GENMAB A/S	27-Mar-25	2:53:50 PM	73	1393.00	CEUX
GENMAB A/S	27-Mar-25	2:53:50 PM	10	1392.00	CEUX
GENMAB A/S	27-Mar-25	2:53:50 PM	41	1393.00	TQEX
GENMAB A/S	27-Mar-25	2:54:16 PM	69	1393.00	XCSE
GENMAB A/S	27-Mar-25	2:54:16 PM	9	1393.00	XCSE
GENMAB A/S	27-Mar-25	2:54:16 PM	4	1393.00	CEUX
GENMAB A/S	27-Mar-25	2:54:16 PM	72	1393.00	CEUX
GENMAB A/S	27-Mar-25	2:54:16 PM	28	1393.00	AQEU
GENMAB A/S	27-Mar-25	2:54:20 PM	76	1393.00	XCSE
GENMAB A/S	27-Mar-25	2:54:27 PM	5	1392.00	CEUX
GENMAB A/S	27-Mar-25	2:54:31 PM	5	1392.00	CEUX
GENMAB A/S	27-Mar-25	2:54:31 PM	15	1392.00	CEUX
GENMAB A/S	27-Mar-25	2:55:28 PM	2	1392.50	XCSE
GENMAB A/S	27-Mar-25	2:55:28 PM	28	1392.50	XCSE
GENMAB A/S	27-Mar-25	2:55:30 PM	48	1392.50	XCSE
GENMAB A/S	27-Mar-25	2:56:07 PM	72	1392.50	XCSE
GENMAB A/S	27-Mar-25	2:56:38 PM	10	1394.00	CEUX
GENMAB A/S	27-Mar-25	2:56:38 PM	21	1394.00	CEUX
GENMAB A/S	27-Mar-25	2:56:51 PM	30	1394.00	XCSE
GENMAB A/S	27-Mar-25	2:56:51 PM	47	1394.00	XCSE
GENMAB A/S	27-Mar-25	2:56:51 PM	46	1394.00	CEUX
GENMAB A/S	27-Mar-25	2:57:09 PM	15	1394.00	XCSE
GENMAB A/S	27-Mar-25	2:57:09 PM	9	1394.00	XCSE
GENMAB A/S	27-Mar-25	2:57:24 PM	22	1393.50	TQEX
GENMAB A/S	27-Mar-25	2:57:29 PM	8	1394.50	XCSE
GENMAB A/S	27-Mar-25	2:57:29 PM	32	1394.50	XCSE
GENMAB A/S	27-Mar-25	2:57:29 PM	31	1394.50	XCSE
GENMAB A/S	27-Mar-25	2:57:29 PM	1	1394.50	XCSE
GENMAB A/S	27-Mar-25	2:57:29 PM	16	1394.50	XCSE
GENMAB A/S	27-Mar-25	2:57:29 PM	10	1394.50	XCSE
GENMAB A/S	27-Mar-25	2:58:45 PM	3	1396.00	CEUX
GENMAB A/S	27-Mar-25	2:58:55 PM	29	1397.00	XCSE
GENMAB A/S	27-Mar-25	2:58:55 PM	4	1397.00	XCSE
GENMAB A/S	27-Mar-25	2:58:55 PM	65	1397.00	XCSE
GENMAB A/S	27-Mar-25	2:58:55 PM	95	1397.00	XCSE
GENMAB A/S	27-Mar-25	2:59:28 PM	1	1396.00	CEUX

111

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	2:59:54 PM	12	1398.00	XCSE
GENMAB A/S	27-Mar-25	2:59:54 PM	49	1398.00	XCSE
GENMAB A/S	27-Mar-25	2:59:54 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	2:59:54 PM	27	1398.00	XCSE
GENMAB A/S	27-Mar-25	2:59:56 PM	52	1398.00	XCSE
GENMAB A/S	27-Mar-25	2:59:56 PM	8	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:00:01 PM	9	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:00:09 PM	13	1399.00	CEUX
GENMAB A/S	27-Mar-25	3:00:10 PM	78	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:00:10 PM	45	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:00:10 PM	29	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:00:10 PM	1	1399.00	CEUX
GENMAB A/S	27-Mar-25	3:00:10 PM	22	1398.50	TQEX
GENMAB A/S	27-Mar-25	3:01:01 PM	2	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:01:01 PM	21	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:01:01 PM	9	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:01:01 PM	10	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:01:01 PM	10	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:01:01 PM	5	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:01:01 PM	4	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:01:01 PM	2	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:01:01 PM	5	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:01:01 PM	23	1401.50	TQEX
GENMAB A/S	27-Mar-25	3:01:22 PM	76	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:01:22 PM	76	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:01:22 PM	19	1402.50	AQEU
GENMAB A/S	27-Mar-25	3:01:22 PM	3	1402.50	AQEU
GENMAB A/S	27-Mar-25	3:01:23 PM	28	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:01:23 PM	77	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:01:23 PM	48	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:01:23 PM	47	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:01:23 PM	28	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:01:23 PM	76	1400.00	CEUX
GENMAB A/S	27-Mar-25	3:01:23 PM	31	1401.50	AQEU
GENMAB A/S	27-Mar-25	3:01:23 PM	22	1400.00	AQEU
GENMAB A/S	27-Mar-25	3:02:03 PM	72	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:02:03 PM	22	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:02:03 PM	26	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:02:13 PM	75	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:02:13 PM	42	1402.50	TQEX
GENMAB A/S	27-Mar-25	3:02:35 PM	30	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:02:35 PM	22	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:03:07 PM	4	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:03:07 PM	9	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:03:15 PM	25	1402.50	XCSE

112

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:03:34 PM	34	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:03:34 PM	77	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:03:34 PM	23	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:03:43 PM	17	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:03:43 PM	40	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:04:28 PM	29	1403.00	AQEU
GENMAB A/S	27-Mar-25	3:04:51 PM	45	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:04:51 PM	9	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:04:51 PM	10	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:04:52 PM	12	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:05:27 PM	54	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:05:27 PM	3	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:05:31 PM	63	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:06:45 PM	32	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:07:07 PM	19	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:07:07 PM	17	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:07:13 PM	50	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:07:15 PM	30	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	25	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	13	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	26	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	43	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	16	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	73	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:07:15 PM	76	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:07:15 PM	73	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:07:15 PM	9	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:07:15 PM	22	1403.00	TQEX
GENMAB A/S	27-Mar-25	3:07:15 PM	22	1402.00	TQEX
GENMAB A/S	27-Mar-25	3:07:15 PM	22	1403.00	AQEU
GENMAB A/S	27-Mar-25	3:07:15 PM	29	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:07:17 PM	40	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:07:18 PM	10	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:07:18 PM	14	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:07:21 PM	33	1401.00	AQEU
GENMAB A/S	27-Mar-25	3:07:27 PM	78	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:07:27 PM	34	1400.50	CEUX
GENMAB A/S	27-Mar-25	3:09:00 PM	40	1402.00	TQEX
GENMAB A/S	27-Mar-25	3:09:35 PM	4	1406.00	XCSE
GENMAB A/S	27-Mar-25	3:09:41 PM	55	1406.50	CEUX
GENMAB A/S	27-Mar-25	3:09:41 PM	17	1406.50	CEUX
GENMAB A/S	27-Mar-25	3:09:42 PM	9	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:09:49 PM	73	1406.50	XCSE
GENMAB A/S	27-Mar-25	3:10:03 PM	11	1409.00	XCSE
GENMAB A/S	27-Mar-25	3:10:04 PM	73	1408.50	XCSE

113

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:10:04 PM	30	1409.00	XCSE
GENMAB A/S	27-Mar-25	3:10:04 PM	9	1409.00	XCSE
GENMAB A/S	27-Mar-25	3:10:04 PM	12	1409.00	XCSE
GENMAB A/S	27-Mar-25	3:10:04 PM	43	1409.00	XCSE
GENMAB A/S	27-Mar-25	3:10:04 PM	4	1409.00	XCSE
GENMAB A/S	27-Mar-25	3:10:04 PM	72	1408.50	CEUX
GENMAB A/S	27-Mar-25	3:10:04 PM	33	1409.00	AQEU
GENMAB A/S	27-Mar-25	3:10:06 PM	72	1408.00	XCSE
GENMAB A/S	27-Mar-25	3:10:06 PM	52	1408.50	CEUX
GENMAB A/S	27-Mar-25	3:10:06 PM	22	1408.50	AQEU
GENMAB A/S	27-Mar-25	3:10:35 PM	9	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	73	1408.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	15	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	15	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	10	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	5	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	15	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	5	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:10:35 PM	48	1407.00	CEUX
GENMAB A/S	27-Mar-25	3:10:35 PM	14	1408.00	CEUX
GENMAB A/S	27-Mar-25	3:10:35 PM	42	1409.00	CEUX
GENMAB A/S	27-Mar-25	3:10:35 PM	13	1408.00	CEUX
GENMAB A/S	27-Mar-25	3:10:35 PM	24	1407.50	AQEU
GENMAB A/S	27-Mar-25	3:10:35 PM	30	1408.50	AQEU
GENMAB A/S	27-Mar-25	3:11:10 PM	22	1408.50	CEUX
GENMAB A/S	27-Mar-25	3:11:22 PM	35	1407.50	XCSE
GENMAB A/S	27-Mar-25	3:11:22 PM	41	1407.50	XCSE
GENMAB A/S	27-Mar-25	3:11:22 PM	27	1407.50	CEUX
GENMAB A/S	27-Mar-25	3:11:22 PM	23	1407.50	AQEU
GENMAB A/S	27-Mar-25	3:12:00 PM	72	1407.00	XCSE
GENMAB A/S	27-Mar-25	3:12:00 PM	22	1407.00	CEUX
GENMAB A/S	27-Mar-25	3:12:00 PM	22	1407.00	TQEX
GENMAB A/S	27-Mar-25	3:12:00 PM	19	1407.00	AQEU
GENMAB A/S	27-Mar-25	3:12:03 PM	5	1407.00	AQEU
GENMAB A/S	27-Mar-25	3:12:06 PM	26	1406.00	XCSE
GENMAB A/S	27-Mar-25	3:12:06 PM	10	1406.00	XCSE
GENMAB A/S	27-Mar-25	3:12:06 PM	40	1406.00	XCSE
GENMAB A/S	27-Mar-25	3:12:11 PM	8	1406.00	AQEU
GENMAB A/S	27-Mar-25	3:12:13 PM	41	1405.50	CEUX
GENMAB A/S	27-Mar-25	3:12:13 PM	24	1406.00	AQEU
GENMAB A/S	27-Mar-25	3:12:43 PM	78	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:12:43 PM	22	1404.00	CEUX
GENMAB A/S	27-Mar-25	3:12:43 PM	24	1405.00	AQEU
GENMAB A/S	27-Mar-25	3:12:43 PM	24	1403.50	AQEU
GENMAB A/S	27-Mar-25	3:12:44 PM	24	1403.00	XCSE

114

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:12:44 PM	50	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:12:59 PM	53	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:12:59 PM	35	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:12:59 PM	17	1402.50	AQEU
GENMAB A/S	27-Mar-25	3:13:19 PM	43	1404.00	XCSE
GENMAB A/S	27-Mar-25	3:13:19 PM	22	1403.50	AQEU
GENMAB A/S	27-Mar-25	3:14:07 PM	18	1404.00	TQEX
GENMAB A/S	27-Mar-25	3:14:10 PM	62	1404.00	XCSE
GENMAB A/S	27-Mar-25	3:14:10 PM	24	1404.00	CEUX
GENMAB A/S	27-Mar-25	3:14:10 PM	16	1404.00	CEUX
GENMAB A/S	27-Mar-25	3:14:10 PM	3	1404.00	AQEU
GENMAB A/S	27-Mar-25	3:14:36 PM	10	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:14:36 PM	4	1404.00	AQEU
GENMAB A/S	27-Mar-25	3:14:36 PM	16	1404.00	AQEU
GENMAB A/S	27-Mar-25	3:14:40 PM	22	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:14:40 PM	30	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:14:48 PM	7	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:14:48 PM	24	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:15:03 PM	43	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:15:03 PM	22	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:15:32 PM	47	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:15:32 PM	21	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:32 PM	36	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:32 PM	5	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:32 PM	20	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:15:32 PM	26	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:15:32 PM	6	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:15:32 PM	2	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:15:32 PM	23	1401.00	TQEX
GENMAB A/S	27-Mar-25	3:15:33 PM	36	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:33 PM	7	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:33 PM	19	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:15:48 PM	60	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:15:51 PM	16	1399.00	CEUX
GENMAB A/S	27-Mar-25	3:15:51 PM	7	1399.00	CEUX
GENMAB A/S	27-Mar-25	3:15:55 PM	3	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:55 PM	21	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:15:55 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:16:14 PM	29	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:16:14 PM	29	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:17:09 PM	19	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:17:13 PM	25	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:17:13 PM	7	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:17:13 PM	29	1396.50	CEUX
GENMAB A/S	27-Mar-25	3:17:13 PM	3	1398.00	CEUX

115

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:17:13 PM	25	1396.50	TQEX
GENMAB A/S	27-Mar-25	3:17:13 PM	23	1398.00	AQEU
GENMAB A/S	27-Mar-25	3:17:13 PM	22	1397.00	AQEU
GENMAB A/S	27-Mar-25	3:17:16 PM	60	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:18:13 PM	15	1397.50	CEUX
GENMAB A/S	27-Mar-25	3:18:34 PM	17	1397.50	CEUX
GENMAB A/S	27-Mar-25	3:19:56 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:19:56 PM	13	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:19:56 PM	41	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:20:34 PM	17	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:20:34 PM	30	1396.50	CEUX
GENMAB A/S	27-Mar-25	3:20:34 PM	22	1396.50	TQEX
GENMAB A/S	27-Mar-25	3:21:09 PM	76	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:21:09 PM	39	1397.00	CEUX
GENMAB A/S	27-Mar-25	3:21:09 PM	22	1397.00	CEUX
GENMAB A/S	27-Mar-25	3:21:17 PM	16	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:21:17 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:21:17 PM	42	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:21:17 PM	42	1397.00	TQEX
GENMAB A/S	27-Mar-25	3:21:17 PM	22	1397.00	AQEU
GENMAB A/S	27-Mar-25	3:21:24 PM	10	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:21:32 PM	10	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:21:32 PM	10	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:21:38 PM	4	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:21:50 PM	39	1396.00	XCSE
GENMAB A/S	27-Mar-25	3:22:05 PM	55	1396.50	CEUX
GENMAB A/S	27-Mar-25	3:22:08 PM	29	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:22:19 PM	11	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:19 PM	11	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:20 PM	47	1397.00	CEUX
GENMAB A/S	27-Mar-25	3:22:28 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:36 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:37 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:37 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:46 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:52 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:22:58 PM	12	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:23:09 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:24:34 PM	41	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:24:34 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:24:34 PM	24	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:24:34 PM	73	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:25:24 PM	1	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:25:24 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:25:24 PM	2	1399.00	XCSE

116

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:25:24 PM	7	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:25:24 PM	14	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:25:58 PM	7	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:25:58 PM	31	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:25:58 PM	42	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:25:58 PM	18	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:01 PM	42	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:01 PM	12	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:01 PM	10	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:01 PM	8	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:01 PM	10	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:07 PM	11	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:26:07 PM	31	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:26:07 PM	18	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:26:07 PM	42	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:26:07 PM	76	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:26:07 PM	22	1403.00	TQEX
GENMAB A/S	27-Mar-25	3:26:07 PM	11	1403.00	AQEU
GENMAB A/S	27-Mar-25	3:26:07 PM	4	1403.00	AQEU
GENMAB A/S	27-Mar-25	3:26:07 PM	11	1403.00	AQEU
GENMAB A/S	27-Mar-25	3:26:20 PM	10	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:26:20 PM	30	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:26:20 PM	10	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:26:20 PM	1	1403.50	CEUX
GENMAB A/S	27-Mar-25	3:26:20 PM	44	1403.50	CEUX
GENMAB A/S	27-Mar-25	3:26:20 PM	4	1403.50	CEUX
GENMAB A/S	27-Mar-25	3:26:20 PM	2	1403.50	CEUX
GENMAB A/S	27-Mar-25	3:26:20 PM	22	1403.50	TQEX
GENMAB A/S	27-Mar-25	3:26:32 PM	76	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:26:32 PM	67	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:26:32 PM	78	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:26:32 PM	32	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:26:32 PM	28	1403.00	AQEU
GENMAB A/S	27-Mar-25	3:27:09 PM	74	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:27:09 PM	23	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:27:09 PM	3	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:27:09 PM	21	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:27:55 PM	77	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:27:55 PM	28	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:27:55 PM	23	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:27:55 PM	2	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:27:58 PM	77	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:28:19 PM	7	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:28:19 PM	69	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:28:56 PM	5	1402.00	CEUX

117

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:29:11 PM	9	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:29:11 PM	18	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:29:11 PM	5	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:29:11 PM	22	1402.00	TQEX
GENMAB A/S	27-Mar-25	3:29:11 PM	42	1402.00	AQEU
GENMAB A/S	27-Mar-25	3:29:15 PM	12	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:29:16 PM	20	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:29:16 PM	34	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:30:15 PM	73	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:30:15 PM	41	1402.00	TQEX
GENMAB A/S	27-Mar-25	3:31:07 PM	72	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:31:07 PM	60	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:31:10 PM	77	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:31:10 PM	5	1401.50	CEUX
GENMAB A/S	27-Mar-25	3:31:10 PM	18	1401.50	CEUX
GENMAB A/S	27-Mar-25	3:31:50 PM	16	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:32:46 PM	4	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:33:01 PM	10	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:33:01 PM	4	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:33:01 PM	9	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	8	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	24	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	30	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	77	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	26	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	74	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	10	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:07 PM	48	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:33:07 PM	22	1401.00	AQEU
GENMAB A/S	27-Mar-25	3:33:07 PM	22	1402.50	AQEU
GENMAB A/S	27-Mar-25	3:33:30 PM	73	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:33:30 PM	10	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:30 PM	64	1402.00	XCSE
GENMAB A/S	27-Mar-25	3:33:30 PM	40	1402.50	CEUX
GENMAB A/S	27-Mar-25	3:34:17 PM	72	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:34:17 PM	48	1405.00	CEUX
GENMAB A/S	27-Mar-25	3:34:17 PM	22	1405.00	TQEX
GENMAB A/S	27-Mar-25	3:34:17 PM	22	1405.00	AQEU
GENMAB A/S	27-Mar-25	3:34:28 PM	45	1404.00	CEUX
GENMAB A/S	27-Mar-25	3:35:06 PM	17	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:35:06 PM	13	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:35:06 PM	5	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:35:06 PM	14	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:35:17 PM	77	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:35:38 PM	19	1404.50	CEUX

118

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:35:38 PM	34	1404.50	CEUX
GENMAB A/S	27-Mar-25	3:36:01 PM	10	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:01 PM	10	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:01 PM	9	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:01 PM	8	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:40 PM	38	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:40 PM	60	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:45 PM	5	1404.00	AQEU
GENMAB A/S	27-Mar-25	3:36:56 PM	6	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:36:56 PM	32	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:37:16 PM	47	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:37:36 PM	41	1404.00	XCSE
GENMAB A/S	27-Mar-25	3:37:36 PM	11	1404.00	XCSE
GENMAB A/S	27-Mar-25	3:37:36 PM	43	1404.00	XCSE
GENMAB A/S	27-Mar-25	3:37:42 PM	50	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:37:42 PM	74	1404.00	CEUX
GENMAB A/S	27-Mar-25	3:37:42 PM	30	1404.00	AQEU
GENMAB A/S	27-Mar-25	3:39:58 PM	42	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:39:58 PM	23	1403.50	XCSE
GENMAB A/S	27-Mar-25	3:39:58 PM	22	1403.50	TQEX
GENMAB A/S	27-Mar-25	3:40:04 PM	46	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:40:07 PM	33	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:40:08 PM	42	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:40:08 PM	44	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:40:08 PM	12	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:40:12 PM	13	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:40:12 PM	11	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:40:13 PM	30	1402.50	AQEU
GENMAB A/S	27-Mar-25	3:40:19 PM	53	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:41:10 PM	38	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:41:10 PM	60	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:41:10 PM	29	1404.50	TQEX
GENMAB A/S	27-Mar-25	3:41:10 PM	8	1404.50	AQEU
GENMAB A/S	27-Mar-25	3:41:24 PM	73	1405.00	CEUX
GENMAB A/S	27-Mar-25	3:41:24 PM	24	1405.00	TQEX
GENMAB A/S	27-Mar-25	3:41:44 PM	30	1405.50	XCSE
GENMAB A/S	27-Mar-25	3:41:44 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	3:41:44 PM	22	1405.50	XCSE
GENMAB A/S	27-Mar-25	3:41:44 PM	37	1405.50	XCSE
GENMAB A/S	27-Mar-25	3:41:53 PM	14	1406.00	XCSE
GENMAB A/S	27-Mar-25	3:42:12 PM	40	1406.50	XCSE
GENMAB A/S	27-Mar-25	3:42:12 PM	4	1406.50	XCSE
GENMAB A/S	27-Mar-25	3:42:12 PM	40	1406.50	XCSE
GENMAB A/S	27-Mar-25	3:42:12 PM	19	1406.50	XCSE
GENMAB A/S	27-Mar-25	3:42:12 PM	33	1406.50	XCSE

119

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:42:12 PM	10	1406.50	XCSE
GENMAB A/S	27-Mar-25	3:42:12 PM	30	1406.50	CEUX
GENMAB A/S	27-Mar-25	3:42:12 PM	47	1406.50	CEUX
GENMAB A/S	27-Mar-25	3:42:12 PM	12	1406.50	TQEX
GENMAB A/S	27-Mar-25	3:42:12 PM	22	1406.50	TQEX
GENMAB A/S	27-Mar-25	3:42:28 PM	77	1405.50	XCSE
GENMAB A/S	27-Mar-25	3:42:28 PM	73	1404.50	XCSE
GENMAB A/S	27-Mar-25	3:42:28 PM	77	1405.50	CEUX
GENMAB A/S	27-Mar-25	3:42:28 PM	37	1405.00	AQEU
GENMAB A/S	27-Mar-25	3:42:40 PM	72	1404.00	CEUX
GENMAB A/S	27-Mar-25	3:42:41 PM	78	1403.00	XCSE
GENMAB A/S	27-Mar-25	3:42:41 PM	73	1403.00	CEUX
GENMAB A/S	27-Mar-25	3:42:42 PM	11	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:42:42 PM	12	1402.50	XCSE
GENMAB A/S	27-Mar-25	3:42:46 PM	49	1402.00	CEUX
GENMAB A/S	27-Mar-25	3:42:56 PM	72	1401.50	XCSE
GENMAB A/S	27-Mar-25	3:43:26 PM	62	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:43:26 PM	22	1400.50	CEUX
GENMAB A/S	27-Mar-25	3:44:03 PM	22	1399.00	CEUX
GENMAB A/S	27-Mar-25	3:44:53 PM	4	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:46:20 PM	13	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:46:20 PM	25	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:46:20 PM	1	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:46:20 PM	10	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:46:20 PM	9	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:46:46 PM	72	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:02 PM	11	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:02 PM	1	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:02 PM	7	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:48:02 PM	30	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:02 PM	27	1400.00	TQEX
GENMAB A/S	27-Mar-25	3:48:02 PM	3	1400.00	AQEU
GENMAB A/S	27-Mar-25	3:48:02 PM	21	1400.00	AQEU
GENMAB A/S	27-Mar-25	3:48:03 PM	13	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:48:21 PM	2	1400.50	AQEU
GENMAB A/S	27-Mar-25	3:48:21 PM	2	1400.50	AQEU
GENMAB A/S	27-Mar-25	3:48:21 PM	20	1400.50	AQEU
GENMAB A/S	27-Mar-25	3:48:21 PM	3	1400.50	AQEU
GENMAB A/S	27-Mar-25	3:48:48 PM	42	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:48:48 PM	77	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:48 PM	9	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:48:48 PM	20	1400.50	XCSE
GENMAB A/S	27-Mar-25	3:48:50 PM	1	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:50 PM	12	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:50 PM	9	1400.00	XCSE

120

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:48:50 PM	14	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:48:57 PM	9	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:49:06 PM	14	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:49:06 PM	61	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:49:06 PM	1	1401.00	CEUX
GENMAB A/S	27-Mar-25	3:49:07 PM	9	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:07 PM	21	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:09 PM	20	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:09 PM	26	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:09 PM	42	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:09 PM	10	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:10 PM	37	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:10 PM	10	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:10 PM	8	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:10 PM	42	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:10 PM	8	1401.00	XCSE
GENMAB A/S	27-Mar-25	3:49:17 PM	76	1400.50	CEUX
GENMAB A/S	27-Mar-25	3:49:21 PM	27	1400.00	TQEX
GENMAB A/S	27-Mar-25	3:49:22 PM	14	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:49:22 PM	4	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:49:44 PM	22	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:49:44 PM	22	1399.00	TQEX
GENMAB A/S	27-Mar-25	3:49:45 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:49:45 PM	6	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:49:45 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:49:45 PM	30	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:49:45 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:49:45 PM	18	1399.00	AQEU
GENMAB A/S	27-Mar-25	3:49:46 PM	22	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:51:53 PM	42	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:51:53 PM	37	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:51:53 PM	42	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:51:53 PM	37	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:51:53 PM	14	1400.00	XCSE
GENMAB A/S	27-Mar-25	3:51:53 PM	36	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:51:53 PM	2	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:51:53 PM	15	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:51:53 PM	71	1399.50	CEUX
GENMAB A/S	27-Mar-25	3:51:53 PM	7	1399.50	TQEX
GENMAB A/S	27-Mar-25	3:51:53 PM	15	1399.50	TQEX
GENMAB A/S	27-Mar-25	3:51:56 PM	17	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:51:56 PM	11	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:52:46 PM	9	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:52:46 PM	9	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:52:46 PM	42	1398.50	XCSE

121

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:52:46 PM	25	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:52:46 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	3:52:46 PM	25	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:52:46 PM	75	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:52:46 PM	22	1398.50	TQEX
GENMAB A/S	27-Mar-25	3:53:35 PM	9	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:53:35 PM	25	1398.50	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	2	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	14	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	42	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	30	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	25	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:58 PM	36	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:54:58 PM	24	1398.00	AQEU
GENMAB A/S	27-Mar-25	3:54:59 PM	18	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:59 PM	39	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:59 PM	29	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:59 PM	30	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:59 PM	42	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:54:59 PM	30	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:56:09 PM	74	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:56:09 PM	37	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:56:09 PM	77	1397.00	CEUX
GENMAB A/S	27-Mar-25	3:56:09 PM	40	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:56:09 PM	27	1397.00	TQEX
GENMAB A/S	27-Mar-25	3:56:09 PM	23	1398.00	TQEX
GENMAB A/S	27-Mar-25	3:56:09 PM	22	1397.00	AQEU
GENMAB A/S	27-Mar-25	3:56:09 PM	33	1398.00	AQEU
GENMAB A/S	27-Mar-25	3:56:10 PM	32	1397.00	CEUX
GENMAB A/S	27-Mar-25	3:56:16 PM	1	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:56:16 PM	44	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:56:16 PM	12	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:56:17 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:56:17 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	3:56:56 PM	34	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:56:56 PM	41	1398.50	CEUX
GENMAB A/S	27-Mar-25	3:57:07 PM	29	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:07 PM	18	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:07 PM	30	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:07 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:07 PM	2	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:07 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:08 PM	98	1399.00	XCSE
GENMAB A/S	27-Mar-25	3:57:08 PM	98	1399.00	XCSE

122

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	3:57:21 PM	29	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:57:21 PM	46	1397.50	XCSE
GENMAB A/S	27-Mar-25	3:57:21 PM	32	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:57:21 PM	40	1398.00	AQEU
GENMAB A/S	27-Mar-25	3:57:39 PM	9	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:59:49 PM	76	1398.00	XCSE
GENMAB A/S	27-Mar-25	3:59:49 PM	32	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:59:49 PM	24	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:59:49 PM	25	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:59:52 PM	28	1398.00	CEUX
GENMAB A/S	27-Mar-25	3:59:52 PM	25	1398.00	AQEU
GENMAB A/S	27-Mar-25	4:00:03 PM	26	1398.50	TQEX
GENMAB A/S	27-Mar-25	4:00:05 PM	26	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:05 PM	8	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:05 PM	1	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:05 PM	10	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:05 PM	8	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:05 PM	36	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:05 PM	4	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:05 PM	5	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:05 PM	5	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:11 PM	15	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:11 PM	1	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:00:11 PM	4	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:11 PM	5	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:11 PM	5	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:11 PM	5	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:12 PM	15	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:00:45 PM	74	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:01:06 PM	41	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:06 PM	12	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:06 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:06 PM	77	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:01:06 PM	36	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:01:06 PM	22	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:01:07 PM	12	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:07 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:07 PM	8	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:07 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:07 PM	78	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:01:07 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:07 PM	32	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:01:21 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:21 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:21 PM	32	1398.00	XCSE

123

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:01:21 PM	78	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:01:21 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:21 PM	77	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:01:21 PM	2	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:01:21 PM	72	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:01:21 PM	5	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:01:21 PM	33	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:01:22 PM	11	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:01:22 PM	9	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:01:22 PM	16	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:01:34 PM	20	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:01:34 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:01:34 PM	7	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:01:34 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:01:34 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:01:34 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	73	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	45	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	2	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	14	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	10	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	41	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:05:02 PM	75	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:05:02 PM	75	1396.00	CEUX
GENMAB A/S	27-Mar-25	4:05:02 PM	25	1396.50	TQEX
GENMAB A/S	27-Mar-25	4:05:02 PM	11	1396.50	AQEU
GENMAB A/S	27-Mar-25	4:05:02 PM	11	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:05:02 PM	19	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:05:02 PM	15	1396.50	AQEU
GENMAB A/S	27-Mar-25	4:05:12 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	24	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	8	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:12 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:05:17 PM	10	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:05:17 PM	6	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:05:17 PM	5	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:05:17 PM	5	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:05:47 PM	73	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:05:47 PM	36	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:05:47 PM	4	1398.50	CEUX

124

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:05:47 PM	3	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:05:47 PM	34	1398.50	AQEU
GENMAB A/S	27-Mar-25	4:06:21 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:06:21 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:06:21 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:06:21 PM	6	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:06:21 PM	24	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:07:20 PM	36	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:07:20 PM	33	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:07:48 PM	8	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:07:48 PM	36	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:07:48 PM	21	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:07:48 PM	14	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:07:48 PM	29	1400.00	TQEX
GENMAB A/S	27-Mar-25	4:07:55 PM	1	1400.00	AQEU
GENMAB A/S	27-Mar-25	4:08:07 PM	44	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:07 PM	75	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:07 PM	15	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:08:07 PM	24	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:08:07 PM	34	1400.00	AQEU
GENMAB A/S	27-Mar-25	4:08:11 PM	30	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:08:11 PM	36	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:08:11 PM	72	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:08:21 PM	19	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:21 PM	41	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:21 PM	3	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:22 PM	10	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:40 PM	26	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:40 PM	30	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:08:40 PM	36	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:08:59 PM	74	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:09:02 PM	12	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:09:36 PM	19	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:36 PM	30	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:40 PM	10	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:10:42 PM	28	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	48	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	45	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	11	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	30	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	25	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	1	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:42 PM	6	1399.50	XCSE

125

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:10:42 PM	30	1399.00	TQEX
GENMAB A/S	27-Mar-25	4:10:42 PM	29	1399.00	AQEU
GENMAB A/S	27-Mar-25	4:10:43 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:43 PM	30	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:43 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:43 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:10:48 PM	77	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:48 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:48 PM	12	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:48 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:48 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:10:48 PM	4	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:10:48 PM	5	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:10:48 PM	4	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:10:48 PM	25	1399.00	TQEX
GENMAB A/S	27-Mar-25	4:11:09 PM	73	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:11:10 PM	3	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:11:12 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	15	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	38	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	44	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	37	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	6	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	11	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:12 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	16	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	45	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	39	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	3	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:13 PM	38	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	14	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	25	1399.00	XCSE

126

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:11:14 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	14	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	45	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	38	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:14 PM	13	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:15 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:15 PM	9	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:15 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:16 PM	8	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:23 PM	13	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	38	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	8	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	17	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:41 PM	8	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:11:48 PM	36	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:48 PM	10	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:11:55 PM	13	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:12:37 PM	10	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	8	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	17	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	45	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	3	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	8	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	32	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	10	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	10	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:37 PM	8	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:46 PM	9	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:50 PM	14	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:12:53 PM	36	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:12:56 PM	7	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:12:57 PM	8	1400.00	XCSE
GENMAB A/S	27-Mar-25	4:13:05 PM	36	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:06 PM	41	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:06 PM	20	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:28 PM	47	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:29 PM	5	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:29 PM	4	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:29 PM	36	1400.00	CEUX

127

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:13:29 PM	5	1400.00	CEUX
GENMAB A/S	27-Mar-25	4:13:44 PM	12	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:44 PM	39	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:44 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:44 PM	4	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:13:44 PM	36	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:13:44 PM	4	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:13:44 PM	5	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:13:45 PM	44	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	17	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	7	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	18	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	9	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	7	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:54 PM	22	1399.50	CEUX
GENMAB A/S	27-Mar-25	4:13:55 PM	2	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:55 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:55 PM	10	1399.50	XCSE
GENMAB A/S	27-Mar-25	4:13:58 PM	74	1399.00	XCSE
GENMAB A/S	27-Mar-25	4:13:58 PM	75	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:13:58 PM	22	1399.00	TQEX
GENMAB A/S	27-Mar-25	4:13:58 PM	23	1399.00	AQEU
GENMAB A/S	27-Mar-25	4:14:18 PM	78	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:14:18 PM	23	1398.00	TQEX
GENMAB A/S	27-Mar-25	4:14:18 PM	10	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:14:26 PM	72	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:14:26 PM	16	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:14:27 PM	25	1397.00	TQEX
GENMAB A/S	27-Mar-25	4:15:02 PM	27	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:15:02 PM	19	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:15:02 PM	16	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:15:04 PM	5	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:15:18 PM	53	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:15:59 PM	10	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:16:08 PM	5	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:16:29 PM	10	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:16:29 PM	12	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:16:29 PM	11	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:16:59 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:16:59 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:16:59 PM	1	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:16:59 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:16:59 PM	9	1397.00	XCSE

128

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:16:59 PM	8	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:16:59 PM	32	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:17:14 PM	30	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:17:14 PM	20	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:17:14 PM	15	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:17:23 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:23 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:23 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:23 PM	26	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:23 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	8	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	9	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	1	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	10	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	11	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	44	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	29	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	12	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	11	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:17:53 PM	22	1396.50	TQEX
GENMAB A/S	27-Mar-25	4:17:54 PM	17	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:54 PM	2	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:55 PM	13	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:55 PM	3	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:55 PM	25	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:55 PM	13	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:56 PM	18	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:56 PM	8	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:56 PM	9	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:56 PM	1	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:58 PM	9	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:17:58 PM	10	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:18:09 PM	28	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:18:09 PM	17	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:18:39 PM	26	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:18:39 PM	7	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:18:39 PM	8	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:18:39 PM	17	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:18:39 PM	8	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:18:39 PM	8	1396.50	XCSE

129

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:18:39 PM	78	1396.00	CEUX
GENMAB A/S	27-Mar-25	4:18:39 PM	10	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:18:39 PM	28	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:18:39 PM	21	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:18:40 PM	11	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:19:08 PM	72	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:20:49 PM	76	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:20:50 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:20:51 PM	2	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:20:51 PM	6	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:21:11 PM	75	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:21:11 PM	32	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:21:29 PM	19	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:21:31 PM	7	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:22:08 PM	15	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:22:08 PM	45	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:22:08 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:22:08 PM	12	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:22:08 PM	1	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:22:08 PM	1	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:22:08 PM	69	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:22:08 PM	31	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:22:08 PM	37	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:22:28 PM	65	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:22:34 PM	19	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:22:45 PM	32	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:22:52 PM	21	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:22:55 PM	49	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:23:03 PM	12	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:23:03 PM	30	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:23:03 PM	34	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:23:08 PM	44	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:23:08 PM	4	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:23:59 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:23:59 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:23:59 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:24:01 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:24:13 PM	12	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:13 PM	19	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:24:13 PM	36	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:24:17 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:17 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:17 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:17 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:17 PM	8	1397.00	XCSE

130

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:24:17 PM	16	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	43	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	41	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	11	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	18	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:18 PM	28	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:19 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:24:44 PM	1	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:24:44 PM	30	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:24:44 PM	1	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:24:44 PM	16	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:24:44 PM	7	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:25:29 PM	17	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:25:29 PM	9	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:25:29 PM	21	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:25:29 PM	12	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:26:08 PM	3	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	46	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	42	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	30	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	14	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	11	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	12	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	13	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	28	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:08 PM	26	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:26:08 PM	24	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:26:08 PM	29	1396.50	TQEX
GENMAB A/S	27-Mar-25	4:26:08 PM	25	1396.50	AQEU
GENMAB A/S	27-Mar-25	4:26:09 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	28	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	9	1397.00	XCSE

131

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:26:09 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	25	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	1	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	45	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:09 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	2	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:10 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:11 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:13 PM	14	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:15 PM	29	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:15 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:16 PM	29	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:16 PM	36	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:26:21 PM	78	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:26:56 PM	12	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:26:56 PM	16	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:27:04 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:27:08 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:08 PM	42	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:08 PM	28	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:08 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:08 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:27 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:27 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:27 PM	23	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:27 PM	5	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:27 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:54 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:54 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:27:54 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:28:11 PM	10	1397.50	XCSE

132

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:28:14 PM	7	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:28:32 PM	12	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:28:37 PM	10	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:28:37 PM	11	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:29:06 PM	9	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:29:50 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:29:50 PM	5	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:29:54 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:29:54 PM	25	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:29:54 PM	1	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:03 PM	75	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:03 PM	42	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:03 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:03 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:03 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:03 PM	30	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:03 PM	30	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:03 PM	37	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:30:03 PM	20	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:30:03 PM	27	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:30:05 PM	19	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:05 PM	30	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:05 PM	2	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:05 PM	12	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:05 PM	35	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:05 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:05 PM	5	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:25 PM	1	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:34 PM	29	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	30	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	24	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	1	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	13	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	2	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	12	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:34 PM	2	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:40 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:40 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:40 PM	8	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:41 PM	7	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:46 PM	11	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:50 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:50 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:50 PM	75	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:30:50 PM	9	1398.00	XCSE

133

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:30:50 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:50 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:30:50 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:50 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:50 PM	28	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:30:50 PM	19	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:30:50 PM	4	1397.50	AQEU
GENMAB A/S	27-Mar-25	4:30:51 PM	5	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:51 PM	5	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:51 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:30:52 PM	12	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:30:52 PM	4	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:30:52 PM	15	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:30:52 PM	19	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:31:05 PM	13	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:31:33 PM	19	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:31:33 PM	24	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:31:35 PM	22	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:31:41 PM	10	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:31:52 PM	78	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:31:52 PM	48	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:31:52 PM	75	1396.00	CEUX
GENMAB A/S	27-Mar-25	4:31:52 PM	39	1395.00	CEUX
GENMAB A/S	27-Mar-25	4:31:52 PM	23	1395.50	TQEX
GENMAB A/S	27-Mar-25	4:31:52 PM	28	1396.50	TQEX
GENMAB A/S	27-Mar-25	4:31:52 PM	38	1395.50	AQEU
GENMAB A/S	27-Mar-25	4:31:52 PM	25	1396.50	AQEU
GENMAB A/S	27-Mar-25	4:31:56 PM	14	1395.00	XCSE
GENMAB A/S	27-Mar-25	4:31:56 PM	10	1395.00	XCSE
GENMAB A/S	27-Mar-25	4:31:56 PM	11	1395.00	XCSE
GENMAB A/S	27-Mar-25	4:31:56 PM	13	1395.00	XCSE
GENMAB A/S	27-Mar-25	4:31:56 PM	1	1395.00	XCSE
GENMAB A/S	27-Mar-25	4:31:56 PM	41	1395.00	XCSE
GENMAB A/S	27-Mar-25	4:32:15 PM	24	1394.00	XCSE
GENMAB A/S	27-Mar-25	4:32:15 PM	31	1394.50	TQEX
GENMAB A/S	27-Mar-25	4:32:15 PM	24	1394.00	AQEU
GENMAB A/S	27-Mar-25	4:32:19 PM	54	1394.00	CEUX
GENMAB A/S	27-Mar-25	4:32:26 PM	43	1394.00	XCSE
GENMAB A/S	27-Mar-25	4:32:26 PM	8	1394.00	XCSE
GENMAB A/S	27-Mar-25	4:32:58 PM	2	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:32:58 PM	43	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:00 PM	32	1394.00	CEUX
GENMAB A/S	27-Mar-25	4:33:14 PM	45	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:14 PM	10	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:14 PM	8	1393.50	XCSE

134

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:33:14 PM	22	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:14 PM	10	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:14 PM	76	1393.50	CEUX
GENMAB A/S	27-Mar-25	4:33:26 PM	7	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:26 PM	16	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:26 PM	17	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:38 PM	38	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:39 PM	31	1393.50	XCSE
GENMAB A/S	27-Mar-25	4:33:49 PM	34	1393.50	TQEX
GENMAB A/S	27-Mar-25	4:33:49 PM	17	1393.50	AQEU
GENMAB A/S	27-Mar-25	4:33:57 PM	9	1394.00	XCSE
GENMAB A/S	27-Mar-25	4:33:57 PM	5	1394.00	XCSE
GENMAB A/S	27-Mar-25	4:33:57 PM	27	1394.00	XCSE
GENMAB A/S	27-Mar-25	4:34:06 PM	16	1394.00	CEUX
GENMAB A/S	27-Mar-25	4:34:16 PM	19	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:16 PM	9	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:17 PM	10	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:17 PM	12	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:26 PM	8	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:26 PM	9	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:26 PM	19	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:36 PM	14	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:36 PM	5	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:38 PM	19	1394.00	CEUX
GENMAB A/S	27-Mar-25	4:34:46 PM	8	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:46 PM	8	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:47 PM	15	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:56 PM	7	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:34:56 PM	17	1394.00	CEUX
GENMAB A/S	27-Mar-25	4:35:22 PM	40	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:35:22 PM	34	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:35:22 PM	39	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:35:22 PM	10	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:35:22 PM	23	1394.50	AQEU
GENMAB A/S	27-Mar-25	4:35:30 PM	33	1394.50	AQEU
GENMAB A/S	27-Mar-25	4:36:02 PM	36	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:36:03 PM	10	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:03 PM	9	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	9	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	10	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	45	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	11	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	24	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	10	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:11 PM	9	1394.00	CEUX

135

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:36:11 PM	3	1394.00	CEUX
GENMAB A/S	27-Mar-25	4:36:13 PM	3	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:20 PM	6	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:36:20 PM	30	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:36:21 PM	41	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:36:44 PM	9	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:44 PM	10	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:36:44 PM	36	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:36:45 PM	28	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:36:59 PM	53	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:37:00 PM	45	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:37:00 PM	18	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:37:00 PM	19	1394.50	XCSE
GENMAB A/S	27-Mar-25	4:37:00 PM	55	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:37:27 PM	77	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:37:27 PM	11	1395.50	CEUX
GENMAB A/S	27-Mar-25	4:37:27 PM	9	1395.50	CEUX
GENMAB A/S	27-Mar-25	4:37:31 PM	65	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:37:31 PM	13	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:37:31 PM	43	1396.50	CEUX
GENMAB A/S	27-Mar-25	4:37:31 PM	16	1395.50	CEUX
GENMAB A/S	27-Mar-25	4:37:31 PM	19	1396.00	TQEX
GENMAB A/S	27-Mar-25	4:37:31 PM	3	1396.00	TQEX
GENMAB A/S	27-Mar-25	4:37:31 PM	35	1396.00	AQEU
GENMAB A/S	27-Mar-25	4:38:04 PM	25	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:38:11 PM	61	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:11 PM	48	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:38:11 PM	17	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:11 PM	72	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:11 PM	36	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:38:11 PM	27	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:38:11 PM	29	1397.00	TQEX
GENMAB A/S	27-Mar-25	4:38:11 PM	23	1398.00	TQEX
GENMAB A/S	27-Mar-25	4:38:26 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:26 PM	22	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:26 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:26 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:26 PM	13	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:26 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:46 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:46 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:46 PM	22	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:46 PM	12	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:46 PM	8	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:38:46 PM	13	1397.00	XCSE

136

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:38:49 PM	76	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:38:49 PM	4	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:38:49 PM	7	1395.50	CEUX
GENMAB A/S	27-Mar-25	4:38:49 PM	3	1395.50	CEUX
GENMAB A/S	27-Mar-25	4:38:49 PM	3	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:38:50 PM	4	1394.50	CEUX
GENMAB A/S	27-Mar-25	4:39:26 PM	11	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:26 PM	9	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:26 PM	7	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:26 PM	13	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:26 PM	10	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:45 PM	2	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:45 PM	10	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:45 PM	9	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:45 PM	17	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:49 PM	10	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:49 PM	9	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:49 PM	10	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:39:49 PM	22	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:40:18 PM	42	1395.50	XCSE
GENMAB A/S	27-Mar-25	4:40:26 PM	3	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:40:27 PM	1	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:40:27 PM	6	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:16 PM	4	1396.00	CEUX
GENMAB A/S	27-Mar-25	4:41:16 PM	4	1396.00	CEUX
GENMAB A/S	27-Mar-25	4:41:16 PM	36	1396.00	CEUX
GENMAB A/S	27-Mar-25	4:41:22 PM	32	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:22 PM	19	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:22 PM	2	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:22 PM	45	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:26 PM	9	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:26 PM	8	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:38 PM	63	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:55 PM	4	1396.00	XCSE
GENMAB A/S	27-Mar-25	4:41:56 PM	27	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:42:24 PM	44	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:24 PM	54	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:25 PM	12	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:42:27 PM	20	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:42:28 PM	66	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:42:29 PM	78	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:42:29 PM	19	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:42:29 PM	27	1398.00	TQEX
GENMAB A/S	27-Mar-25	4:42:29 PM	23	1398.00	AQEU
GENMAB A/S	27-Mar-25	4:42:50 PM	36	1397.50	CEUX

137

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:42:50 PM	34	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:42:50 PM	21	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:42:50 PM	23	1397.00	TQEX
GENMAB A/S	27-Mar-25	4:42:50 PM	23	1397.00	AQEU
GENMAB A/S	27-Mar-25	4:42:51 PM	50	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	45	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	29	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	10	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	38	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	5	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:51 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	8	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	30	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	8	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	30	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	8	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:42:52 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:43:06 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:43:08 PM	53	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:43:08 PM	9	1398.00	XCSE
GENMAB A/S	27-Mar-25	4:43:24 PM	19	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:43:36 PM	13	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:43:36 PM	27	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:43:36 PM	4	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:43:36 PM	45	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:43:36 PM	9	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:43:40 PM	7	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:43:40 PM	63	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:43:52 PM	25	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:43:52 PM	56	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:43:52 PM	22	1398.00	AQEU
GENMAB A/S	27-Mar-25	4:44:24 PM	8	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:44:24 PM	9	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:44:24 PM	14	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:44:24 PM	41	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:44:31 PM	78	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:44:31 PM	36	1398.00	CEUX
GENMAB A/S	27-Mar-25	4:44:54 PM	22	1398.00	AQEU
GENMAB A/S	27-Mar-25	4:45:12 PM	73	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:45:12 PM	24	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:45:28 PM	42	1397.50	XCSE

138

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:45:40 PM	35	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:45:44 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:45:44 PM	21	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:45:44 PM	9	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:46:02 PM	5	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:46:02 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:46:02 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:46:02 PM	5	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:46:03 PM	11	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:03 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:46:07 PM	7	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:07 PM	14	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:08 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:09 PM	12	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:13 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:14 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:18 PM	11	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:18 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:19 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:23 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:23 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:24 PM	13	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:46:29 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:46:29 PM	78	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:46:29 PM	10	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:46:29 PM	5	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:29 PM	45	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:29 PM	4	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:29 PM	65	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:29 PM	4	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:29 PM	27	1397.00	AQEU
GENMAB A/S	27-Mar-25	4:46:30 PM	16	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:46:30 PM	12	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:46:30 PM	15	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:30 PM	37	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:46:41 PM	9	1397.00	XCSE
GENMAB A/S	27-Mar-25	4:47:01 PM	20	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:01 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:01 PM	8	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:01 PM	34	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:01 PM	24	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:02 PM	7	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:09 PM	15	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:19 PM	11	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:47:19 PM	15	1397.50	CEUX

139

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:47:19 PM	17	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:48:21 PM	35	1396.50	XCSE
GENMAB A/S	27-Mar-25	4:48:22 PM	9	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:48:22 PM	63	1397.00	CEUX
GENMAB A/S	27-Mar-25	4:49:47 PM	9	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:47 PM	36	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:54 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:49:54 PM	8	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:49:54 PM	9	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:49:54 PM	10	1397.50	XCSE
GENMAB A/S	27-Mar-25	4:49:54 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:54 PM	5	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:54 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:55 PM	9	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:55 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:55 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:55 PM	23	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:55 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:49:55 PM	2	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:49:55 PM	2	1397.50	TQEX
GENMAB A/S	27-Mar-25	4:49:58 PM	8	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:50:16 PM	4	1397.50	CEUX
GENMAB A/S	27-Mar-25	4:50:16 PM	39	1398.00	AQEU
GENMAB A/S	27-Mar-25	4:50:19 PM	98	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:50:19 PM	78	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:50:19 PM	74	1398.50	CEUX
GENMAB A/S	27-Mar-25	4:50:20 PM	13	1398.50	AQEU
GENMAB A/S	27-Mar-25	4:50:31 PM	36	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:50:31 PM	78	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:50:31 PM	24	1399.00	CEUX
GENMAB A/S	27-Mar-25	4:50:31 PM	2	1399.00	TQEX
GENMAB A/S	27-Mar-25	4:50:31 PM	2	1399.00	TQEX
GENMAB A/S	27-Mar-25	4:50:37 PM	32	1398.50	XCSE
GENMAB A/S	27-Mar-25	4:51:00 PM	71	1402.00	CEUX
GENMAB A/S	27-Mar-25	4:51:00 PM	27	1402.00	CEUX
GENMAB A/S	27-Mar-25	4:51:00 PM	24	1402.00	CEUX
GENMAB A/S	27-Mar-25	4:51:00 PM	11	1402.00	TQEX
GENMAB A/S	27-Mar-25	4:51:00 PM	11	1402.00	TQEX
GENMAB A/S	27-Mar-25	4:51:09 PM	74	1401.50	XCSE
GENMAB A/S	27-Mar-25	4:51:09 PM	32	1402.00	CEUX
GENMAB A/S	27-Mar-25	4:51:09 PM	2	1402.00	TQEX
GENMAB A/S	27-Mar-25	4:51:09 PM	11	1402.00	TQEX
GENMAB A/S	27-Mar-25	4:51:09 PM	2	1402.00	TQEX
GENMAB A/S	27-Mar-25	4:51:09 PM	23	1401.50	TQEX
GENMAB A/S	27-Mar-25	4:51:09 PM	29	1401.50	AQEU

140

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:51:16 PM	77	1401.50	XCSE
GENMAB A/S	27-Mar-25	4:51:23 PM	25	1402.00	CEUX
GENMAB A/S	27-Mar-25	4:51:46 PM	3	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:46 PM	11	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:46 PM	22	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:47 PM	36	1403.00	CEUX
GENMAB A/S	27-Mar-25	4:51:47 PM	25	1403.00	AQEU
GENMAB A/S	27-Mar-25	4:51:51 PM	8	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	73	1402.50	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	10	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	17	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	45	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	24	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	9	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	45	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	28	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	10	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:51 PM	25	1403.00	CEUX
GENMAB A/S	27-Mar-25	4:51:51 PM	4	1403.00	CEUX
GENMAB A/S	27-Mar-25	4:51:51 PM	5	1403.00	CEUX
GENMAB A/S	27-Mar-25	4:51:51 PM	36	1403.00	CEUX
GENMAB A/S	27-Mar-25	4:51:51 PM	2	1403.00	CEUX
GENMAB A/S	27-Mar-25	4:51:51 PM	44	1402.50	CEUX
GENMAB A/S	27-Mar-25	4:51:51 PM	31	1402.50	TQEX
GENMAB A/S	27-Mar-25	4:51:51 PM	10	1402.00	AQEU
GENMAB A/S	27-Mar-25	4:51:52 PM	8	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	13	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	9	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	45	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	8	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	9	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	45	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	8	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	9	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	30	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	2	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	6	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	1	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	8	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	45	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:51:52 PM	14	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:52:03 PM	10	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:52:03 PM	45	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:52:03 PM	31	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:52:03 PM	9	1403.00	XCSE

141

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:52:03 PM	3	1403.00	XCSE
GENMAB A/S	27-Mar-25	4:52:19 PM	30	1403.50	CEUX
GENMAB A/S	27-Mar-25	4:52:19 PM	3	1403.50	TQEX
GENMAB A/S	27-Mar-25	4:52:19 PM	19	1403.50	TQEX
GENMAB A/S	27-Mar-25	4:52:20 PM	25	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	31	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	64	1403.50	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	45	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	22	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	2	1403.50	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	73	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:52:30 PM	17	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:52:30 PM	2	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:52:30 PM	32	1405.00	CEUX
GENMAB A/S	27-Mar-25	4:52:30 PM	22	1405.00	CEUX
GENMAB A/S	27-Mar-25	4:52:30 PM	6	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:52:30 PM	26	1404.50	TQEX
GENMAB A/S	27-Mar-25	4:52:30 PM	11	1403.50	TQEX
GENMAB A/S	27-Mar-25	4:52:30 PM	23	1404.00	AQEU
GENMAB A/S	27-Mar-25	4:52:30 PM	12	1404.50	AQEU
GENMAB A/S	27-Mar-25	4:52:31 PM	22	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:52:31 PM	25	1404.00	AQEU
GENMAB A/S	27-Mar-25	4:52:32 PM	18	1404.00	TQEX
GENMAB A/S	27-Mar-25	4:52:43 PM	51	1404.00	XCSE
GENMAB A/S	27-Mar-25	4:52:50 PM	12	1404.00	TQEX
GENMAB A/S	27-Mar-25	4:53:16 PM	10	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:53:18 PM	17	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	4	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	2	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:35 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:36 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:36 PM	4	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:36 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:38 PM	4	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:38 PM	4	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:38 PM	4	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:38 PM	36	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:39 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:39 PM	5	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:53:39 PM	4	1404.50	CEUX

142

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	27-Mar-25	4:53:49 PM	8	1403.50	XCSE
GENMAB A/S	27-Mar-25	4:53:57 PM	10	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:53:57 PM	10	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:54:03 PM	17	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:54:10 PM	41	1404.00	CEUX
GENMAB A/S	27-Mar-25	4:54:13 PM	19	1404.00	TQEX
GENMAB A/S	27-Mar-25	4:54:13 PM	10	1404.00	TQEX
GENMAB A/S	27-Mar-25	4:54:21 PM	45	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:54:21 PM	8	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:54:21 PM	10	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:54:21 PM	10	1404.50	XCSE
GENMAB A/S	27-Mar-25	4:54:29 PM	78	1404.00	XCSE
GENMAB A/S	27-Mar-25	4:54:37 PM	10	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:37 PM	1	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:37 PM	9	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:37 PM	9	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:37 PM	45	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:37 PM	14	1404.50	CEUX
GENMAB A/S	27-Mar-25	4:54:38 PM	10	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:38 PM	17	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:38 PM	45	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:38 PM	8	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:38 PM	10	1405.00	XCSE
GENMAB A/S	27-Mar-25	4:54:52 PM	28	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	11	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	30	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	10	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	30	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	10	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	8	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	8	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:53 PM	30	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:54 PM	10	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:54 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:54 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:56 PM	30	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:56 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:56 PM	9	1405.50	XCSE
GENMAB A/S	27-Mar-25	4:54:56 PM	10	1405.50	XCSE
GENMAB A/S	28-Mar-25	10:09:21 AM	16	1387.00	TQEX
GENMAB A/S	28-Mar-25	10:10:35 AM	62	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:10:35 AM	64	1387.00	XCSE

143

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	10:10:35 AM	73	1386.00	CEUX
GENMAB A/S	28-Mar-25	10:10:35 AM	50	1387.00	TQEX
GENMAB A/S	28-Mar-25	10:10:35 AM	64	1386.00	TQEX
GENMAB A/S	28-Mar-25	10:10:35 AM	71	1386.50	AQEU
GENMAB A/S	28-Mar-25	10:10:35 AM	49	1385.50	AQEU
GENMAB A/S	28-Mar-25	10:10:35 AM	21	1385.50	AQEU
GENMAB A/S	28-Mar-25	10:12:11 AM	59	1387.50	CEUX
GENMAB A/S	28-Mar-25	10:12:11 AM	8	1387.50	AQEU
GENMAB A/S	28-Mar-25	10:12:11 AM	14	1387.50	AQEU
GENMAB A/S	28-Mar-25	10:21:09 AM	36	1388.50	CEUX
GENMAB A/S	28-Mar-25	10:21:09 AM	25	1388.50	CEUX
GENMAB A/S	28-Mar-25	10:21:09 AM	79	1388.50	CEUX
GENMAB A/S	28-Mar-25	10:21:09 AM	25	1388.50	TQEX
GENMAB A/S	28-Mar-25	10:21:09 AM	22	1388.50	AQEU
GENMAB A/S	28-Mar-25	10:21:10 AM	17	1389.50	TQEX
GENMAB A/S	28-Mar-25	10:21:13 AM	10	1389.50	TQEX
GENMAB A/S	28-Mar-25	10:22:43 AM	55	1389.50	XCSE
GENMAB A/S	28-Mar-25	10:22:43 AM	23	1389.50	XCSE
GENMAB A/S	28-Mar-25	10:22:43 AM	36	1389.50	CEUX
GENMAB A/S	28-Mar-25	10:22:45 AM	34	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:22:45 AM	15	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:22:54 AM	41	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:22:54 AM	11	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:22:54 AM	30	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:24:35 AM	36	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:25:32 AM	1	1389.50	XCSE
GENMAB A/S	28-Mar-25	10:25:32 AM	73	1389.50	XCSE
GENMAB A/S	28-Mar-25	10:25:32 AM	28	1389.50	TQEX
GENMAB A/S	28-Mar-25	10:25:39 AM	20	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	53	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	26	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	12	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	21	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	41	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	28	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	32	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:25:39 AM	15	1389.00	CEUX
GENMAB A/S	28-Mar-25	10:25:40 AM	58	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:12 AM	41	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:12 AM	26	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:12 AM	30	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:12 AM	36	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:26:28 AM	26	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:28 AM	41	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:28 AM	30	1390.00	XCSE

144

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	10:26:28 AM	4	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:26:28 AM	24	1389.50	TQEX
GENMAB A/S	28-Mar-25	10:26:29 AM	79	1389.50	XCSE
GENMAB A/S	28-Mar-25	10:26:29 AM	5	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:26:29 AM	5	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:26:29 AM	17	1389.50	TQEX
GENMAB A/S	28-Mar-25	10:26:29 AM	14	1389.50	TQEX
GENMAB A/S	28-Mar-25	10:26:38 AM	10	1390.50	CEUX
GENMAB A/S	28-Mar-25	10:26:38 AM	13	1390.50	CEUX
GENMAB A/S	28-Mar-25	10:26:38 AM	43	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:26:43 AM	22	1390.50	TQEX
GENMAB A/S	28-Mar-25	10:27:44 AM	54	1391.00	XCSE
GENMAB A/S	28-Mar-25	10:27:44 AM	34	1391.00	XCSE
GENMAB A/S	28-Mar-25	10:27:44 AM	13	1391.00	XCSE
GENMAB A/S	28-Mar-25	10:27:44 AM	33	1391.00	XCSE
GENMAB A/S	28-Mar-25	10:27:45 AM	28	1391.50	TQEX
GENMAB A/S	28-Mar-25	10:28:46 AM	43	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:28:46 AM	41	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:28:46 AM	78	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:28:46 AM	17	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:28:46 AM	80	1392.00	CEUX
GENMAB A/S	28-Mar-25	10:28:46 AM	24	1392.00	AQEU
GENMAB A/S	28-Mar-25	10:29:45 AM	17	1393.00	XCSE
GENMAB A/S	28-Mar-25	10:29:45 AM	41	1393.00	XCSE
GENMAB A/S	28-Mar-25	10:29:45 AM	43	1393.00	XCSE
GENMAB A/S	28-Mar-25	10:29:45 AM	32	1392.50	CEUX
GENMAB A/S	28-Mar-25	10:29:45 AM	26	1392.50	TQEX
GENMAB A/S	28-Mar-25	10:29:49 AM	76	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:29:49 AM	61	1392.50	XCSE
GENMAB A/S	28-Mar-25	10:29:49 AM	14	1392.00	CEUX
GENMAB A/S	28-Mar-25	10:29:49 AM	66	1392.00	CEUX
GENMAB A/S	28-Mar-25	10:29:51 AM	45	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:29:51 AM	14	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:30:05 AM	78	1392.00	XCSE
GENMAB A/S	28-Mar-25	10:30:05 AM	17	1392.00	CEUX
GENMAB A/S	28-Mar-25	10:30:05 AM	62	1392.00	CEUX
GENMAB A/S	28-Mar-25	10:30:19 AM	30	1391.50	XCSE
GENMAB A/S	28-Mar-25	10:30:19 AM	41	1391.50	XCSE
GENMAB A/S	28-Mar-25	10:30:19 AM	16	1391.50	XCSE
GENMAB A/S	28-Mar-25	10:30:20 AM	79	1391.00	XCSE
GENMAB A/S	28-Mar-25	10:30:20 AM	76	1391.00	CEUX
GENMAB A/S	28-Mar-25	10:31:38 AM	79	1390.00	XCSE
GENMAB A/S	28-Mar-25	10:31:38 AM	75	1390.00	CEUX
GENMAB A/S	28-Mar-25	10:32:12 AM	29	1389.00	TQEX
GENMAB A/S	28-Mar-25	10:32:24 AM	76	1388.50	XCSE

145

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	10:32:24 AM	76	1388.50	CEUX
GENMAB A/S	28-Mar-25	10:32:25 AM	2	1387.50	XCSE
GENMAB A/S	28-Mar-25	10:32:25 AM	77	1387.50	XCSE
GENMAB A/S	28-Mar-25	10:32:26 AM	45	1387.00	CEUX
GENMAB A/S	28-Mar-25	10:32:28 AM	11	1387.00	CEUX
GENMAB A/S	28-Mar-25	10:32:30 AM	74	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:32:30 AM	12	1385.50	CEUX
GENMAB A/S	28-Mar-25	10:32:30 AM	35	1385.50	CEUX
GENMAB A/S	28-Mar-25	10:33:05 AM	14	1384.50	CEUX
GENMAB A/S	28-Mar-25	10:33:12 AM	6	1385.00	AQEU
GENMAB A/S	28-Mar-25	10:33:35 AM	77	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:33:35 AM	25	1386.50	CEUX
GENMAB A/S	28-Mar-25	10:33:35 AM	3	1386.50	TQEX
GENMAB A/S	28-Mar-25	10:35:26 AM	74	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:36:00 AM	76	1385.50	XCSE
GENMAB A/S	28-Mar-25	10:36:00 AM	25	1385.50	CEUX
GENMAB A/S	28-Mar-25	10:37:31 AM	33	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:37:31 AM	17	1386.50	CEUX
GENMAB A/S	28-Mar-25	10:38:57 AM	52	1386.50	CEUX
GENMAB A/S	28-Mar-25	10:40:02 AM	30	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:40:02 AM	80	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:40:02 AM	41	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:40:02 AM	12	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:40:02 AM	73	1386.50	CEUX
GENMAB A/S	28-Mar-25	10:40:02 AM	27	1386.00	TQEX
GENMAB A/S	28-Mar-25	10:40:02 AM	22	1386.50	AQEU
GENMAB A/S	28-Mar-25	10:40:03 AM	18	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:40:03 AM	43	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:40:37 AM	50	1387.50	CEUX
GENMAB A/S	28-Mar-25	10:44:41 AM	26	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:44:41 AM	55	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:44:41 AM	13	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:44:41 AM	23	1387.00	TQEX
GENMAB A/S	28-Mar-25	10:44:52 AM	13	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:44:52 AM	7	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	12	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	41	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	30	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	53	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	7	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	11	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	18	1387.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	13	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	12	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	30	1386.00	XCSE

146

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	10:45:50 AM	79	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	35	1386.50	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	41	1386.00	XCSE
GENMAB A/S	28-Mar-25	10:45:50 AM	56	1385.50	CEUX
GENMAB A/S	28-Mar-25	10:45:50 AM	58	1386.50	CEUX
GENMAB A/S	28-Mar-25	10:45:50 AM	5	1386.00	TQEX
GENMAB A/S	28-Mar-25	10:45:50 AM	26	1386.50	AQEU
GENMAB A/S	28-Mar-25	10:45:51 AM	23	1385.50	XCSE
GENMAB A/S	28-Mar-25	10:46:02 AM	27	1385.50	XCSE
GENMAB A/S	28-Mar-25	10:46:02 AM	30	1385.50	XCSE
GENMAB A/S	28-Mar-25	10:46:14 AM	15	1385.00	AQEU
GENMAB A/S	28-Mar-25	10:46:44 AM	10	1384.50	XCSE
GENMAB A/S	28-Mar-25	10:46:44 AM	58	1384.50	XCSE
GENMAB A/S	28-Mar-25	10:46:44 AM	29	1385.00	TQEX
GENMAB A/S	28-Mar-25	10:46:44 AM	1	1385.00	AQEU
GENMAB A/S	28-Mar-25	10:47:06 AM	9	1384.50	XCSE
GENMAB A/S	28-Mar-25	10:48:07 AM	24	1384.00	CEUX
GENMAB A/S	28-Mar-25	10:48:10 AM	12	1384.00	XCSE
GENMAB A/S	28-Mar-25	10:48:10 AM	41	1384.00	XCSE
GENMAB A/S	28-Mar-25	10:48:21 AM	41	1384.00	XCSE
GENMAB A/S	28-Mar-25	10:48:21 AM	6	1384.00	XCSE
GENMAB A/S	28-Mar-25	10:48:41 AM	77	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:48:41 AM	64	1382.50	CEUX
GENMAB A/S	28-Mar-25	10:48:41 AM	16	1382.50	CEUX
GENMAB A/S	28-Mar-25	10:48:41 AM	23	1383.50	TQEX
GENMAB A/S	28-Mar-25	10:48:41 AM	38	1383.50	AQEU
GENMAB A/S	28-Mar-25	10:49:21 AM	74	1382.00	XCSE
GENMAB A/S	28-Mar-25	10:49:21 AM	9	1382.00	TQEX
GENMAB A/S	28-Mar-25	10:49:21 AM	20	1382.00	TQEX
GENMAB A/S	28-Mar-25	10:49:26 AM	24	1382.00	AQEU
GENMAB A/S	28-Mar-25	10:51:01 AM	27	1382.00	XCSE
GENMAB A/S	28-Mar-25	10:51:01 AM	19	1382.00	XCSE
GENMAB A/S	28-Mar-25	10:51:01 AM	14	1382.00	XCSE
GENMAB A/S	28-Mar-25	10:51:01 AM	41	1382.00	XCSE
GENMAB A/S	28-Mar-25	10:51:01 AM	4	1382.00	AQEU
GENMAB A/S	28-Mar-25	10:51:24 AM	77	1381.00	XCSE
GENMAB A/S	28-Mar-25	10:51:24 AM	59	1381.00	CEUX
GENMAB A/S	28-Mar-25	10:51:24 AM	15	1381.00	CEUX
GENMAB A/S	28-Mar-25	10:51:24 AM	23	1381.50	TQEX
GENMAB A/S	28-Mar-25	10:51:24 AM	24	1381.00	AQEU
GENMAB A/S	28-Mar-25	10:52:02 AM	76	1380.00	XCSE
GENMAB A/S	28-Mar-25	10:52:02 AM	13	1380.00	CEUX
GENMAB A/S	28-Mar-25	10:52:02 AM	25	1381.50	CEUX
GENMAB A/S	28-Mar-25	10:52:02 AM	66	1380.00	CEUX
GENMAB A/S	28-Mar-25	10:52:02 AM	2	1380.00	AQEU

147

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	10:52:10 AM	51	1381.50	CEUX
GENMAB A/S	28-Mar-25	10:54:31 AM	37	1382.50	XCSE
GENMAB A/S	28-Mar-25	10:54:31 AM	36	1382.50	XCSE
GENMAB A/S	28-Mar-25	10:54:31 AM	15	1382.50	CEUX
GENMAB A/S	28-Mar-25	10:54:31 AM	9	1382.50	CEUX
GENMAB A/S	28-Mar-25	10:54:31 AM	50	1382.50	CEUX
GENMAB A/S	28-Mar-25	10:57:47 AM	13	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:47 AM	41	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:47 AM	41	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:47 AM	11	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:47 AM	11	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:47 AM	12	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:48 AM	11	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:48 AM	12	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:48 AM	41	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	41	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	11	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	41	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	11	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	38	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	30	1383.00	XCSE
GENMAB A/S	28-Mar-25	10:57:50 AM	78	1382.50	CEUX
GENMAB A/S	28-Mar-25	10:57:50 AM	16	1382.00	AQEU
GENMAB A/S	28-Mar-25	10:58:09 AM	78	1382.00	XCSE
GENMAB A/S	28-Mar-25	10:58:09 AM	26	1382.00	TQEX
GENMAB A/S	28-Mar-25	10:58:09 AM	15	1382.00	AQEU
GENMAB A/S	28-Mar-25	10:59:21 AM	77	1381.00	XCSE
GENMAB A/S	28-Mar-25	10:59:21 AM	32	1381.50	CEUX
GENMAB A/S	28-Mar-25	10:59:21 AM	26	1381.50	CEUX
GENMAB A/S	28-Mar-25	10:59:21 AM	14	1381.00	AQEU
GENMAB A/S	28-Mar-25	10:59:21 AM	8	1381.00	AQEU
GENMAB A/S	28-Mar-25	11:00:37 AM	13	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:00:37 AM	18	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:00:37 AM	74	1380.50	CEUX
GENMAB A/S	28-Mar-25	11:00:37 AM	22	1380.50	TQEX
GENMAB A/S	28-Mar-25	11:00:57 AM	2	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:00:57 AM	14	1380.00	AQEU
GENMAB A/S	28-Mar-25	11:03:27 AM	22	1382.00	TQEX
GENMAB A/S	28-Mar-25	11:04:01 AM	40	1381.50	XCSE
GENMAB A/S	28-Mar-25	11:04:01 AM	40	1381.50	XCSE
GENMAB A/S	28-Mar-25	11:04:01 AM	75	1381.50	CEUX
GENMAB A/S	28-Mar-25	11:05:47 AM	4	1380.50	XCSE
GENMAB A/S	28-Mar-25	11:06:28 AM	37	1381.50	CEUX
GENMAB A/S	28-Mar-25	11:06:28 AM	11	1381.50	CEUX
GENMAB A/S	28-Mar-25	11:06:28 AM	10	1381.50	CEUX

148

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	11:06:51 AM	22	1381.00	TQEX
GENMAB A/S	28-Mar-25	11:06:51 AM	15	1381.00	AQEU
GENMAB A/S	28-Mar-25	11:06:52 AM	72	1380.50	XCSE
GENMAB A/S	28-Mar-25	11:06:52 AM	19	1381.00	AQEU
GENMAB A/S	28-Mar-25	11:07:11 AM	8	1381.50	CEUX
GENMAB A/S	28-Mar-25	11:07:11 AM	3	1381.50	CEUX
GENMAB A/S	28-Mar-25	11:09:59 AM	8	1382.50	CEUX
GENMAB A/S	28-Mar-25	11:10:09 AM	71	1382.50	CEUX
GENMAB A/S	28-Mar-25	11:10:09 AM	15	1382.50	CEUX
GENMAB A/S	28-Mar-25	11:11:49 AM	41	1382.50	XCSE
GENMAB A/S	28-Mar-25	11:11:49 AM	1	1382.50	XCSE
GENMAB A/S	28-Mar-25	11:11:51 AM	20	1382.00	XCSE
GENMAB A/S	28-Mar-25	11:13:00 AM	59	1382.00	XCSE
GENMAB A/S	28-Mar-25	11:13:04 AM	31	1382.00	TQEX
GENMAB A/S	28-Mar-25	11:13:07 AM	23	1382.00	CEUX
GENMAB A/S	28-Mar-25	11:13:07 AM	25	1382.00	AQEU
GENMAB A/S	28-Mar-25	11:13:11 AM	12	1382.00	XCSE
GENMAB A/S	28-Mar-25	11:13:11 AM	32	1382.00	CEUX
GENMAB A/S	28-Mar-25	11:13:11 AM	73	1382.50	CEUX
GENMAB A/S	28-Mar-25	11:13:11 AM	28	1382.50	CEUX
GENMAB A/S	28-Mar-25	11:13:11 AM	1	1382.00	TQEX
GENMAB A/S	28-Mar-25	11:13:11 AM	34	1382.00	TQEX
GENMAB A/S	28-Mar-25	11:13:19 AM	101	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:19 AM	78	1381.50	XCSE
GENMAB A/S	28-Mar-25	11:13:19 AM	65	1381.50	CEUX
GENMAB A/S	28-Mar-25	11:13:19 AM	23	1381.00	TQEX
GENMAB A/S	28-Mar-25	11:13:19 AM	6	1381.00	AQEU
GENMAB A/S	28-Mar-25	11:13:19 AM	20	1381.00	AQEU
GENMAB A/S	28-Mar-25	11:13:20 AM	101	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:20 AM	42	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:20 AM	101	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:20 AM	59	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:20 AM	9	1380.50	CEUX
GENMAB A/S	28-Mar-25	11:13:21 AM	101	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:21 AM	101	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:22 AM	9	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:22 AM	92	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:22 AM	101	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:23 AM	3	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:23 AM	62	1381.00	XCSE
GENMAB A/S	28-Mar-25	11:13:32 AM	77	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:13:32 AM	80	1380.50	XCSE
GENMAB A/S	28-Mar-25	11:13:32 AM	34	1380.50	CEUX
GENMAB A/S	28-Mar-25	11:13:32 AM	33	1380.50	CEUX
GENMAB A/S	28-Mar-25	11:13:32 AM	8	1380.00	AQEU

149

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	11:13:43 AM	74	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:13:43 AM	20	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:13:43 AM	57	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:13:45 AM	22	1378.50	AQEU
GENMAB A/S	28-Mar-25	11:14:23 AM	10	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:14:23 AM	69	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:15:58 AM	20	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:16:00 AM	17	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:16:21 AM	1	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:16:21 AM	13	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:16:38 AM	16	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:16:51 AM	41	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:16:51 AM	11	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:16:51 AM	12	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:17:17 AM	75	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:18:20 AM	17	1377.50	AQEU
GENMAB A/S	28-Mar-25	11:18:26 AM	59	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:18:26 AM	30	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:18:26 AM	5	1377.50	AQEU
GENMAB A/S	28-Mar-25	11:18:45 AM	25	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:18:45 AM	3	1377.50	TQEX
GENMAB A/S	28-Mar-25	11:18:53 AM	53	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:18:53 AM	19	1377.50	TQEX
GENMAB A/S	28-Mar-25	11:19:04 AM	45	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:19:04 AM	15	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:20:00 AM	21	1376.50	TQEX
GENMAB A/S	28-Mar-25	11:20:01 AM	9	1377.00	XCSE
GENMAB A/S	28-Mar-25	11:20:01 AM	61	1377.00	XCSE
GENMAB A/S	28-Mar-25	11:21:14 AM	3	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:21:15 AM	18	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:21:15 AM	41	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:21:15 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:21:39 AM	25	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:21:39 AM	8	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:21:39 AM	38	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:23:33 AM	52	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:33 AM	49	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:33 AM	11	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:23:33 AM	20	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:23:52 AM	41	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:52 AM	13	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:52 AM	13	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:53 AM	11	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:53 AM	33	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:23:53 AM	26	1378.50	XCSE

150

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	11:24:37 AM	45	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:25:57 AM	35	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:25:57 AM	36	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:25:58 AM	1	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:26:42 AM	41	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:26:42 AM	41	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:26:42 AM	11	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:26:42 AM	31	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:28:06 AM	76	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:28:06 AM	41	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:28:06 AM	14	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:28:06 AM	66	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:28:06 AM	32	1378.50	TQEX
GENMAB A/S	28-Mar-25	11:28:06 AM	39	1378.50	AQEU
GENMAB A/S	28-Mar-25	11:28:47 AM	27	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:29:08 AM	34	1379.50	TQEX
GENMAB A/S	28-Mar-25	11:29:18 AM	36	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:30:28 AM	75	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:30:28 AM	28	1379.00	AQEU
GENMAB A/S	28-Mar-25	11:30:30 AM	41	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:30:30 AM	23	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:30:30 AM	1	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:31:58 AM	10	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:31:58 AM	7	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:31:58 AM	5	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:31:59 AM	1	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:31:59 AM	33	1378.50	TQEX
GENMAB A/S	28-Mar-25	11:32:00 AM	77	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:32:00 AM	5	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:32:00 AM	44	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:32:00 AM	30	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:32:00 AM	22	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:32:58 AM	26	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:32:58 AM	44	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:33:21 AM	14	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:33:22 AM	41	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:33:22 AM	11	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:33:27 AM	26	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:34:17 AM	52	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:34:46 AM	15	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:34:46 AM	25	1379.00	TQEX
GENMAB A/S	28-Mar-25	11:35:08 AM	68	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:35:08 AM	11	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:35:08 AM	32	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:35:10 AM	41	1379.00	XCSE

151

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	11:35:52 AM	11	1379.00	XCSE
GENMAB A/S	28-Mar-25	11:36:37 AM	24	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:36:37 AM	36	1379.00	CEUX
GENMAB A/S	28-Mar-25	11:36:47 AM	41	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:47 AM	31	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:47 AM	13	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:47 AM	12	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:47 AM	17	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:47 AM	12	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:47 AM	41	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	27	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	41	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	30	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	13	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	41	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	19	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:36:48 AM	11	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:37:21 AM	13	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:37:21 AM	37	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:37:55 AM	10	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:37:55 AM	12	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:37:55 AM	13	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:38:19 AM	9	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:38:19 AM	13	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:38:43 AM	12	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:38:43 AM	41	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:38:43 AM	31	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:38:50 AM	16	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:38:57 AM	34	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:39:03 AM	32	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:39:16 AM	32	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:40:12 AM	26	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:40:22 AM	44	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:40:22 AM	77	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:40:22 AM	50	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:40:22 AM	10	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:40:22 AM	69	1379.50	CEUX
GENMAB A/S	28-Mar-25	11:40:22 AM	39	1379.50	TQEX
GENMAB A/S	28-Mar-25	11:42:16 AM	5	1380.50	XCSE
GENMAB A/S	28-Mar-25	11:42:16 AM	80	1381.00	CEUX
GENMAB A/S	28-Mar-25	11:44:27 AM	18	1380.50	XCSE
GENMAB A/S	28-Mar-25	11:44:27 AM	73	1380.50	XCSE
GENMAB A/S	28-Mar-25	11:44:27 AM	22	1380.50	TQEX
GENMAB A/S	28-Mar-25	11:44:27 AM	22	1380.50	AQEU
GENMAB A/S	28-Mar-25	11:44:28 AM	43	1380.50	XCSE

152

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	11:44:38 AM	3	1380.50	CEUX
GENMAB A/S	28-Mar-25	11:44:38 AM	53	1380.50	CEUX
GENMAB A/S	28-Mar-25	11:45:05 AM	59	1380.00	CEUX
GENMAB A/S	28-Mar-25	11:45:05 AM	20	1380.00	CEUX
GENMAB A/S	28-Mar-25	11:45:37 AM	22	1380.00	XCSE
GENMAB A/S	28-Mar-25	11:45:37 AM	1	1380.00	XCSE
GENMAB A/S	28-Mar-25	11:46:46 AM	12	1380.00	AQEU
GENMAB A/S	28-Mar-25	11:47:13 AM	25	1380.00	AQEU
GENMAB A/S	28-Mar-25	11:47:21 AM	79	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:47:34 AM	24	1379.50	TQEX
GENMAB A/S	28-Mar-25	11:47:44 AM	23	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:47:44 AM	11	1379.50	XCSE
GENMAB A/S	28-Mar-25	11:47:55 AM	14	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:48:30 AM	14	1378.50	TQEX
GENMAB A/S	28-Mar-25	11:48:47 AM	58	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:49:57 AM	22	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:52:34 AM	21	1378.50	XCSE
GENMAB A/S	28-Mar-25	11:52:34 AM	28	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:52:35 AM	14	1378.50	CEUX
GENMAB A/S	28-Mar-25	11:52:35 AM	8	1378.50	TQEX
GENMAB A/S	28-Mar-25	11:54:27 AM	74	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:54:27 AM	36	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:54:27 AM	23	1377.50	TQEX
GENMAB A/S	28-Mar-25	11:54:28 AM	8	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:54:28 AM	31	1377.00	XCSE
GENMAB A/S	28-Mar-25	11:54:28 AM	36	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:54:29 AM	26	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:54:29 AM	43	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:54:29 AM	1	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:54:29 AM	53	1377.50	XCSE
GENMAB A/S	28-Mar-25	11:56:17 AM	12	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:56:17 AM	14	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:56:51 AM	16	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:56:51 AM	17	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:56:51 AM	12	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:56:51 AM	30	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:56:52 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:56:52 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:56:53 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:56:57 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:56:59 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:00 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:10 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	13	1378.00	XCSE

153

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	11:57:15 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:15 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:16 AM	14	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:57:17 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:17 AM	30	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:17 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:17 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:17 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:17 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:18 AM	37	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:18 AM	13	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:18 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:18 AM	35	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:57:29 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:29 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:55 AM	31	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:55 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:56 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:56 AM	11	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:56 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:56 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:56 AM	12	1377.50	CEUX
GENMAB A/S	28-Mar-25	11:57:57 AM	12	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:57:59 AM	7	1378.00	XCSE
GENMAB A/S	28-Mar-25	11:59:40 AM	46	1377.00	XCSE
GENMAB A/S	28-Mar-25	11:59:40 AM	79	1378.00	CEUX
GENMAB A/S	28-Mar-25	11:59:46 AM	6	1378.00	CEUX
GENMAB A/S	28-Mar-25	12:02:27 PM	20	1377.50	CEUX
GENMAB A/S	28-Mar-25	12:02:28 PM	44	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:28 PM	1	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	14	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	41	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	10	1376.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	13	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	15	1376.50	XCSE

154

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:02:46 PM	9	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	13	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	12	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	9	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	79	1376.00	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	41	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	4	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	30	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	16	1377.50	XCSE
GENMAB A/S	28-Mar-25	12:02:46 PM	36	1377.50	CEUX
GENMAB A/S	28-Mar-25	12:02:46 PM	20	1377.00	CEUX
GENMAB A/S	28-Mar-25	12:02:46 PM	44	1376.50	CEUX
GENMAB A/S	28-Mar-25	12:02:46 PM	34	1376.50	CEUX
GENMAB A/S	28-Mar-25	12:02:46 PM	5	1377.00	CEUX
GENMAB A/S	28-Mar-25	12:02:46 PM	5	1377.00	CEUX
GENMAB A/S	28-Mar-25	12:02:46 PM	11	1376.50	TQEX
GENMAB A/S	28-Mar-25	12:02:46 PM	15	1376.50	TQEX
GENMAB A/S	28-Mar-25	12:02:47 PM	18	1376.00	XCSE
GENMAB A/S	28-Mar-25	12:02:47 PM	19	1375.50	CEUX
GENMAB A/S	28-Mar-25	12:02:55 PM	33	1375.50	CEUX
GENMAB A/S	28-Mar-25	12:02:55 PM	22	1375.50	CEUX
GENMAB A/S	28-Mar-25	12:03:35 PM	41	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:03:35 PM	78	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:03:35 PM	15	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:03:35 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:03:35 PM	28	1375.00	TQEX
GENMAB A/S	28-Mar-25	12:03:37 PM	23	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:03:37 PM	54	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:03:38 PM	35	1374.50	XCSE
GENMAB A/S	28-Mar-25	12:03:38 PM	33	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:03:38 PM	43	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:03:38 PM	44	1374.50	XCSE
GENMAB A/S	28-Mar-25	12:03:38 PM	27	1374.00	TQEX
GENMAB A/S	28-Mar-25	12:06:43 PM	77	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:08:25 PM	23	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:09:07 PM	55	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:09:13 PM	30	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:09:13 PM	29	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:09:37 PM	50	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:10:46 PM	10	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:10:46 PM	20	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:10:46 PM	34	1375.00	CEUX
GENMAB A/S	28-Mar-25	12:11:17 PM	14	1375.00	CEUX
GENMAB A/S	28-Mar-25	12:11:45 PM	29	1375.00	CEUX
GENMAB A/S	28-Mar-25	12:11:58 PM	32	1375.00	TQEX

155

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:12:10 PM	2	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:10 PM	25	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:10 PM	41	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:10 PM	8	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:10 PM	3	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:10 PM	30	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:12 PM	4	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:12 PM	13	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:47 PM	23	1374.50	AQEU
GENMAB A/S	28-Mar-25	12:12:48 PM	32	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:48 PM	11	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:48 PM	39	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:48 PM	11	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:48 PM	15	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:12:49 PM	13	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:49 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:49 PM	41	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:49 PM	11	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:49 PM	13	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:49 PM	32	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:50 PM	11	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:50 PM	10	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:50 PM	13	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:50 PM	13	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:50 PM	13	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:51 PM	5	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:51 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:12:51 PM	28	1375.00	XCSE
GENMAB A/S	28-Mar-25	12:13:03 PM	16	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:13:03 PM	58	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:13:03 PM	75	1373.50	XCSE
GENMAB A/S	28-Mar-25	12:13:03 PM	61	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:13:03 PM	10	1372.00	CEUX
GENMAB A/S	28-Mar-25	12:13:03 PM	70	1372.00	CEUX
GENMAB A/S	28-Mar-25	12:13:03 PM	79	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:13:03 PM	27	1372.50	TQEX
GENMAB A/S	28-Mar-25	12:13:03 PM	3	1372.50	TQEX
GENMAB A/S	28-Mar-25	12:13:03 PM	22	1373.50	TQEX
GENMAB A/S	28-Mar-25	12:13:03 PM	23	1373.50	AQEU
GENMAB A/S	28-Mar-25	12:13:03 PM	18	1372.00	AQEU
GENMAB A/S	28-Mar-25	12:13:03 PM	4	1372.00	AQEU
GENMAB A/S	28-Mar-25	12:13:04 PM	15	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:13:04 PM	18	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:13:18 PM	44	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:13:18 PM	24	1371.50	TQEX

156

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:14:23 PM	3	1371.50	TQEX
GENMAB A/S	28-Mar-25	12:18:22 PM	44	1371.50	CEUX
GENMAB A/S	28-Mar-25	12:18:47 PM	5	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	11	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	12	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	30	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	30	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	35	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	12	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	24	1371.50	XCSE
GENMAB A/S	28-Mar-25	12:18:47 PM	43	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:18:48 PM	74	1370.50	XCSE
GENMAB A/S	28-Mar-25	12:18:48 PM	74	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:18:48 PM	6	1369.00	CEUX
GENMAB A/S	28-Mar-25	12:18:48 PM	77	1370.50	CEUX
GENMAB A/S	28-Mar-25	12:18:48 PM	55	1369.00	CEUX
GENMAB A/S	28-Mar-25	12:18:48 PM	31	1370.50	TQEX
GENMAB A/S	28-Mar-25	12:19:10 PM	8	1368.50	XCSE
GENMAB A/S	28-Mar-25	12:19:10 PM	60	1368.50	XCSE
GENMAB A/S	28-Mar-25	12:20:42 PM	75	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:24:21 PM	53	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:24:21 PM	1	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:24:21 PM	6	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:24:21 PM	9	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:25:21 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:25:21 PM	19	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:25:21 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:26:10 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:26:10 PM	22	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:26:57 PM	42	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:32:27 PM	1	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:32:27 PM	53	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:32:27 PM	16	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:32:27 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:32:28 PM	11	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:32:39 PM	12	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:32:39 PM	48	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:32:39 PM	39	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:32:53 PM	12	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:32:53 PM	46	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:32:53 PM	43	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:34:17 PM	32	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:34:17 PM	77	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:34:17 PM	14	1372.50	TQEX
GENMAB A/S	28-Mar-25	12:34:17 PM	25	1372.50	TQEX

157

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:34:44 PM	15	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:34:44 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	42	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	22	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	30	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	50	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	32	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	30	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	21	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	16	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:35:33 PM	4	1372.00	AQEU
GENMAB A/S	28-Mar-25	12:35:34 PM	2	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:34 PM	8	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:34 PM	12	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:34 PM	11	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:34 PM	1	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:35 PM	12	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:35 PM	11	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:35 PM	30	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:35 PM	30	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:36 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:36 PM	2	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:35:36 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:36 PM	37	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:35:36 PM	30	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:36:27 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:36:27 PM	42	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:36:27 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:36:27 PM	32	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:37:11 PM	11	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:37:11 PM	11	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:37:11 PM	32	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:38:00 PM	2	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:38:24 PM	96	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:38:28 PM	4	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:38:28 PM	59	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:38:32 PM	10	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:39:21 PM	74	1372.50	XCSE
GENMAB A/S	28-Mar-25	12:39:21 PM	1	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:41:44 PM	25	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:41:44 PM	5	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:41:44 PM	70	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:41:44 PM	44	1374.50	TQEX
GENMAB A/S	28-Mar-25	12:41:44 PM	22	1374.50	AQEU
GENMAB A/S	28-Mar-25	12:41:45 PM	1	1374.50	XCSE

158

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:41:45 PM	1	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:42:28 PM	36	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:43:00 PM	10	1374.50	CEUX
GENMAB A/S	28-Mar-25	12:45:47 PM	78	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:48:15 PM	1	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:48:15 PM	36	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:48:17 PM	6	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:48:28 PM	5	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:48:35 PM	10	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:48:37 PM	35	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:48:37 PM	25	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:48:37 PM	10	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:48:37 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:48:37 PM	3	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:48:38 PM	1	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:50:00 PM	10	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:50:30 PM	5	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:50:30 PM	5	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:50:43 PM	1	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:00 PM	10	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:18 PM	6	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:18 PM	6	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:18 PM	5	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:45 PM	6	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:45 PM	6	1373.50	CEUX
GENMAB A/S	28-Mar-25	12:51:45 PM	6	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:45 PM	6	1374.00	CEUX
GENMAB A/S	28-Mar-25	12:51:52 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:52 PM	41	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:52 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:53 PM	12	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:53 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:54 PM	7	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:54 PM	12	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:54 PM	12	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:55 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:55 PM	10	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:55 PM	30	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:55 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:56 PM	30	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:56 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:56 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:59 PM	74	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:51:59 PM	16	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:59 PM	30	1374.00	XCSE

159

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:51:59 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:59 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	12:51:59 PM	70	1373.50	CEUX
GENMAB A/S	28-Mar-25	12:51:59 PM	35	1373.50	CEUX
GENMAB A/S	28-Mar-25	12:51:59 PM	36	1373.50	CEUX
GENMAB A/S	28-Mar-25	12:51:59 PM	30	1373.50	CEUX
GENMAB A/S	28-Mar-25	12:51:59 PM	45	1373.50	TQEX
GENMAB A/S	28-Mar-25	12:51:59 PM	25	1373.00	AQEU
GENMAB A/S	28-Mar-25	12:52:00 PM	49	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:00 PM	11	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:00 PM	36	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:52:00 PM	6	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:52:00 PM	6	1373.00	CEUX
GENMAB A/S	28-Mar-25	12:52:00 PM	34	1373.50	CEUX
GENMAB A/S	28-Mar-25	12:52:02 PM	3	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:02 PM	42	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:04 PM	2	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:04 PM	30	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:04 PM	42	1373.00	XCSE
GENMAB A/S	28-Mar-25	12:52:14 PM	77	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:52:14 PM	101	1372.00	XCSE
GENMAB A/S	28-Mar-25	12:52:14 PM	79	1372.50	CEUX
GENMAB A/S	28-Mar-25	12:52:14 PM	37	1372.50	TQEX
GENMAB A/S	28-Mar-25	12:52:14 PM	19	1372.00	AQEU
GENMAB A/S	28-Mar-25	12:52:33 PM	76	1370.50	XCSE
GENMAB A/S	28-Mar-25	12:52:33 PM	45	1371.00	CEUX
GENMAB A/S	28-Mar-25	12:52:33 PM	34	1371.00	CEUX
GENMAB A/S	28-Mar-25	12:52:33 PM	32	1371.00	TQEX
GENMAB A/S	28-Mar-25	12:52:36 PM	79	1370.00	CEUX
GENMAB A/S	28-Mar-25	12:52:36 PM	42	1370.00	TQEX
GENMAB A/S	28-Mar-25	12:52:36 PM	28	1370.00	AQEU
GENMAB A/S	28-Mar-25	12:52:38 PM	46	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:52:38 PM	30	1369.50	XCSE
GENMAB A/S	28-Mar-25	12:54:59 PM	34	1370.00	CEUX
GENMAB A/S	28-Mar-25	12:54:59 PM	26	1370.00	CEUX
GENMAB A/S	28-Mar-25	12:55:00 PM	30	1370.00	XCSE
GENMAB A/S	28-Mar-25	12:55:00 PM	8	1370.00	XCSE
GENMAB A/S	28-Mar-25	12:55:00 PM	9	1370.00	XCSE
GENMAB A/S	28-Mar-25	12:55:00 PM	3	1370.00	CEUX
GENMAB A/S	28-Mar-25	12:55:00 PM	15	1370.00	CEUX
GENMAB A/S	28-Mar-25	12:55:00 PM	16	1370.00	TQEX
GENMAB A/S	28-Mar-25	12:57:17 PM	79	1370.00	XCSE
GENMAB A/S	28-Mar-25	12:57:17 PM	1	1370.00	XCSE
GENMAB A/S	28-Mar-25	12:57:17 PM	9	1370.00	XCSE
GENMAB A/S	28-Mar-25	12:57:17 PM	42	1370.00	XCSE

160

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	12:57:17 PM	10	1370.00	TQEX
GENMAB A/S	28-Mar-25	12:57:45 PM	26	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:57:45 PM	10	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:57:46 PM	11	1371.00	XCSE
GENMAB A/S	28-Mar-25	12:57:48 PM	58	1371.00	XCSE
GENMAB A/S	28-Mar-25	1:00:07 PM	78	1370.00	CEUX
GENMAB A/S	28-Mar-25	1:01:17 PM	72	1369.50	XCSE
GENMAB A/S	28-Mar-25	1:02:46 PM	42	1369.50	XCSE
GENMAB A/S	28-Mar-25	1:02:46 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	1:02:46 PM	4	1369.50	XCSE
GENMAB A/S	28-Mar-25	1:02:46 PM	44	1369.50	XCSE
GENMAB A/S	28-Mar-25	1:02:46 PM	35	1369.50	AQEU
GENMAB A/S	28-Mar-25	1:05:17 PM	12	1369.50	CEUX
GENMAB A/S	28-Mar-25	1:05:18 PM	33	1369.50	CEUX
GENMAB A/S	28-Mar-25	1:05:18 PM	38	1369.50	CEUX
GENMAB A/S	28-Mar-25	1:05:29 PM	6	1369.00	CEUX
GENMAB A/S	28-Mar-25	1:05:43 PM	32	1369.00	CEUX
GENMAB A/S	28-Mar-25	1:06:13 PM	32	1369.00	CEUX
GENMAB A/S	28-Mar-25	1:06:35 PM	11	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:06:35 PM	42	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:06:35 PM	5	1369.00	CEUX
GENMAB A/S	28-Mar-25	1:06:35 PM	16	1369.00	TQEX
GENMAB A/S	28-Mar-25	1:06:35 PM	6	1369.00	TQEX
GENMAB A/S	28-Mar-25	1:06:36 PM	15	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:06:36 PM	19	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:06:36 PM	42	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	9	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	12	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	25	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	32	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	42	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	16	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	11	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	7	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	6	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	6	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	78	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	11	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	42	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	18	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:16 PM	3	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:37 PM	32	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:07:38 PM	33	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:38 PM	4	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:51 PM	12	1369.00	XCSE

161

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	1:07:51 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	1:07:54 PM	4	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:08:21 PM	42	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:08:21 PM	43	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:08:21 PM	13	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:08:21 PM	1	1368.50	XCSE
GENMAB A/S	28-Mar-25	1:08:38 PM	32	1368.50	CEUX
GENMAB A/S	28-Mar-25	1:08:57 PM	14	1368.00	TQEX
GENMAB A/S	28-Mar-25	1:08:57 PM	13	1368.00	TQEX
GENMAB A/S	28-Mar-25	1:09:28 PM	28	1368.00	CEUX
GENMAB A/S	28-Mar-25	1:09:28 PM	12	1368.00	CEUX
GENMAB A/S	28-Mar-25	1:09:28 PM	32	1368.00	CEUX
GENMAB A/S	28-Mar-25	1:09:28 PM	30	1368.00	CEUX
GENMAB A/S	28-Mar-25	1:11:19 PM	77	1367.50	XCSE
GENMAB A/S	28-Mar-25	1:11:19 PM	24	1367.50	XCSE
GENMAB A/S	28-Mar-25	1:11:19 PM	79	1367.50	CEUX
GENMAB A/S	28-Mar-25	1:14:17 PM	60	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:14:17 PM	41	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:14:17 PM	25	1367.00	TQEX
GENMAB A/S	28-Mar-25	1:16:27 PM	74	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:16:28 PM	15	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:16:28 PM	1	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:16:28 PM	48	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:16:28 PM	35	1366.50	CEUX
GENMAB A/S	28-Mar-25	1:16:31 PM	9	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:16:31 PM	48	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:16:31 PM	44	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:16:31 PM	79	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:16:31 PM	42	1366.50	CEUX
GENMAB A/S	28-Mar-25	1:16:58 PM	10	1368.00	CEUX
GENMAB A/S	28-Mar-25	1:17:18 PM	9	1368.00	XCSE
GENMAB A/S	28-Mar-25	1:17:18 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	1:17:18 PM	32	1368.00	CEUX
GENMAB A/S	28-Mar-25	1:17:39 PM	10	1368.00	XCSE
GENMAB A/S	28-Mar-25	1:17:39 PM	32	1368.00	XCSE
GENMAB A/S	28-Mar-25	1:17:39 PM	45	1367.50	XCSE
GENMAB A/S	28-Mar-25	1:17:39 PM	79	1368.00	XCSE
GENMAB A/S	28-Mar-25	1:17:39 PM	14	1367.50	XCSE
GENMAB A/S	28-Mar-25	1:17:39 PM	78	1367.50	CEUX
GENMAB A/S	28-Mar-25	1:17:39 PM	30	1367.50	TQEX
GENMAB A/S	28-Mar-25	1:17:40 PM	77	1367.00	XCSE
GENMAB A/S	28-Mar-25	1:17:41 PM	9	1366.50	CEUX
GENMAB A/S	28-Mar-25	1:18:47 PM	69	1366.50	CEUX
GENMAB A/S	28-Mar-25	1:18:47 PM	29	1366.50	TQEX
GENMAB A/S	28-Mar-25	1:20:10 PM	54	1366.50	CEUX

162

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	1:20:10 PM	22	1366.50	CEUX
GENMAB A/S	28-Mar-25	1:20:10 PM	22	1366.50	TQEX
GENMAB A/S	28-Mar-25	1:20:11 PM	75	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:20:11 PM	76	1365.50	CEUX
GENMAB A/S	28-Mar-25	1:20:11 PM	25	1366.00	AQEU
GENMAB A/S	28-Mar-25	1:20:13 PM	22	1365.00	AQEU
GENMAB A/S	28-Mar-25	1:23:39 PM	48	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:23:39 PM	30	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:23:39 PM	1	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:23:45 PM	8	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:24:35 PM	78	1365.00	CEUX
GENMAB A/S	28-Mar-25	1:24:35 PM	28	1365.00	TQEX
GENMAB A/S	28-Mar-25	1:24:40 PM	18	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:24:40 PM	25	1365.00	AQEU
GENMAB A/S	28-Mar-25	1:24:41 PM	20	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:24:42 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:24:42 PM	48	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:25:08 PM	48	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:25:08 PM	1	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:25:08 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:25:08 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:25:19 PM	79	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:26:26 PM	13	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:26:26 PM	9	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:26:31 PM	31	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:26:51 PM	1	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:26:51 PM	4	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:27:46 PM	20	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:27:46 PM	34	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:27:46 PM	11	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:27:46 PM	24	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:27:46 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:27:50 PM	31	1364.00	CEUX
GENMAB A/S	28-Mar-25	1:27:50 PM	43	1364.00	CEUX
GENMAB A/S	28-Mar-25	1:27:52 PM	20	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:28:43 PM	34	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:28:43 PM	18	1363.50	TQEX
GENMAB A/S	28-Mar-25	1:28:43 PM	4	1363.50	TQEX
GENMAB A/S	28-Mar-25	1:30:26 PM	11	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:30:26 PM	1	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:30:27 PM	25	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:30:27 PM	46	1363.00	CEUX
GENMAB A/S	28-Mar-25	1:30:27 PM	32	1363.00	CEUX
GENMAB A/S	28-Mar-25	1:30:29 PM	1	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:30:37 PM	5	1362.50	XCSE

163

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	1:30:37 PM	45	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:30:37 PM	23	1362.00	TQEX
GENMAB A/S	28-Mar-25	1:30:37 PM	1	1362.00	TQEX
GENMAB A/S	28-Mar-25	1:30:53 PM	12	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:30:54 PM	11	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:32:14 PM	27	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:32:19 PM	32	1363.00	TQEX
GENMAB A/S	28-Mar-25	1:32:25 PM	83	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:32:25 PM	48	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:32:26 PM	13	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:34:03 PM	12	1362.00	XCSE
GENMAB A/S	28-Mar-25	1:34:03 PM	47	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:34:03 PM	41	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:34:03 PM	48	1362.00	XCSE
GENMAB A/S	28-Mar-25	1:34:03 PM	11	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:34:03 PM	75	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:34:03 PM	12	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:34:31 PM	9	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:34:31 PM	13	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:34:41 PM	13	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:34:41 PM	12	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:34:41 PM	8	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:35:28 PM	14	1362.00	CEUX
GENMAB A/S	28-Mar-25	1:37:08 PM	13	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:08 PM	48	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:08 PM	76	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:08 PM	11	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:08 PM	18	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:37:08 PM	34	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:37:08 PM	24	1360.50	TQEX
GENMAB A/S	28-Mar-25	1:37:09 PM	12	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:37:23 PM	13	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:23 PM	11	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:23 PM	11	1361.50	XCSE
GENMAB A/S	28-Mar-25	1:37:23 PM	30	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:37:23 PM	32	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:37:46 PM	65	1362.00	XCSE
GENMAB A/S	28-Mar-25	1:37:46 PM	12	1362.00	XCSE
GENMAB A/S	28-Mar-25	1:37:46 PM	14	1362.00	AQEU
GENMAB A/S	28-Mar-25	1:37:46 PM	8	1362.00	AQEU
GENMAB A/S	28-Mar-25	1:38:53 PM	79	1362.00	XCSE
GENMAB A/S	28-Mar-25	1:38:53 PM	32	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:38:53 PM	47	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:38:53 PM	80	1361.50	CEUX
GENMAB A/S	28-Mar-25	1:38:53 PM	22	1362.00	TQEX

164

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	1:38:53 PM	23	1361.00	AQEU
GENMAB A/S	28-Mar-25	1:38:53 PM	28	1362.00	AQEU
GENMAB A/S	28-Mar-25	1:40:54 PM	12	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:40:54 PM	36	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:40:54 PM	13	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:40:54 PM	1	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:40:54 PM	39	1361.00	XCSE
GENMAB A/S	28-Mar-25	1:42:37 PM	23	1362.50	AQEU
GENMAB A/S	28-Mar-25	1:43:00 PM	34	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:00 PM	44	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:00 PM	25	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:43:00 PM	12	1362.50	TQEX
GENMAB A/S	28-Mar-25	1:43:25 PM	29	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:43:26 PM	13	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:26 PM	43	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:26 PM	7	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:26 PM	16	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:26 PM	10	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:43:26 PM	22	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:43:38 PM	26	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:43:41 PM	12	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:41 PM	43	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:43:41 PM	6	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:44:18 PM	3	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:44:18 PM	12	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:44:18 PM	2	1362.50	CEUX
GENMAB A/S	28-Mar-25	1:44:25 PM	1	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:44:25 PM	2	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:44:25 PM	1	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:44:45 PM	12	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:44:45 PM	8	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:44:51 PM	10	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:45:26 PM	5	1363.00	XCSE
GENMAB A/S	28-Mar-25	1:46:05 PM	31	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:05 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:05 PM	13	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:05 PM	2	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:05 PM	9	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:06 PM	14	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:06 PM	8	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:06 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:06 PM	1	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:06 PM	1	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:21 PM	11	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:21 PM	11	1363.50	XCSE

165

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	1:46:41 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:41 PM	9	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:41 PM	13	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:46:53 PM	25	1362.50	XCSE
GENMAB A/S	28-Mar-25	1:47:16 PM	5	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:16 PM	11	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:16 PM	24	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:16 PM	6	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:16 PM	17	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:17 PM	22	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:17 PM	17	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:17 PM	8	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:21 PM	5	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:47:21 PM	41	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:47:38 PM	1	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:47:38 PM	23	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:48:25 PM	7	1363.50	XCSE
GENMAB A/S	28-Mar-25	1:48:25 PM	10	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:49:25 PM	25	1363.50	CEUX
GENMAB A/S	28-Mar-25	1:50:09 PM	34	1365.00	CEUX
GENMAB A/S	28-Mar-25	1:50:09 PM	15	1365.00	CEUX
GENMAB A/S	28-Mar-25	1:50:09 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	1:50:09 PM	23	1365.00	CEUX
GENMAB A/S	28-Mar-25	1:50:09 PM	13	1365.00	TQEX
GENMAB A/S	28-Mar-25	1:53:11 PM	34	1365.50	CEUX
GENMAB A/S	28-Mar-25	1:53:11 PM	1	1365.50	AQEU
GENMAB A/S	28-Mar-25	1:53:11 PM	21	1365.50	AQEU
GENMAB A/S	28-Mar-25	1:53:33 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:53:33 PM	15	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:53:33 PM	9	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:53:33 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:53:34 PM	7	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:00 PM	33	1366.00	TQEX
GENMAB A/S	28-Mar-25	1:54:12 PM	43	1365.50	CEUX
GENMAB A/S	28-Mar-25	1:54:14 PM	17	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:14 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:14 PM	36	1366.00	CEUX
GENMAB A/S	28-Mar-25	1:54:14 PM	6	1366.00	CEUX
GENMAB A/S	28-Mar-25	1:54:14 PM	80	1366.00	CEUX
GENMAB A/S	28-Mar-25	1:54:15 PM	36	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:15 PM	14	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:26 PM	41	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:26 PM	23	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:26 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:26 PM	10	1366.00	XCSE

166

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	1:54:27 PM	26	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:54:27 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	1	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	3	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:00 PM	42	1366.50	XCSE
GENMAB A/S	28-Mar-25	1:55:19 PM	36	1366.00	CEUX
GENMAB A/S	28-Mar-25	1:55:31 PM	19	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:55:31 PM	44	1366.00	XCSE
GENMAB A/S	28-Mar-25	1:55:31 PM	24	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:55:31 PM	51	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:55:31 PM	43	1366.00	CEUX
GENMAB A/S	28-Mar-25	1:55:31 PM	79	1366.00	CEUX
GENMAB A/S	28-Mar-25	1:55:31 PM	3	1366.00	TQEX
GENMAB A/S	28-Mar-25	1:55:31 PM	33	1366.00	TQEX
GENMAB A/S	28-Mar-25	1:55:31 PM	29	1366.00	TQEX
GENMAB A/S	28-Mar-25	1:56:57 PM	36	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:56:57 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:56:57 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:56:57 PM	5	1365.50	AQEU
GENMAB A/S	28-Mar-25	1:56:58 PM	100	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:56:58 PM	14	1365.50	XCSE
GENMAB A/S	28-Mar-25	1:57:19 PM	80	1365.00	CEUX
GENMAB A/S	28-Mar-25	1:57:41 PM	8	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:57:41 PM	41	1365.00	XCSE
GENMAB A/S	28-Mar-25	1:58:46 PM	76	1364.50	XCSE
GENMAB A/S	28-Mar-25	1:58:46 PM	23	1365.00	TQEX
GENMAB A/S	28-Mar-25	1:58:46 PM	6	1364.50	AQEU
GENMAB A/S	28-Mar-25	1:58:48 PM	21	1365.50	AQEU
GENMAB A/S	28-Mar-25	2:00:55 PM	42	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:00:55 PM	1	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:00:55 PM	18	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:00:55 PM	30	1367.50	AQEU
GENMAB A/S	28-Mar-25	2:01:28 PM	40	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:01:28 PM	53	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:01:28 PM	8	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:01:45 PM	25	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:02:05 PM	42	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:02:05 PM	13	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:02:05 PM	30	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:02:36 PM	74	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:03:08 PM	11	1367.00	CEUX

167

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:03:08 PM	1	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:03:28 PM	10	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:03:28 PM	12	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:04:25 PM	32	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:04:35 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:04:35 PM	20	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:04:35 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:04:45 PM	20	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:04:45 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:04:45 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:04:45 PM	78	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:04:45 PM	27	1366.50	TQEX
GENMAB A/S	28-Mar-25	2:05:12 PM	30	1366.50	AQEU
GENMAB A/S	28-Mar-25	2:05:21 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:05:21 PM	31	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:05:51 PM	23	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:05:51 PM	1	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:05:51 PM	10	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:05:51 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:05:51 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:06:41 PM	75	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:06:41 PM	34	1365.00	XCSE
GENMAB A/S	28-Mar-25	2:06:41 PM	78	1365.00	XCSE
GENMAB A/S	28-Mar-25	2:06:41 PM	74	1365.50	CEUX
GENMAB A/S	28-Mar-25	2:06:41 PM	20	1364.00	CEUX
GENMAB A/S	28-Mar-25	2:06:41 PM	14	1364.00	CEUX
GENMAB A/S	28-Mar-25	2:06:41 PM	24	1365.50	TQEX
GENMAB A/S	28-Mar-25	2:06:41 PM	2	1365.00	TQEX
GENMAB A/S	28-Mar-25	2:06:41 PM	23	1365.00	AQEU
GENMAB A/S	28-Mar-25	2:06:41 PM	2	1364.00	AQEU
GENMAB A/S	28-Mar-25	2:06:41 PM	2	1366.50	AQEU
GENMAB A/S	28-Mar-25	2:06:41 PM	23	1365.50	AQEU
GENMAB A/S	28-Mar-25	2:06:41 PM	29	1364.00	AQEU
GENMAB A/S	28-Mar-25	2:07:46 PM	4	1364.00	CEUX
GENMAB A/S	28-Mar-25	2:08:37 PM	34	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:08:37 PM	43	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:09:47 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:09:47 PM	22	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:09:47 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:04 PM	72	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:11:04 PM	4	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:11:04 PM	29	1366.50	TQEX
GENMAB A/S	28-Mar-25	2:11:04 PM	29	1366.50	AQEU
GENMAB A/S	28-Mar-25	2:11:05 PM	44	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:11:31 PM	23	1367.00	XCSE

168

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:11:31 PM	1	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:31 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:31 PM	14	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:31 PM	24	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:32 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:32 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:32 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:32 PM	24	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:11:32 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:12:11 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:12:11 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:13:25 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:13:25 PM	32	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:13:58 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:13:58 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:13:58 PM	42	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:13:58 PM	2	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:13:58 PM	26	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:13:58 PM	75	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:13:58 PM	80	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:13:58 PM	23	1366.50	TQEX
GENMAB A/S	28-Mar-25	2:13:58 PM	29	1366.50	AQEU
GENMAB A/S	28-Mar-25	2:14:13 PM	20	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:14:13 PM	43	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:14:51 PM	47	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:15:25 PM	21	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:15:25 PM	1	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:15:41 PM	43	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:15:41 PM	6	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:15:41 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:16:00 PM	21	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:16:00 PM	55	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:16:25 PM	3	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:16:26 PM	14	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:16:47 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:16:47 PM	11	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:16:47 PM	11	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:17:01 PM	74	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:17:04 PM	22	1366.50	TQEX
GENMAB A/S	28-Mar-25	2:17:28 PM	9	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:17:28 PM	56	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:17:28 PM	36	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:17:50 PM	26	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:17:50 PM	52	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:18:25 PM	11	1366.00	XCSE

169

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:18:25 PM	24	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:18:25 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:18:27 PM	37	1365.00	XCSE
GENMAB A/S	28-Mar-25	2:18:27 PM	20	1364.50	XCSE
GENMAB A/S	28-Mar-25	2:18:27 PM	79	1365.50	XCSE
GENMAB A/S	28-Mar-25	2:18:27 PM	65	1365.00	CEUX
GENMAB A/S	28-Mar-25	2:18:27 PM	14	1365.00	CEUX
GENMAB A/S	28-Mar-25	2:18:27 PM	30	1365.00	TQEX
GENMAB A/S	28-Mar-25	2:18:27 PM	22	1365.50	AQEU
GENMAB A/S	28-Mar-25	2:18:37 PM	44	1364.50	XCSE
GENMAB A/S	28-Mar-25	2:18:37 PM	10	1364.50	XCSE
GENMAB A/S	28-Mar-25	2:18:37 PM	27	1364.50	AQEU
GENMAB A/S	28-Mar-25	2:18:39 PM	34	1364.00	CEUX
GENMAB A/S	28-Mar-25	2:19:09 PM	6	1364.00	CEUX
GENMAB A/S	28-Mar-25	2:19:16 PM	76	1363.50	XCSE
GENMAB A/S	28-Mar-25	2:19:16 PM	22	1363.50	TQEX
GENMAB A/S	28-Mar-25	2:22:27 PM	74	1365.50	XCSE
GENMAB A/S	28-Mar-25	2:23:25 PM	46	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:23:25 PM	34	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:23:43 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:23:43 PM	67	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:23:43 PM	78	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:23:43 PM	31	1367.00	TQEX
GENMAB A/S	28-Mar-25	2:23:43 PM	17	1367.00	AQEU
GENMAB A/S	28-Mar-25	2:23:43 PM	3	1367.00	AQEU
GENMAB A/S	28-Mar-25	2:23:43 PM	7	1367.00	AQEU
GENMAB A/S	28-Mar-25	2:24:00 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:24:30 PM	14	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:24:30 PM	30	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:24:30 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:25:26 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:25:48 PM	12	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:25:48 PM	10	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:25:48 PM	5	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:25:48 PM	29	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:26:17 PM	79	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:26:23 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:26:23 PM	14	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:27:50 PM	32	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:27:50 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:27:50 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:27:50 PM	5	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:27:50 PM	29	1367.50	CEUX
GENMAB A/S	28-Mar-25	2:27:50 PM	37	1367.50	CEUX
GENMAB A/S	28-Mar-25	2:27:50 PM	30	1367.50	CEUX

170

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:27:50 PM	41	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:27:50 PM	5	1367.50	CEUX
GENMAB A/S	28-Mar-25	2:27:50 PM	34	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:27:50 PM	22	1367.00	TQEX
GENMAB A/S	28-Mar-25	2:27:50 PM	22	1367.00	AQEU
GENMAB A/S	28-Mar-25	2:28:25 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:25 PM	76	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:25 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:28:25 PM	42	1366.50	XCSE
GENMAB A/S	28-Mar-25	2:28:25 PM	10	1366.00	AQEU
GENMAB A/S	28-Mar-25	2:28:41 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:41 PM	29	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:41 PM	30	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:41 PM	25	1366.00	TQEX
GENMAB A/S	28-Mar-25	2:28:41 PM	14	1366.00	AQEU
GENMAB A/S	28-Mar-25	2:28:44 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:44 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:44 PM	21	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:44 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:28:48 PM	32	1366.00	CEUX
GENMAB A/S	28-Mar-25	2:29:05 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:29:05 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	2:30:00 PM	10	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:30:00 PM	7	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:30:00 PM	42	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:30:00 PM	26	1367.00	XCSE
GENMAB A/S	28-Mar-25	2:30:00 PM	16	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:30:00 PM	10	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:30:00 PM	30	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:30:00 PM	34	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:30:00 PM	5	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:30:00 PM	11	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:30:00 PM	2	1366.50	CEUX
GENMAB A/S	28-Mar-25	2:30:00 PM	10	1367.00	CEUX
GENMAB A/S	28-Mar-25	2:30:01 PM	101	1367.50	XCSE
GENMAB A/S	28-Mar-25	2:30:20 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:20 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:20 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:20 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:20 PM	3	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:20 PM	5	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:29 PM	16	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:30:29 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:30:29 PM	7	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:30:29 PM	12	1368.50	XCSE

171

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:30:29 PM	42	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:30:37 PM	30	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:37 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:38 PM	5	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:38 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:38 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:38 PM	10	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:38 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:30:38 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:31:12 PM	75	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:31:12 PM	75	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:31:12 PM	36	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:31:12 PM	10	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:31:12 PM	11	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:31:12 PM	33	1370.50	TQEX
GENMAB A/S	28-Mar-25	2:31:12 PM	22	1370.50	AQEU
GENMAB A/S	28-Mar-25	2:31:16 PM	42	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:31:16 PM	20	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:31:16 PM	36	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:31:16 PM	2	1370.50	TQEX
GENMAB A/S	28-Mar-25	2:31:16 PM	22	1370.50	TQEX
GENMAB A/S	28-Mar-25	2:31:16 PM	34	1370.50	AQEU
GENMAB A/S	28-Mar-25	2:31:26 PM	2	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:31:31 PM	46	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:31:31 PM	24	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:31:47 PM	20	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:32:17 PM	62	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:32:17 PM	14	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:32:17 PM	15	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:32:17 PM	36	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:32:25 PM	18	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:32:49 PM	44	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:32:49 PM	80	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:32:49 PM	3	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:32:49 PM	36	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:32:49 PM	29	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:32:49 PM	48	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:32:49 PM	22	1371.50	TQEX
GENMAB A/S	28-Mar-25	2:32:49 PM	31	1371.50	AQEU
GENMAB A/S	28-Mar-25	2:33:05 PM	8	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:33:05 PM	14	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:33:05 PM	32	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:33:09 PM	42	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:33:09 PM	12	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:33:24 PM	17	1371.00	XCSE

172

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:33:24 PM	12	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:33:24 PM	64	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:33:24 PM	42	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:33:24 PM	10	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:33:24 PM	30	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:33:24 PM	74	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:33:24 PM	28	1370.50	TQEX
GENMAB A/S	28-Mar-25	2:33:27 PM	79	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:33:40 PM	78	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:33:59 PM	30	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:33:59 PM	25	1370.50	TQEX
GENMAB A/S	28-Mar-25	2:34:17 PM	75	1369.50	XCSE
GENMAB A/S	28-Mar-25	2:34:17 PM	76	1369.50	CEUX
GENMAB A/S	28-Mar-25	2:34:17 PM	34	1369.50	TQEX
GENMAB A/S	28-Mar-25	2:34:38 PM	27	1369.50	CEUX
GENMAB A/S	28-Mar-25	2:34:38 PM	1	1369.50	CEUX
GENMAB A/S	28-Mar-25	2:34:38 PM	22	1369.50	CEUX
GENMAB A/S	28-Mar-25	2:35:25 PM	3	1370.00	CEUX
GENMAB A/S	28-Mar-25	2:35:25 PM	30	1370.00	CEUX
GENMAB A/S	28-Mar-25	2:35:26 PM	3	1370.00	CEUX
GENMAB A/S	28-Mar-25	2:35:26 PM	58	1370.00	CEUX
GENMAB A/S	28-Mar-25	2:35:35 PM	78	1369.50	CEUX
GENMAB A/S	28-Mar-25	2:35:35 PM	22	1369.50	TQEX
GENMAB A/S	28-Mar-25	2:35:42 PM	42	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	14	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	50	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	9	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	19	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	42	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:42 PM	76	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:35:51 PM	42	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:35:51 PM	1	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:35:51 PM	18	1368.50	AQEU
GENMAB A/S	28-Mar-25	2:35:51 PM	4	1368.50	AQEU
GENMAB A/S	28-Mar-25	2:35:57 PM	4	1368.50	XCSE
GENMAB A/S	28-Mar-25	2:35:57 PM	1	1368.50	AQEU
GENMAB A/S	28-Mar-25	2:36:01 PM	75	1368.00	XCSE
GENMAB A/S	28-Mar-25	2:36:01 PM	80	1368.00	CEUX
GENMAB A/S	28-Mar-25	2:36:12 PM	25	1368.00	TQEX
GENMAB A/S	28-Mar-25	2:38:27 PM	62	1370.00	XCSE
GENMAB A/S	28-Mar-25	2:38:32 PM	35	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:38:33 PM	30	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:38:33 PM	14	1371.00	CEUX

173

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:38:56 PM	38	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:38:56 PM	10	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:38:56 PM	13	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:39:19 PM	38	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:39:19 PM	15	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:40:47 PM	36	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:40:47 PM	78	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:40:47 PM	26	1373.00	AQEU
GENMAB A/S	28-Mar-25	2:41:07 PM	23	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:07 PM	54	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:07 PM	36	1372.50	TQEX
GENMAB A/S	28-Mar-25	2:41:08 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:08 PM	12	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:08 PM	12	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:08 PM	5	1372.50	CEUX
GENMAB A/S	28-Mar-25	2:41:08 PM	6	1372.50	CEUX
GENMAB A/S	28-Mar-25	2:41:08 PM	36	1372.50	CEUX
GENMAB A/S	28-Mar-25	2:41:09 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:09 PM	4	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:09 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:41:09 PM	61	1372.50	CEUX
GENMAB A/S	28-Mar-25	2:42:01 PM	76	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:42:05 PM	62	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:05 PM	36	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:42:06 PM	36	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:42:06 PM	5	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:42:14 PM	36	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:42:15 PM	16	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:15 PM	32	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:42:26 PM	13	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:26 PM	13	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:26 PM	44	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:26 PM	11	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:26 PM	11	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:42:28 PM	54	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:43:16 PM	74	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:43:22 PM	78	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:43:22 PM	5	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:43:22 PM	80	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:43:22 PM	39	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:43:22 PM	11	1371.00	TQEX
GENMAB A/S	28-Mar-25	2:43:22 PM	49	1372.00	TQEX
GENMAB A/S	28-Mar-25	2:43:22 PM	41	1371.00	TQEX
GENMAB A/S	28-Mar-25	2:43:22 PM	3	1371.00	TQEX
GENMAB A/S	28-Mar-25	2:43:22 PM	11	1371.00	TQEX

174

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:43:35 PM	74	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:44:50 PM	24	1372.50	TQEX
GENMAB A/S	28-Mar-25	2:44:58 PM	60	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:44:58 PM	19	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:44:58 PM	75	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:44:58 PM	77	1372.00	CEUX
GENMAB A/S	28-Mar-25	2:44:58 PM	23	1372.00	AQEU
GENMAB A/S	28-Mar-25	2:44:59 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:44:59 PM	64	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:44:59 PM	15	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	15	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	30	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	42	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	6	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	13	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:00 PM	12	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:45:01 PM	77	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:01 PM	101	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:01 PM	30	1371.00	CEUX
GENMAB A/S	28-Mar-25	2:45:01 PM	22	1371.50	TQEX
GENMAB A/S	28-Mar-25	2:45:02 PM	11	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	12	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	42	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	22	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	13	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	42	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	16	1370.00	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	11	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	12	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:02 PM	13	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:07 PM	3	1370.00	XCSE
GENMAB A/S	28-Mar-25	2:45:11 PM	22	1370.00	AQEU
GENMAB A/S	28-Mar-25	2:45:26 PM	3	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:26 PM	1	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:45:29 PM	101	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:29 PM	101	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:29 PM	101	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:30 PM	101	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:30 PM	101	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:45:55 PM	39	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:55 PM	4	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:55 PM	16	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:55 PM	42	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	12	1372.50	XCSE

175

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:45:56 PM	20	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	12	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	16	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	2	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	42	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	11	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	13	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	50	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:45:56 PM	24	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:46:36 PM	12	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:46:36 PM	2	1372.50	XCSE
GENMAB A/S	28-Mar-25	2:46:53 PM	41	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:46:53 PM	75	1371.00	XCSE
GENMAB A/S	28-Mar-25	2:46:53 PM	75	1372.00	XCSE
GENMAB A/S	28-Mar-25	2:46:53 PM	60	1371.50	XCSE
GENMAB A/S	28-Mar-25	2:46:53 PM	74	1371.50	CEUX
GENMAB A/S	28-Mar-25	2:46:53 PM	22	1371.50	TQEX
GENMAB A/S	28-Mar-25	2:47:01 PM	13	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:47:01 PM	77	1370.00	XCSE
GENMAB A/S	28-Mar-25	2:47:01 PM	50	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:47:01 PM	38	1370.50	XCSE
GENMAB A/S	28-Mar-25	2:47:01 PM	34	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:47:01 PM	45	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:47:01 PM	31	1370.00	TQEX
GENMAB A/S	28-Mar-25	2:47:56 PM	101	1370.00	XCSE
GENMAB A/S	28-Mar-25	2:47:56 PM	78	1370.00	XCSE
GENMAB A/S	28-Mar-25	2:47:56 PM	21	1369.50	XCSE
GENMAB A/S	28-Mar-25	2:47:56 PM	30	1369.50	XCSE
GENMAB A/S	28-Mar-25	2:47:56 PM	9	1369.50	XCSE
GENMAB A/S	28-Mar-25	2:47:56 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	2:47:56 PM	54	1369.50	CEUX
GENMAB A/S	28-Mar-25	2:47:56 PM	77	1370.50	CEUX
GENMAB A/S	28-Mar-25	2:47:57 PM	30	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:47:57 PM	12	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:47:57 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:47:57 PM	41	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:47:57 PM	5	1369.00	XCSE
GENMAB A/S	28-Mar-25	2:48:58 PM	29	1369.00	CEUX
GENMAB A/S	28-Mar-25	2:48:58 PM	11	1369.00	CEUX
GENMAB A/S	28-Mar-25	2:49:27 PM	74	1369.50	XCSE
GENMAB A/S	28-Mar-25	2:50:54 PM	74	1374.00	XCSE
GENMAB A/S	28-Mar-25	2:50:54 PM	16	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:50:54 PM	42	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:50:54 PM	32	1373.50	TQEX
GENMAB A/S	28-Mar-25	2:51:07 PM	5	1373.50	XCSE

176

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:51:07 PM	30	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	43	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	21	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	50	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	77	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	11	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	42	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:51:07 PM	76	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:51:08 PM	8	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:51:08 PM	17	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:51:08 PM	12	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:00 PM	42	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:00 PM	30	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:00 PM	42	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:00 PM	64	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:52:00 PM	12	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:52:00 PM	22	1373.50	TQEX
GENMAB A/S	28-Mar-25	2:52:08 PM	13	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:08 PM	24	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:08 PM	12	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:09 PM	9	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:52:09 PM	13	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:52:09 PM	77	1373.00	CEUX
GENMAB A/S	28-Mar-25	2:52:09 PM	22	1373.00	AQEU
GENMAB A/S	28-Mar-25	2:52:21 PM	41	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:52:41 PM	14	1373.00	XCSE
GENMAB A/S	28-Mar-25	2:52:53 PM	33	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:53 PM	11	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:53 PM	42	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:52:53 PM	12	1373.50	XCSE
GENMAB A/S	28-Mar-25	2:54:03 PM	74	1374.00	CEUX
GENMAB A/S	28-Mar-25	2:54:03 PM	22	1374.00	AQEU
GENMAB A/S	28-Mar-25	2:54:04 PM	4	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:04 PM	61	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:04 PM	26	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:04 PM	40	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:04 PM	12	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:04 PM	42	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:04 PM	11	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:31 PM	13	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:54:31 PM	13	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:55:21 PM	69	1375.00	XCSE
GENMAB A/S	28-Mar-25	2:55:21 PM	32	1375.00	XCSE
GENMAB A/S	28-Mar-25	2:55:22 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	2:55:25 PM	8	1374.50	TQEX

177

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	2:55:32 PM	12	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:56:27 PM	2	1375.50	CEUX
GENMAB A/S	28-Mar-25	2:56:38 PM	9	1375.00	AQEU
GENMAB A/S	28-Mar-25	2:57:25 PM	37	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:57:25 PM	5	1375.50	XCSE
GENMAB A/S	28-Mar-25	2:57:25 PM	18	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:57:25 PM	10	1374.50	XCSE
GENMAB A/S	28-Mar-25	2:57:25 PM	20	1375.50	CEUX
GENMAB A/S	28-Mar-25	2:57:25 PM	13	1375.00	AQEU
GENMAB A/S	28-Mar-25	2:57:25 PM	8	1374.00	AQEU
GENMAB A/S	28-Mar-25	2:58:13 PM	25	1375.00	XCSE
GENMAB A/S	28-Mar-25	2:58:13 PM	53	1375.00	XCSE
GENMAB A/S	28-Mar-25	2:58:13 PM	8	1375.00	XCSE
GENMAB A/S	28-Mar-25	2:58:25 PM	29	1376.00	CEUX
GENMAB A/S	28-Mar-25	2:58:25 PM	10	1376.00	CEUX
GENMAB A/S	28-Mar-25	2:58:25 PM	21	1376.00	CEUX
GENMAB A/S	28-Mar-25	2:58:40 PM	40	1376.00	XCSE
GENMAB A/S	28-Mar-25	2:59:02 PM	15	1375.50	CEUX
GENMAB A/S	28-Mar-25	2:59:02 PM	78	1375.50	CEUX
GENMAB A/S	28-Mar-25	2:59:02 PM	41	1375.50	TQEX
GENMAB A/S	28-Mar-25	2:59:25 PM	2	1375.50	XCSE
GENMAB A/S	28-Mar-25	2:59:26 PM	7	1375.50	CEUX
GENMAB A/S	28-Mar-25	2:59:59 PM	10	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	3	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	16	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	9	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	11	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	55	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	11	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	13	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	2	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	1	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	4	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	6	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	7	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	2	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	10	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	69	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	31	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:00:00 PM	26	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	38	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	13	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	2	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	20	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	29	1373.00	CEUX

178

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:00:00 PM	3	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	7	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	6	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	5	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	3	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	15	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:00:00 PM	6	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	16	1374.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	8	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	3	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	5	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	2	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	3	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:00:00 PM	15	1374.00	AQEU
GENMAB A/S	28-Mar-25	3:00:00 PM	7	1373.00	AQEU
GENMAB A/S	28-Mar-25	3:00:00 PM	3	1373.00	AQEU
GENMAB A/S	28-Mar-25	3:00:25 PM	5	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:00:25 PM	5	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:00:26 PM	31	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:00:28 PM	1	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:00:28 PM	4	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:01:03 PM	78	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:01:03 PM	80	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:01:03 PM	31	1374.00	TQEX
GENMAB A/S	28-Mar-25	3:01:03 PM	10	1373.00	AQEU
GENMAB A/S	28-Mar-25	3:01:38 PM	3	1372.50	XCSE
GENMAB A/S	28-Mar-25	3:01:38 PM	5	1372.50	XCSE
GENMAB A/S	28-Mar-25	3:01:38 PM	2	1372.50	XCSE
GENMAB A/S	28-Mar-25	3:01:38 PM	14	1372.50	XCSE
GENMAB A/S	28-Mar-25	3:01:38 PM	1	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:01:38 PM	73	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:01:38 PM	8	1373.00	AQEU
GENMAB A/S	28-Mar-25	3:02:17 PM	54	1372.50	XCSE
GENMAB A/S	28-Mar-25	3:02:26 PM	10	1372.50	TQEX
GENMAB A/S	28-Mar-25	3:02:26 PM	17	1372.50	TQEX
GENMAB A/S	28-Mar-25	3:03:12 PM	76	1372.00	CEUX
GENMAB A/S	28-Mar-25	3:03:12 PM	36	1372.50	CEUX
GENMAB A/S	28-Mar-25	3:03:12 PM	6	1372.50	CEUX
GENMAB A/S	28-Mar-25	3:04:07 PM	80	1371.50	XCSE
GENMAB A/S	28-Mar-25	3:04:17 PM	14	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:17 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:17 PM	34	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:17 PM	42	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	32	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	53	1372.00	XCSE

179

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:04:18 PM	10	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	13	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	16	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	20	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:18 PM	12	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:19 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:19 PM	11	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:19 PM	20	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:04:28 PM	14	1372.00	CEUX
GENMAB A/S	28-Mar-25	3:04:28 PM	7	1372.00	CEUX
GENMAB A/S	28-Mar-25	3:04:28 PM	29	1372.00	CEUX
GENMAB A/S	28-Mar-25	3:04:28 PM	12	1372.00	CEUX
GENMAB A/S	28-Mar-25	3:06:02 PM	62	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:06:47 PM	62	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:07:01 PM	17	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:07:30 PM	20	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:07:30 PM	41	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:07:55 PM	37	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:07:56 PM	13	1374.50	XCSE
GENMAB A/S	28-Mar-25	3:07:56 PM	12	1374.50	XCSE
GENMAB A/S	28-Mar-25	3:07:56 PM	14	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:07:57 PM	10	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:07:57 PM	65	1374.00	CEUX
GENMAB A/S	28-Mar-25	3:07:57 PM	23	1374.00	AQEU
GENMAB A/S	28-Mar-25	3:08:00 PM	40	1375.00	CEUX
GENMAB A/S	28-Mar-25	3:08:48 PM	10	1375.00	CEUX
GENMAB A/S	28-Mar-25	3:09:00 PM	11	1375.00	CEUX
GENMAB A/S	28-Mar-25	3:09:47 PM	36	1375.50	XCSE
GENMAB A/S	28-Mar-25	3:10:13 PM	40	1375.50	XCSE
GENMAB A/S	28-Mar-25	3:10:13 PM	1	1375.50	XCSE
GENMAB A/S	28-Mar-25	3:10:13 PM	15	1375.50	XCSE
GENMAB A/S	28-Mar-25	3:10:13 PM	58	1375.50	CEUX
GENMAB A/S	28-Mar-25	3:10:13 PM	36	1375.50	CEUX
GENMAB A/S	28-Mar-25	3:10:13 PM	21	1375.50	CEUX
GENMAB A/S	28-Mar-25	3:10:13 PM	15	1375.50	CEUX
GENMAB A/S	28-Mar-25	3:10:13 PM	37	1375.50	TQEX
GENMAB A/S	28-Mar-25	3:10:14 PM	10	1375.50	CEUX
GENMAB A/S	28-Mar-25	3:10:42 PM	76	1376.00	CEUX
GENMAB A/S	28-Mar-25	3:10:42 PM	28	1376.00	TQEX
GENMAB A/S	28-Mar-25	3:10:52 PM	38	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	13	1375.00	XCSE

180

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:10:52 PM	6	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	42	1374.50	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	38	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	30	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	12	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	74	1374.50	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	4	1375.00	XCSE
GENMAB A/S	28-Mar-25	3:10:52 PM	2	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:52 PM	59	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:10:52 PM	6	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:52 PM	4	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:52 PM	16	1374.50	CEUX
GENMAB A/S	28-Mar-25	3:10:52 PM	7	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:52 PM	31	1374.50	TQEX
GENMAB A/S	28-Mar-25	3:10:52 PM	20	1373.50	TQEX
GENMAB A/S	28-Mar-25	3:10:52 PM	20	1373.50	AQEU
GENMAB A/S	28-Mar-25	3:10:52 PM	25	1376.00	AQEU
GENMAB A/S	28-Mar-25	3:10:52 PM	2	1373.50	AQEU
GENMAB A/S	28-Mar-25	3:10:53 PM	3	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:53 PM	3	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:53 PM	53	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:10:53 PM	1	1373.00	CEUX
GENMAB A/S	28-Mar-25	3:11:00 PM	30	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:11:00 PM	42	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:11:00 PM	42	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:11:00 PM	11	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:11:00 PM	11	1373.50	XCSE
GENMAB A/S	28-Mar-25	3:11:00 PM	77	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:11:18 PM	5	1373.00	XCSE
GENMAB A/S	28-Mar-25	3:11:35 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:35 PM	16	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:35 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:35 PM	19	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:35 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:35 PM	17	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:11:35 PM	6	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:11:35 PM	30	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:11:35 PM	20	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:11:35 PM	25	1373.50	AQEU
GENMAB A/S	28-Mar-25	3:11:36 PM	15	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	15	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	5	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	13	1374.00	XCSE

181

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:11:36 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	3	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	14	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	30	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:36 PM	12	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	9	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	12	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	4	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	3	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:37 PM	5	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	2	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	19	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	6	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	16	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:55 PM	23	1373.50	AQEU
GENMAB A/S	28-Mar-25	3:11:56 PM	13	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:56 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:56 PM	11	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:56 PM	12	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:11:56 PM	42	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:12:03 PM	2	1374.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	60	1372.50	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	8	1373.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	1	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	13	1373.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	66	1373.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	76	1372.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	20	1373.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	4	1373.00	XCSE
GENMAB A/S	28-Mar-25	3:12:27 PM	23	1373.50	CEUX
GENMAB A/S	28-Mar-25	3:12:27 PM	74	1372.50	CEUX
GENMAB A/S	28-Mar-25	3:12:27 PM	22	1372.50	TQEX
GENMAB A/S	28-Mar-25	3:12:55 PM	64	1371.50	CEUX
GENMAB A/S	28-Mar-25	3:12:55 PM	12	1371.50	CEUX

182

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:13:10 PM	80	1371.00	XCSE
GENMAB A/S	28-Mar-25	3:13:10 PM	42	1371.00	XCSE
GENMAB A/S	28-Mar-25	3:13:10 PM	17	1371.00	XCSE
GENMAB A/S	28-Mar-25	3:13:15 PM	79	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:13:15 PM	17	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:13:15 PM	53	1370.00	CEUX
GENMAB A/S	28-Mar-25	3:14:21 PM	80	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:14:21 PM	27	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:14:21 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:15:00 PM	43	1370.50	TQEX
GENMAB A/S	28-Mar-25	3:15:28 PM	2	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:16:21 PM	1	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:16:37 PM	75	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:16:37 PM	1	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:16:42 PM	101	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:16:42 PM	74	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:16:42 PM	22	1370.00	AQEU
GENMAB A/S	28-Mar-25	3:16:43 PM	101	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:16:43 PM	42	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:16:43 PM	59	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:16:43 PM	80	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:16:53 PM	40	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:16:53 PM	22	1369.50	TQEX
GENMAB A/S	28-Mar-25	3:16:58 PM	74	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:16:58 PM	23	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:16:58 PM	25	1368.50	AQEU
GENMAB A/S	28-Mar-25	3:17:10 PM	12	1368.50	AQEU
GENMAB A/S	28-Mar-25	3:17:10 PM	10	1368.50	AQEU
GENMAB A/S	28-Mar-25	3:17:47 PM	35	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:17:47 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:17:47 PM	35	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:17:47 PM	16	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:18:54 PM	50	1368.50	CEUX
GENMAB A/S	28-Mar-25	3:18:54 PM	22	1368.50	AQEU
GENMAB A/S	28-Mar-25	3:18:56 PM	15	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:18:56 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:18:56 PM	30	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:18:56 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:18:56 PM	80	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:18:56 PM	14	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:21:12 PM	73	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:21:12 PM	2	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:21:12 PM	75	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:21:12 PM	22	1369.50	TQEX
GENMAB A/S	28-Mar-25	3:21:25 PM	12	1369.50	XCSE

183

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:21:26 PM	6	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:22:27 PM	53	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:22:30 PM	4	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:23:10 PM	28	1370.00	TQEX
GENMAB A/S	28-Mar-25	3:24:37 PM	74	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:24:42 PM	11	1370.00	AQEU
GENMAB A/S	28-Mar-25	3:25:10 PM	30	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:25:10 PM	11	1370.00	AQEU
GENMAB A/S	28-Mar-25	3:25:43 PM	9	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:25:57 PM	71	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:25:57 PM	36	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:25:57 PM	34	1370.50	AQEU
GENMAB A/S	28-Mar-25	3:26:25 PM	13	1371.00	XCSE
GENMAB A/S	28-Mar-25	3:26:25 PM	6	1371.00	CEUX
GENMAB A/S	28-Mar-25	3:26:28 PM	6	1371.00	CEUX
GENMAB A/S	28-Mar-25	3:27:26 PM	22	1371.00	CEUX
GENMAB A/S	28-Mar-25	3:27:50 PM	3	1371.00	XCSE
GENMAB A/S	28-Mar-25	3:27:50 PM	11	1371.00	CEUX
GENMAB A/S	28-Mar-25	3:28:29 PM	24	1371.00	TQEX
GENMAB A/S	28-Mar-25	3:28:29 PM	13	1371.00	TQEX
GENMAB A/S	28-Mar-25	3:28:38 PM	61	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:28:38 PM	15	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:29:26 PM	12	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:30:43 PM	34	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:30:43 PM	16	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:30:47 PM	20	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:30:59 PM	13	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	42	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	22	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	35	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	4	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	44	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	20	1370.50	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	79	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:30:59 PM	7	1370.50	CEUX
GENMAB A/S	28-Mar-25	3:30:59 PM	46	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:30:59 PM	25	1370.00	TQEX
GENMAB A/S	28-Mar-25	3:31:00 PM	12	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	11	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	20	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	20	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	12	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	12	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	42	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	12	1370.00	XCSE

184

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:31:00 PM	12	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	13	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:00 PM	21	1369.50	TQEX
GENMAB A/S	28-Mar-25	3:31:00 PM	3	1369.50	TQEX
GENMAB A/S	28-Mar-25	3:31:01 PM	42	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:01 PM	13	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:01 PM	19	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:01 PM	42	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:01 PM	11	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:01 PM	13	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:02 PM	5	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:02 PM	11	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:22 PM	12	1370.00	XCSE
GENMAB A/S	28-Mar-25	3:31:30 PM	31	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:31:30 PM	45	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:31:30 PM	27	1369.50	TQEX
GENMAB A/S	28-Mar-25	3:31:31 PM	2	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	30	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:47 PM	36	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:31:47 PM	6	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:31:47 PM	5	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:31:51 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:51 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:51 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:52 PM	3	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:52 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:52 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:53 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:55 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:55 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:55 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:55 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:55 PM	12	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:31:56 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	41	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	11	1369.50	XCSE

185

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:31:56 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:56 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:57 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:31:58 PM	13	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:32:08 PM	10	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:32:08 PM	15	1369.50	CEUX
GENMAB A/S	28-Mar-25	3:32:10 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:32:10 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:32:11 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:32:11 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:32:18 PM	7	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:32:32 PM	52	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:32:32 PM	6	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:32:32 PM	17	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:32:32 PM	69	1368.50	CEUX
GENMAB A/S	28-Mar-25	3:32:32 PM	42	1368.50	TQEX
GENMAB A/S	28-Mar-25	3:33:13 PM	23	1368.00	AQEU
GENMAB A/S	28-Mar-25	3:33:26 PM	35	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:33:26 PM	1	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:33:27 PM	4	1368.50	XCSE
GENMAB A/S	28-Mar-25	3:33:27 PM	73	1368.50	XCSE
GENMAB A/S	28-Mar-25	3:33:28 PM	2	1368.50	XCSE
GENMAB A/S	28-Mar-25	3:33:29 PM	20	1368.50	XCSE
GENMAB A/S	28-Mar-25	3:33:48 PM	53	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:09 PM	24	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:09 PM	78	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:34:25 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	20	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	44	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	25	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	3	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:25 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:34:28 PM	3	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:34:28 PM	11	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:34:28 PM	78	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:34:37 PM	20	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:34:37 PM	3	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:34:37 PM	10	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:34:48 PM	20	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:34:48 PM	20	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:34:51 PM	4	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:36:00 PM	36	1369.00	XCSE

186

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:36:00 PM	43	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:36:15 PM	4	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:36:15 PM	1	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:36:20 PM	75	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:36:28 PM	12	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:36:28 PM	65	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:36:28 PM	11	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:36:28 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	3:36:28 PM	39	1369.50	XCSE
GENMAB A/S	28-Mar-25	3:37:38 PM	23	1368.50	TQEX
GENMAB A/S	28-Mar-25	3:37:47 PM	76	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:18 PM	75	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:38:18 PM	5	1369.00	CEUX
GENMAB A/S	28-Mar-25	3:38:31 PM	50	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:38:31 PM	24	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:38:38 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:38 PM	9	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:38 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:39 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:39 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:39 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:39 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:39 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:39 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:40 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:40 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:40 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:40 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:40 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:40 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:41 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:42 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:42 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:42 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:42 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:42 PM	33	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:42 PM	33	1368.00	XCSE

187

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:38:42 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:51 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:38:51 PM	8	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:39:11 PM	2	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:39:11 PM	15	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:39:11 PM	53	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:39:17 PM	80	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:40:27 PM	46	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:41:05 PM	34	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:41:05 PM	35	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:41:05 PM	8	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:41:07 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:41:08 PM	32	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:41:38 PM	6	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:41:38 PM	6	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:43:01 PM	30	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:43:01 PM	45	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:43:01 PM	25	1367.00	TQEX
GENMAB A/S	28-Mar-25	3:43:14 PM	23	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:43:26 PM	54	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:43:26 PM	20	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:43:26 PM	1	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:43:57 PM	44	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:05 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:05 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:05 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:06 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:10 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:10 PM	42	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:42 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:44:42 PM	36	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:45:34 PM	35	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:45:34 PM	41	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:45:44 PM	16	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:44 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:44 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:44 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:44 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:44 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:44 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:45 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:45 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	39	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	40	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	11	1367.00	XCSE

188

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:45:49 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	39	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:49 PM	1	1366.50	AQEU
GENMAB A/S	28-Mar-25	3:45:49 PM	20	1366.50	AQEU
GENMAB A/S	28-Mar-25	3:45:49 PM	10	1366.50	AQEU
GENMAB A/S	28-Mar-25	3:45:50 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	39	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	34	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	39	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:50 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:51 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:51 PM	35	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:51 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:45:51 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:46:07 PM	77	1366.00	XCSE
GENMAB A/S	28-Mar-25	3:46:07 PM	22	1366.00	TQEX
GENMAB A/S	28-Mar-25	3:46:08 PM	22	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:46:08 PM	20	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:46:51 PM	74	1366.50	XCSE
GENMAB A/S	28-Mar-25	3:46:51 PM	12	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:46:51 PM	25	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:46:51 PM	48	1366.50	TQEX
GENMAB A/S	28-Mar-25	3:46:57 PM	75	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:52:12 PM	8	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:52:12 PM	8	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:13 PM	9	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:22 PM	4	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:52:22 PM	4	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:22 PM	2	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:29 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:29 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:30 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:30 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:33 PM	32	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:38 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	3:52:38 PM	9	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:39 PM	27	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:39 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:39 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:39 PM	6	1368.00	CEUX

189

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:52:48 PM	3	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:52:53 PM	24	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:53:07 PM	31	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:53:27 PM	1	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:55:15 PM	13	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:15 PM	13	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:15 PM	1	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:15 PM	78	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:55:15 PM	42	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:15 PM	11	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	18	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	24	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	6	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	17	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	42	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	13	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:16 PM	82	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:55:28 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:55:28 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:55:28 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:55:28 PM	5	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:55:28 PM	13	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:55:28 PM	14	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:55:28 PM	5	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:55:57 PM	26	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:55:57 PM	36	1367.00	CEUX
GENMAB A/S	28-Mar-25	3:56:01 PM	67	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:56:01 PM	11	1366.50	CEUX
GENMAB A/S	28-Mar-25	3:56:01 PM	3	1366.50	TQEX
GENMAB A/S	28-Mar-25	3:57:31 PM	11	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:57:31 PM	25	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:57:31 PM	10	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:57:31 PM	20	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:58:16 PM	36	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:58:25 PM	11	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:58:26 PM	9	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:58:47 PM	77	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:58:47 PM	36	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:58:47 PM	66	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:58:48 PM	23	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:58:48 PM	78	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:25 PM	10	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:26 PM	16	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	80	1367.00	XCSE
GENMAB A/S	28-Mar-25	3:59:57 PM	5	1367.50	CEUX

190

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	3:59:57 PM	6	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	36	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	78	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	14	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:57 PM	30	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:58 PM	91	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:59:58 PM	2	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:59:58 PM	8	1367.50	XCSE
GENMAB A/S	28-Mar-25	3:59:58 PM	5	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:58 PM	25	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:58 PM	76	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:58 PM	6	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:59 PM	5	1367.50	CEUX
GENMAB A/S	28-Mar-25	3:59:59 PM	33	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:59 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:59 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	3:59:59 PM	36	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:00:00 PM	13	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:00:00 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:00:02 PM	32	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:00:18 PM	2	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:00:21 PM	78	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:00:21 PM	32	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:00:31 PM	41	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:31 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:31 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:31 PM	60	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:31 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:31 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:31 PM	6	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:00:31 PM	68	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:00:31 PM	76	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:00:31 PM	39	1367.00	AQEU
GENMAB A/S	28-Mar-25	4:00:32 PM	44	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:32 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:32 PM	35	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:32 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:45 PM	4	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:45 PM	30	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:45 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:45 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:45 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	11	1367.00	XCSE

191

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:00:46 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	30	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	3	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	33	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	38	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	47	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	1	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:46 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:47 PM	1	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:47 PM	14	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:00:58 PM	42	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:00:58 PM	59	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:01:00 PM	34	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:00 PM	43	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:00 PM	79	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:01:06 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:06 PM	41	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:06 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:06 PM	11	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:06 PM	11	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:07 PM	2	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:13 PM	28	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:01:13 PM	18	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:13 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:13 PM	42	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:01:13 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:01:13 PM	76	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:01:13 PM	22	1365.50	AQEU
GENMAB A/S	28-Mar-25	4:01:15 PM	28	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:01:15 PM	59	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:01:25 PM	11	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:01:25 PM	12	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:02:23 PM	7	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:02:24 PM	8	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:02:26 PM	1	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:02:26 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:02:55 PM	37	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:02:55 PM	34	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:02:55 PM	40	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:02:55 PM	23	1365.50	AQEU

192

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:02:56 PM	39	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:02:56 PM	42	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:02:56 PM	24	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:03:05 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:03:28 PM	10	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:03:46 PM	34	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:03:46 PM	46	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:04:42 PM	11	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:04:52 PM	32	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:04:52 PM	41	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:04:52 PM	30	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:05:00 PM	11	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:05:11 PM	77	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:05:25 PM	12	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:05:43 PM	43	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:05:43 PM	37	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:05:43 PM	1	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:05:43 PM	38	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:05:43 PM	76	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:05:43 PM	25	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:06:37 PM	60	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:07:25 PM	1	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:07:25 PM	10	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:07:26 PM	1	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:07:30 PM	11	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:07:30 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:07:30 PM	36	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:07:30 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:07:30 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:07:30 PM	41	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:08:07 PM	14	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:07 PM	36	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:07 PM	78	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:07 PM	44	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:08:16 PM	23	1364.50	AQEU
GENMAB A/S	28-Mar-25	4:08:25 PM	36	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:25 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:25 PM	6	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:26 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:26 PM	52	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:26 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:26 PM	23	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:27 PM	24	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:27 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:27 PM	12	1365.00	XCSE

193

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:08:27 PM	51	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:27 PM	11	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:28 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:28 PM	27	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:30 PM	11	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:30 PM	11	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:33 PM	11	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:08:38 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:38 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:38 PM	12	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:48 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:48 PM	7	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:48 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:48 PM	19	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:08:54 PM	42	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:08:54 PM	12	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:08:54 PM	42	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:08:54 PM	1	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:09:25 PM	3	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:09:25 PM	2	1364.50	AQEU
GENMAB A/S	28-Mar-25	4:09:29 PM	10	1364.50	AQEU
GENMAB A/S	28-Mar-25	4:10:02 PM	41	1364.50	TQEX
GENMAB A/S	28-Mar-25	4:10:07 PM	25	1364.50	AQEU
GENMAB A/S	28-Mar-25	4:10:48 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:10:48 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:10:54 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:03 PM	2	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:11:19 PM	36	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:11:19 PM	6	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:11:19 PM	6	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:11:19 PM	9	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:11:19 PM	34	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:11:26 PM	10	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:11:32 PM	32	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:11:39 PM	42	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:39 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:39 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:39 PM	18	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:39 PM	15	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:40 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:40 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:40 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:40 PM	78	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:41 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:11:41 PM	13	1366.00	XCSE

194

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:11:57 PM	11	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:12:03 PM	2	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:12:26 PM	3	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	74	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:12:27 PM	74	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	2	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	2	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	2	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	2	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	6	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	15	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	3	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:27 PM	31	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:12:35 PM	41	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:37 PM	32	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	3	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	32	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	25	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	42	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	80	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	20	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	1	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	5	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	5	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	21	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	43	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	17	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	12	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	5	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	2	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	30	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	8	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	10	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	15	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	10	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	36	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	4	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	4	1363.50	CEUX

195

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:12:46 PM	3	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	10	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:12:46 PM	46	1364.50	TQEX
GENMAB A/S	28-Mar-25	4:12:47 PM	34	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:12:47 PM	2	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:13:27 PM	71	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:27 PM	6	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:27 PM	36	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:13:28 PM	41	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:28 PM	21	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:28 PM	8	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:28 PM	42	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:28 PM	11	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:28 PM	10	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:28 PM	5	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:29 PM	11	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:29 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:29 PM	11	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:32 PM	13	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:32 PM	13	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:32 PM	42	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:13:33 PM	22	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:13:56 PM	44	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:00 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:00 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:00 PM	16	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:10 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:10 PM	42	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:10 PM	12	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:14:40 PM	11	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:14:40 PM	66	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:14:43 PM	12	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:43 PM	10	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:43 PM	77	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:43 PM	12	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:14:43 PM	35	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:14:43 PM	10	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:14:43 PM	29	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:14:52 PM	31	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	42	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	11	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	11	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	12	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	33	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	13	1364.00	XCSE

196

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:14:52 PM	11	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	27	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:52 PM	13	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:53 PM	13	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:53 PM	30	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:53 PM	12	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:53 PM	13	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:53 PM	12	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:53 PM	42	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:54 PM	64	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:54 PM	15	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:55 PM	21	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:55 PM	42	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:55 PM	27	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:55 PM	13	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:55 PM	61	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:57 PM	11	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:14:57 PM	27	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:15:10 PM	80	1364.00	XCSE
GENMAB A/S	28-Mar-25	4:15:10 PM	79	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:15:10 PM	23	1364.00	TQEX
GENMAB A/S	28-Mar-25	4:15:59 PM	27	1364.00	AQEU
GENMAB A/S	28-Mar-25	4:16:13 PM	75	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:13 PM	4	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:13 PM	32	1364.00	CEUX
GENMAB A/S	28-Mar-25	4:16:13 PM	12	1364.00	AQEU
GENMAB A/S	28-Mar-25	4:16:14 PM	1	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:14 PM	3	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:14 PM	13	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:14 PM	75	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:15 PM	43	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:34 PM	25	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:16:51 PM	77	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:17:25 PM	12	1363.50	AQEU
GENMAB A/S	28-Mar-25	4:17:57 PM	4	1363.50	AQEU
GENMAB A/S	28-Mar-25	4:19:00 PM	28	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:19:00 PM	52	1363.50	XCSE
GENMAB A/S	28-Mar-25	4:19:00 PM	36	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:19:00 PM	7	1363.50	AQEU
GENMAB A/S	28-Mar-25	4:19:00 PM	2	1363.50	AQEU
GENMAB A/S	28-Mar-25	4:19:27 PM	2	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:19:27 PM	16	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:19:50 PM	11	1363.50	CEUX
GENMAB A/S	28-Mar-25	4:21:07 PM	49	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:21:07 PM	31	1364.50	XCSE

197

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:21:07 PM	27	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:21:07 PM	56	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:07 PM	77	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:07 PM	45	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:07 PM	35	1364.50	AQEU
GENMAB A/S	28-Mar-25	4:21:08 PM	14	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:30 PM	75	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:21:30 PM	8	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:21:30 PM	7	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:21:34 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:21:34 PM	6	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:21:34 PM	6	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:21:34 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:21:34 PM	17	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:43 PM	58	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:43 PM	36	1364.50	CEUX
GENMAB A/S	28-Mar-25	4:21:44 PM	4	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:21:44 PM	41	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:23:07 PM	46	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:23:32 PM	95	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:23:32 PM	2	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:23:32 PM	18	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:23:32 PM	14	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:23:32 PM	8	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:23:32 PM	10	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:23:57 PM	29	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:24:00 PM	30	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:24:00 PM	28	1365.00	TQEX
GENMAB A/S	28-Mar-25	4:24:00 PM	8	1365.00	AQEU
GENMAB A/S	28-Mar-25	4:24:03 PM	8	1365.00	AQEU
GENMAB A/S	28-Mar-25	4:24:37 PM	34	1364.50	XCSE
GENMAB A/S	28-Mar-25	4:24:37 PM	8	1365.00	AQEU
GENMAB A/S	28-Mar-25	4:25:28 PM	8	1365.00	AQEU
GENMAB A/S	28-Mar-25	4:26:28 PM	1	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:28 PM	59	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:28 PM	6	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:28 PM	11	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:32 PM	53	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:32 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:32 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:32 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:32 PM	36	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:32 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:32 PM	6	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:33 PM	24	1365.00	CEUX

198

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:26:33 PM	21	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:33 PM	6	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:35 PM	12	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:35 PM	11	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:35 PM	13	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:35 PM	5	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:36 PM	42	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:26:36 PM	31	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:36 PM	21	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:41 PM	73	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:26:53 PM	45	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:26:53 PM	36	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:26:53 PM	34	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:26:54 PM	41	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	28	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	17	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	5	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	48	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	8	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	31	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:49 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:50 PM	18	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:27:50 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:28:00 PM	3	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:28:27 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:28:27 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:28:42 PM	43	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:28:42 PM	28	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:28:42 PM	36	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:28:42 PM	54	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:28:44 PM	11	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:29:03 PM	13	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:29:17 PM	35	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:17 PM	6	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:29:17 PM	36	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:29:17 PM	5	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:29:17 PM	25	1365.50	AQEU
GENMAB A/S	28-Mar-25	4:29:26 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	12	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	11	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	18	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	12	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	30	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	30	1365.50	XCSE

199

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:29:26 PM	11	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	12	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	30	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	21	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:26 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	36	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	17	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	26	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:26 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:29:27 PM	12	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:27 PM	9	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:29:27 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:30:17 PM	11	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:30:25 PM	2	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:30:43 PM	10	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:30:49 PM	3	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:31:04 PM	12	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:31:05 PM	42	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:31:31 PM	20	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:31:31 PM	30	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:31:37 PM	36	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:31:46 PM	62	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:31:55 PM	31	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:00 PM	11	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:00 PM	10	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:03 PM	15	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:03 PM	11	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:11 PM	58	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:12 PM	34	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:15 PM	28	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:16 PM	8	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:32:16 PM	17	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:16 PM	56	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:32:17 PM	2	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:32:28 PM	63	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:32:28 PM	10	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:32:28 PM	22	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:32:28 PM	15	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:32:28 PM	16	1366.00	AQEU

200

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:32:45 PM	51	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:46 PM	7	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:32:46 PM	64	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:32:46 PM	22	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:32:47 PM	23	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:32:48 PM	5	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:33:07 PM	48	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:33:26 PM	10	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:26 PM	25	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:26 PM	2	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:26 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:26 PM	53	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:26 PM	75	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:33:26 PM	24	1366.50	TQEX
GENMAB A/S	28-Mar-25	4:33:27 PM	9	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:27 PM	42	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:27 PM	50	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:28 PM	73	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:31 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:31 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:31 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:31 PM	53	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:38 PM	5	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:39 PM	18	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:39 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:39 PM	53	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:39 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:40 PM	43	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:53 PM	53	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:53 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:53 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:33:54 PM	10	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:33:59 PM	16	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:34:00 PM	40	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:34:00 PM	22	1366.50	AQEU
GENMAB A/S	28-Mar-25	4:34:37 PM	5	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:34:37 PM	42	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:34:37 PM	36	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:34:37 PM	13	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:34:41 PM	30	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:34:41 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:34:41 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:34:41 PM	1	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:34:45 PM	7	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:34:45 PM	10	1367.00	XCSE

201

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:34:45 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:34:45 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:34:45 PM	30	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:34:45 PM	53	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:34:51 PM	12	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:34:51 PM	13	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:35:01 PM	1	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:35:01 PM	2	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:35:01 PM	25	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:35:01 PM	1	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:35:01 PM	32	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:35:01 PM	28	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:01 PM	22	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:01 PM	3	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:03 PM	3	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:03 PM	2	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:03 PM	3	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:03 PM	7	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:03 PM	15	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	2	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	1	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	3	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	3	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	10	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	2	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	3	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:03 PM	3	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:35:08 PM	79	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	5	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	53	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	15	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	7	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	11	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	10	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:08 PM	28	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:35:20 PM	76	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:20 PM	21	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:35:20 PM	10	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:35:20 PM	45	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:35:20 PM	25	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:35:20 PM	3	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:35:20 PM	7	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:35:20 PM	4	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:35:20 PM	4	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:35:20 PM	2	1368.50	TQEX

202

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:35:20 PM	2	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:35:20 PM	22	1369.00	AQEU
GENMAB A/S	28-Mar-25	4:35:25 PM	10	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:25 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:25 PM	11	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:26 PM	5	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:34 PM	25	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:35:34 PM	7	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:34 PM	14	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:35:37 PM	18	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:35:37 PM	12	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:35:37 PM	9	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:35:37 PM	36	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:35:37 PM	20	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:35:37 PM	6	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:35:37 PM	48	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:35:37 PM	5	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:35:37 PM	5	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:35:37 PM	3	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:35:37 PM	3	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:35:37 PM	2	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:35:37 PM	6	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:35:37 PM	17	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:35:37 PM	5	1367.00	TQEX
GENMAB A/S	28-Mar-25	4:36:18 PM	65	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:18 PM	36	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:27 PM	15	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:36:30 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:30 PM	22	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:30 PM	1	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:30 PM	13	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:30 PM	53	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:30 PM	12	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:36:31 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:31 PM	10	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:36:31 PM	53	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:31 PM	2	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:31 PM	24	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:36:31 PM	23	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:36:42 PM	7	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:36:57 PM	10	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:36:57 PM	11	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:36:57 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:36:57 PM	3	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:36:57 PM	8	1368.00	CEUX

203

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:36:59 PM	69	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:37:08 PM	6	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:37:08 PM	15	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:37:08 PM	6	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:37:08 PM	12	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:37:26 PM	7	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:37:26 PM	22	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:37:37 PM	10	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:37:37 PM	6	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:37:37 PM	6	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:37:37 PM	25	1367.00	AQEU
GENMAB A/S	28-Mar-25	4:37:46 PM	10	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:37:46 PM	63	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:38:34 PM	26	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:38:34 PM	30	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:38:34 PM	15	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:38:47 PM	65	1367.00	CEUX
GENMAB A/S	28-Mar-25	4:39:14 PM	22	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:39:14 PM	75	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:39:14 PM	8	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:39:16 PM	83	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:39:17 PM	12	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:39:37 PM	11	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:39:48 PM	52	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:40:32 PM	1	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:32 PM	1	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:32 PM	5	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:33 PM	90	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:40:33 PM	9	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:40:40 PM	53	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:40 PM	11	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:40 PM	3	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:45 PM	39	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:40:48 PM	53	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:48 PM	10	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:48 PM	12	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:48 PM	79	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:48 PM	12	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:40:48 PM	27	1367.50	TQEX
GENMAB A/S	28-Mar-25	4:41:00 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	32	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	42	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	2	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	25	1368.00	XCSE

204

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:41:00 PM	46	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	10	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:00 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:01 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:01 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:01 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:01 PM	93	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:03 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:03 PM	53	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:03 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:03 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:04 PM	12	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:04 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:04 PM	11	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:15 PM	5	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:41:17 PM	56	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:41:37 PM	53	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:41:37 PM	12	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:41:37 PM	11	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:41:39 PM	93	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:41:40 PM	53	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:41:40 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:41:40 PM	11	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:42:05 PM	12	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:42:05 PM	11	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:42:05 PM	53	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:42:06 PM	39	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:42:15 PM	46	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:42:18 PM	35	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:42:18 PM	19	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:42:18 PM	17	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:42:18 PM	42	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:42:18 PM	9	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:42:18 PM	42	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:42:18 PM	25	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:42:23 PM	13	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:42:23 PM	9	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:42:23 PM	12	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:43:02 PM	52	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:43:02 PM	11	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:43:02 PM	101	1369.00	CEUX
GENMAB A/S	28-Mar-25	4:43:18 PM	49	1369.00	CEUX
GENMAB A/S	28-Mar-25	4:43:27 PM	26	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:43:36 PM	28	1369.00	XCSE

205

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:43:36 PM	53	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:43:38 PM	37	1369.00	CEUX
GENMAB A/S	28-Mar-25	4:43:38 PM	8	1369.00	CEUX
GENMAB A/S	28-Mar-25	4:43:46 PM	40	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:43:46 PM	29	1369.00	AQEU
GENMAB A/S	28-Mar-25	4:43:49 PM	22	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:44:02 PM	28	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:02 PM	19	1369.00	XCSE
GENMAB A/S	28-Mar-25	4:44:08 PM	13	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:08 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:08 PM	53	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:08 PM	50	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:08 PM	20	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:44:08 PM	22	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:44:13 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:23 PM	7	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:44:28 PM	10	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:44:28 PM	28	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:44:28 PM	10	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:44:28 PM	22	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:00 PM	12	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:08 PM	24	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:08 PM	42	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:28 PM	1	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:28 PM	4	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:28 PM	31	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:45:28 PM	2	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:46:15 PM	41	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:46:17 PM	33	1368.50	TQEX
GENMAB A/S	28-Mar-25	4:46:22 PM	11	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:22 PM	5	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:22 PM	1	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:22 PM	5	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:22 PM	42	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:46:24 PM	13	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:24 PM	1	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:24 PM	11	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:24 PM	44	1368.50	CEUX
GENMAB A/S	28-Mar-25	4:46:29 PM	30	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:29 PM	13	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:29 PM	53	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:29 PM	13	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:29 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:29 PM	8	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:29 PM	5	1368.50	XCSE

206

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:46:29 PM	12	1368.50	XCSE
GENMAB A/S	28-Mar-25	4:46:47 PM	21	1368.00	AQEU
GENMAB A/S	28-Mar-25	4:47:24 PM	1	1368.00	AQEU
GENMAB A/S	28-Mar-25	4:47:25 PM	30	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:47:25 PM	21	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:47:26 PM	11	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:47:37 PM	22	1368.00	AQEU
GENMAB A/S	28-Mar-25	4:47:55 PM	47	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:47:55 PM	34	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:47:55 PM	11	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:02 PM	47	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:48:02 PM	12	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:04 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:04 PM	42	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:04 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:05 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:48:05 PM	13	1368.00	XCSE
GENMAB A/S	28-Mar-25	4:48:05 PM	36	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:05 PM	2	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:05 PM	2	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:05 PM	11	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:07 PM	33	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:48:07 PM	37	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:07 PM	25	1367.50	TQEX
GENMAB A/S	28-Mar-25	4:48:07 PM	2	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:07 PM	11	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:07 PM	3	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:07 PM	6	1368.00	TQEX
GENMAB A/S	28-Mar-25	4:48:25 PM	33	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:48:36 PM	41	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:48:36 PM	8	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:48:52 PM	14	1367.00	AQEU
GENMAB A/S	28-Mar-25	4:48:52 PM	5	1367.00	AQEU
GENMAB A/S	28-Mar-25	4:48:55 PM	12	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:48:55 PM	34	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:49:19 PM	27	1368.00	AQEU
GENMAB A/S	28-Mar-25	4:49:26 PM	78	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:49:26 PM	17	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:49:26 PM	51	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:49:26 PM	5	1368.00	CEUX
GENMAB A/S	28-Mar-25	4:49:26 PM	18	1367.50	CEUX
GENMAB A/S	28-Mar-25	4:49:26 PM	23	1367.50	TQEX
GENMAB A/S	28-Mar-25	4:49:27 PM	13	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:49:27 PM	11	1367.50	XCSE
GENMAB A/S	28-Mar-25	4:49:45 PM	8	1367.00	AQEU

207

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:50:00 PM	11	1367.00	XCSE
GENMAB A/S	28-Mar-25	4:50:00 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:50:00 PM	8	1366.50	TQEX
GENMAB A/S	28-Mar-25	4:50:14 PM	25	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:50:14 PM	5	1366.50	TQEX
GENMAB A/S	28-Mar-25	4:50:19 PM	6	1366.50	TQEX
GENMAB A/S	28-Mar-25	4:50:19 PM	4	1366.50	TQEX
GENMAB A/S	28-Mar-25	4:50:24 PM	5	1366.50	TQEX
GENMAB A/S	28-Mar-25	4:50:47 PM	1	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:50:52 PM	1	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:50:57 PM	10	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:50:57 PM	5	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:50:57 PM	16	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:50:57 PM	1	1366.00	AQEU
GENMAB A/S	28-Mar-25	4:51:07 PM	42	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:07 PM	33	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:07 PM	24	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:07 PM	11	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:51:08 PM	2	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:08 PM	33	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:09 PM	101	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:51:09 PM	51	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:10 PM	12	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:10 PM	35	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:51:11 PM	13	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:51:11 PM	26	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:11 PM	30	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:51:12 PM	1	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:51:27 PM	45	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:51:27 PM	22	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:51:32 PM	12	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:51:32 PM	21	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:51:47 PM	70	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:52:07 PM	4	1365.00	XCSE
GENMAB A/S	28-Mar-25	4:52:10 PM	12	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:52:10 PM	35	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:52:10 PM	13	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:52:10 PM	10	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:52:10 PM	31	1366.00	CEUX
GENMAB A/S	28-Mar-25	4:52:34 PM	100	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:52:34 PM	11	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:52:34 PM	9	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:52:55 PM	5	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:52:57 PM	8	1365.00	CEUX
GENMAB A/S	28-Mar-25	4:52:57 PM	6	1365.50	CEUX

208

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:52:58 PM	53	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:52:58 PM	18	1365.00	AQEU
GENMAB A/S	28-Mar-25	4:52:59 PM	5	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:52:59 PM	5	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:02 PM	11	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:19 PM	10	1365.00	AQEU
GENMAB A/S	28-Mar-25	4:53:26 PM	36	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:27 PM	13	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:53:27 PM	3	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:53:27 PM	85	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:53:27 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:27 PM	5	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:27 PM	6	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:27 PM	42	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:27 PM	2	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:53:27 PM	3	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:53:27 PM	3	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:53:27 PM	12	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:53:27 PM	2	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:53:28 PM	12	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:28 PM	62	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:28 PM	5	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:53:28 PM	22	1365.50	TQEX
GENMAB A/S	28-Mar-25	4:53:29 PM	6	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:53:38 PM	8	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:53:41 PM	42	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:41 PM	42	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:41 PM	6	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:41 PM	6	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:41 PM	5	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:51 PM	42	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:51 PM	6	1366.50	CEUX
GENMAB A/S	28-Mar-25	4:53:55 PM	101	1366.00	XCSE
GENMAB A/S	28-Mar-25	4:53:55 PM	33	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:53:55 PM	30	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:53:55 PM	7	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:53:55 PM	4	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:53:55 PM	5	1366.00	TQEX
GENMAB A/S	28-Mar-25	4:54:02 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:02 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:03 PM	26	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:03 PM	64	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:03 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:04 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:04 PM	12	1366.50	XCSE

209

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 26 – March 28, 2025

GENMAB A/S	28-Mar-25	4:54:04 PM	30	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:04 PM	6	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:04 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:04 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:05 PM	55	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:07 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:07 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:07 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:14 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:14 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:14 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:15 PM	100	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:15 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:15 PM	13	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:15 PM	53	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:19 PM	100	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:33 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	1	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	12	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:40 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:41 PM	11	1366.50	XCSE
GENMAB A/S	28-Mar-25	4:54:45 PM	25	1365.50	CEUX
GENMAB A/S	28-Mar-25	4:54:51 PM	20	1365.50	AQEU
GENMAB A/S	28-Mar-25	4:54:56 PM	23	1365.50	XCSE
GENMAB A/S	28-Mar-25	4:54:58 PM	21	1365.50	XCSE

210