Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

Issuer	Date	Time CET	Quantity	Price (DKK)	Venue
GENMAB A/S	31-Mar-2025	09:42:24 AM	61	1345.50	TQEX
GENMAB A/S	31-Mar-2025	09:42:24 AM	73	1345.50	CEUX
GENMAB A/S	31-Mar-2025	09:42:25 AM	68	1345.50	XCSE
GENMAB A/S	31-Mar-2025	09:42:25 AM	72	1345.00	AQEU
GENMAB A/S	31-Mar-2025	09:42:44 AM	64	1344.50	XCSE
GENMAB A/S	31-Mar-2025	09:42:44 AM	71	1344.50	TQEX
GENMAB A/S	31-Mar-2025	09:42:44 AM	68	1344.50	CEUX
GENMAB A/S	31-Mar-2025	09:42:46 AM	72	1343.50	XCSE
GENMAB A/S	31-Mar-2025	09:42:46 AM	11	1343.50	TQEX
GENMAB A/S	31-Mar-2025	09:42:46 AM	67	1343.50	CEUX
GENMAB A/S	31-Mar-2025	09:42:51 AM	63	1343.50	TQEX
GENMAB A/S	31-Mar-2025	09:44:45 AM	43	1348.00	XCSE
GENMAB A/S	31-Mar-2025	09:45:27 AM	14	1347.50	CEUX
GENMAB A/S	31-Mar-2025	09:45:27 AM	41	1347.50	CEUX
GENMAB A/S	31-Mar-2025	09:45:38 AM	39	1347.00	XCSE
GENMAB A/S	31-Mar-2025	09:45:47 AM	36	1346.50	CEUX
GENMAB A/S	31-Mar-2025	09:45:47 AM	42	1346.50	AQEU
GENMAB A/S	31-Mar-2025	09:46:23 AM	34	1346.00	XCSE
GENMAB A/S	31-Mar-2025	09:46:45 AM	11	1345.50	CEUX
GENMAB A/S	31-Mar-2025	09:46:45 AM	24	1345.50	CEUX
GENMAB A/S	31-Mar-2025	09:46:45 AM	22	1345.50	AQEU
GENMAB A/S	31-Mar-2025	09:49:19 AM	76	1346.50	XCSE
GENMAB A/S	31-Mar-2025	09:49:19 AM	25	1346.50	AQEU
GENMAB A/S	31-Mar-2025	09:49:36 AM	61	1346.00	CEUX
GENMAB A/S	31-Mar-2025	09:50:25 AM	79	1345.50	XCSE
GENMAB A/S	31-Mar-2025	09:50:25 AM	54	1346.00	CEUX
GENMAB A/S	31-Mar-2025	09:51:29 AM	83	1346.00	XCSE
GENMAB A/S	31-Mar-2025	09:51:29 AM	25	1346.00	CEUX
GENMAB A/S	31-Mar-2025	09:51:29 AM	31	1346.00	CEUX
GENMAB A/S	31-Mar-2025	09:53:50 AM	23	1346.50	AQEU
GENMAB A/S	31-Mar-2025	09:54:10 AM	36	1347.00	CEUX
GENMAB A/S	31-Mar-2025	09:54:10 AM	36	1347.00	CEUX
GENMAB A/S	31-Mar-2025	09:54:11 AM	23	1346.50	AQEU
GENMAB A/S	31-Mar-2025	09:55:37 AM	76	1345.50	XCSE
GENMAB A/S	31-Mar-2025	09:55:37 AM	25	1346.00	CEUX
GENMAB A/S	31-Mar-2025	09:55:37 AM	13	1346.00	CEUX
GENMAB A/S	31-Mar-2025	09:55:45 AM	53	1345.00	CEUX
GENMAB A/S	31-Mar-2025	09:55:48 AM	65	1344.50	XCSE
GENMAB A/S	31-Mar-2025	09:55:48 AM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	09:58:21 AM	2	1345.00	XCSE
GENMAB A/S	31-Mar-2025	09:58:27 AM	62	1345.50	CEUX
GENMAB A/S	31-Mar-2025	09:58:46 AM	75	1345.00	XCSE
GENMAB A/S	31-Mar-2025	09:58:46 AM	22	1345.00	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	09:58:48 AM	3	1344.50	CEUX
GENMAB A/S	31-Mar-2025	09:58:48 AM	54	1344.50	CEUX
GENMAB A/S	31-Mar-2025	10:00:47 AM	30	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:00:47 AM	37	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:01:35 AM	1	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:01:35 AM	21	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:01:35 AM	79	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:02:43 AM	64	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:03:16 AM	80	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:03:42 AM	46	1343.50	CEUX
GENMAB A/S	31-Mar-2025	10:03:49 AM	83	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:03:49 AM	33	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:03:49 AM	29	1343.00	TQEX
GENMAB A/S	31-Mar-2025	10:04:12 AM	50	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:04:12 AM	22	1343.00	TQEX
GENMAB A/S	31-Mar-2025	10:04:12 AM	50	1343.00	CEUX
GENMAB A/S	31-Mar-2025	10:04:12 AM	19	1343.00	CEUX
GENMAB A/S	31-Mar-2025	10:04:44 AM	81	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:05:10 AM	10	1342.00	CEUX
GENMAB A/S	31-Mar-2025	10:05:39 AM	51	1342.00	CEUX
GENMAB A/S	31-Mar-2025	10:06:25 AM	20	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:06:26 AM	15	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:07:14 AM	6	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:07:14 AM	74	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:07:20 AM	8	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:07:20 AM	5	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:07:20 AM	8	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:07:28 AM	53	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:07:31 AM	25	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:07:41 AM	43	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:07:41 AM	31	1342.00	TQEX
GENMAB A/S	31-Mar-2025	10:08:07 AM	58	1341.50	CEUX
GENMAB A/S	31-Mar-2025	10:08:13 AM	7	1341.50	CEUX
GENMAB A/S	31-Mar-2025	10:10:40 AM	24	1341.00	XCSE
GENMAB A/S	31-Mar-2025	10:10:40 AM	54	1341.00	XCSE
GENMAB A/S	31-Mar-2025	10:10:49 AM	57	1340.50	CEUX
GENMAB A/S	31-Mar-2025	10:15:26 AM	22	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:15:33 AM	6	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:15:33 AM	52	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:17:26 AM	16	1343.50	CEUX
GENMAB A/S	31-Mar-2025	10:17:55 AM	10	1343.50	CEUX
GENMAB A/S	31-Mar-2025	10:19:29 AM	40	1343.50	TQEX
GENMAB A/S	31-Mar-2025	10:19:29 AM	57	1343.50	CEUX
GENMAB A/S	31-Mar-2025	10:20:12 AM	62	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:20:12 AM	20	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	10:20:12 AM	44	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:12 AM	37	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:12 AM	17	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:12 AM	6	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	82	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	81	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	37	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	30	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	15	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	22	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:20:19 AM	62	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:20:42 AM	27	1342.50	TQEX
GENMAB A/S	31-Mar-2025	10:20:42 AM	83	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:21:51 AM	31	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:21:51 AM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:21:51 AM	30	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:21:51 AM	5	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:21:59 AM	1	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:31 AM	79	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:23:31 AM	30	1343.50	TQEX
GENMAB A/S	31-Mar-2025	10:23:31 AM	81	1344.00	CEUX
GENMAB A/S	31-Mar-2025	10:23:34 AM	77	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	16	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	56	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	8	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	44	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	20	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:34 AM	40	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:23:55 AM	81	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:24:02 AM	78	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:24:16 AM	26	1342.50	TQEX
GENMAB A/S	31-Mar-2025	10:24:43 AM	10	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:24:48 AM	3	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:25:11 AM	65	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:26:29 AM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	10:26:29 AM	24	1344.50	CEUX
GENMAB A/S	31-Mar-2025	10:28:00 AM	69	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:28:00 AM	7	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:28:00 AM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:28:00 AM	2	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:28:55 AM	26	1345.50	XCSE
GENMAB A/S	31-Mar-2025	10:28:55 AM	7	1345.50	CEUX
GENMAB A/S	31-Mar-2025	10:30:57 AM	22	1347.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	10:30:57 AM	80	1347.50	CEUX
GENMAB A/S	31-Mar-2025	10:32:24 AM	51	1347.00	XCSE
GENMAB A/S	31-Mar-2025	10:32:24 AM	26	1347.00	XCSE
GENMAB A/S	31-Mar-2025	10:32:51 AM	76	1346.50	CEUX
GENMAB A/S	31-Mar-2025	10:32:51 AM	36	1346.50	CEUX
GENMAB A/S	31-Mar-2025	10:33:08 AM	1	1347.00	XCSE
GENMAB A/S	31-Mar-2025	10:33:14 AM	43	1347.00	XCSE
GENMAB A/S	31-Mar-2025	10:33:30 AM	35	1347.00	XCSE
GENMAB A/S	31-Mar-2025	10:34:35 AM	79	1346.50	CEUX
GENMAB A/S	31-Mar-2025	10:35:17 AM	83	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:35:17 AM	26	1346.00	TQEX
GENMAB A/S	31-Mar-2025	10:35:17 AM	36	1346.00	CEUX
GENMAB A/S	31-Mar-2025	10:35:17 AM	5	1346.00	CEUX
GENMAB A/S	31-Mar-2025	10:36:15 AM	82	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:36:15 AM	30	1345.00	TQEX
GENMAB A/S	31-Mar-2025	10:36:15 AM	83	1345.50	CEUX
GENMAB A/S	31-Mar-2025	10:37:30 AM	35	1344.00	CEUX
GENMAB A/S	31-Mar-2025	10:37:47 AM	42	1344.00	CEUX
GENMAB A/S	31-Mar-2025	10:37:52 AM	45	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:37:52 AM	32	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:43:19 AM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:43:19 AM	17	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:43:19 AM	22	1343.00	TQEX
GENMAB A/S	31-Mar-2025	10:43:19 AM	76	1343.00	CEUX
GENMAB A/S	31-Mar-2025	10:43:23 AM	22	1343.00	AQEU
GENMAB A/S	31-Mar-2025	10:43:36 AM	30	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:43:52 AM	46	1342.50	XCSE
GENMAB A/S	31-Mar-2025	10:45:15 AM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:45:15 AM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	10:47:02 AM	22	1342.00	TQEX
GENMAB A/S	31-Mar-2025	10:47:02 AM	16	1342.00	CEUX
GENMAB A/S	31-Mar-2025	10:47:02 AM	66	1342.00	CEUX
GENMAB A/S	31-Mar-2025	10:47:28 AM	26	1342.00	AQEU
GENMAB A/S	31-Mar-2025	10:47:33 AM	44	1342.00	XCSE
GENMAB A/S	31-Mar-2025	10:47:56 AM	28	1343.00	XCSE
GENMAB A/S	31-Mar-2025	10:47:58 AM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	10:47:58 AM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	10:48:28 AM	14	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:48:28 AM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	10:50:31 AM	4	1344.50	XCSE
GENMAB A/S	31-Mar-2025	10:50:46 AM	3	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:51:38 AM	1	1345.50	XCSE
GENMAB A/S	31-Mar-2025	10:52:46 AM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:52:46 AM	13	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:52:46 AM	22	1346.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	10:52:46 AM	4	1346.00	CEUX
GENMAB A/S	31-Mar-2025	10:52:46 AM	5	1346.00	CEUX
GENMAB A/S	31-Mar-2025	10:52:46 AM	5	1346.00	CEUX
GENMAB A/S	31-Mar-2025	10:53:16 AM	23	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:53:18 AM	13	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:53:18 AM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:53:18 AM	1	1346.00	XCSE
GENMAB A/S	31-Mar-2025	10:53:18 AM	36	1346.00	CEUX
GENMAB A/S	31-Mar-2025	10:55:05 AM	29	1345.50	TQEX
GENMAB A/S	31-Mar-2025	10:55:05 AM	35	1345.50	CEUX
GENMAB A/S	31-Mar-2025	10:55:05 AM	45	1345.50	CEUX
GENMAB A/S	31-Mar-2025	10:55:51 AM	78	1345.00	XCSE
GENMAB A/S	31-Mar-2025	10:55:55 AM	36	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:30 AM	13	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:32 AM	9	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:32 AM	5	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:33 AM	10	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:56 AM	6	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:57 AM	6	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:57 AM	5	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:56:57 AM	6	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:59:49 AM	23	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:59:49 AM	36	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:59:49 AM	22	1345.00	CEUX
GENMAB A/S	31-Mar-2025	10:59:55 AM	55	1344.00	XCSE
GENMAB A/S	31-Mar-2025	10:59:55 AM	23	1344.50	TQEX
GENMAB A/S	31-Mar-2025	10:59:55 AM	77	1344.50	CEUX
GENMAB A/S	31-Mar-2025	10:59:55 AM	27	1344.50	AQEU
GENMAB A/S	31-Mar-2025	11:03:08 AM	22	1343.50	AQEU
GENMAB A/S	31-Mar-2025	11:03:08 AM	26	1343.50	TQEX
GENMAB A/S	31-Mar-2025	11:03:08 AM	26	1343.50	CEUX
GENMAB A/S	31-Mar-2025	11:03:08 AM	52	1343.50	CEUX
GENMAB A/S	31-Mar-2025	11:03:55 AM	53	1343.00	XCSE
GENMAB A/S	31-Mar-2025	11:03:56 AM	17	1343.00	XCSE
GENMAB A/S	31-Mar-2025	11:03:56 AM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	11:03:56 AM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	11:03:56 AM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	11:03:58 AM	6	1343.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:16 AM	5	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:16 AM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:16 AM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:16 AM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:16 AM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:17 AM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:24 AM	12	1344.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:06:40 AM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:06:53 AM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	11:07:01 AM	43	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:07:01 AM	7	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:07:01 AM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:07:01 AM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:07:01 AM	1	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:09:28 AM	7	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:09:28 AM	38	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:09:28 AM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:09:29 AM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:09:29 AM	38	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:09:29 AM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	81	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	6	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	38	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	26	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	13	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:11:12 AM	36	1345.00	CEUX
GENMAB A/S	31-Mar-2025	11:11:12 AM	5	1345.00	CEUX
GENMAB A/S	31-Mar-2025	11:11:12 AM	81	1344.50	CEUX
GENMAB A/S	31-Mar-2025	11:12:20 AM	78	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:12:20 AM	77	1346.00	CEUX
GENMAB A/S	31-Mar-2025	11:12:21 AM	13	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:12:21 AM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:12:21 AM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:12:21 AM	36	1346.00	CEUX
GENMAB A/S	31-Mar-2025	11:12:21 AM	6	1346.00	CEUX
GENMAB A/S	31-Mar-2025	11:12:21 AM	6	1346.00	CEUX
GENMAB A/S	31-Mar-2025	11:13:09 AM	1	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:09 AM	32	1345.50	AQEU
GENMAB A/S	31-Mar-2025	11:13:09 AM	32	1346.00	CEUX
GENMAB A/S	31-Mar-2025	11:13:10 AM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	14	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	30	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	12	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	37	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	1	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	48	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	30	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	12	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	12	1346.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	1	1346.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:13:10 AM	77	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	38	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	31	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:10 AM	29	1345.00	TQEX
GENMAB A/S	31-Mar-2025	11:13:10 AM	24	1345.00	CEUX
GENMAB A/S	31-Mar-2025	11:13:10 AM	55	1345.00	CEUX
GENMAB A/S	31-Mar-2025	11:13:11 AM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:11 AM	13	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:11 AM	21	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:12 AM	96	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:13:27 AM	6	1344.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:13 AM	1	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:13 AM	12	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:13 AM	38	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:13 AM	11	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:13 AM	27	1345.00	CEUX
GENMAB A/S	31-Mar-2025	11:14:14 AM	62	1345.00	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	16	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	34	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	11:14:14 AM	11	1345.50	CEUX
GENMAB A/S	31-Mar-2025	11:22:27 AM	76	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:22:27 AM	20	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:22:27 AM	36	1347.00	AQEU
GENMAB A/S	31-Mar-2025	11:22:27 AM	25	1347.00	CEUX
GENMAB A/S	31-Mar-2025	11:23:02 AM	28	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:23:02 AM	44	1346.50	TQEX
GENMAB A/S	31-Mar-2025	11:23:02 AM	1	1346.50	CEUX
GENMAB A/S	31-Mar-2025	11:23:02 AM	76	1346.50	CEUX
GENMAB A/S	31-Mar-2025	11:23:02 AM	5	1346.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:35 AM	52	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:25:38 AM	31	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:38 AM	5	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:38 AM	5	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:38 AM	6	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:39 AM	12	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:39 AM	24	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:39 AM	5	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:39 AM	6	1347.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:25:39 AM	8	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:40 AM	36	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:40 AM	5	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:25:59 AM	29	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:26:00 AM	11	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:26:12 AM	13	1347.50	XCSE
GENMAB A/S	31-Mar-2025	11:26:12 AM	14	1347.50	XCSE
GENMAB A/S	31-Mar-2025	11:26:12 AM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	11:26:12 AM	35	1347.50	XCSE
GENMAB A/S	31-Mar-2025	11:26:12 AM	31	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:26:12 AM	37	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:26:12 AM	26	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:26:12 AM	6	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:26:12 AM	5	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:27:14 AM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:27:14 AM	11	1347.00	XCSE
GENMAB A/S	31-Mar-2025	11:27:14 AM	42	1347.00	TQEX
GENMAB A/S	31-Mar-2025	11:27:14 AM	79	1347.00	CEUX
GENMAB A/S	31-Mar-2025	11:27:14 AM	30	1347.00	CEUX
GENMAB A/S	31-Mar-2025	11:27:14 AM	6	1347.00	CEUX
GENMAB A/S	31-Mar-2025	11:27:14 AM	5	1347.00	CEUX
GENMAB A/S	31-Mar-2025	11:28:44 AM	50	1348.00	XCSE
GENMAB A/S	31-Mar-2025	11:29:04 AM	2	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:04 AM	9	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:04 AM	9	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:04 AM	5	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:05 AM	15	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:05 AM	5	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:05 AM	6	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:06 AM	5	1349.00	CEUX
GENMAB A/S	31-Mar-2025	11:29:11 AM	15	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:29:11 AM	23	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:30:34 AM	18	1350.50	CEUX
GENMAB A/S	31-Mar-2025	11:30:34 AM	25	1350.50	CEUX
GENMAB A/S	31-Mar-2025	11:31:03 AM	40	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:31:03 AM	1	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:31:03 AM	1	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:31:08 AM	14	1351.50	CEUX
GENMAB A/S	31-Mar-2025	11:31:24 AM	12	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:31:24 AM	24	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:31:24 AM	77	1351.00	CEUX
GENMAB A/S	31-Mar-2025	11:31:58 AM	6	1351.50	CEUX
GENMAB A/S	31-Mar-2025	11:32:37 AM	29	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:32:37 AM	38	1352.50	XCSE
GENMAB A/S	31-Mar-2025	11:32:37 AM	29	1352.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:32:37 AM	8	1352.50	XCSE
GENMAB A/S	31-Mar-2025	11:32:37 AM	7	1352.00	CEUX
GENMAB A/S	31-Mar-2025	11:32:37 AM	71	1352.00	CEUX
GENMAB A/S	31-Mar-2025	11:32:37 AM	22	1352.00	CEUX
GENMAB A/S	31-Mar-2025	11:32:38 AM	2	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:32:38 AM	41	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:32:38 AM	9	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	2	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	74	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	45	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	38	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	21	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	36	1350.50	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	12	1350.50	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	29	1350.50	XCSE
GENMAB A/S	31-Mar-2025	11:34:02 AM	42	1351.50	TQEX
GENMAB A/S	31-Mar-2025	11:34:02 AM	79	1352.00	CEUX
GENMAB A/S	31-Mar-2025	11:34:02 AM	78	1351.00	CEUX
GENMAB A/S	31-Mar-2025	11:34:10 AM	31	1350.50	TQEX
GENMAB A/S	31-Mar-2025	11:34:11 AM	9	1350.50	TQEX
GENMAB A/S	31-Mar-2025	11:35:49 AM	30	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	38	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	11	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	25	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	11	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	1	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	13	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	38	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	35	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	11	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	13	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	38	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:49 AM	10	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:50 AM	13	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:50 AM	59	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:35:50 AM	11	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:36:04 AM	55	1351.50	TQEX
GENMAB A/S	31-Mar-2025	11:37:45 AM	35	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:37:45 AM	18	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:37:45 AM	26	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:37:45 AM	1	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:37:45 AM	1	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:39:19 AM	80	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:19 AM	18	1351.00	AQEU
GENMAB A/S	31-Mar-2025	11:39:19 AM	2	1351.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:39:19 AM	79	1351.00	CEUX
GENMAB A/S	31-Mar-2025	11:39:53 AM	43	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	38	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	12	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	11	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	22	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	1	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	8	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	22	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	3	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	12	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:53 AM	8	1351.00	AQEU
GENMAB A/S	31-Mar-2025	11:39:54 AM	22	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:39:54 AM	1	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:40:17 AM	43	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:40:17 AM	26	1351.50	XCSE
GENMAB A/S	31-Mar-2025	11:41:01 AM	31	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:41:01 AM	12	1352.00	XCSE
GENMAB A/S	31-Mar-2025	11:41:06 AM	67	1351.50	TQEX
GENMAB A/S	31-Mar-2025	11:42:21 AM	81	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:21 AM	8	1351.00	CEUX
GENMAB A/S	31-Mar-2025	11:42:42 AM	44	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:42 AM	34	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:42 AM	24	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:42 AM	1	1351.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:42 AM	33	1351.00	AQEU
GENMAB A/S	31-Mar-2025	11:42:42 AM	70	1351.00	CEUX
GENMAB A/S	31-Mar-2025	11:42:42 AM	32	1351.00	CEUX
GENMAB A/S	31-Mar-2025	11:42:44 AM	80	1350.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:44 AM	104	1350.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:44 AM	44	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:44 AM	60	1350.50	TQEX
GENMAB A/S	31-Mar-2025	11:42:44 AM	44	1349.50	TQEX
GENMAB A/S	31-Mar-2025	11:42:44 AM	29	1350.00	AQEU
GENMAB A/S	31-Mar-2025	11:42:44 AM	80	1350.00	CEUX
GENMAB A/S	31-Mar-2025	11:42:45 AM	38	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	4	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	23	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	38	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	11	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	13	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	15	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:45 AM	23	1349.00	AQEU
GENMAB A/S	31-Mar-2025	11:42:45 AM	4	1349.00	AQEU
GENMAB A/S	31-Mar-2025	11:42:46 AM	12	1349.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:42:46 AM	23	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	38	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	31	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	15	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	23	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	19	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	13	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:42:46 AM	21	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:42:46 AM	9	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:43:00 AM	1	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:43:00 AM	1	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	41	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	13	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	1	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	5	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	12	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	10	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	5	1349.00	XCSE
GENMAB A/S	31-Mar-2025	11:45:04 AM	34	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:45:04 AM	17	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:47:10 AM	6	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:48:27 AM	82	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:49:44 AM	34	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:49:44 AM	38	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:51:47 AM	3	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:51:47 AM	1	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:51:47 AM	20	1348.00	TQEX
GENMAB A/S	31-Mar-2025	11:51:47 AM	11	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:51:48 AM	1	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:52:01 AM	11	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:52:01 AM	11	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:52:58 AM	4	1348.00	TQEX
GENMAB A/S	31-Mar-2025	11:52:58 AM	23	1348.00	AQEU
GENMAB A/S	31-Mar-2025	11:54:49 AM	79	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:54:49 AM	78	1348.50	CEUX
GENMAB A/S	31-Mar-2025	11:54:51 AM	38	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:54:51 AM	12	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:54:51 AM	14	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:54:51 AM	12	1348.50	XCSE
GENMAB A/S	31-Mar-2025	11:54:53 AM	28	1348.00	AQEU
GENMAB A/S	31-Mar-2025	11:55:38 AM	80	1347.50	XCSE
GENMAB A/S	31-Mar-2025	11:55:38 AM	46	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:55:38 AM	31	1347.50	CEUX
GENMAB A/S	31-Mar-2025	11:55:54 AM	30	1347.00	TQEX
GENMAB A/S	31-Mar-2025	11:56:30 AM	77	1346.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	11:56:30 AM	81	1346.50	CEUX
GENMAB A/S	31-Mar-2025	11:56:36 AM	26	1346.50	AQEU
GENMAB A/S	31-Mar-2025	11:57:29 AM	22	1347.00	TQEX
GENMAB A/S	31-Mar-2025	11:58:03 AM	53	1346.50	XCSE
GENMAB A/S	31-Mar-2025	11:58:03 AM	28	1346.50	XCSE
GENMAB A/S	31-Mar-2025	11:58:03 AM	29	1346.50	AQEU
GENMAB A/S	31-Mar-2025	11:58:03 AM	69	1346.50	CEUX
GENMAB A/S	31-Mar-2025	11:58:23 AM	25	1346.00	TQEX
GENMAB A/S	31-Mar-2025	12:00:01 PM	79	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:00:01 PM	29	1346.00	AQEU
GENMAB A/S	31-Mar-2025	12:00:12 PM	12	1347.00	XCSE
GENMAB A/S	31-Mar-2025	12:00:12 PM	22	1347.00	XCSE
GENMAB A/S	31-Mar-2025	12:00:12 PM	12	1347.00	XCSE
GENMAB A/S	31-Mar-2025	12:01:41 PM	78	1346.50	CEUX
GENMAB A/S	31-Mar-2025	12:02:36 PM	44	1347.00	XCSE
GENMAB A/S	31-Mar-2025	12:02:36 PM	11	1347.00	XCSE
GENMAB A/S	31-Mar-2025	12:03:49 PM	80	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:03:49 PM	22	1346.00	AQEU
GENMAB A/S	31-Mar-2025	12:04:06 PM	82	1346.00	CEUX
GENMAB A/S	31-Mar-2025	12:04:16 PM	12	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:04:16 PM	6	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:04:16 PM	4	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:04:16 PM	38	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:05:36 PM	32	1346.50	XCSE
GENMAB A/S	31-Mar-2025	12:05:36 PM	13	1346.50	XCSE
GENMAB A/S	31-Mar-2025	12:05:36 PM	1	1346.50	XCSE
GENMAB A/S	31-Mar-2025	12:05:56 PM	1	1346.50	XCSE
GENMAB A/S	31-Mar-2025	12:06:22 PM	11	1346.50	XCSE
GENMAB A/S	31-Mar-2025	12:06:23 PM	83	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:07:37 PM	64	1345.00	XCSE
GENMAB A/S	31-Mar-2025	12:07:37 PM	32	1345.50	TQEX
GENMAB A/S	31-Mar-2025	12:08:37 PM	1	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:08:37 PM	19	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:08:37 PM	1	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:08:37 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	12:09:19 PM	83	1345.00	CEUX
GENMAB A/S	31-Mar-2025	12:09:31 PM	82	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:09:31 PM	27	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:09:31 PM	15	1343.50	XCSE
GENMAB A/S	31-Mar-2025	12:09:31 PM	30	1343.50	XCSE
GENMAB A/S	31-Mar-2025	12:09:31 PM	34	1343.50	XCSE
GENMAB A/S	31-Mar-2025	12:09:31 PM	29	1344.50	TQEX
GENMAB A/S	31-Mar-2025	12:09:31 PM	8	1345.00	AQEU
GENMAB A/S	31-Mar-2025	12:09:31 PM	15	1345.00	AQEU
GENMAB A/S	31-Mar-2025	12:09:31 PM	24	1343.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	12:09:31 PM	76	1344.00	CEUX
GENMAB A/S	31-Mar-2025	12:09:31 PM	7	1342.50	CEUX
GENMAB A/S	31-Mar-2025	12:09:31 PM	10	1342.50	CEUX
GENMAB A/S	31-Mar-2025	12:10:18 PM	75	1343.50	CEUX
GENMAB A/S	31-Mar-2025	12:11:35 PM	37	1343.00	AQEU
GENMAB A/S	31-Mar-2025	12:12:07 PM	44	1343.00	XCSE
GENMAB A/S	31-Mar-2025	12:12:07 PM	38	1343.00	XCSE
GENMAB A/S	31-Mar-2025	12:12:08 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:03 PM	30	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:03 PM	38	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:03 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:03 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:03 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:37 PM	44	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:37 PM	30	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:37 PM	18	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:15:37 PM	7	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:16:23 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:16:26 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:19:30 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	12:20:29 PM	78	1344.50	XCSE
GENMAB A/S	31-Mar-2025	12:20:29 PM	20	1344.50	CEUX
GENMAB A/S	31-Mar-2025	12:27:37 PM	1	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:27:37 PM	3	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:27:37 PM	2	1345.00	CEUX
GENMAB A/S	31-Mar-2025	12:27:37 PM	77	1345.00	CEUX
GENMAB A/S	31-Mar-2025	12:27:37 PM	28	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:27:38 PM	13	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:28:09 PM	56	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:30:15 PM	1	1346.00	XCSE
GENMAB A/S	31-Mar-2025	12:30:15 PM	36	1346.00	CEUX
GENMAB A/S	31-Mar-2025	12:30:47 PM	21	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:30:47 PM	33	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:30:47 PM	48	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:30:59 PM	33	1345.50	XCSE
GENMAB A/S	31-Mar-2025	12:30:59 PM	17	1345.00	AQEU
GENMAB A/S	31-Mar-2025	12:31:21 PM	11	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:31:21 PM	1	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:31:21 PM	15	1345.50	CEUX
GENMAB A/S	31-Mar-2025	12:32:10 PM	15	1345.00	TQEX
GENMAB A/S	31-Mar-2025	12:32:10 PM	13	1345.00	TQEX
GENMAB A/S	31-Mar-2025	12:32:10 PM	16	1345.00	AQEU
GENMAB A/S	31-Mar-2025	12:32:12 PM	82	1344.50	XCSE
GENMAB A/S	31-Mar-2025	12:32:24 PM	31	1344.00	AQEU
GENMAB A/S	31-Mar-2025	12:32:24 PM	5	1344.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	12:32:59 PM	28	1344.00	TQEX
GENMAB A/S	31-Mar-2025	12:32:59 PM	73	1344.00	CEUX
GENMAB A/S	31-Mar-2025	12:33:27 PM	78	1343.50	XCSE
GENMAB A/S	31-Mar-2025	12:34:09 PM	23	1343.00	TQEX
GENMAB A/S	31-Mar-2025	12:34:14 PM	24	1343.00	AQEU
GENMAB A/S	31-Mar-2025	12:34:14 PM	1	1342.50	CEUX
GENMAB A/S	31-Mar-2025	12:36:46 PM	79	1342.00	XCSE
GENMAB A/S	31-Mar-2025	12:36:46 PM	54	1342.50	CEUX
GENMAB A/S	31-Mar-2025	12:36:56 PM	43	1341.50	XCSE
GENMAB A/S	31-Mar-2025	12:36:56 PM	1	1341.50	XCSE
GENMAB A/S	31-Mar-2025	12:36:56 PM	30	1341.50	XCSE
GENMAB A/S	31-Mar-2025	12:36:56 PM	3	1341.50	XCSE
GENMAB A/S	31-Mar-2025	12:36:56 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	12:36:56 PM	28	1341.50	TQEX
GENMAB A/S	31-Mar-2025	12:37:03 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	12:37:18 PM	21	1342.50	XCSE
GENMAB A/S	31-Mar-2025	12:37:18 PM	42	1342.50	XCSE
GENMAB A/S	31-Mar-2025	12:37:23 PM	11	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	12:37:34 PM	33	1,342.00	XCSE
GENMAB A/S	31-Mar-2025	12:37:34 PM	30	1,342.00	TQEX
GENMAB A/S	31-Mar-2025	12:37:34 PM	24	1,342.00	AQEU
GENMAB A/S	31-Mar-2025	12:37:34 PM	1	1,342.00	AQEU
GENMAB A/S	31-Mar-2025	12:37:34 PM	77	1,342.00	CEUX
GENMAB A/S	31-Mar-2025	12:39:16 PM	80	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	12:39:16 PM	79	1,341.00	CEUX
GENMAB A/S	31-Mar-2025	12:39:18 PM	77	1,340.00	XCSE
GENMAB A/S	31-Mar-2025	12:40:35 PM	3	1,339.50	CEUX
GENMAB A/S	31-Mar-2025	12:40:35 PM	78	1,339.50	CEUX
GENMAB A/S	31-Mar-2025	12:41:28 PM	5	1,339.00	XCSE
GENMAB A/S	31-Mar-2025	12:41:28 PM	73	1,339.00	XCSE
GENMAB A/S	31-Mar-2025	12:41:28 PM	83	1,338.50	CEUX
GENMAB A/S	31-Mar-2025	12:41:57 PM	76	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	12:41:57 PM	76	1,337.50	CEUX
GENMAB A/S	31-Mar-2025	12:44:03 PM	44	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	12:44:03 PM	1	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	12:44:03 PM	1	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	12:48:34 PM	10	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	50	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	12	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	44	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	11	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	12	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	12	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	25	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	11	1,340.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	12:48:56 PM	12	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:56 PM	72	1,340.50	CEUX
GENMAB A/S	31-Mar-2025	12:48:57 PM	41	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:57 PM	37	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:57 PM	12	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:57 PM	11	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:57 PM	26	1,340.00	TQEX
GENMAB A/S	31-Mar-2025	12:48:58 PM	81	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:58 PM	27	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	12:48:58 PM	81	1,339.50	CEUX
GENMAB A/S	31-Mar-2025	12:49:00 PM	29	1,339.00	TQEX
GENMAB A/S	31-Mar-2025	12:49:00 PM	26	1,339.00	AQEU
GENMAB A/S	31-Mar-2025	12:49:13 PM	79	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	12:49:13 PM	2	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	12:49:13 PM	64	1,338.50	CEUX
GENMAB A/S	31-Mar-2025	12:52:48 PM	27	1,338.00	AQEU
GENMAB A/S	31-Mar-2025	12:52:49 PM	69	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	12:52:49 PM	10	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	12:52:53 PM	38	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	12:52:59 PM	80	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	12:54:27 PM	34	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	12:54:27 PM	44	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	12:54:27 PM	22	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	12:54:27 PM	2	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	12:54:27 PM	20	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	12:56:17 PM	35	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	12:56:19 PM	22	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	12:56:19 PM	18	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	12:56:23 PM	65	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	12:59:55 PM	37	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	12:59:55 PM	5	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	12:59:55 PM	13	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	12:59:55 PM	29	1,336.00	CEUX
GENMAB A/S	31-Mar-2025	12:59:58 PM	13	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:00:01 PM	34	1,336.00	CEUX
GENMAB A/S	31-Mar-2025	13:00:33 PM	13	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:00:33 PM	11	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:00:33 PM	37	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:00:33 PM	12	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:01:01 PM	44	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:01:09 PM	80	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:01:09 PM	24	1,336.00	TQEX
GENMAB A/S	31-Mar-2025	13:01:09 PM	5	1,336.00	CEUX
GENMAB A/S	31-Mar-2025	13:01:53 PM	42	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:01:53 PM	11	1,336.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	13:01:53 PM	13	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:01:53 PM	22	1,336.00	AQEU
GENMAB A/S	31-Mar-2025	13:02:14 PM	83	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:02:21 PM	6	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	13:02:21 PM	11	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	13:03:26 PM	1	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:04:24 PM	2	1,340.50	TQEX
GENMAB A/S	31-Mar-2025	13:04:25 PM	22	1,340.50	TQEX
GENMAB A/S	31-Mar-2025	13:05:40 PM	62	1,341.00	CEUX
GENMAB A/S	31-Mar-2025	13:06:01 PM	83	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:06:01 PM	1	1,340.50	AQEU
GENMAB A/S	31-Mar-2025	13:06:01 PM	24	1,340.50	AQEU
GENMAB A/S	31-Mar-2025	13:06:16 PM	13	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:06:23 PM	11	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:06:39 PM	12	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:06:39 PM	12	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:06:39 PM	35	1,340.00	CEUX
GENMAB A/S	31-Mar-2025	13:06:39 PM	24	1,340.00	CEUX
GENMAB A/S	31-Mar-2025	13:09:36 PM	2	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:09:36 PM	1	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:10:03 PM	26	1,341.00	TQEX
GENMAB A/S	31-Mar-2025	13:12:06 PM	25	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:12:06 PM	51	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:12:06 PM	22	1,340.50	CEUX
GENMAB A/S	31-Mar-2025	13:15:07 PM	37	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	9	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	13	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	1	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	13	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	13	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	37	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	2	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:07 PM	13	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:08 PM	37	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:08 PM	11	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:08 PM	13	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:09 PM	1	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:09 PM	74	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:09 PM	3	1,340.50	XCSE
GENMAB A/S	31-Mar-2025	13:15:09 PM	23	1,340.50	TQEX
GENMAB A/S	31-Mar-2025	13:15:09 PM	54	1,340.50	CEUX
GENMAB A/S	31-Mar-2025	13:15:09 PM	13	1,340.50	CEUX
GENMAB A/S	31-Mar-2025	13:16:16 PM	12	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:16:16 PM	12	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:16:16 PM	11	1,341.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	13:17:00 PM	12	1,343.50	XCSE
GENMAB A/S	31-Mar-2025	13:17:21 PM	10	1,343.50	XCSE
GENMAB A/S	31-Mar-2025	13:17:21 PM	60	1,343.50	XCSE
GENMAB A/S	31-Mar-2025	13:17:21 PM	37	1,343.50	XCSE
GENMAB A/S	31-Mar-2025	13:17:21 PM	66	1,343.50	CEUX
GENMAB A/S	31-Mar-2025	13:19:19 PM	79	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:19:20 PM	44	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:19:20 PM	13	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:19:20 PM	12	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:19:20 PM	57	1,342.50	CEUX
GENMAB A/S	31-Mar-2025	13:19:20 PM	2	1,342.50	CEUX
GENMAB A/S	31-Mar-2025	13:19:20 PM	6	1,342.50	CEUX
GENMAB A/S	31-Mar-2025	13:20:00 PM	1	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	80	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	28	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	76	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	80	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	25	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	37	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	13	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	7	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	22	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:34 PM	23	1,342.00	TQEX
GENMAB A/S	31-Mar-2025	13:20:34 PM	43	1,342.50	CEUX
GENMAB A/S	31-Mar-2025	13:20:36 PM	83	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:36 PM	45	1,341.50	CEUX
GENMAB A/S	31-Mar-2025	13:20:41 PM	12	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:41 PM	12	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:20:45 PM	15	1,342.00	AQEU
GENMAB A/S	31-Mar-2025	13:21:25 PM	1	1,343.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:25 PM	1	1,343.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:41 PM	81	1,342.50	XCSE
GENMAB A/S	31-Mar-2025	13:22:41 PM	79	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:22:41 PM	45	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:41 PM	37	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:22:41 PM	22	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:22:41 PM	18	1,342.00	AQEU
GENMAB A/S	31-Mar-2025	13:22:41 PM	24	1,342.50	CEUX
GENMAB A/S	31-Mar-2025	13:22:41 PM	27	1,341.00	CEUX
GENMAB A/S	31-Mar-2025	13:22:51 PM	30	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:51 PM	8	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:51 PM	37	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:51 PM	12	1,341.00	XCSE
GENMAB A/S	31-Mar-2025	13:22:51 PM	17	1,341.50	XCSE
GENMAB A/S	31-Mar-2025	13:22:51 PM	79	1,340.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	13:22:51 PM	25	1,340.50	AQEU
GENMAB A/S	31-Mar-2025	13:23:00 PM	7	1,339.00	XCSE
GENMAB A/S	31-Mar-2025	13:23:00 PM	72	1,339.00	XCSE
GENMAB A/S	31-Mar-2025	13:23:00 PM	23	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:23:00 PM	30	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:23:00 PM	11	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:23:00 PM	37	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:23:00 PM	3	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:24:05 PM	41	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:24:05 PM	30	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:24:05 PM	1	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:24:05 PM	1	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:24:05 PM	31	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:25:13 PM	23	1,339.00	CEUX
GENMAB A/S	31-Mar-2025	13:26:25 PM	1	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:26:25 PM	1	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:26:25 PM	1	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:26:25 PM	2	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:26:25 PM	2	1,339.50	XCSE
GENMAB A/S	31-Mar-2025	13:26:38 PM	10	1,339.00	CEUX
GENMAB A/S	31-Mar-2025	13:26:38 PM	6	1,339.00	CEUX
GENMAB A/S	31-Mar-2025	13:26:38 PM	8	1,339.00	CEUX
GENMAB A/S	31-Mar-2025	13:27:19 PM	82	1,339.00	XCSE
GENMAB A/S	31-Mar-2025	13:27:19 PM	22	1,339.00	TQEX
GENMAB A/S	31-Mar-2025	13:28:57 PM	12	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:28:57 PM	21	1,339.00	XCSE
GENMAB A/S	31-Mar-2025	13:28:57 PM	11	1,338.50	AQEU
GENMAB A/S	31-Mar-2025	13:28:57 PM	5	1,338.50	AQEU
GENMAB A/S	31-Mar-2025	13:28:57 PM	19	1,338.50	AQEU
GENMAB A/S	31-Mar-2025	13:28:57 PM	30	1,339.00	CEUX
GENMAB A/S	31-Mar-2025	13:30:26 PM	1	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:30:26 PM	1	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	79	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	1	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	12	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	30	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	37	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	10	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	14	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:31:24 PM	29	1,338.00	CEUX
GENMAB A/S	31-Mar-2025	13:32:26 PM	81	1,338.50	XCSE
GENMAB A/S	31-Mar-2025	13:33:05 PM	25	1,338.00	AQEU
GENMAB A/S	31-Mar-2025	13:33:05 PM	3	1,338.00	AQEU
GENMAB A/S	31-Mar-2025	13:33:05 PM	32	1,338.00	CEUX
GENMAB A/S	31-Mar-2025	13:33:26 PM	22	1,337.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	13:35:08 PM	82	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	13:35:48 PM	22	1,336.50	AQEU
GENMAB A/S	31-Mar-2025	13:35:48 PM	23	1,336.50	CEUX
GENMAB A/S	31-Mar-2025	13:37:26 PM	80	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:37:57 PM	22	1,337.50	TQEX
GENMAB A/S	31-Mar-2025	13:38:01 PM	43	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	13:38:32 PM	26	1,337.00	AQEU
GENMAB A/S	31-Mar-2025	13:40:49 PM	82	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	13:40:49 PM	22	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	13:40:49 PM	54	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	13:41:56 PM	40	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	13:43:02 PM	17	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:43:02 PM	62	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:43:02 PM	50	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:43:02 PM	8	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	13:43:26 PM	12	1,336.00	CEUX
GENMAB A/S	31-Mar-2025	13:45:37 PM	82	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:45:37 PM	40	1,336.50	TQEX
GENMAB A/S	31-Mar-2025	13:47:15 PM	1	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	13:49:30 PM	82	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	13:49:30 PM	51	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	13:49:53 PM	12	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	13:49:53 PM	10	1,338.00	XCSE
GENMAB A/S	31-Mar-2025	13:50:26 PM	1	1,337.50	XCSE
GENMAB A/S	31-Mar-2025	13:52:04 PM	82	1,337.00	CEUX
GENMAB A/S	31-Mar-2025	13:52:25 PM	1	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	13:52:25 PM	13	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	13:52:26 PM	3	1,337.00	XCSE
GENMAB A/S	31-Mar-2025	13:53:22 PM	80	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:53:24 PM	17	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:53:24 PM	11	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:53:24 PM	11	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:53:26 PM	2	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:53:26 PM	3	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:53:34 PM	40	1,336.00	CEUX
GENMAB A/S	31-Mar-2025	13:54:28 PM	13	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:28 PM	12	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:35 PM	13	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:35 PM	11	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:35 PM	12	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:35 PM	13	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:36 PM	11	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:36 PM	11	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:54:36 PM	82	1,336.00	CEUX
GENMAB A/S	31-Mar-2025	13:54:55 PM	12	1,336.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	13:54:55 PM	10	1,336.50	XCSE
GENMAB A/S	31-Mar-2025	13:55:25 PM	11	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:55:25 PM	11	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:57:25 PM	1	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:57:26 PM	12	1,336.00	XCSE
GENMAB A/S	31-Mar-2025	13:59:45 PM	6	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	13:59:52 PM	73	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	13:59:52 PM	22	1,335.50	TQEX
GENMAB A/S	31-Mar-2025	13:59:53 PM	42	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	13:59:53 PM	14	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	13:59:53 PM	12	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	13:59:53 PM	10	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:00:00 PM	1	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:00:00 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:00:00 PM	35	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:00:00 PM	8	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:00:25 PM	30	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:00:25 PM	12	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:00:25 PM	11	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:00:25 PM	36	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:00:25 PM	1	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:00:25 PM	9	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:01:01 PM	11	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:01:01 PM	11	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:01:15 PM	2	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:01:15 PM	11	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:03:17 PM	80	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:03:17 PM	32	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:03:19 PM	22	1,334.50	CEUX
GENMAB A/S	31-Mar-2025	14:03:19 PM	56	1,334.50	CEUX
GENMAB A/S	31-Mar-2025	14:05:19 PM	69	1,334.00	XCSE
GENMAB A/S	31-Mar-2025	14:06:00 PM	22	1,334.50	TQEX
GENMAB A/S	31-Mar-2025	14:09:26 PM	3	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:09:26 PM	1	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:10:25 PM	1	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:10:25 PM	1	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:10:25 PM	2	1,335.50	XCSE
GENMAB A/S	31-Mar-2025	14:10:25 PM	11	1,335.50	CEUX
GENMAB A/S	31-Mar-2025	14:10:26 PM	7	1,335.50	CEUX
GENMAB A/S	31-Mar-2025	14:10:34 PM	83	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:02 PM	64	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:11:11 PM	26	1,335.00	TQEX
GENMAB A/S	31-Mar-2025	14:11:11 PM	26	1,335.00	AQEU
GENMAB A/S	31-Mar-2025	14:11:11 PM	13	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:11:11 PM	15	1,335.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	14:11:21 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:21 PM	36	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:11:21 PM	5	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:11:22 PM	12	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:22 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:22 PM	14	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:22 PM	28	1,335.00	CEUX
GENMAB A/S	31-Mar-2025	14:11:23 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:23 PM	1	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:23 PM	14	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:23 PM	12	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:23 PM	13	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:23 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:24 PM	13	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:25 PM	12	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:26 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:26 PM	12	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:26 PM	42	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	12	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	1	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	28	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	13	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	41	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	9	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	12	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	11	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	28	1,334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	4	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	11	1,335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	38	1335.00	XCSE
GENMAB A/S	31-Mar-2025	14:11:27 PM	27	1334.50	AQEU
GENMAB A/S	31-Mar-2025	14:11:27 PM	79	1334.50	CEUX
GENMAB A/S	31-Mar-2025	14:11:28 PM	11	1334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:28 PM	11	1334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:35 PM	17	1334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:35 PM	12	1334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:35 PM	42	1334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:35 PM	4	1334.50	XCSE
GENMAB A/S	31-Mar-2025	14:11:35 PM	7	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:12:21 PM	22	1333.50	TQEX
GENMAB A/S	31-Mar-2025	14:12:21 PM	78	1333.50	CEUX
GENMAB A/S	31-Mar-2025	14:12:36 PM	3	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:12:40 PM	5	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:13:05 PM	1	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:13:05 PM	12	1333.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	14:13:05 PM	12	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:13:05 PM	19	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:13:26 PM	13	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:14:25 PM	2	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:14:25 PM	75	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:14:25 PM	28	1332.50	TQEX
GENMAB A/S	31-Mar-2025	14:14:25 PM	81	1332.50	CEUX
GENMAB A/S	31-Mar-2025	14:17:24 PM	23	1331.50	AQEU
GENMAB A/S	31-Mar-2025	14:17:24 PM	82	1331.50	CEUX
GENMAB A/S	31-Mar-2025	14:17:28 PM	3	1331.50	XCSE
GENMAB A/S	31-Mar-2025	14:17:28 PM	48	1331.00	XCSE
GENMAB A/S	31-Mar-2025	14:18:18 PM	83	1332.00	XCSE
GENMAB A/S	31-Mar-2025	14:18:18 PM	31	1332.00	TQEX
GENMAB A/S	31-Mar-2025	14:18:18 PM	76	1332.00	CEUX
GENMAB A/S	31-Mar-2025	14:18:28 PM	70	1332.00	XCSE
GENMAB A/S	31-Mar-2025	14:18:28 PM	8	1332.00	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	11	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	11	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	1	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	1	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	12	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	13	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	42	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	12	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	6	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:02 PM	9	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:03 PM	12	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:03 PM	13	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:03 PM	17	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:03 PM	11	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:03 PM	11	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:03 PM	12	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:09 PM	12	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:19:15 PM	12	1332.50	XCSE
GENMAB A/S	31-Mar-2025	14:20:09 PM	29	1332.50	TQEX
GENMAB A/S	31-Mar-2025	14:20:19 PM	15	1332.00	XCSE
GENMAB A/S	31-Mar-2025	14:20:46 PM	27	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:21:14 PM	27	1333.50	TQEX
GENMAB A/S	31-Mar-2025	14:21:25 PM	1	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:21:26 PM	14	1333.50	CEUX
GENMAB A/S	31-Mar-2025	14:23:09 PM	23	1333.50	TQEX
GENMAB A/S	31-Mar-2025	14:23:26 PM	1	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:23:26 PM	1	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:23:56 PM	23	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:23:56 PM	77	1335.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	14:23:56 PM	24	1335.50	TQEX
GENMAB A/S	31-Mar-2025	14:23:56 PM	82	1335.00	CEUX
GENMAB A/S	31-Mar-2025	14:25:00 PM	1	1335.50	XCSE
GENMAB A/S	31-Mar-2025	14:25:00 PM	6	1335.50	XCSE
GENMAB A/S	31-Mar-2025	14:25:44 PM	1	1335.50	XCSE
GENMAB A/S	31-Mar-2025	14:25:46 PM	21	1335.50	CEUX
GENMAB A/S	31-Mar-2025	14:27:00 PM	1	1336.50	XCSE
GENMAB A/S	31-Mar-2025	14:27:19 PM	9	1337.50	XCSE
GENMAB A/S	31-Mar-2025	14:28:26 PM	82	1337.00	XCSE
GENMAB A/S	31-Mar-2025	14:28:26 PM	78	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:28:26 PM	78	1335.00	XCSE
GENMAB A/S	31-Mar-2025	14:28:26 PM	76	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:28:26 PM	104	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:28:26 PM	23	1337.00	TQEX
GENMAB A/S	31-Mar-2025	14:28:26 PM	1	1335.50	TQEX
GENMAB A/S	31-Mar-2025	14:28:26 PM	21	1335.50	TQEX
GENMAB A/S	31-Mar-2025	14:28:26 PM	22	1337.00	AQEU
GENMAB A/S	31-Mar-2025	14:28:26 PM	36	1336.00	AQEU
GENMAB A/S	31-Mar-2025	14:28:26 PM	26	1335.50	AQEU
GENMAB A/S	31-Mar-2025	14:28:26 PM	24	1334.00	AQEU
GENMAB A/S	31-Mar-2025	14:28:26 PM	81	1337.00	CEUX
GENMAB A/S	31-Mar-2025	14:28:26 PM	81	1335.50	CEUX
GENMAB A/S	31-Mar-2025	14:28:26 PM	65	1334.00	CEUX
GENMAB A/S	31-Mar-2025	14:28:26 PM	16	1334.00	CEUX
GENMAB A/S	31-Mar-2025	14:28:26 PM	32	1334.50	CEUX
GENMAB A/S	31-Mar-2025	14:28:30 PM	104	1333.50	XCSE
GENMAB A/S	31-Mar-2025	14:28:30 PM	23	1333.50	AQEU
GENMAB A/S	31-Mar-2025	14:30:00 PM	76	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:00 PM	22	1334.00	AQEU
GENMAB A/S	31-Mar-2025	14:30:01 PM	43	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:01 PM	29	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:01 PM	25	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:01 PM	7	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:08 PM	76	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:13 PM	22	1334.00	AQEU
GENMAB A/S	31-Mar-2025	14:30:13 PM	76	1333.50	CEUX
GENMAB A/S	31-Mar-2025	14:30:45 PM	83	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:30:45 PM	22	1333.00	AQEU
GENMAB A/S	31-Mar-2025	14:33:05 PM	36	1335.00	XCSE
GENMAB A/S	31-Mar-2025	14:33:05 PM	46	1335.00	XCSE
GENMAB A/S	31-Mar-2025	14:33:33 PM	78	1334.00	XCSE
GENMAB A/S	31-Mar-2025	14:33:33 PM	23	1334.00	AQEU
GENMAB A/S	31-Mar-2025	14:33:33 PM	32	1334.00	CEUX
GENMAB A/S	31-Mar-2025	14:33:42 PM	41	1333.50	CEUX
GENMAB A/S	31-Mar-2025	14:33:42 PM	39	1333.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	14:33:54 PM	81	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:34:07 PM	26	1333.00	AQEU
GENMAB A/S	31-Mar-2025	14:34:12 PM	10	1332.50	CEUX
GENMAB A/S	31-Mar-2025	14:34:12 PM	66	1332.50	CEUX
GENMAB A/S	31-Mar-2025	14:34:17 PM	79	1332.00	XCSE
GENMAB A/S	31-Mar-2025	14:34:31 PM	58	1331.50	CEUX
GENMAB A/S	31-Mar-2025	14:34:31 PM	10	1331.50	CEUX
GENMAB A/S	31-Mar-2025	14:34:31 PM	12	1331.50	CEUX
GENMAB A/S	31-Mar-2025	14:37:17 PM	30	1332.50	TQEX
GENMAB A/S	31-Mar-2025	14:37:17 PM	70	1332.50	CEUX
GENMAB A/S	31-Mar-2025	14:38:26 PM	3	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:38:26 PM	11	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:38:26 PM	11	1333.00	XCSE
GENMAB A/S	31-Mar-2025	14:39:26 PM	36	1333.50	CEUX
GENMAB A/S	31-Mar-2025	14:41:36 PM	1	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:36 PM	12	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:36 PM	11	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:36 PM	11	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:36 PM	1	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	22	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	12	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	11	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	4	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	42	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	25	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	11	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	11	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	12	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	12	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:37 PM	30	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:38 PM	11	1336.00	XCSE
GENMAB A/S	31-Mar-2025	14:41:41 PM	80	1335.50	XCSE
GENMAB A/S	31-Mar-2025	14:42:55 PM	11	1335.50	XCSE
GENMAB A/S	31-Mar-2025	14:42:55 PM	23	1336.00	TQEX
GENMAB A/S	31-Mar-2025	14:43:25 PM	20	1337.00	XCSE
GENMAB A/S	31-Mar-2025	14:43:31 PM	15	1337.50	CEUX
GENMAB A/S	31-Mar-2025	14:43:45 PM	12	1338.00	XCSE
GENMAB A/S	31-Mar-2025	14:43:45 PM	10	1338.00	XCSE
GENMAB A/S	31-Mar-2025	14:43:57 PM	77	1337.50	XCSE
GENMAB A/S	31-Mar-2025	14:43:57 PM	62	1337.50	CEUX
GENMAB A/S	31-Mar-2025	14:44:01 PM	33	1337.50	AQEU
GENMAB A/S	31-Mar-2025	14:45:26 PM	2	1337.50	XCSE
GENMAB A/S	31-Mar-2025	14:45:26 PM	1	1337.50	XCSE
GENMAB A/S	31-Mar-2025	14:45:26 PM	1	1337.50	XCSE
GENMAB A/S	31-Mar-2025	14:47:08 PM	76	1338.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	14:47:09 PM	22	1338.00	TQEX
GENMAB A/S	31-Mar-2025	14:47:09 PM	33	1338.00	AQEU
GENMAB A/S	31-Mar-2025	14:47:10 PM	81	1337.50	XCSE
GENMAB A/S	31-Mar-2025	14:47:10 PM	77	1337.50	CEUX
GENMAB A/S	31-Mar-2025	14:48:12 PM	11	1338.50	CEUX
GENMAB A/S	31-Mar-2025	14:48:25 PM	14	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:48:25 PM	42	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:48:25 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:48:25 PM	9	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:48:26 PM	9	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:00 PM	29	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:00 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:15 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:15 PM	10	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:45 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:45 PM	20	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:45 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:49:45 PM	28	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:50:25 PM	41	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:50:25 PM	4	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:50:25 PM	19	1338.50	AQEU
GENMAB A/S	31-Mar-2025	14:50:25 PM	66	1338.50	CEUX
GENMAB A/S	31-Mar-2025	14:50:32 PM	4	1338.50	AQEU
GENMAB A/S	31-Mar-2025	14:51:51 PM	76	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:51:51 PM	65	1338.50	CEUX
GENMAB A/S	31-Mar-2025	14:51:51 PM	15	1338.50	CEUX
GENMAB A/S	31-Mar-2025	14:52:02 PM	5	1338.00	TQEX
GENMAB A/S	31-Mar-2025	14:52:02 PM	17	1338.00	TQEX
GENMAB A/S	31-Mar-2025	14:52:31 PM	1	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:52:32 PM	102	1338.00	XCSE
GENMAB A/S	31-Mar-2025	14:52:32 PM	33	1338.00	AQEU
GENMAB A/S	31-Mar-2025	14:53:03 PM	19	1338.50	CEUX
GENMAB A/S	31-Mar-2025	14:53:03 PM	57	1338.50	CEUX
GENMAB A/S	31-Mar-2025	14:53:19 PM	22	1338.00	TQEX
GENMAB A/S	31-Mar-2025	14:54:25 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:54:25 PM	14	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:54:25 PM	1	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:54:26 PM	1	1338.50	XCSE
GENMAB A/S	31-Mar-2025	14:56:26 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:56:26 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:57:31 PM	80	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:57:31 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:04 PM	41	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:04 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:04 PM	13	1339.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	14:59:04 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:26 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:26 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:27 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:27 PM	2	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:27 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:27 PM	16	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:49 PM	41	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:49 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:49 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:49 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:55 PM	4	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:55 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	14:59:55 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:00:14 PM	12	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:00:23 PM	6	1340.50	CEUX
GENMAB A/S	31-Mar-2025	15:00:23 PM	6	1340.50	CEUX
GENMAB A/S	31-Mar-2025	15:00:32 PM	3	1340.00	XCSE
GENMAB A/S	31-Mar-2025	15:00:32 PM	79	1340.00	XCSE
GENMAB A/S	31-Mar-2025	15:00:32 PM	31	1340.00	TQEX
GENMAB A/S	31-Mar-2025	15:00:32 PM	82	1340.00	CEUX
GENMAB A/S	31-Mar-2025	15:03:25 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:04:06 PM	82	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:05:25 PM	32	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:05:41 PM	41	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:05:41 PM	2	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:05:41 PM	1	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:05:41 PM	22	1344.50	TQEX
GENMAB A/S	31-Mar-2025	15:05:41 PM	83	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:06:25 PM	44	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	3	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	28	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	3	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	1	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	36	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:25 PM	1	1344.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:06:26 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:26 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:26 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:26 PM	36	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:06:26 PM	6	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:07:26 PM	42	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:07:26 PM	1	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:07:26 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:08:09 PM	79	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:08:25 PM	17	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:26 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:37 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:47 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:47 PM	34	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:51 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:51 PM	34	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:57 PM	16	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:08:57 PM	6	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:00 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:00 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:00 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:00 PM	8	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:05 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:05 PM	16	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:09:08 PM	83	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:09:08 PM	26	1343.50	TQEX
GENMAB A/S	31-Mar-2025	15:09:08 PM	23	1343.50	AQEU
GENMAB A/S	31-Mar-2025	15:09:08 PM	7	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:09:08 PM	31	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:09:10 PM	82	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:09:10 PM	24	1342.50	TQEX
GENMAB A/S	31-Mar-2025	15:09:10 PM	56	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:09:10 PM	21	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:09:10 PM	82	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:09:32 PM	70	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:10:48 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:10:48 PM	23	1342.50	AQEU
GENMAB A/S	31-Mar-2025	15:11:03 PM	1	1342.50	AQEU
GENMAB A/S	31-Mar-2025	15:11:56 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:11:57 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:12:03 PM	3	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:12:17 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:12:17 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:12:17 PM	14	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:14:00 PM	2	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:14:00 PM	30	1343.00	TQEX
GENMAB A/S	31-Mar-2025	15:14:00 PM	34	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:14:00 PM	45	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:14:03 PM	78	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:14:03 PM	24	1342.50	AQEU
GENMAB A/S	31-Mar-2025	15:14:25 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:14:26 PM	2	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:15:19 PM	81	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:15:19 PM	32	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:18:26 PM	31	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:18:27 PM	11	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	47	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:21:02 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:21:02 PM	28	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:21:02 PM	29	1343.00	TQEX
GENMAB A/S	31-Mar-2025	15:21:02 PM	36	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	27	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	9	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	18	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	30	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	20	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:02 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:21:26 PM	8	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:22:12 PM	12	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:22:25 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:22:25 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:22:25 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:22:25 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:22:25 PM	36	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:22:39 PM	26	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:22:39 PM	37	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:22:39 PM	36	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:22:39 PM	5	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:22:39 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:40 PM	20	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:40 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:40 PM	5	1343.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:22:40 PM	26	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:40 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:44 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:49 PM	4	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:22:51 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:23:27 PM	1	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:23:34 PM	77	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:23:58 PM	9	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:24:26 PM	52	1343.00	TQEX
GENMAB A/S	31-Mar-2025	15:24:26 PM	74	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:24:27 PM	14	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:24:27 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:24:27 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:24:59 PM	76	1342.50	XCSE
GENMAB A/S	31-Mar-2025	15:25:27 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:25:27 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:25:27 PM	13	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:25:27 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:25:27 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:25:34 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	15:25:51 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:51 PM	30	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:51 PM	17	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:51 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:51 PM	9	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:51 PM	24	1342.50	AQEU
GENMAB A/S	31-Mar-2025	15:25:52 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	3	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	30	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	9	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	19	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	24	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:52 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:53 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:53 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:53 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:53 PM	13	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:25:53 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:53 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	18	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	29	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	16	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:54 PM	5	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	16	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:55 PM	31	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	7	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	16	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	37	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:25:56 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:26:26 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:26:30 PM	41	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:26:30 PM	9	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:26:30 PM	18	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:26:30 PM	23	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	4	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	15	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	16	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	12	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	1	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	36	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:26:30 PM	4	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:00 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:27:00 PM	1	1345.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:27:00 PM	3	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:27:00 PM	12	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:03 PM	15	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:03 PM	15	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:21 PM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:27:21 PM	10	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:22 PM	6	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:27:36 PM	27	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:37 PM	3	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:27:37 PM	11	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:38 PM	16	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:27:39 PM	6	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:27:54 PM	1	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:28:00 PM	3	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:28:00 PM	30	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:28:00 PM	15	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:28:49 PM	51	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:29:03 PM	29	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:29:03 PM	7	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:29:14 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:29:14 PM	63	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:29:14 PM	22	1345.50	AQEU
GENMAB A/S	31-Mar-2025	15:29:15 PM	36	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:29:15 PM	13	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:29:20 PM	42	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:29:21 PM	7	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:29:22 PM	25	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:29:23 PM	16	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:29:27 PM	2	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:29:39 PM	28	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:29:49 PM	12	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:29:49 PM	98	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:30:07 PM	34	1347.50	TQEX
GENMAB A/S	31-Mar-2025	15:30:10 PM	36	1347.50	TQEX
GENMAB A/S	31-Mar-2025	15:30:10 PM	36	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:30:10 PM	5	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:30:10 PM	6	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:30:11 PM	27	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:30:14 PM	17	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	14	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	37	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	14	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	37	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	2	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	79	1346.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:30:17 PM	37	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	13	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	12	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	30	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:30:17 PM	66	1346.00	TQEX
GENMAB A/S	31-Mar-2025	15:30:17 PM	64	1345.00	TQEX
GENMAB A/S	31-Mar-2025	15:30:17 PM	22	1346.00	AQEU
GENMAB A/S	31-Mar-2025	15:30:17 PM	22	1345.00	AQEU
GENMAB A/S	31-Mar-2025	15:30:17 PM	10	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:30:17 PM	80	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:30:17 PM	82	1345.00	CEUX
GENMAB A/S	31-Mar-2025	15:31:05 PM	79	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:31:05 PM	25	1347.00	TQEX
GENMAB A/S	31-Mar-2025	15:31:05 PM	31	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:31:05 PM	23	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:31:22 PM	53	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:31:22 PM	36	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:31:22 PM	30	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:31:28 PM	22	1347.00	TQEX
GENMAB A/S	31-Mar-2025	15:31:28 PM	25	1347.00	AQEU
GENMAB A/S	31-Mar-2025	15:31:28 PM	79	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:31:29 PM	41	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:31:29 PM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:31:32 PM	19	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:31:32 PM	12	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:03 PM	27	1348.50	TQEX
GENMAB A/S	31-Mar-2025	15:32:19 PM	78	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:19 PM	81	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:32:19 PM	10	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:32:19 PM	12	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:32:26 PM	21	1348.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:26 PM	13	1348.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:26 PM	12	1348.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:26 PM	76	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:32:29 PM	16	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	60	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	37	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	44	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	37	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:29 PM	62	1347.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:32:29 PM	20	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:32:30 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:30 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:30 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:30 PM	13	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:30 PM	37	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:30 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:46 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:46 PM	37	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:49 PM	43	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:49 PM	10	1346.50	AQEU
GENMAB A/S	31-Mar-2025	15:32:49 PM	71	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:32:51 PM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:51 PM	83	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	30	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	37	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	11	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	30	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	12	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	11	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:52 PM	30	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:55 PM	5	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:32:55 PM	28	1346.00	TQEX
GENMAB A/S	31-Mar-2025	15:32:55 PM	7	1346.50	AQEU
GENMAB A/S	31-Mar-2025	15:32:55 PM	6	1346.50	AQEU
GENMAB A/S	31-Mar-2025	15:32:55 PM	83	1346.00	CEUX
GENMAB A/S	31-Mar-2025	15:32:56 PM	5	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:32:56 PM	74	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:33:15 PM	44	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:33:15 PM	37	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:33:15 PM	23	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:33:28 PM	2	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:33:50 PM	81	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:33:50 PM	23	1346.00	TQEX
GENMAB A/S	31-Mar-2025	15:34:04 PM	50	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	22	1345.50	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	19	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	41	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	12	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	14	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:04 PM	37	1346.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:34:04 PM	77	1345.50	CEUX
GENMAB A/S	31-Mar-2025	15:34:04 PM	2	1345.50	CEUX
GENMAB A/S	31-Mar-2025	15:34:15 PM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:15 PM	11	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:15 PM	37	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:15 PM	31	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:15 PM	13	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:15 PM	1	1346.00	XCSE
GENMAB A/S	31-Mar-2025	15:34:16 PM	80	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:34:16 PM	26	1344.50	TQEX
GENMAB A/S	31-Mar-2025	15:34:16 PM	82	1344.50	CEUX
GENMAB A/S	31-Mar-2025	15:34:19 PM	41	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:34:39 PM	82	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:11 PM	82	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:35:11 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:35:11 PM	24	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:35:11 PM	23	1344.50	TQEX
GENMAB A/S	31-Mar-2025	15:35:11 PM	74	1344.50	CEUX
GENMAB A/S	31-Mar-2025	15:35:11 PM	3	1344.50	CEUX
GENMAB A/S	31-Mar-2025	15:35:12 PM	79	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:13 PM	23	1344.00	AQEU
GENMAB A/S	31-Mar-2025	15:35:42 PM	6	1344.00	AQEU
GENMAB A/S	31-Mar-2025	15:35:55 PM	16	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:55 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:55 PM	19	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:55 PM	14	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:55 PM	27	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:55 PM	9	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:35:55 PM	18	1345.00	XCSE
GENMAB A/S	31-Mar-2025	15:36:03 PM	82	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:36:03 PM	22	1344.00	TQEX
GENMAB A/S	31-Mar-2025	15:36:03 PM	18	1344.00	AQEU
GENMAB A/S	31-Mar-2025	15:36:03 PM	81	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:36:05 PM	79	1343.00	XCSE
GENMAB A/S	31-Mar-2025	15:36:07 PM	76	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:36:15 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:36:15 PM	29	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:36:21 PM	83	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:36:21 PM	80	1340.50	CEUX
GENMAB A/S	31-Mar-2025	15:36:29 PM	83	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:36:59 PM	83	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:37:18 PM	23	1338.50	TQEX
GENMAB A/S	31-Mar-2025	15:37:39 PM	45	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:39:05 PM	1	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:39:05 PM	25	1340.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:39:05 PM	82	1340.50	CEUX
GENMAB A/S	31-Mar-2025	15:39:25 PM	78	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:39:25 PM	43	1341.00	XCSE
GENMAB A/S	31-Mar-2025	15:39:25 PM	61	1341.00	XCSE
GENMAB A/S	31-Mar-2025	15:39:25 PM	35	1340.50	AQEU
GENMAB A/S	31-Mar-2025	15:39:25 PM	5	1340.50	AQEU
GENMAB A/S	31-Mar-2025	15:39:25 PM	76	1340.50	CEUX
GENMAB A/S	31-Mar-2025	15:39:26 PM	37	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:39:26 PM	11	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:39:26 PM	12	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:39:26 PM	44	1340.50	XCSE
GENMAB A/S	31-Mar-2025	15:39:31 PM	26	1339.50	TQEX
GENMAB A/S	31-Mar-2025	15:39:31 PM	26	1339.50	AQEU
GENMAB A/S	31-Mar-2025	15:39:31 PM	79	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:39:37 PM	77	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:39:37 PM	82	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:39:49 PM	17	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:40:09 PM	7	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:40:15 PM	4	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:40:15 PM	2	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:40:15 PM	3	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:40:24 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:40:24 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:40:39 PM	36	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:41:11 PM	42	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:41:11 PM	50	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:41:11 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:41:11 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:41:11 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:41:19 PM	71	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:42:04 PM	46	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:06 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:06 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:06 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:06 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:26 PM	41	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:26 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:26 PM	14	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:26 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:26 PM	4	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:42:27 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:19 PM	104	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:19 PM	5	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:43:19 PM	80	1338.00	CEUX
GENMAB A/S	31-Mar-2025	15:43:20 PM	41	1338.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:43:20 PM	63	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:20 PM	24	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:20 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:20 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:20 PM	36	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:20 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:20 PM	21	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:21 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:21 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:23 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:24 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:24 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:25 PM	29	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:25 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:25 PM	41	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:25 PM	11	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:25 PM	69	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:27 PM	8	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:41 PM	5	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:43:41 PM	6	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:43:41 PM	22	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:43:55 PM	79	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:43:55 PM	30	1337.00	TQEX
GENMAB A/S	31-Mar-2025	15:43:55 PM	79	1337.00	CEUX
GENMAB A/S	31-Mar-2025	15:44:01 PM	78	1336.00	XCSE
GENMAB A/S	31-Mar-2025	15:44:01 PM	24	1336.00	TQEX
GENMAB A/S	31-Mar-2025	15:44:01 PM	11	1336.00	CEUX
GENMAB A/S	31-Mar-2025	15:44:01 PM	31	1336.00	CEUX
GENMAB A/S	31-Mar-2025	15:45:17 PM	16	1336.00	XCSE
GENMAB A/S	31-Mar-2025	15:45:31 PM	31	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:43 PM	41	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:43 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:43 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:44 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:44 PM	30	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:44 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:44 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:44 PM	12	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:45 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:45 PM	16	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:51 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	15	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	49	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	12	1338.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:45:52 PM	15	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	12	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	49	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	30	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:45:52 PM	37	1337.50	TQEX
GENMAB A/S	31-Mar-2025	15:45:52 PM	9	1337.50	CEUX
GENMAB A/S	31-Mar-2025	15:46:03 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:46:03 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:46:05 PM	13	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:46:06 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:46:14 PM	2	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:46:14 PM	2	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:46:14 PM	1	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:46:15 PM	2	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:46:15 PM	2	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:47:00 PM	83	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:47:00 PM	41	1338.50	TQEX
GENMAB A/S	31-Mar-2025	15:47:00 PM	11	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:47:00 PM	37	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:47:00 PM	43	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:47:04 PM	11	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:47:04 PM	39	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:47:04 PM	12	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:47:04 PM	42	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:47:04 PM	52	1337.50	CEUX
GENMAB A/S	31-Mar-2025	15:47:28 PM	7	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:47:58 PM	21	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:47:58 PM	16	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:47:58 PM	18	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:00 PM	38	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:48:00 PM	22	1339.00	AQEU
GENMAB A/S	31-Mar-2025	15:48:00 PM	21	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:00 PM	14	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:00 PM	11	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:00 PM	6	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:00 PM	6	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:00 PM	1	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:05 PM	39	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:48:05 PM	8	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:48:05 PM	12	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:48:05 PM	11	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:48:05 PM	18	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:48:05 PM	34	1339.00	TQEX
GENMAB A/S	31-Mar-2025	15:48:05 PM	36	1339.00	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:48:05 PM	3	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:05 PM	80	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:05 PM	13	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:48:13 PM	76	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:22 PM	7	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:27 PM	16	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:28 PM	22	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:29 PM	25	1339.00	TQEX
GENMAB A/S	31-Mar-2025	15:48:29 PM	2	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:29 PM	77	1339.00	CEUX
GENMAB A/S	31-Mar-2025	15:48:32 PM	44	1338.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:09 PM	7	1338.00	TQEX
GENMAB A/S	31-Mar-2025	15:49:09 PM	27	1338.00	TQEX
GENMAB A/S	31-Mar-2025	15:49:09 PM	36	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:09 PM	5	1338.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:19 PM	1	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:19 PM	1	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:19 PM	1	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:19 PM	9	1338.00	CEUX
GENMAB A/S	31-Mar-2025	15:49:19 PM	13	1338.00	CEUX
GENMAB A/S	31-Mar-2025	15:49:20 PM	1	1338.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:26 PM	6	1338.00	CEUX
GENMAB A/S	31-Mar-2025	15:49:38 PM	77	1337.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	19	1337.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	12	1337.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	82	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	11	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	12	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	39	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	8	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:38 PM	37	1337.00	TQEX
GENMAB A/S	31-Mar-2025	15:49:38 PM	22	1336.50	AQEU
GENMAB A/S	31-Mar-2025	15:49:38 PM	20	1337.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:38 PM	32	1337.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:38 PM	80	1336.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:39 PM	12	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	12	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	39	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	11	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	12	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	18	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	11	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:39 PM	11	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:40 PM	13	1336.50	XCSE
GENMAB A/S	31-Mar-2025	15:49:49 PM	32	1337.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:49:49 PM	11	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:49 PM	9	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:49 PM	13	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:49 PM	12	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:49 PM	27	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:49 PM	61	1336.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:53 PM	39	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:53 PM	13	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:53 PM	12	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:53 PM	20	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:53 PM	44	1337.00	XCSE
GENMAB A/S	31-Mar-2025	15:49:53 PM	9	1336.50	CEUX
GENMAB A/S	31-Mar-2025	15:49:53 PM	6	1336.50	CEUX
GENMAB A/S	31-Mar-2025	15:50:04 PM	1	1337.50	XCSE
GENMAB A/S	31-Mar-2025	15:50:04 PM	3	1337.50	XCSE
GENMAB A/S	31-Mar-2025	15:50:41 PM	79	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:50:41 PM	3	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:50:41 PM	61	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:50:41 PM	11	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:50:41 PM	23	1339.50	TQEX
GENMAB A/S	31-Mar-2025	15:50:41 PM	24	1339.50	AQEU
GENMAB A/S	31-Mar-2025	15:50:41 PM	80	1339.50	CEUX
GENMAB A/S	31-Mar-2025	15:51:00 PM	50	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:00 PM	39	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:51:00 PM	15	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:51:00 PM	2	1338.50	TQEX
GENMAB A/S	31-Mar-2025	15:51:01 PM	4	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:01 PM	13	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:07 PM	12	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:07 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:08 PM	1	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:16 PM	5	1339.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:18 PM	11	1339.50	XCSE
GENMAB A/S	31-Mar-2025	15:51:27 PM	14	1340.00	XCSE
GENMAB A/S	31-Mar-2025	15:51:31 PM	12	1340.00	CEUX
GENMAB A/S	31-Mar-2025	15:51:56 PM	2	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:51:56 PM	20	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:51:56 PM	36	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:51:58 PM	32	1342.00	CEUX
GENMAB A/S	31-Mar-2025	15:52:00 PM	15	1342.00	TQEX
GENMAB A/S	31-Mar-2025	15:52:00 PM	7	1342.00	TQEX
GENMAB A/S	31-Mar-2025	15:52:03 PM	83	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	29	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	41	1341.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:52:03 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	10	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	28	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:03 PM	23	1341.00	TQEX
GENMAB A/S	31-Mar-2025	15:52:03 PM	72	1341.00	CEUX
GENMAB A/S	31-Mar-2025	15:52:03 PM	6	1341.00	CEUX
GENMAB A/S	31-Mar-2025	15:52:05 PM	18	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:05 PM	2	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:05 PM	28	1341.00	CEUX
GENMAB A/S	31-Mar-2025	15:52:06 PM	20	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:06 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:06 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:08 PM	1	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:08 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:52:22 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	15:53:26 PM	3	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:53:36 PM	12	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:53:36 PM	13	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:53:49 PM	78	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:53:49 PM	43	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:53:49 PM	43	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:53:49 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	15:54:01 PM	83	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:01 PM	42	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:01 PM	22	1343.50	TQEX
GENMAB A/S	31-Mar-2025	15:54:01 PM	23	1343.50	AQEU
GENMAB A/S	31-Mar-2025	15:54:01 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:54:01 PM	5	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:54:01 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:54:01 PM	83	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:54:03 PM	83	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:03 PM	18	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:54:03 PM	63	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:54:05 PM	1	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:08 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:09 PM	42	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:09 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:09 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:09 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:09 PM	24	1343.50	TQEX
GENMAB A/S	31-Mar-2025	15:54:09 PM	25	1343.50	AQEU
GENMAB A/S	31-Mar-2025	15:54:10 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:10 PM	11	1344.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:54:10 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:25 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	39	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	30	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	9	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	3	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	22	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:37 PM	30	1344.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:47 PM	78	1343.50	XCSE
GENMAB A/S	31-Mar-2025	15:54:47 PM	18	1343.50	TQEX
GENMAB A/S	31-Mar-2025	15:54:47 PM	4	1343.50	TQEX
GENMAB A/S	31-Mar-2025	15:54:47 PM	77	1343.50	CEUX
GENMAB A/S	31-Mar-2025	15:55:02 PM	23	1344.50	AQEU
GENMAB A/S	31-Mar-2025	15:55:13 PM	18	1344.00	CEUX
GENMAB A/S	31-Mar-2025	15:56:02 PM	2	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:56:02 PM	3	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:56:02 PM	1	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:56:49 PM	1	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:56:49 PM	25	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:56:49 PM	9	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:56:49 PM	28	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:56:50 PM	36	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:56:50 PM	6	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:56:50 PM	5	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:56:50 PM	20	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:56:51 PM	10	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:56:54 PM	36	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:56:56 PM	36	1348.50	CEUX
GENMAB A/S	31-Mar-2025	15:57:00 PM	79	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:00 PM	41	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:00 PM	39	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:00 PM	19	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:00 PM	5	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:00 PM	29	1347.50	TQEX
GENMAB A/S	31-Mar-2025	15:57:00 PM	28	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:57:00 PM	35	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:57:00 PM	47	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:57:00 PM	34	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:57:02 PM	39	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:02 PM	31	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:03 PM	13	1347.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:57:03 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:03 PM	39	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:03 PM	35	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:03 PM	81	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:03 PM	23	1346.50	TQEX
GENMAB A/S	31-Mar-2025	15:57:03 PM	83	1346.50	CEUX
GENMAB A/S	31-Mar-2025	15:57:04 PM	21	1346.50	AQEU
GENMAB A/S	31-Mar-2025	15:57:05 PM	11	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:05 PM	4	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:05 PM	11	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:11 PM	44	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:11 PM	13	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:11 PM	39	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:11 PM	8	1347.00	XCSE
GENMAB A/S	31-Mar-2025	15:57:26 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:26 PM	39	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:26 PM	35	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:57:26 PM	82	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:57:27 PM	8	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:04 PM	77	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:04 PM	31	1347.50	TQEX
GENMAB A/S	31-Mar-2025	15:58:04 PM	34	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:58:05 PM	41	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:05 PM	39	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:05 PM	24	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:05 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:05 PM	13	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:07 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:07 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:07 PM	18	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:58:37 PM	82	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:37 PM	43	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:37 PM	12	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:37 PM	24	1347.50	TQEX
GENMAB A/S	31-Mar-2025	15:58:37 PM	34	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:58:38 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:38 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:38 PM	11	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:38 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:46 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:46 PM	13	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:46 PM	13	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:46 PM	30	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:46 PM	79	1346.50	XCSE
GENMAB A/S	31-Mar-2025	15:58:46 PM	18	1347.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	15:58:46 PM	34	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:58:46 PM	22	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:58:46 PM	8	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:15 PM	30	1346.50	TQEX
GENMAB A/S	31-Mar-2025	15:59:23 PM	2	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:59:23 PM	6	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:59:23 PM	6	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:59:23 PM	32	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:59:24 PM	46	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:59:29 PM	42	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:59:30 PM	39	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:30 PM	30	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:30 PM	11	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:30 PM	10	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:30 PM	12	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:30 PM	2	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:34 PM	20	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:34 PM	2	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:38 PM	22	1347.00	TQEX
GENMAB A/S	31-Mar-2025	15:59:38 PM	43	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:59:41 PM	6	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:41 PM	6	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:41 PM	20	1348.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:41 PM	81	1347.00	CEUX
GENMAB A/S	31-Mar-2025	15:59:41 PM	52	1347.50	AQEU
GENMAB A/S	31-Mar-2025	15:59:43 PM	79	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:59:48 PM	5	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:48 PM	12	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:48 PM	12	1348.00	XCSE
GENMAB A/S	31-Mar-2025	15:59:55 PM	80	1347.50	XCSE
GENMAB A/S	31-Mar-2025	15:59:55 PM	73	1347.50	CEUX
GENMAB A/S	31-Mar-2025	15:59:55 PM	53	1347.50	AQEU
GENMAB A/S	31-Mar-2025	16:00:00 PM	79	1346.50	XCSE
GENMAB A/S	31-Mar-2025	16:00:00 PM	35	1346.50	CEUX
GENMAB A/S	31-Mar-2025	16:00:00 PM	46	1346.50	CEUX
GENMAB A/S	31-Mar-2025	16:00:00 PM	2	1346.50	AQEU
GENMAB A/S	31-Mar-2025	16:00:04 PM	82	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:00:04 PM	13	1345.00	TQEX
GENMAB A/S	31-Mar-2025	16:00:04 PM	11	1345.00	TQEX
GENMAB A/S	31-Mar-2025	16:00:04 PM	81	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:00:04 PM	24	1345.50	AQEU
GENMAB A/S	31-Mar-2025	16:00:06 PM	10	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:00:25 PM	54	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:00:25 PM	22	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:00:25 PM	38	1344.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:00:25 PM	19	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:00:26 PM	14	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:00:29 PM	20	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:00:29 PM	2	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:00:29 PM	43	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:01:09 PM	57	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:01:36 PM	38	1344.50	AQEU
GENMAB A/S	31-Mar-2025	16:01:49 PM	24	1344.00	TQEX
GENMAB A/S	31-Mar-2025	16:01:49 PM	51	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:01:49 PM	3	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:01:51 PM	62	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:01:51 PM	16	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:01:51 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:01:51 PM	47	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:01:51 PM	4	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:01:51 PM	41	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:02:17 PM	20	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:02:19 PM	43	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:19 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:19 PM	23	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:02:19 PM	30	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:02:21 PM	42	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:21 PM	30	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:21 PM	8	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:23 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:27 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:28 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:02:54 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:03:08 PM	6	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:03:11 PM	8	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:03:35 PM	78	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:35 PM	8	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:35 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:35 PM	14	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:03:35 PM	11	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:03:35 PM	80	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:03:35 PM	28	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:03:36 PM	30	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	39	1343.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:03:36 PM	37	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:36 PM	4	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:37 PM	6	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:37 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:38 PM	19	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:38 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:38 PM	41	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:03:39 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:39 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:40 PM	30	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:41 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:41 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:41 PM	33	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:41 PM	8	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:03:42 PM	17	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:03:55 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:55 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:55 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:55 PM	14	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:55 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:03:55 PM	15	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:04:09 PM	66	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:04:09 PM	15	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:04:09 PM	26	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:04:43 PM	4	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:04:47 PM	22	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:04:47 PM	56	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:04:47 PM	23	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:04:47 PM	45	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:04:47 PM	35	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:04:51 PM	7	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:05:09 PM	78	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:05:09 PM	54	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:05:09 PM	29	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:05:09 PM	12	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:05:21 PM	23	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:06:00 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:06:04 PM	22	1344.00	TQEX
GENMAB A/S	31-Mar-2025	16:06:04 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:06:04 PM	36	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:06:25 PM	53	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:06:25 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:06:25 PM	23	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:06:25 PM	12	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:06:26 PM	13	1344.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:06:39 PM	29	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:06:42 PM	67	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:06:42 PM	11	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:06:42 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:06:42 PM	20	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:06:43 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:06:43 PM	14	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:06:43 PM	28	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:06:44 PM	1	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:00 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:00 PM	22	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:05 PM	76	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:05 PM	22	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:07:05 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:07:05 PM	29	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:07:05 PM	22	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:07:05 PM	76	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:07:07 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:07 PM	22	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:07 PM	40	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:07:26 PM	2	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:32 PM	29	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:32 PM	21	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:54 PM	32	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:07:56 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	36	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	5	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	62	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	19	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:56 PM	22	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:07:56 PM	80	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:07:57 PM	44	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:57 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:57 PM	15	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:07:57 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:08:00 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:08:00 PM	34	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:08:00 PM	31	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:08:01 PM	42	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:08:05 PM	27	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:05 PM	28	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:05 PM	24	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:05 PM	32	1342.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:08:05 PM	6	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:26 PM	1	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:26 PM	3	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:55 PM	3	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:08:55 PM	10	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:09:03 PM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:09:05 PM	3	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:09:29 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:09:29 PM	36	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:09:48 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:09:48 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:09:49 PM	93	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:09:53 PM	47	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:09:53 PM	29	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:09:59 PM	33	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:10:01 PM	32	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:10:08 PM	41	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:08 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:08 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:08 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:08 PM	20	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:10:25 PM	3	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:25 PM	14	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:25 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:25 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:10:49 PM	47	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:10:49 PM	31	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:10:49 PM	59	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:10:51 PM	25	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:11:13 PM	22	1342.50	AQEU
GENMAB A/S	31-Mar-2025	16:11:23 PM	14	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:11:24 PM	24	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:11:24 PM	18	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:11:25 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:11:25 PM	27	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:11:25 PM	36	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:11:25 PM	10	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:11:49 PM	31	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:12:08 PM	45	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:08 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:08 PM	7	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:08 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:08 PM	20	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:08 PM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:09 PM	1	1342.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:12:09 PM	28	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:15 PM	76	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	36	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	5	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	40	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	3	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	2	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	17	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:12:15 PM	1	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:15 PM	6	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:15 PM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:15 PM	5	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:15 PM	6	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:18 PM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:12:39 PM	83	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:13:00 PM	21	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:19 PM	68	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:19 PM	8	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:19 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:19 PM	2	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:19 PM	10	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:19 PM	47	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:13:19 PM	79	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:19 PM	23	1342.50	AQEU
GENMAB A/S	31-Mar-2025	16:13:21 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:25 PM	3	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:25 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:25 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:25 PM	3	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:25 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:25 PM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:25 PM	30	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:26 PM	72	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:26 PM	72	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:26 PM	11	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:26 PM	10	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:27 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	35	1342.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:13:27 PM	31	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:27 PM	11	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:28 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:28 PM	21	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:33 PM	80	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:13:33 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:33 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:33 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:33 PM	36	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	36	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	4	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	68	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:34 PM	40	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:35 PM	32	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:35 PM	36	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:35 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:35 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:35 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:44 PM	24	1341.50	TQEX
GENMAB A/S	31-Mar-2025	16:13:44 PM	50	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:44 PM	32	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:45 PM	36	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:45 PM	11	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:45 PM	21	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:13:49 PM	3	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:13:49 PM	80	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:05 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:14:05 PM	36	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:14:05 PM	29	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:14:11 PM	26	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:14:11 PM	57	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:14:42 PM	11	1344.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:14:42 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	7	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:58 PM	16	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:14:58 PM	6	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:14:58 PM	3	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:14:59 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:59 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:14:59 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	15	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	2	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:05 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:07 PM	20	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:15:10 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:15:10 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:15:16 PM	11	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:15:39 PM	63	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:15:39 PM	22	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:15:53 PM	44	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:15:53 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:15:54 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:15:54 PM	15	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:15:55 PM	28	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:16:00 PM	1	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:16:00 PM	7	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:16:07 PM	77	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:16:25 PM	2	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:16:25 PM	11	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:16:26 PM	16	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:16:26 PM	2	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:16:48 PM	19	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:16:48 PM	3	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:16:59 PM	76	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:16:59 PM	82	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:17:26 PM	1	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:17:30 PM	30	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:17:39 PM	2	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:00 PM	31	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:18:10 PM	75	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	39	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	25	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	40	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	3	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	13	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	11	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	24	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	39	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	13	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	1	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:10 PM	20	1341.50	TQEX
GENMAB A/S	31-Mar-2025	16:18:10 PM	19	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:10 PM	56	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:10 PM	2	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:10 PM	20	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:11 PM	21	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:11 PM	14	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:13 PM	19	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:14 PM	3	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:18:14 PM	11	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:18:53 PM	78	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:19:00 PM	11	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:00 PM	21	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:00 PM	9	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:00 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:00 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:04 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:04 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:04 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:04 PM	7	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:04 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:04 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:04 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:04 PM	79	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:19:05 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	36	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	5	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	13	1343.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:19:05 PM	26	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:05 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	30	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	25	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	26	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	1	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	38	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	36	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	30	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	26	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	5	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	26	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:06 PM	23	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:07 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:07 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:07 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:07 PM	29	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:25 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:25 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:25 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:25 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:25 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:25 PM	14	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:45 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:45 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:45 PM	17	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:45 PM	36	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:19:48 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:48 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:48 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:49 PM	23	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:19:51 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:20:08 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:20:08 PM	19	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:08 PM	58	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:22 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:20:22 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:20:22 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:20:22 PM	50	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:20:22 PM	6	1343.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:20:22 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:22 PM	27	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:22 PM	22	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:22 PM	22	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:22 PM	22	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:22 PM	1	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:23 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:23 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:24 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:33 PM	27	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:20:33 PM	43	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:20:33 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:49 PM	2	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:20:51 PM	14	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:09 PM	80	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:09 PM	2	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:21:38 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:38 PM	5	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:38 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:38 PM	35	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:49 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:52 PM	44	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	20	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	28	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	20	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	49	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	2	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:52 PM	49	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:21:52 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:21:53 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	20	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	22	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:53 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:54 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:54 PM	15	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:54 PM	10	1344.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:21:54 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:54 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:54 PM	10	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:56 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:56 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:21:57 PM	14	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:22:03 PM	82	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:22:03 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:22:03 PM	83	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:22:03 PM	22	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:22:13 PM	10	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:22:13 PM	73	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:22:13 PM	22	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:22:14 PM	19	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:22:14 PM	63	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:22:23 PM	37	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:22:24 PM	23	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:22:24 PM	2	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:22:24 PM	37	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:22:24 PM	43	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:22:24 PM	39	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:23:04 PM	27	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:09 PM	44	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:10 PM	5	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:10 PM	27	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:23:26 PM	2	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:26 PM	15	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:23:29 PM	27	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:30 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:30 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:30 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:30 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:30 PM	24	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:23:31 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	10	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:31 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:32 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:32 PM	10	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:32 PM	2	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:23:32 PM	11	1344.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:23:38 PM	49	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:38 PM	9	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:23:39 PM	59	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:23:39 PM	18	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:23:39 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:23:59 PM	79	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:23:59 PM	1	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:24:12 PM	30	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:24:12 PM	53	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:24:25 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:24:25 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:24:33 PM	50	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:24:39 PM	80	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:24:39 PM	36	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:24:45 PM	32	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:24:46 PM	44	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:24:46 PM	12	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:24:51 PM	24	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:51 PM	56	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:51 PM	10	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:24:51 PM	23	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:24:51 PM	22	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:24:52 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:52 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:52 PM	10	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:52 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:52 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:53 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:53 PM	10	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:24:59 PM	26	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:24:59 PM	35	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:24:59 PM	16	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:25:03 PM	48	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:03 PM	12	1341.50	TQEX
GENMAB A/S	31-Mar-2025	16:25:06 PM	22	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:06 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:11 PM	24	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:25:16 PM	34	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:25:16 PM	18	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:25:25 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:25 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:25 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:25 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:25 PM	24	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:25 PM	1	1342.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:25:33 PM	18	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:25:35 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:35 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:48 PM	32	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:48 PM	24	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:25:49 PM	9	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:25:49 PM	71	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:26:14 PM	20	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:26:19 PM	46	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:19 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:19 PM	3	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:26:19 PM	9	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:26:26 PM	43	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:26 PM	29	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:26 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:26 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:27 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:27 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:28 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:28 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:30 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:30 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:30 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:30 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:30 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:30 PM	19	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:31 PM	26	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:26:32 PM	32	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:26:33 PM	10	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:34 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:34 PM	9	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:42 PM	31	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:26:43 PM	5	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:26:51 PM	5	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:26:51 PM	15	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:26:51 PM	22	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:26:51 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:26:51 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:26:51 PM	30	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:26:51 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:26:58 PM	22	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:26:58 PM	32	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:26:58 PM	40	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:27:03 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:27:03 PM	3	1343.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:27:05 PM	1	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:27:06 PM	16	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:27:15 PM	4	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:19 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:28 PM	25	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:31 PM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:34 PM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:38 PM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:40 PM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:47 PM	8	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:47 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:47 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:48 PM	16	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:27:51 PM	26	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:27:51 PM	32	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:27:56 PM	78	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:28:02 PM	60	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:02 PM	22	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:28:02 PM	75	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:28:02 PM	22	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:28:05 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	57	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	20	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	19	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:07 PM	24	1342.00	TQEX
GENMAB A/S	31-Mar-2025	16:28:07 PM	59	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:28:07 PM	22	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:28:08 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	20	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:08 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:13 PM	77	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:13 PM	40	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:28:15 PM	35	1342.00	TQEX
GENMAB A/S	31-Mar-2025	16:28:15 PM	7	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:28:15 PM	29	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:28:25 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:25 PM	30	1342.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:28:25 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:25 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:26 PM	39	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:28:49 PM	78	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:50 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:50 PM	19	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:50 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:28:50 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:04 PM	79	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:29:07 PM	13	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:29:14 PM	38	1341.50	TQEX
GENMAB A/S	31-Mar-2025	16:29:14 PM	19	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:29:14 PM	27	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:29:15 PM	36	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:25 PM	5	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:25 PM	1	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:25 PM	1	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:25 PM	2	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:25 PM	30	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:25 PM	35	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:49 PM	60	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:29:59 PM	83	1340.50	XCSE
GENMAB A/S	31-Mar-2025	16:29:59 PM	42	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:30:06 PM	18	1341.00	TQEX
GENMAB A/S	31-Mar-2025	16:30:06 PM	18	1341.00	TQEX
GENMAB A/S	31-Mar-2025	16:30:14 PM	41	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:30:14 PM	5	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:30:18 PM	11	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:30:25 PM	9	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:30:35 PM	15	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:30:39 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:30:40 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:30:40 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:30:40 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:30:55 PM	12	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:31:22 PM	77	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:31:25 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:25 PM	8	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:25 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:25 PM	24	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:25 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:31 PM	36	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:31:31 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:31:31 PM	6	1343.00	CEUX
GENMAB A/S	31-Mar-2025	16:31:31 PM	7	1343.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:31:32 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:32 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:31:56 PM	1	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:31:56 PM	31	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:31:57 PM	17	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:31:58 PM	5	1343.00	AQEU
GENMAB A/S	31-Mar-2025	16:32:03 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:03 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:03 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:03 PM	25	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:03 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:03 PM	36	1342.50	TQEX
GENMAB A/S	31-Mar-2025	16:32:03 PM	80	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:32:03 PM	1	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:32:06 PM	58	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:06 PM	25	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:50 PM	83	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:32:59 PM	83	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:33:07 PM	26	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:33:07 PM	4	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:33:07 PM	13	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:33:09 PM	18	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:27 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:33:27 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:33:28 PM	18	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:28 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:28 PM	21	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:28 PM	22	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:28 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:42 PM	6	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:33:47 PM	26	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:03 PM	18	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:34:04 PM	57	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:34:15 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:15 PM	10	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:15 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:15 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:15 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:35 PM	40	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:34:35 PM	6	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:34:35 PM	24	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:34:35 PM	1	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:34:45 PM	77	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:34:45 PM	42	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:34:45 PM	2	1344.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:34:45 PM	22	1344.00	AQEU
GENMAB A/S	31-Mar-2025	16:34:55 PM	25	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:35:03 PM	19	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:35:04 PM	3	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:35:23 PM	18	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:23 PM	24	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:23 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:23 PM	12	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:23 PM	68	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:35:25 PM	22	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:35 PM	2	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:36 PM	13	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:42 PM	24	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:35:59 PM	23	1342.50	AQEU
GENMAB A/S	31-Mar-2025	16:36:00 PM	41	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:00 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:00 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:00 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:00 PM	36	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:36:00 PM	5	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:36:07 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:07 PM	63	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:36:07 PM	27	1342.00	TQEX
GENMAB A/S	31-Mar-2025	16:36:07 PM	55	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:36:12 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:12 PM	9	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:12 PM	2	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:12 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:14 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:31 PM	11	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:36:37 PM	47	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:45 PM	23	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:45 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:36:45 PM	25	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:37:11 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:37:19 PM	66	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:37:19 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:37:37 PM	16	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:37:37 PM	55	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:37:38 PM	36	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:37:40 PM	19	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:37:46 PM	31	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:37:46 PM	73	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:37:46 PM	13	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:37:46 PM	32	1344.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:38:01 PM	12	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:38:01 PM	26	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:38:01 PM	14	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:38:01 PM	32	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:38:06 PM	98	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:38:06 PM	6	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:38:07 PM	35	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:38:11 PM	32	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:38:37 PM	79	1346.00	CEUX
GENMAB A/S	31-Mar-2025	16:39:09 PM	61	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:39:09 PM	36	1346.00	CEUX
GENMAB A/S	31-Mar-2025	16:39:26 PM	15	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:39:26 PM	41	1345.50	TQEX
GENMAB A/S	31-Mar-2025	16:39:26 PM	36	1346.00	CEUX
GENMAB A/S	31-Mar-2025	16:39:27 PM	30	1345.50	AQEU
GENMAB A/S	31-Mar-2025	16:39:59 PM	76	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	60	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	39	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	39	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	18	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:39:59 PM	34	1344.50	TQEX
GENMAB A/S	31-Mar-2025	16:39:59 PM	68	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:39:59 PM	23	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:39:59 PM	31	1344.50	AQEU
GENMAB A/S	31-Mar-2025	16:40:00 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:40:00 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:40:01 PM	31	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:40:01 PM	61	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:09 PM	16	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:10 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:40:23 PM	42	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:23 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:40:23 PM	29	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:40:23 PM	23	1344.50	AQEU
GENMAB A/S	31-Mar-2025	16:40:26 PM	76	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:40:29 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:29 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:31 PM	23	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:40:31 PM	16	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:40:33 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:40:34 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:34 PM	39	1344.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:40:34 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:44 PM	20	1344.50	AQEU
GENMAB A/S	31-Mar-2025	16:40:45 PM	9	1344.50	AQEU
GENMAB A/S	31-Mar-2025	16:40:46 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:40:56 PM	30	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:06 PM	21	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:06 PM	29	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:06 PM	38	1344.50	TQEX
GENMAB A/S	31-Mar-2025	16:41:06 PM	30	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:19 PM	59	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:20 PM	8	1344.50	TQEX
GENMAB A/S	31-Mar-2025	16:41:34 PM	17	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:34 PM	5	1344.50	TQEX
GENMAB A/S	31-Mar-2025	16:41:34 PM	25	1344.50	TQEX
GENMAB A/S	31-Mar-2025	16:41:35 PM	2	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:35 PM	2	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:35 PM	14	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:35 PM	20	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:35 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:35 PM	23	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:35 PM	23	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:35 PM	23	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:35 PM	10	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:41:46 PM	43	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	30	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	31	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	5	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	37	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	77	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:46 PM	36	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:41:46 PM	47	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:41:47 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:47 PM	45	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:47 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:47 PM	8	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:47 PM	10	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:48 PM	10	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:52 PM	39	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:52 PM	12	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:41:52 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:42:01 PM	12	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:01 PM	11	1344.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:42:05 PM	25	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:42:19 PM	78	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:42:19 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:19 PM	30	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:31 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:31 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:31 PM	16	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:49 PM	25	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:42:49 PM	10	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:42:49 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:42:49 PM	45	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:42:59 PM	77	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:42:59 PM	50	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:42:59 PM	50	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:43:03 PM	82	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:03 PM	34	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:43:03 PM	42	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:43:04 PM	11	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:04 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:04 PM	6	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:05 PM	13	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:06 PM	3	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:12 PM	22	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:12 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:12 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:27 PM	8	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:43:29 PM	82	1343.50	XCSE
GENMAB A/S	31-Mar-2025	16:43:31 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:43:36 PM	30	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:36 PM	14	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:36 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:36 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:36 PM	9	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:37 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:37 PM	4	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:40 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:43:41 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:43:41 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:43:56 PM	27	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:43:59 PM	25	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:01 PM	2	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:44:14 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:44:14 PM	18	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:44:16 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:44:17 PM	14	1343.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:44:25 PM	22	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:25 PM	2	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:25 PM	23	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:31 PM	1	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:31 PM	11	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:31 PM	37	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:31 PM	9	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:44:55 PM	23	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:44:56 PM	30	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:44:59 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:44:59 PM	22	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:44:59 PM	49	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:45:11 PM	32	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	4	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	3	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:11 PM	18	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:45:11 PM	1	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:45:12 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:12 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:13 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:13 PM	39	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:13 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:13 PM	14	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:20 PM	48	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:20 PM	10	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:45:20 PM	5	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:45:25 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:45:26 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:26 PM	18	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:31 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:45:31 PM	11	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:45:33 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:58 PM	39	1344.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:45:58 PM	50	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:58 PM	15	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:45:59 PM	24	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:45:59 PM	50	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:45:59 PM	20	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:46:19 PM	11	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:46:19 PM	35	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:46:24 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:46:28 PM	19	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:28 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:28 PM	12	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:28 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	39	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	38	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	3	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	42	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	13	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	18	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	12	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	15	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	4	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:29 PM	32	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:46:30 PM	19	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	38	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	23	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	16	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:30 PM	38	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:31 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:31 PM	39	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:31 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:31 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:31 PM	11	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:32 PM	22	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:36 PM	20	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:46:36 PM	7	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:46:59 PM	59	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:46:59 PM	36	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:46:59 PM	36	1344.50	CEUX
GENMAB A/S	31-Mar-2025	16:46:59 PM	15	1344.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:47:13 PM	15	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:13 PM	29	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:13 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:13 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:13 PM	2	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:13 PM	14	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:13 PM	12	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:47:13 PM	9	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:47:13 PM	36	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:47:14 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:18 PM	37	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:18 PM	40	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:18 PM	27	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:18 PM	23	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:18 PM	28	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:18 PM	19	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:18 PM	3	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:19 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:19 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:20 PM	11	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:20 PM	11	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:20 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:21 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:21 PM	11	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:21 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:23 PM	13	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:23 PM	12	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:23 PM	39	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:24 PM	12	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:24 PM	12	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:24 PM	80	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:25 PM	11	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:28 PM	36	1345.50	TQEX
GENMAB A/S	31-Mar-2025	16:47:31 PM	34	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:32 PM	7	1345.50	XCSE
GENMAB A/S	31-Mar-2025	16:47:33 PM	18	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:33 PM	5	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:33 PM	16	1345.50	CEUX
GENMAB A/S	31-Mar-2025	16:47:47 PM	78	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:47 PM	43	1345.00	TQEX
GENMAB A/S	31-Mar-2025	16:47:47 PM	49	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:47:48 PM	41	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:49 PM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:49 PM	14	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:50 PM	11	1345.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:47:50 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:50 PM	39	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:50 PM	13	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:51 PM	13	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:53 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	39	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	31	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	8	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:54 PM	11	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:55 PM	12	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:55 PM	39	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:55 PM	5	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:55 PM	39	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:47:58 PM	25	1345.00	CEUX
GENMAB A/S	31-Mar-2025	16:47:59 PM	46	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:48:00 PM	1	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:48:00 PM	3	1345.00	XCSE
GENMAB A/S	31-Mar-2025	16:48:03 PM	22	1344.50	AQEU
GENMAB A/S	31-Mar-2025	16:48:13 PM	40	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:48:13 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:48:13 PM	13	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:48:24 PM	4	1344.50	XCSE
GENMAB A/S	31-Mar-2025	16:48:24 PM	20	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:48:52 PM	32	1344.00	TQEX
GENMAB A/S	31-Mar-2025	16:48:52 PM	26	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:52 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:52 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:52 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:52 PM	28	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:52 PM	20	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:52 PM	17	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:48:58 PM	31	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:00 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:49:00 PM	3	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:49:00 PM	13	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:01 PM	29	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:10 PM	1	1344.00	XCSE
GENMAB A/S	31-Mar-2025	16:49:32 PM	36	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:32 PM	24	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:32 PM	10	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:33 PM	6	1344.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:49:33 PM	5	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:49:33 PM	6	1344.00	CEUX
GENMAB A/S	31-Mar-2025	16:50:01 PM	35	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:01 PM	2	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:50:01 PM	2	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:50:01 PM	18	1343.50	TQEX
GENMAB A/S	31-Mar-2025	16:50:01 PM	37	1343.50	AQEU
GENMAB A/S	31-Mar-2025	16:50:03 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:03 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:03 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:03 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:04 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:05 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:05 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:06 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:06 PM	5	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:06 PM	50	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:06 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:06 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:07 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:07 PM	6	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:07 PM	27	1343.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:09 PM	30	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:09 PM	20	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:09 PM	39	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:09 PM	11	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:09 PM	4	1343.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:09 PM	22	1343.00	TQEX
GENMAB A/S	31-Mar-2025	16:50:09 PM	29	1342.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:11 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:11 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:12 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:12 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:12 PM	15	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:14 PM	29	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:14 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:14 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:14 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	10	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:15 PM	13	1342.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:50:15 PM	24	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:50:16 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	1	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:16 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:17 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:17 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:17 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:18 PM	13	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:18 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:18 PM	39	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:18 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:19 PM	14	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:19 PM	12	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:19 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:19 PM	6	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:19 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:19 PM	11	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:20 PM	1	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:20 PM	1	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:22 PM	80	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:22 PM	29	1342.00	TQEX
GENMAB A/S	31-Mar-2025	16:50:33 PM	26	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:34 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:34 PM	22	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:34 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:50:34 PM	23	1341.00	TQEX
GENMAB A/S	31-Mar-2025	16:50:40 PM	81	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:50:42 PM	9	1341.00	AQEU
GENMAB A/S	31-Mar-2025	16:50:43 PM	18	1341.00	AQEU
GENMAB A/S	31-Mar-2025	16:50:52 PM	8	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:52 PM	37	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:52 PM	35	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:53 PM	4	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:55 PM	5	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:58 PM	36	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:59 PM	22	1341.00	TQEX
GENMAB A/S	31-Mar-2025	16:50:59 PM	14	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:50:59 PM	2	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:51:13 PM	31	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:51:21 PM	11	1341.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:51:21 PM	39	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:51:22 PM	65	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:51:28 PM	19	1341.00	AQEU
GENMAB A/S	31-Mar-2025	16:51:31 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:34 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:36 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:40 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:41 PM	22	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:41 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:41 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:43 PM	17	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:44 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:45 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:45 PM	15	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:45 PM	1	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:51:45 PM	25	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:51:47 PM	25	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:47 PM	50	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:47 PM	16	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:48 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:48 PM	25	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:48 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	82	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	14	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	27	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:49 PM	29	1341.00	TQEX
GENMAB A/S	31-Mar-2025	16:51:49 PM	22	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:51:49 PM	10	1341.00	AQEU
GENMAB A/S	31-Mar-2025	16:51:50 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	12	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	36	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:50 PM	11	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	13	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	36	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	11	1341.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:51:51 PM	39	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	2	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:51:51 PM	25	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:51:51 PM	36	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:51:51 PM	6	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:51:51 PM	5	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:51:51 PM	22	1341.00	AQEU
GENMAB A/S	31-Mar-2025	16:51:55 PM	22	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:51:55 PM	18	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:01 PM	36	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:52:01 PM	26	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:52:05 PM	32	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:05 PM	38	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:05 PM	1	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:05 PM	3	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:19 PM	24	1341.00	TQEX
GENMAB A/S	31-Mar-2025	16:52:25 PM	36	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:52:25 PM	29	1341.00	AQEU
GENMAB A/S	31-Mar-2025	16:52:27 PM	25	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:27 PM	39	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:27 PM	11	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:27 PM	12	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:27 PM	13	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:27 PM	4	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:28 PM	7	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:28 PM	39	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:28 PM	13	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:28 PM	12	1341.00	XCSE
GENMAB A/S	31-Mar-2025	16:52:31 PM	50	1340.50	XCSE
GENMAB A/S	31-Mar-2025	16:52:31 PM	36	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:52:39 PM	41	1340.50	TQEX
GENMAB A/S	31-Mar-2025	16:52:39 PM	30	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:52:39 PM	32	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:52:47 PM	26	1340.50	XCSE
GENMAB A/S	31-Mar-2025	16:52:47 PM	32	1341.00	CEUX
GENMAB A/S	31-Mar-2025	16:53:05 PM	15	1340.50	XCSE
GENMAB A/S	31-Mar-2025	16:53:05 PM	30	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:19 PM	36	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:19 PM	23	1340.00	CEUX
GENMAB A/S	31-Mar-2025	16:53:28 PM	28	1340.50	AQEU
GENMAB A/S	31-Mar-2025	16:53:29 PM	35	1340.00	CEUX
GENMAB A/S	31-Mar-2025	16:53:44 PM	10	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:44 PM	18	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:44 PM	35	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:44 PM	8	1340.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	31-Mar-2025	16:53:44 PM	18	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:44 PM	15	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:53:45 PM	18	1340.50	CEUX
GENMAB A/S	31-Mar-2025	16:54:10 PM	83	1341.50	CEUX
GENMAB A/S	31-Mar-2025	16:54:20 PM	40	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:54:20 PM	24	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:54:20 PM	45	1342.00	TQEX
GENMAB A/S	31-Mar-2025	16:54:20 PM	41	1342.00	CEUX
GENMAB A/S	31-Mar-2025	16:54:20 PM	22	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:54:20 PM	14	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:54:29 PM	22	1342.00	TQEX
GENMAB A/S	31-Mar-2025	16:54:29 PM	26	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:54:43 PM	30	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:54:43 PM	12	1342.00	XCSE
GENMAB A/S	31-Mar-2025	16:54:43 PM	27	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:54:43 PM	35	1342.50	XCSE
GENMAB A/S	31-Mar-2025	16:54:46 PM	55	1341.50	XCSE
GENMAB A/S	31-Mar-2025	16:54:46 PM	17	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:54:46 PM	5	1342.00	AQEU
GENMAB A/S	31-Mar-2025	16:54:46 PM	10	1342.50	AQEU
GENMAB A/S	31-Mar-2025	16:54:46 PM	13	1342.50	AQEU
GENMAB A/S	31-Mar-2025	16:54:46 PM	21	1342.50	AQEU
GENMAB A/S	01-Apr-2025	09:12:57 AM	74	1271.50	XCSE
GENMAB A/S	01-Apr-2025	09:13:14 AM	47	1272.00	XCSE
GENMAB A/S	01-Apr-2025	09:13:14 AM	72	1272.00	CEUX
GENMAB A/S	01-Apr-2025	09:13:29 AM	27	1276.00	CEUX
GENMAB A/S	01-Apr-2025	09:13:38 AM	74	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:13:50 AM	54	1277.50	XCSE
GENMAB A/S	01-Apr-2025	09:13:50 AM	1	1277.50	AQEU
GENMAB A/S	01-Apr-2025	09:13:50 AM	1	1277.50	AQEU
GENMAB A/S	01-Apr-2025	09:14:05 AM	54	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:14:05 AM	68	1280.50	AQEU
GENMAB A/S	01-Apr-2025	09:14:20 AM	60	1285.00	XCSE
GENMAB A/S	01-Apr-2025	09:14:23 AM	51	1284.00	XCSE
GENMAB A/S	01-Apr-2025	09:14:23 AM	55	1283.00	XCSE
GENMAB A/S	01-Apr-2025	09:14:23 AM	67	1283.50	TQEX
GENMAB A/S	01-Apr-2025	09:14:23 AM	48	1284.00	AQEU
GENMAB A/S	01-Apr-2025	09:14:23 AM	46	1283.00	AQEU
GENMAB A/S	01-Apr-2025	09:14:23 AM	40	1284.00	CEUX
GENMAB A/S	01-Apr-2025	09:14:23 AM	39	1283.00	CEUX
GENMAB A/S	01-Apr-2025	09:14:29 AM	26	1281.50	XCSE
GENMAB A/S	01-Apr-2025	09:14:29 AM	75	1282.00	TQEX
GENMAB A/S	01-Apr-2025	09:14:29 AM	34	1282.00	AQEU
GENMAB A/S	01-Apr-2025	09:14:29 AM	41	1282.00	CEUX
GENMAB A/S	01-Apr-2025	09:14:29 AM	28	1281.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	09:14:34 AM	36	1280.50	TQEX
GENMAB A/S	01-Apr-2025	09:14:34 AM	37	1280.50	TQEX
GENMAB A/S	01-Apr-2025	09:14:42 AM	25	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:15:05 AM	23	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:15:05 AM	38	1281.00	CEUX
GENMAB A/S	01-Apr-2025	09:15:40 AM	3	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:15:40 AM	39	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:15:40 AM	38	1281.00	CEUX
GENMAB A/S	01-Apr-2025	09:15:52 AM	23	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:15:52 AM	25	1280.00	CEUX
GENMAB A/S	01-Apr-2025	09:17:26 AM	79	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:17:26 AM	53	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:18:09 AM	24	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:18:15 AM	43	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:18:23 AM	23	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:18:25 AM	18	1278.50	XCSE
GENMAB A/S	01-Apr-2025	09:18:31 AM	5	1278.50	XCSE
GENMAB A/S	01-Apr-2025	09:19:06 AM	10	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:19:06 AM	11	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:19:06 AM	61	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:19:20 AM	81	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:19:48 AM	9	1281.50	XCSE
GENMAB A/S	01-Apr-2025	09:19:48 AM	12	1281.50	XCSE
GENMAB A/S	01-Apr-2025	09:20:04 AM	48	1283.50	XCSE
GENMAB A/S	01-Apr-2025	09:20:04 AM	12	1283.50	XCSE
GENMAB A/S	01-Apr-2025	09:20:04 AM	11	1283.50	XCSE
GENMAB A/S	01-Apr-2025	09:20:04 AM	10	1283.50	XCSE
GENMAB A/S	01-Apr-2025	09:20:15 AM	15	1283.50	XCSE
GENMAB A/S	01-Apr-2025	09:20:21 AM	86	1284.00	XCSE
GENMAB A/S	01-Apr-2025	09:20:29 AM	13	1283.00	XCSE
GENMAB A/S	01-Apr-2025	09:20:29 AM	67	1283.00	XCSE
GENMAB A/S	01-Apr-2025	09:20:29 AM	64	1283.00	CEUX
GENMAB A/S	01-Apr-2025	09:20:29 AM	13	1283.00	CEUX
GENMAB A/S	01-Apr-2025	09:20:48 AM	80	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:20:48 AM	49	1282.50	CEUX
GENMAB A/S	01-Apr-2025	09:21:03 AM	73	1281.50	CEUX
GENMAB A/S	01-Apr-2025	09:21:28 AM	5	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:21:28 AM	80	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:21:28 AM	39	1282.00	CEUX
GENMAB A/S	01-Apr-2025	09:21:52 AM	81	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:21:52 AM	85	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:21:52 AM	29	1281.50	CEUX
GENMAB A/S	01-Apr-2025	09:22:06 AM	8	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:22:06 AM	57	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:22:31 AM	64	1281.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	09:22:34 AM	14	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:22:44 AM	28	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:23:23 AM	79	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:23:35 AM	81	1279.50	XCSE
GENMAB A/S	01-Apr-2025	09:23:36 AM	35	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:24:57 AM	85	1281.00	XCSE
GENMAB A/S	01-Apr-2025	09:24:59 AM	24	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:24:59 AM	29	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:26:25 AM	7	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:26:28 AM	72	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:26:28 AM	46	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:26:28 AM	27	1280.00	TQEX
GENMAB A/S	01-Apr-2025	09:26:28 AM	17	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:26:28 AM	41	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:26:29 AM	34	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:26:29 AM	16	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:26:32 AM	78	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:26:32 AM	1	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:26:55 AM	37	1278.50	TQEX
GENMAB A/S	01-Apr-2025	09:26:55 AM	32	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:27:18 AM	81	1278.00	XCSE
GENMAB A/S	01-Apr-2025	09:27:18 AM	33	1278.00	TQEX
GENMAB A/S	01-Apr-2025	09:27:18 AM	48	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:27:18 AM	14	1277.00	CEUX
GENMAB A/S	01-Apr-2025	09:27:18 AM	10	1277.00	CEUX
GENMAB A/S	01-Apr-2025	09:27:52 AM	54	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:27:52 AM	29	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:27:52 AM	62	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:28:56 AM	85	1279.50	XCSE
GENMAB A/S	01-Apr-2025	09:28:56 AM	34	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:28:56 AM	25	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:28:59 AM	16	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:28:59 AM	69	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:30:07 AM	81	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:30:07 AM	84	1279.50	XCSE
GENMAB A/S	01-Apr-2025	09:30:07 AM	38	1279.50	TQEX
GENMAB A/S	01-Apr-2025	09:30:07 AM	75	1280.50	CEUX
GENMAB A/S	01-Apr-2025	09:30:07 AM	8	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:30:07 AM	15	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:30:07 AM	53	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:30:10 AM	31	1279.00	TQEX
GENMAB A/S	01-Apr-2025	09:30:28 AM	77	1281.50	XCSE
GENMAB A/S	01-Apr-2025	09:30:28 AM	8	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:30:28 AM	19	1281.00	CEUX
GENMAB A/S	01-Apr-2025	09:30:28 AM	23	1281.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	09:30:34 AM	55	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:30:34 AM	23	1280.00	CEUX
GENMAB A/S	01-Apr-2025	09:30:46 AM	35	1280.00	XCSE
GENMAB A/S	01-Apr-2025	09:30:56 AM	42	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:30:56 AM	8	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:31:17 AM	17	1279.50	TQEX
GENMAB A/S	01-Apr-2025	09:31:24 AM	32	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:31:24 AM	1	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:31:24 AM	30	1279.00	CEUX
GENMAB A/S	01-Apr-2025	09:31:44 AM	5	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:31:44 AM	21	1279.50	CEUX
GENMAB A/S	01-Apr-2025	09:31:53 AM	23	1279.00	XCSE
GENMAB A/S	01-Apr-2025	09:32:04 AM	26	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:33:33 AM	29	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:33:40 AM	18	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:33:58 AM	25	1278.00	XCSE
GENMAB A/S	01-Apr-2025	09:33:58 AM	27	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:33:58 AM	4	1278.50	CEUX
GENMAB A/S	01-Apr-2025	09:33:58 AM	3	1277.50	CEUX
GENMAB A/S	01-Apr-2025	09:33:58 AM	24	1277.50	CEUX
GENMAB A/S	01-Apr-2025	09:34:36 AM	27	1277.50	XCSE
GENMAB A/S	01-Apr-2025	09:34:36 AM	54	1277.50	XCSE
GENMAB A/S	01-Apr-2025	09:34:40 AM	9	1277.00	CEUX
GENMAB A/S	01-Apr-2025	09:34:40 AM	20	1277.00	CEUX
GENMAB A/S	01-Apr-2025	09:34:54 AM	41	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:34:54 AM	27	1276.00	CEUX
GENMAB A/S	01-Apr-2025	09:34:55 AM	37	1275.50	XCSE
GENMAB A/S	01-Apr-2025	09:34:58 AM	2	1275.50	XCSE
GENMAB A/S	01-Apr-2025	09:34:58 AM	17	1275.50	XCSE
GENMAB A/S	01-Apr-2025	09:35:14 AM	86	1275.00	XCSE
GENMAB A/S	01-Apr-2025	09:35:18 AM	79	1274.00	XCSE
GENMAB A/S	01-Apr-2025	09:35:18 AM	35	1274.50	TQEX
GENMAB A/S	01-Apr-2025	09:35:18 AM	30	1274.50	CEUX
GENMAB A/S	01-Apr-2025	09:35:35 AM	34	1275.50	TQEX
GENMAB A/S	01-Apr-2025	09:35:37 AM	39	1275.00	XCSE
GENMAB A/S	01-Apr-2025	09:35:54 AM	23	1275.00	CEUX
GENMAB A/S	01-Apr-2025	09:36:58 AM	86	1277.50	XCSE
GENMAB A/S	01-Apr-2025	09:36:58 AM	18	1277.00	CEUX
GENMAB A/S	01-Apr-2025	09:36:58 AM	15	1277.00	CEUX
GENMAB A/S	01-Apr-2025	09:36:58 AM	29	1277.00	AQEU
GENMAB A/S	01-Apr-2025	09:37:00 AM	66	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:37:00 AM	3	1276.00	CEUX
GENMAB A/S	01-Apr-2025	09:37:00 AM	29	1276.00	CEUX
GENMAB A/S	01-Apr-2025	09:37:00 AM	32	1276.00	AQEU
GENMAB A/S	01-Apr-2025	09:38:03 AM	55	1276.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	09:38:03 AM	27	1276.00	CEUX
GENMAB A/S	01-Apr-2025	09:38:03 AM	28	1276.00	AQEU
GENMAB A/S	01-Apr-2025	09:38:15 AM	64	1275.00	XCSE
GENMAB A/S	01-Apr-2025	09:38:15 AM	31	1275.00	CEUX
GENMAB A/S	01-Apr-2025	09:38:40 AM	50	1274.00	XCSE
GENMAB A/S	01-Apr-2025	09:38:40 AM	23	1274.00	CEUX
GENMAB A/S	01-Apr-2025	09:39:05 AM	43	1275.00	XCSE
GENMAB A/S	01-Apr-2025	09:39:05 AM	28	1275.00	CEUX
GENMAB A/S	01-Apr-2025	09:39:40 AM	11	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:39:40 AM	23	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:39:40 AM	9	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:39:40 AM	7	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:39:49 AM	1	1277.50	CEUX
GENMAB A/S	01-Apr-2025	09:39:53 AM	34	1277.50	CEUX
GENMAB A/S	01-Apr-2025	09:39:55 AM	26	1276.50	XCSE
GENMAB A/S	01-Apr-2025	09:40:18 AM	26	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:40:18 AM	20	1280.50	XCSE
GENMAB A/S	01-Apr-2025	09:40:18 AM	30	1280.50	AQEU
GENMAB A/S	01-Apr-2025	09:40:18 AM	3	1280.50	AQEU
GENMAB A/S	01-Apr-2025	09:41:48 AM	83	1284.00	XCSE
GENMAB A/S	01-Apr-2025	09:41:48 AM	28	1285.50	XCSE
GENMAB A/S	01-Apr-2025	09:41:48 AM	25	1286.00	XCSE
GENMAB A/S	01-Apr-2025	09:41:54 AM	33	1285.00	XCSE
GENMAB A/S	01-Apr-2025	09:41:54 AM	29	1284.50	TQEX
GENMAB A/S	01-Apr-2025	09:41:55 AM	56	1284.00	XCSE
GENMAB A/S	01-Apr-2025	09:41:55 AM	50	1284.00	CEUX
GENMAB A/S	01-Apr-2025	09:41:58 AM	23	1283.00	XCSE
GENMAB A/S	01-Apr-2025	09:41:58 AM	26	1283.50	TQEX
GENMAB A/S	01-Apr-2025	09:41:58 AM	56	1283.00	CEUX
GENMAB A/S	01-Apr-2025	09:42:21 AM	31	1282.50	AQEU
GENMAB A/S	01-Apr-2025	09:42:21 AM	11	1282.50	AQEU
GENMAB A/S	01-Apr-2025	09:43:03 AM	29	1284.50	XCSE
GENMAB A/S	01-Apr-2025	09:43:31 AM	18	1285.00	TQEX
GENMAB A/S	01-Apr-2025	09:43:31 AM	9	1285.00	TQEX
GENMAB A/S	01-Apr-2025	09:43:31 AM	32	1285.00	CEUX
GENMAB A/S	01-Apr-2025	09:43:59 AM	30	1284.50	XCSE
GENMAB A/S	01-Apr-2025	09:43:59 AM	26	1284.50	AQEU
GENMAB A/S	01-Apr-2025	09:44:01 AM	25	1284.00	CEUX
GENMAB A/S	01-Apr-2025	09:44:08 AM	29	1283.50	XCSE
GENMAB A/S	01-Apr-2025	09:44:08 AM	23	1283.00	CEUX
GENMAB A/S	01-Apr-2025	09:44:08 AM	25	1283.00	AQEU
GENMAB A/S	01-Apr-2025	09:44:11 AM	26	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:44:11 AM	28	1282.00	CEUX
GENMAB A/S	01-Apr-2025	09:44:33 AM	29	1282.50	CEUX
GENMAB A/S	01-Apr-2025	09:46:24 AM	27	1282.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	09:46:55 AM	81	1283.00	XCSE
GENMAB A/S	01-Apr-2025	09:46:55 AM	30	1282.00	XCSE
GENMAB A/S	01-Apr-2025	09:46:56 AM	77	1282.50	XCSE
GENMAB A/S	01-Apr-2025	09:46:56 AM	16	1282.50	CEUX
GENMAB A/S	01-Apr-2025	09:46:56 AM	33	1282.50	CEUX
GENMAB A/S	01-Apr-2025	09:48:05 AM	86	1285.00	XCSE
GENMAB A/S	01-Apr-2025	09:48:31 AM	60	1286.50	XCSE
GENMAB A/S	01-Apr-2025	09:48:31 AM	23	1286.50	TQEX
GENMAB A/S	01-Apr-2025	09:48:31 AM	19	1286.50	CEUX
GENMAB A/S	01-Apr-2025	09:48:31 AM	15	1286.50	CEUX
GENMAB A/S	01-Apr-2025	09:48:31 AM	15	1286.50	CEUX
GENMAB A/S	01-Apr-2025	09:48:33 AM	40	1287.00	XCSE
GENMAB A/S	01-Apr-2025	09:49:33 AM	23	1286.50	CEUX
GENMAB A/S	01-Apr-2025	09:49:52 AM	13	1285.50	XCSE
GENMAB A/S	01-Apr-2025	09:49:52 AM	54	1285.50	XCSE
GENMAB A/S	01-Apr-2025	09:49:52 AM	45	1285.50	CEUX
GENMAB A/S	01-Apr-2025	09:50:26 AM	43	1288.50	CEUX
GENMAB A/S	01-Apr-2025	09:51:11 AM	81	1288.50	XCSE
GENMAB A/S	01-Apr-2025	09:53:12 AM	9	1287.50	XCSE
GENMAB A/S	01-Apr-2025	09:53:12 AM	23	1288.00	TQEX
GENMAB A/S	01-Apr-2025	09:53:12 AM	37	1288.00	CEUX
GENMAB A/S	01-Apr-2025	09:53:18 AM	54	1287.50	XCSE
GENMAB A/S	01-Apr-2025	09:53:18 AM	3	1287.50	XCSE
GENMAB A/S	01-Apr-2025	09:53:27 AM	46	1287.00	CEUX
GENMAB A/S	01-Apr-2025	09:53:27 AM	32	1287.00	AQEU
GENMAB A/S	01-Apr-2025	09:55:13 AM	5	1287.50	XCSE
GENMAB A/S	01-Apr-2025	09:55:14 AM	2	1287.50	XCSE
GENMAB A/S	01-Apr-2025	09:55:23 AM	23	1288.00	XCSE
GENMAB A/S	01-Apr-2025	09:56:01 AM	4	1288.00	XCSE
GENMAB A/S	01-Apr-2025	09:56:55 AM	5	1287.50	AQEU
GENMAB A/S	01-Apr-2025	09:57:02 AM	23	1289.50	XCSE
GENMAB A/S	01-Apr-2025	09:57:02 AM	26	1289.50	XCSE
GENMAB A/S	01-Apr-2025	09:57:02 AM	38	1289.50	XCSE
GENMAB A/S	01-Apr-2025	09:57:05 AM	80	1290.50	XCSE
GENMAB A/S	01-Apr-2025	09:57:05 AM	23	1290.00	TQEX
GENMAB A/S	01-Apr-2025	09:57:05 AM	86	1290.00	CEUX
GENMAB A/S	01-Apr-2025	09:57:10 AM	65	1291.00	CEUX
GENMAB A/S	01-Apr-2025	09:57:33 AM	82	1290.50	XCSE
GENMAB A/S	01-Apr-2025	09:57:33 AM	17	1290.50	AQEU
GENMAB A/S	01-Apr-2025	09:57:44 AM	23	1290.50	TQEX
GENMAB A/S	01-Apr-2025	09:57:44 AM	15	1290.50	AQEU
GENMAB A/S	01-Apr-2025	09:58:30 AM	40	1290.00	CEUX
GENMAB A/S	01-Apr-2025	09:58:31 AM	7	1290.50	XCSE
GENMAB A/S	01-Apr-2025	09:59:30 AM	80	1289.50	XCSE
GENMAB A/S	01-Apr-2025	09:59:30 AM	27	1289.50	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	09:59:31 AM	34	1290.00	XCSE
GENMAB A/S	01-Apr-2025	09:59:33 AM	8	1289.50	TQEX
GENMAB A/S	01-Apr-2025	10:00:23 AM	20	1289.50	AQEU
GENMAB A/S	01-Apr-2025	10:00:31 AM	3	1289.50	AQEU
GENMAB A/S	01-Apr-2025	10:00:34 AM	28	1289.50	XCSE
GENMAB A/S	01-Apr-2025	10:00:34 AM	30	1289.50	XCSE
GENMAB A/S	01-Apr-2025	10:00:34 AM	26	1289.50	XCSE
GENMAB A/S	01-Apr-2025	10:00:34 AM	10	1289.50	XCSE
GENMAB A/S	01-Apr-2025	10:00:34 AM	14	1289.50	XCSE
GENMAB A/S	01-Apr-2025	10:00:34 AM	81	1288.00	XCSE
GENMAB A/S	01-Apr-2025	10:00:34 AM	84	1289.00	CEUX
GENMAB A/S	01-Apr-2025	10:00:35 AM	52	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:01:00 AM	60	1287.50	XCSE
GENMAB A/S	01-Apr-2025	10:01:16 AM	85	1288.50	XCSE
GENMAB A/S	01-Apr-2025	10:01:33 AM	49	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:02:01 AM	21	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:02:02 AM	30	1287.50	TQEX
GENMAB A/S	01-Apr-2025	10:02:02 AM	12	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:02:02 AM	9	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:02:40 AM	19	1287.50	XCSE
GENMAB A/S	01-Apr-2025	10:02:40 AM	5	1287.50	XCSE
GENMAB A/S	01-Apr-2025	10:02:41 AM	23	1287.00	CEUX
GENMAB A/S	01-Apr-2025	10:02:44 AM	84	1286.50	XCSE
GENMAB A/S	01-Apr-2025	10:04:45 AM	68	1288.50	XCSE
GENMAB A/S	01-Apr-2025	10:04:45 AM	32	1289.00	XCSE
GENMAB A/S	01-Apr-2025	10:04:45 AM	8	1289.00	XCSE
GENMAB A/S	01-Apr-2025	10:05:01 AM	80	1288.00	XCSE
GENMAB A/S	01-Apr-2025	10:05:01 AM	4	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:05:01 AM	56	1288.00	CEUX
GENMAB A/S	01-Apr-2025	10:09:15 AM	8	1294.50	AQEU
GENMAB A/S	01-Apr-2025	10:09:27 AM	38	1295.50	XCSE
GENMAB A/S	01-Apr-2025	10:09:42 AM	38	1295.50	XCSE
GENMAB A/S	01-Apr-2025	10:09:42 AM	19	1295.50	XCSE
GENMAB A/S	01-Apr-2025	10:09:42 AM	15	1295.50	XCSE
GENMAB A/S	01-Apr-2025	10:09:42 AM	83	1295.00	CEUX
GENMAB A/S	01-Apr-2025	10:09:43 AM	3	1295.50	XCSE
GENMAB A/S	01-Apr-2025	10:10:03 AM	94	1296.00	XCSE
GENMAB A/S	01-Apr-2025	10:10:03 AM	14	1296.00	XCSE
GENMAB A/S	01-Apr-2025	10:10:14 AM	86	1296.00	CEUX
GENMAB A/S	01-Apr-2025	10:10:47 AM	86	1295.50	XCSE
GENMAB A/S	01-Apr-2025	10:10:47 AM	31	1295.50	TQEX
GENMAB A/S	01-Apr-2025	10:10:47 AM	27	1295.50	AQEU
GENMAB A/S	01-Apr-2025	10:11:05 AM	34	1299.00	XCSE
GENMAB A/S	01-Apr-2025	10:11:05 AM	74	1299.00	XCSE
GENMAB A/S	01-Apr-2025	10:11:20 AM	10	1299.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	10:11:43 AM	62	1298.50	XCSE
GENMAB A/S	01-Apr-2025	10:11:46 AM	31	1300.00	XCSE
GENMAB A/S	01-Apr-2025	10:11:46 AM	16	1300.00	XCSE
GENMAB A/S	01-Apr-2025	10:12:06 AM	28	1303.00	TQEX
GENMAB A/S	01-Apr-2025	10:12:16 AM	81	1302.00	XCSE
GENMAB A/S	01-Apr-2025	10:12:16 AM	23	1302.00	TQEX
GENMAB A/S	01-Apr-2025	10:12:16 AM	80	1301.50	CEUX
GENMAB A/S	01-Apr-2025	10:12:16 AM	24	1302.50	AQEU
GENMAB A/S	01-Apr-2025	10:12:18 AM	28	1301.00	XCSE
GENMAB A/S	01-Apr-2025	10:12:18 AM	54	1301.00	XCSE
GENMAB A/S	01-Apr-2025	10:12:25 AM	25	1300.00	CEUX
GENMAB A/S	01-Apr-2025	10:13:06 AM	18	1300.50	XCSE
GENMAB A/S	01-Apr-2025	10:14:05 AM	83	1302.50	XCSE
GENMAB A/S	01-Apr-2025	10:14:27 AM	29	1304.00	XCSE
GENMAB A/S	01-Apr-2025	10:14:27 AM	52	1304.00	XCSE
GENMAB A/S	01-Apr-2025	10:14:30 AM	15	1303.50	AQEU
GENMAB A/S	01-Apr-2025	10:14:30 AM	26	1303.50	AQEU
GENMAB A/S	01-Apr-2025	10:15:38 AM	5	1305.00	XCSE
GENMAB A/S	01-Apr-2025	10:15:38 AM	80	1305.00	XCSE
GENMAB A/S	01-Apr-2025	10:15:38 AM	41	1305.00	CEUX
GENMAB A/S	01-Apr-2025	10:15:38 AM	44	1305.00	CEUX
GENMAB A/S	01-Apr-2025	10:16:00 AM	35	1306.00	CEUX
GENMAB A/S	01-Apr-2025	10:16:00 AM	50	1306.00	CEUX
GENMAB A/S	01-Apr-2025	10:16:04 AM	33	1305.50	TQEX
GENMAB A/S	01-Apr-2025	10:16:11 AM	84	1305.00	XCSE
GENMAB A/S	01-Apr-2025	10:16:11 AM	79	1304.00	XCSE
GENMAB A/S	01-Apr-2025	10:16:11 AM	81	1305.00	CEUX
GENMAB A/S	01-Apr-2025	10:16:11 AM	85	1304.00	CEUX
GENMAB A/S	01-Apr-2025	10:19:04 AM	13	1309.50	XCSE
GENMAB A/S	01-Apr-2025	10:19:18 AM	80	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:19:26 AM	33	1310.50	AQEU
GENMAB A/S	01-Apr-2025	10:19:47 AM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:19:47 AM	72	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:19:47 AM	23	1311.00	TQEX
GENMAB A/S	01-Apr-2025	10:19:47 AM	58	1311.00	CEUX
GENMAB A/S	01-Apr-2025	10:20:19 AM	23	1311.50	TQEX
GENMAB A/S	01-Apr-2025	10:20:19 AM	41	1312.00	CEUX
GENMAB A/S	01-Apr-2025	10:20:19 AM	24	1312.00	CEUX
GENMAB A/S	01-Apr-2025	10:20:19 AM	32	1311.50	AQEU
GENMAB A/S	01-Apr-2025	10:20:21 AM	80	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:20:21 AM	25	1311.00	CEUX
GENMAB A/S	01-Apr-2025	10:20:22 AM	23	1310.50	AQEU
GENMAB A/S	01-Apr-2025	10:20:47 AM	81	1310.00	XCSE
GENMAB A/S	01-Apr-2025	10:20:47 AM	18	1310.00	CEUX
GENMAB A/S	01-Apr-2025	10:20:47 AM	49	1310.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	10:20:49 AM	86	1309.00	XCSE
GENMAB A/S	01-Apr-2025	10:20:49 AM	3	1308.00	XCSE
GENMAB A/S	01-Apr-2025	10:20:49 AM	82	1308.00	XCSE
GENMAB A/S	01-Apr-2025	10:20:49 AM	31	1308.50	AQEU
GENMAB A/S	01-Apr-2025	10:20:56 AM	2	1309.00	CEUX
GENMAB A/S	01-Apr-2025	10:20:56 AM	21	1309.00	CEUX
GENMAB A/S	01-Apr-2025	10:23:11 AM	84	1313.00	XCSE
GENMAB A/S	01-Apr-2025	10:23:12 AM	44	1313.00	TQEX
GENMAB A/S	01-Apr-2025	10:24:06 AM	47	1313.50	CEUX
GENMAB A/S	01-Apr-2025	10:24:07 AM	60	1313.00	XCSE
GENMAB A/S	01-Apr-2025	10:25:02 AM	82	1312.00	XCSE
GENMAB A/S	01-Apr-2025	10:25:02 AM	35	1312.00	CEUX
GENMAB A/S	01-Apr-2025	10:27:04 AM	79	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:27:04 AM	34	1311.00	CEUX
GENMAB A/S	01-Apr-2025	10:27:42 AM	83	1310.50	XCSE
GENMAB A/S	01-Apr-2025	10:29:19 AM	3	1310.50	XCSE
GENMAB A/S	01-Apr-2025	10:30:08 AM	20	1311.00	AQEU
GENMAB A/S	01-Apr-2025	10:31:04 AM	3	1311.00	AQEU
GENMAB A/S	01-Apr-2025	10:31:57 AM	7	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:31:57 AM	29	1310.50	XCSE
GENMAB A/S	01-Apr-2025	10:31:57 AM	11	1310.50	TQEX
GENMAB A/S	01-Apr-2025	10:32:19 AM	54	1310.50	XCSE
GENMAB A/S	01-Apr-2025	10:32:19 AM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	10:32:19 AM	11	1310.50	XCSE
GENMAB A/S	01-Apr-2025	10:32:30 AM	19	1310.50	TQEX
GENMAB A/S	01-Apr-2025	10:32:30 AM	8	1310.50	TQEX
GENMAB A/S	01-Apr-2025	10:32:52 AM	33	1310.00	XCSE
GENMAB A/S	01-Apr-2025	10:32:52 AM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	10:32:52 AM	20	1310.00	XCSE
GENMAB A/S	01-Apr-2025	10:32:52 AM	40	1310.00	XCSE
GENMAB A/S	01-Apr-2025	10:32:52 AM	34	1310.00	CEUX
GENMAB A/S	01-Apr-2025	10:32:52 AM	19	1310.00	AQEU
GENMAB A/S	01-Apr-2025	10:32:52 AM	12	1310.00	AQEU
GENMAB A/S	01-Apr-2025	10:33:10 AM	77	1309.50	XCSE
GENMAB A/S	01-Apr-2025	10:33:48 AM	58	1308.50	XCSE
GENMAB A/S	01-Apr-2025	10:33:48 AM	25	1308.50	CEUX
GENMAB A/S	01-Apr-2025	10:34:23 AM	65	1307.50	CEUX
GENMAB A/S	01-Apr-2025	10:36:04 AM	72	1311.00	CEUX
GENMAB A/S	01-Apr-2025	10:36:11 AM	15	1311.50	XCSE
GENMAB A/S	01-Apr-2025	10:36:11 AM	4	1311.50	XCSE
GENMAB A/S	01-Apr-2025	10:36:11 AM	29	1311.50	XCSE
GENMAB A/S	01-Apr-2025	10:36:11 AM	20	1311.50	XCSE
GENMAB A/S	01-Apr-2025	10:36:11 AM	31	1311.50	XCSE
GENMAB A/S	01-Apr-2025	10:36:11 AM	14	1311.00	CEUX
GENMAB A/S	01-Apr-2025	10:36:24 AM	18	1311.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	10:36:47 AM	85	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:37:17 AM	64	1311.00	CEUX
GENMAB A/S	01-Apr-2025	10:38:18 AM	84	1312.00	XCSE
GENMAB A/S	01-Apr-2025	10:38:59 AM	86	1312.00	XCSE
GENMAB A/S	01-Apr-2025	10:38:59 AM	80	1311.00	XCSE
GENMAB A/S	01-Apr-2025	10:38:59 AM	80	1310.00	XCSE
GENMAB A/S	01-Apr-2025	10:38:59 AM	79	1312.00	CEUX
GENMAB A/S	01-Apr-2025	10:39:00 AM	26	1312.50	AQEU
GENMAB A/S	01-Apr-2025	10:39:01 AM	23	1313.50	TQEX
GENMAB A/S	01-Apr-2025	10:39:47 AM	57	1312.50	XCSE
GENMAB A/S	01-Apr-2025	10:39:47 AM	23	1312.50	TQEX
GENMAB A/S	01-Apr-2025	10:39:47 AM	51	1313.00	CEUX
GENMAB A/S	01-Apr-2025	10:39:47 AM	62	1312.00	CEUX
GENMAB A/S	01-Apr-2025	10:40:35 AM	23	1312.00	CEUX
GENMAB A/S	01-Apr-2025	10:42:09 AM	27	1316.00	AQEU
GENMAB A/S	01-Apr-2025	10:42:14 AM	80	1317.00	XCSE
GENMAB A/S	01-Apr-2025	10:42:14 AM	33	1316.50	CEUX
GENMAB A/S	01-Apr-2025	10:42:14 AM	10	1316.50	CEUX
GENMAB A/S	01-Apr-2025	10:42:14 AM	8	1316.50	CEUX
GENMAB A/S	01-Apr-2025	10:42:14 AM	24	1317.00	AQEU
GENMAB A/S	01-Apr-2025	10:42:20 AM	79	1317.00	XCSE
GENMAB A/S	01-Apr-2025	10:42:20 AM	23	1316.50	CEUX
GENMAB A/S	01-Apr-2025	10:42:20 AM	34	1317.00	CEUX
GENMAB A/S	01-Apr-2025	10:42:35 AM	80	1316.00	XCSE
GENMAB A/S	01-Apr-2025	10:42:35 AM	26	1317.00	TQEX
GENMAB A/S	01-Apr-2025	10:42:35 AM	26	1316.50	AQEU
GENMAB A/S	01-Apr-2025	10:43:03 AM	23	1316.00	XCSE
GENMAB A/S	01-Apr-2025	10:43:27 AM	19	1315.50	CEUX
GENMAB A/S	01-Apr-2025	10:43:43 AM	32	1315.50	CEUX
GENMAB A/S	01-Apr-2025	10:43:43 AM	23	1315.50	AQEU
GENMAB A/S	01-Apr-2025	10:44:39 AM	24	1315.50	CEUX
GENMAB A/S	01-Apr-2025	10:44:44 AM	81	1315.00	XCSE
GENMAB A/S	01-Apr-2025	10:49:06 AM	18	1317.00	CEUX
GENMAB A/S	01-Apr-2025	10:49:06 AM	39	1317.00	CEUX
GENMAB A/S	01-Apr-2025	10:50:26 AM	18	1319.00	TQEX
GENMAB A/S	01-Apr-2025	10:51:06 AM	6	1319.00	TQEX
GENMAB A/S	01-Apr-2025	10:51:55 AM	50	1319.50	XCSE
GENMAB A/S	01-Apr-2025	10:51:55 AM	33	1319.50	XCSE
GENMAB A/S	01-Apr-2025	10:51:55 AM	42	1319.50	TQEX
GENMAB A/S	01-Apr-2025	10:51:55 AM	80	1319.50	CEUX
GENMAB A/S	01-Apr-2025	10:51:55 AM	24	1319.50	AQEU
GENMAB A/S	01-Apr-2025	10:53:02 AM	85	1318.00	XCSE
GENMAB A/S	01-Apr-2025	10:53:02 AM	23	1318.50	XCSE
GENMAB A/S	01-Apr-2025	10:53:02 AM	15	1318.50	XCSE
GENMAB A/S	01-Apr-2025	10:53:02 AM	10	1318.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	10:53:02 AM	68	1318.50	CEUX
GENMAB A/S	01-Apr-2025	10:55:01 AM	81	1318.00	XCSE
GENMAB A/S	01-Apr-2025	10:55:01 AM	30	1318.00	XCSE
GENMAB A/S	01-Apr-2025	10:55:01 AM	26	1318.00	XCSE
GENMAB A/S	01-Apr-2025	10:55:47 AM	18	1317.50	CEUX
GENMAB A/S	01-Apr-2025	10:55:47 AM	48	1317.50	CEUX
GENMAB A/S	01-Apr-2025	10:56:16 AM	50	1319.00	XCSE
GENMAB A/S	01-Apr-2025	10:56:16 AM	13	1319.00	XCSE
GENMAB A/S	01-Apr-2025	10:56:16 AM	27	1319.00	XCSE
GENMAB A/S	01-Apr-2025	10:56:16 AM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	10:56:16 AM	6	1319.00	XCSE
GENMAB A/S	01-Apr-2025	10:56:44 AM	80	1319.00	XCSE
GENMAB A/S	01-Apr-2025	10:56:44 AM	62	1319.00	CEUX
GENMAB A/S	01-Apr-2025	10:57:00 AM	9	1319.50	XCSE
GENMAB A/S	01-Apr-2025	10:57:00 AM	9	1319.50	XCSE
GENMAB A/S	01-Apr-2025	10:57:00 AM	12	1319.50	XCSE
GENMAB A/S	01-Apr-2025	10:57:15 AM	86	1319.50	XCSE
GENMAB A/S	01-Apr-2025	10:57:17 AM	23	1318.50	TQEX
GENMAB A/S	01-Apr-2025	10:59:04 AM	79	1318.00	XCSE
GENMAB A/S	01-Apr-2025	10:59:04 AM	18	1318.00	CEUX
GENMAB A/S	01-Apr-2025	10:59:04 AM	39	1318.00	CEUX
GENMAB A/S	01-Apr-2025	11:01:02 AM	32	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:02 AM	12	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:02 AM	10	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:02 AM	12	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:02 AM	2	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:02 AM	10	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:02 AM	9	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:05 AM	10	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:05 AM	9	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:05 AM	11	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:25 AM	7	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:01:40 AM	18	1317.50	AQEU
GENMAB A/S	01-Apr-2025	11:03:01 AM	50	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:03:01 AM	12	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:03:01 AM	12	1318.50	XCSE
GENMAB A/S	01-Apr-2025	11:03:01 AM	80	1318.00	XCSE
GENMAB A/S	01-Apr-2025	11:03:01 AM	24	1318.00	TQEX
GENMAB A/S	01-Apr-2025	11:03:01 AM	10	1318.00	CEUX
GENMAB A/S	01-Apr-2025	11:03:01 AM	13	1318.00	CEUX
GENMAB A/S	01-Apr-2025	11:03:01 AM	62	1318.00	CEUX
GENMAB A/S	01-Apr-2025	11:03:02 AM	13	1318.00	CEUX
GENMAB A/S	01-Apr-2025	11:03:18 AM	23	1319.00	XCSE
GENMAB A/S	01-Apr-2025	11:03:37 AM	48	1320.50	XCSE
GENMAB A/S	01-Apr-2025	11:03:38 AM	35	1320.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	11:03:38 AM	23	1320.50	AQEU
GENMAB A/S	01-Apr-2025	11:03:54 AM	45	1320.00	TQEX
GENMAB A/S	01-Apr-2025	11:03:54 AM	67	1320.00	CEUX
GENMAB A/S	01-Apr-2025	11:04:04 AM	84	1319.50	XCSE
GENMAB A/S	01-Apr-2025	11:04:04 AM	10	1319.50	AQEU
GENMAB A/S	01-Apr-2025	11:04:04 AM	3	1319.50	AQEU
GENMAB A/S	01-Apr-2025	11:04:04 AM	3	1319.50	AQEU
GENMAB A/S	01-Apr-2025	11:05:09 AM	14	1320.00	XCSE
GENMAB A/S	01-Apr-2025	11:05:09 AM	66	1320.00	XCSE
GENMAB A/S	01-Apr-2025	11:07:00 AM	34	1323.00	XCSE
GENMAB A/S	01-Apr-2025	11:07:00 AM	49	1323.00	XCSE
GENMAB A/S	01-Apr-2025	11:07:00 AM	81	1322.50	CEUX
GENMAB A/S	01-Apr-2025	11:07:00 AM	23	1322.50	AQEU
GENMAB A/S	01-Apr-2025	11:08:01 AM	83	1322.00	XCSE
GENMAB A/S	01-Apr-2025	11:08:02 AM	19	1321.50	CEUX
GENMAB A/S	01-Apr-2025	11:08:02 AM	57	1321.50	CEUX
GENMAB A/S	01-Apr-2025	11:08:23 AM	15	1320.50	XCSE
GENMAB A/S	01-Apr-2025	11:08:23 AM	69	1320.50	XCSE
GENMAB A/S	01-Apr-2025	11:08:23 AM	82	1320.50	CEUX
GENMAB A/S	01-Apr-2025	11:08:26 AM	83	1319.00	XCSE
GENMAB A/S	01-Apr-2025	11:08:26 AM	86	1318.00	XCSE
GENMAB A/S	01-Apr-2025	11:08:26 AM	46	1319.00	CEUX
GENMAB A/S	01-Apr-2025	11:08:26 AM	10	1318.00	CEUX
GENMAB A/S	01-Apr-2025	11:08:40 AM	82	1317.00	XCSE
GENMAB A/S	01-Apr-2025	11:10:11 AM	28	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:10:11 AM	10	1314.00	CEUX
GENMAB A/S	01-Apr-2025	11:10:12 AM	17	1314.00	CEUX
GENMAB A/S	01-Apr-2025	11:11:20 AM	24	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:11:20 AM	25	1313.00	CEUX
GENMAB A/S	01-Apr-2025	11:11:21 AM	26	1312.50	XCSE
GENMAB A/S	01-Apr-2025	11:11:37 AM	19	1312.00	CEUX
GENMAB A/S	01-Apr-2025	11:11:37 AM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	11:11:42 AM	1	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:11:42 AM	39	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:11:42 AM	36	1311.50	AQEU
GENMAB A/S	01-Apr-2025	11:13:37 AM	27	1312.00	TQEX
GENMAB A/S	01-Apr-2025	11:13:38 AM	12	1311.50	CEUX
GENMAB A/S	01-Apr-2025	11:13:42 AM	86	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:13:42 AM	23	1311.50	CEUX
GENMAB A/S	01-Apr-2025	11:13:42 AM	9	1311.50	CEUX
GENMAB A/S	01-Apr-2025	11:16:57 AM	10	1313.00	XCSE
GENMAB A/S	01-Apr-2025	11:16:59 AM	70	1313.00	XCSE
GENMAB A/S	01-Apr-2025	11:16:59 AM	53	1313.00	CEUX
GENMAB A/S	01-Apr-2025	11:17:32 AM	6	1312.50	TQEX
GENMAB A/S	01-Apr-2025	11:17:32 AM	19	1312.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	11:17:32 AM	48	1312.50	CEUX
GENMAB A/S	01-Apr-2025	11:18:57 AM	30	1315.00	XCSE
GENMAB A/S	01-Apr-2025	11:18:57 AM	30	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:18:57 AM	19	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:18:57 AM	15	1316.00	AQEU
GENMAB A/S	01-Apr-2025	11:18:57 AM	7	1316.00	AQEU
GENMAB A/S	01-Apr-2025	11:18:57 AM	34	1316.00	CEUX
GENMAB A/S	01-Apr-2025	11:18:57 AM	20	1316.00	CEUX
GENMAB A/S	01-Apr-2025	11:18:58 AM	1	1316.00	AQEU
GENMAB A/S	01-Apr-2025	11:19:01 AM	54	1315.00	CEUX
GENMAB A/S	01-Apr-2025	11:19:04 AM	79	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:19:04 AM	35	1314.50	AQEU
GENMAB A/S	01-Apr-2025	11:19:06 AM	26	1314.00	CEUX
GENMAB A/S	01-Apr-2025	11:19:06 AM	14	1314.00	CEUX
GENMAB A/S	01-Apr-2025	11:19:55 AM	80	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:21:12 AM	3	1316.00	TQEX
GENMAB A/S	01-Apr-2025	11:21:12 AM	24	1316.00	TQEX
GENMAB A/S	01-Apr-2025	11:21:23 AM	20	1316.00	AQEU
GENMAB A/S	01-Apr-2025	11:22:45 AM	81	1316.00	XCSE
GENMAB A/S	01-Apr-2025	11:22:45 AM	26	1315.50	CEUX
GENMAB A/S	01-Apr-2025	11:23:27 AM	7	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:23:28 AM	23	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:23:28 AM	50	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:23:28 AM	43	1315.50	CEUX
GENMAB A/S	01-Apr-2025	11:23:36 AM	79	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:23:36 AM	25	1314.50	CEUX
GENMAB A/S	01-Apr-2025	11:24:02 AM	78	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:24:02 AM	24	1313.50	CEUX
GENMAB A/S	01-Apr-2025	11:24:09 AM	29	1312.50	AQEU
GENMAB A/S	01-Apr-2025	11:24:09 AM	21	1312.00	CEUX
GENMAB A/S	01-Apr-2025	11:24:10 AM	80	1312.00	XCSE
GENMAB A/S	01-Apr-2025	11:24:14 AM	36	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:24:23 AM	23	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:24:37 AM	31	1312.50	XCSE
GENMAB A/S	01-Apr-2025	11:24:58 AM	28	1312.00	TQEX
GENMAB A/S	01-Apr-2025	11:25:08 AM	9	1312.50	XCSE
GENMAB A/S	01-Apr-2025	11:25:17 AM	18	1313.00	CEUX
GENMAB A/S	01-Apr-2025	11:25:28 AM	20	1312.50	XCSE
GENMAB A/S	01-Apr-2025	11:25:28 AM	29	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:25:28 AM	23	1310.50	XCSE
GENMAB A/S	01-Apr-2025	11:25:28 AM	29	1311.50	AQEU
GENMAB A/S	01-Apr-2025	11:25:28 AM	29	1312.00	CEUX
GENMAB A/S	01-Apr-2025	11:25:31 AM	32	1309.50	XCSE
GENMAB A/S	01-Apr-2025	11:27:05 AM	18	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:27:32 AM	24	1311.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	11:27:32 AM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:27:32 AM	14	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:28:54 AM	7	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:28:54 AM	42	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:29:10 AM	20	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:30:16 AM	7	1311.00	AQEU
GENMAB A/S	01-Apr-2025	11:30:16 AM	23	1311.00	TQEX
GENMAB A/S	01-Apr-2025	11:30:27 AM	22	1311.00	AQEU
GENMAB A/S	01-Apr-2025	11:30:27 AM	3	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:32:08 AM	77	1312.00	XCSE
GENMAB A/S	01-Apr-2025	11:32:08 AM	45	1312.00	CEUX
GENMAB A/S	01-Apr-2025	11:32:54 AM	18	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:33:08 AM	24	1311.50	AQEU
GENMAB A/S	01-Apr-2025	11:33:08 AM	23	1311.50	TQEX
GENMAB A/S	01-Apr-2025	11:33:08 AM	7	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:33:54 AM	1	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:34:54 AM	15	1311.00	CEUX
GENMAB A/S	01-Apr-2025	11:35:10 AM	24	1310.50	XCSE
GENMAB A/S	01-Apr-2025	11:35:17 AM	29	1310.00	CEUX
GENMAB A/S	01-Apr-2025	11:36:03 AM	7	1310.00	CEUX
GENMAB A/S	01-Apr-2025	11:38:33 AM	10	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:38:33 AM	38	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:38:33 AM	10	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:38:33 AM	11	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:38:45 AM	18	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:39:23 AM	14	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:39:23 AM	34	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:39:23 AM	33	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:39:37 AM	22	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:39:37 AM	22	1316.00	XCSE
GENMAB A/S	01-Apr-2025	11:39:37 AM	19	1316.00	XCSE
GENMAB A/S	01-Apr-2025	11:40:19 AM	23	1316.00	AQEU
GENMAB A/S	01-Apr-2025	11:40:19 AM	30	1316.00	CEUX
GENMAB A/S	01-Apr-2025	11:40:19 AM	36	1316.00	CEUX
GENMAB A/S	01-Apr-2025	11:40:19 AM	19	1316.00	CEUX
GENMAB A/S	01-Apr-2025	11:40:45 AM	86	1315.50	XCSE
GENMAB A/S	01-Apr-2025	11:40:45 AM	66	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:40:45 AM	18	1315.50	TQEX
GENMAB A/S	01-Apr-2025	11:40:45 AM	12	1315.50	TQEX
GENMAB A/S	01-Apr-2025	11:40:45 AM	86	1315.00	CEUX
GENMAB A/S	01-Apr-2025	11:41:31 AM	45	1314.00	AQEU
GENMAB A/S	01-Apr-2025	11:41:31 AM	78	1314.00	CEUX
GENMAB A/S	01-Apr-2025	11:43:59 AM	80	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:43:59 AM	15	1314.50	XCSE
GENMAB A/S	01-Apr-2025	11:44:54 AM	18	1314.00	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	11:44:54 AM	5	1314.00	CEUX
GENMAB A/S	01-Apr-2025	11:44:57 AM	80	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:44:57 AM	13	1314.00	XCSE
GENMAB A/S	01-Apr-2025	11:44:57 AM	38	1314.00	XCSE
GENMAB A/S	01-Apr-2025	11:45:58 AM	81	1313.00	XCSE
GENMAB A/S	01-Apr-2025	11:45:58 AM	30	1313.00	TQEX
GENMAB A/S	01-Apr-2025	11:45:58 AM	57	1313.00	CEUX
GENMAB A/S	01-Apr-2025	11:47:57 AM	48	1313.00	CEUX
GENMAB A/S	01-Apr-2025	11:48:35 AM	23	1313.00	XCSE
GENMAB A/S	01-Apr-2025	11:48:35 AM	16	1313.00	XCSE
GENMAB A/S	01-Apr-2025	11:48:35 AM	11	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:48:35 AM	16	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:48:35 AM	6	1313.50	XCSE
GENMAB A/S	01-Apr-2025	11:49:45 AM	86	1313.00	XCSE
GENMAB A/S	01-Apr-2025	11:50:03 AM	56	1313.00	CEUX
GENMAB A/S	01-Apr-2025	11:51:14 AM	26	1312.50	TQEX
GENMAB A/S	01-Apr-2025	11:51:21 AM	83	1312.00	XCSE
GENMAB A/S	01-Apr-2025	11:51:21 AM	41	1312.00	CEUX
GENMAB A/S	01-Apr-2025	11:56:03 AM	43	1311.50	CEUX
GENMAB A/S	01-Apr-2025	11:59:39 AM	35	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:59:39 AM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:59:59 AM	31	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:59:59 AM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	11:59:59 AM	7	1311.50	XCSE
GENMAB A/S	01-Apr-2025	12:00:00 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	12:00:50 PM	84	1311.00	XCSE
GENMAB A/S	01-Apr-2025	12:00:50 PM	49	1310.50	CEUX
GENMAB A/S	01-Apr-2025	12:01:00 PM	24	1310.00	TQEX
GENMAB A/S	01-Apr-2025	12:01:07 PM	81	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:07 PM	24	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:07 PM	38	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:07 PM	17	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:07 PM	35	1309.50	CEUX
GENMAB A/S	01-Apr-2025	12:01:23 PM	38	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:23 PM	17	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:23 PM	10	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:23 PM	31	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:23 PM	10	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:23 PM	2	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:01:23 PM	23	1309.00	TQEX
GENMAB A/S	01-Apr-2025	12:01:27 PM	80	1308.50	XCSE
GENMAB A/S	01-Apr-2025	12:02:57 PM	84	1309.00	CEUX
GENMAB A/S	01-Apr-2025	12:03:14 PM	20	1309.00	XCSE
GENMAB A/S	01-Apr-2025	12:03:32 PM	61	1309.00	XCSE
GENMAB A/S	01-Apr-2025	12:03:47 PM	82	1308.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	12:03:47 PM	79	1308.00	CEUX
GENMAB A/S	01-Apr-2025	12:04:35 PM	85	1307.00	XCSE
GENMAB A/S	01-Apr-2025	12:09:25 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:09:25 PM	38	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:09:25 PM	20	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:09:25 PM	31	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:09:35 PM	4	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:09:58 PM	86	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:10:08 PM	31	1307.50	TQEX
GENMAB A/S	01-Apr-2025	12:10:08 PM	64	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:10:08 PM	22	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:11:03 PM	83	1307.00	XCSE
GENMAB A/S	01-Apr-2025	12:12:23 PM	12	1308.50	XCSE
GENMAB A/S	01-Apr-2025	12:12:24 PM	4	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:12:24 PM	75	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:14:25 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	12:14:25 PM	11	1308.50	XCSE
GENMAB A/S	01-Apr-2025	12:14:44 PM	32	1307.00	XCSE
GENMAB A/S	01-Apr-2025	12:14:44 PM	27	1308.00	TQEX
GENMAB A/S	01-Apr-2025	12:14:44 PM	25	1308.00	AQEU
GENMAB A/S	01-Apr-2025	12:14:44 PM	84	1308.00	CEUX
GENMAB A/S	01-Apr-2025	12:14:50 PM	86	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:16:19 PM	84	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:16:19 PM	2	1308.00	AQEU
GENMAB A/S	01-Apr-2025	12:16:19 PM	1	1308.00	AQEU
GENMAB A/S	01-Apr-2025	12:20:48 PM	25	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:20:48 PM	12	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:20:48 PM	17	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:20:48 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:20:48 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:20:48 PM	31	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:20:48 PM	27	1308.00	AQEU
GENMAB A/S	01-Apr-2025	12:20:48 PM	7	1308.00	AQEU
GENMAB A/S	01-Apr-2025	12:20:48 PM	1	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:21:58 PM	108	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:21:58 PM	26	1307.50	TQEX
GENMAB A/S	01-Apr-2025	12:21:58 PM	65	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:23:41 PM	51	1307.00	XCSE
GENMAB A/S	01-Apr-2025	12:24:09 PM	23	1306.50	TQEX
GENMAB A/S	01-Apr-2025	12:24:09 PM	30	1306.50	CEUX
GENMAB A/S	01-Apr-2025	12:24:09 PM	55	1306.50	CEUX
GENMAB A/S	01-Apr-2025	12:24:32 PM	80	1306.00	XCSE
GENMAB A/S	01-Apr-2025	12:24:32 PM	34	1306.50	XCSE
GENMAB A/S	01-Apr-2025	12:24:32 PM	29	1306.50	XCSE
GENMAB A/S	01-Apr-2025	12:24:32 PM	18	1306.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	12:24:32 PM	27	1306.50	XCSE
GENMAB A/S	01-Apr-2025	12:25:14 PM	3	1305.50	CEUX
GENMAB A/S	01-Apr-2025	12:25:14 PM	72	1305.50	CEUX
GENMAB A/S	01-Apr-2025	12:26:06 PM	4	1305.50	XCSE
GENMAB A/S	01-Apr-2025	12:26:06 PM	10	1305.50	XCSE
GENMAB A/S	01-Apr-2025	12:30:07 PM	24	1306.00	TQEX
GENMAB A/S	01-Apr-2025	12:30:07 PM	41	1306.00	AQEU
GENMAB A/S	01-Apr-2025	12:30:07 PM	38	1306.00	CEUX
GENMAB A/S	01-Apr-2025	12:30:07 PM	47	1306.00	CEUX
GENMAB A/S	01-Apr-2025	12:30:08 PM	82	1305.50	XCSE
GENMAB A/S	01-Apr-2025	12:30:08 PM	33	1306.00	XCSE
GENMAB A/S	01-Apr-2025	12:30:08 PM	14	1306.00	XCSE
GENMAB A/S	01-Apr-2025	12:30:08 PM	59	1306.00	XCSE
GENMAB A/S	01-Apr-2025	12:30:08 PM	2	1306.00	XCSE
GENMAB A/S	01-Apr-2025	12:30:08 PM	9	1305.50	XCSE
GENMAB A/S	01-Apr-2025	12:30:14 PM	70	1305.50	XCSE
GENMAB A/S	01-Apr-2025	12:30:29 PM	23	1305.00	TQEX
GENMAB A/S	01-Apr-2025	12:30:29 PM	83	1305.00	CEUX
GENMAB A/S	01-Apr-2025	12:31:33 PM	59	1305.00	CEUX
GENMAB A/S	01-Apr-2025	12:31:35 PM	79	1304.50	XCSE
GENMAB A/S	01-Apr-2025	12:33:08 PM	75	1304.00	CEUX
GENMAB A/S	01-Apr-2025	12:42:48 PM	108	1310.00	XCSE
GENMAB A/S	01-Apr-2025	12:42:49 PM	18	1310.00	XCSE
GENMAB A/S	01-Apr-2025	12:44:00 PM	20	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:44:00 PM	8	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:44:00 PM	12	1309.50	CEUX
GENMAB A/S	01-Apr-2025	12:44:00 PM	69	1309.50	CEUX
GENMAB A/S	01-Apr-2025	12:44:33 PM	82	1309.00	XCSE
GENMAB A/S	01-Apr-2025	12:44:33 PM	35	1309.00	AQEU
GENMAB A/S	01-Apr-2025	12:45:52 PM	24	1308.50	TQEX
GENMAB A/S	01-Apr-2025	12:45:52 PM	79	1308.50	CEUX
GENMAB A/S	01-Apr-2025	12:47:16 PM	22	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:49:17 PM	28	1310.00	TQEX
GENMAB A/S	01-Apr-2025	12:50:11 PM	1	1309.50	AQEU
GENMAB A/S	01-Apr-2025	12:50:56 PM	9	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:50:56 PM	53	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:50:56 PM	26	1309.50	AQEU
GENMAB A/S	01-Apr-2025	12:50:58 PM	11	1309.00	CEUX
GENMAB A/S	01-Apr-2025	12:51:31 PM	39	1309.00	CEUX
GENMAB A/S	01-Apr-2025	12:52:09 PM	30	1309.50	XCSE
GENMAB A/S	01-Apr-2025	12:52:09 PM	16	1309.00	CEUX
GENMAB A/S	01-Apr-2025	12:52:58 PM	15	1309.00	CEUX
GENMAB A/S	01-Apr-2025	12:53:00 PM	79	1308.50	XCSE
GENMAB A/S	01-Apr-2025	12:53:00 PM	38	1308.50	XCSE
GENMAB A/S	01-Apr-2025	12:53:00 PM	14	1308.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	12:53:00 PM	23	1308.50	TQEX
GENMAB A/S	01-Apr-2025	12:56:55 PM	2	1308.00	XCSE
GENMAB A/S	01-Apr-2025	12:56:55 PM	24	1308.00	CEUX
GENMAB A/S	01-Apr-2025	12:59:15 PM	79	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:15 PM	7	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:15 PM	38	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:15 PM	27	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:15 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:15 PM	29	1307.50	TQEX
GENMAB A/S	01-Apr-2025	12:59:15 PM	79	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:59:15 PM	36	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:59:15 PM	1	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:59:15 PM	33	1307.50	CEUX
GENMAB A/S	01-Apr-2025	12:59:16 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:16 PM	2	1307.50	XCSE
GENMAB A/S	01-Apr-2025	12:59:18 PM	3	1307.50	XCSE
GENMAB A/S	01-Apr-2025	13:01:28 PM	4	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:01:28 PM	4	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:01:28 PM	36	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:01:28 PM	16	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:02:06 PM	27	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:02:43 PM	27	1307.50	AQEU
GENMAB A/S	01-Apr-2025	13:02:59 PM	38	1308.00	XCSE
GENMAB A/S	01-Apr-2025	13:02:59 PM	7	1308.00	XCSE
GENMAB A/S	01-Apr-2025	13:02:59 PM	31	1308.00	XCSE
GENMAB A/S	01-Apr-2025	13:02:59 PM	26	1308.00	XCSE
GENMAB A/S	01-Apr-2025	13:02:59 PM	23	1307.50	TQEX
GENMAB A/S	01-Apr-2025	13:02:59 PM	5	1307.50	AQEU
GENMAB A/S	01-Apr-2025	13:02:59 PM	53	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:04:36 PM	23	1307.50	TQEX
GENMAB A/S	01-Apr-2025	13:04:36 PM	79	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:04:50 PM	68	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:04:50 PM	9	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:05:10 PM	25	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:05:10 PM	38	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:05:10 PM	84	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:05:10 PM	25	1306.50	TQEX
GENMAB A/S	01-Apr-2025	13:05:10 PM	34	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:05:10 PM	46	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:05:11 PM	38	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:05:11 PM	42	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:05:50 PM	86	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:06:05 PM	38	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:06:05 PM	13	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:06:05 PM	11	1306.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	13:06:05 PM	31	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:06:05 PM	80	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:12:41 PM	10	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:12:48 PM	2	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:13:46 PM	12	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:46 PM	38	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:46 PM	31	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:47 PM	9	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:47 PM	38	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:47 PM	11	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:47 PM	9	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:47 PM	31	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:50 PM	38	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:50 PM	11	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:50 PM	10	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:13:50 PM	1	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:14:00 PM	12	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:14:00 PM	38	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:14:00 PM	31	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:14:00 PM	27	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:14:07 PM	37	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:14:07 PM	38	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:14:07 PM	28	1306.50	TQEX
GENMAB A/S	01-Apr-2025	13:14:07 PM	29	1306.50	AQEU
GENMAB A/S	01-Apr-2025	13:14:48 PM	85	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:14:48 PM	41	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:14:48 PM	72	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:14:50 PM	11	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:14:50 PM	41	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:11 PM	38	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:11 PM	32	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:11 PM	79	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:16:11 PM	4	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:16:12 PM	32	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	97	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	10	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	1	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	85	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	4	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	1	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:16:12 PM	86	1305.00	CEUX
GENMAB A/S	01-Apr-2025	13:16:12 PM	84	1304.00	CEUX
GENMAB A/S	01-Apr-2025	13:17:16 PM	3	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:20:14 PM	86	1305.50	CEUX
GENMAB A/S	01-Apr-2025	13:20:38 PM	83	1305.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	13:20:38 PM	25	1305.00	TQEX
GENMAB A/S	01-Apr-2025	13:21:17 PM	80	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:17 PM	24	1305.00	CEUX
GENMAB A/S	01-Apr-2025	13:21:18 PM	38	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:18 PM	12	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:18 PM	12	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:18 PM	11	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:18 PM	30	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:18 PM	5	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:19 PM	10	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:19 PM	38	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:19 PM	11	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:21:19 PM	12	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:22:05 PM	11	1305.00	XCSE
GENMAB A/S	01-Apr-2025	13:24:27 PM	16	1305.00	TQEX
GENMAB A/S	01-Apr-2025	13:24:27 PM	52	1305.00	CEUX
GENMAB A/S	01-Apr-2025	13:25:27 PM	20	1304.50	XCSE
GENMAB A/S	01-Apr-2025	13:25:27 PM	64	1304.50	XCSE
GENMAB A/S	01-Apr-2025	13:26:03 PM	4	1304.00	CEUX
GENMAB A/S	01-Apr-2025	13:29:09 PM	18	1304.00	CEUX
GENMAB A/S	01-Apr-2025	13:30:12 PM	18	1304.00	CEUX
GENMAB A/S	01-Apr-2025	13:30:12 PM	42	1304.00	CEUX
GENMAB A/S	01-Apr-2025	13:31:14 PM	1	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	77	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	34	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	38	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	8	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	26	1303.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	81	1302.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:14 PM	30	1303.50	TQEX
GENMAB A/S	01-Apr-2025	13:31:14 PM	86	1302.50	CEUX
GENMAB A/S	01-Apr-2025	13:31:15 PM	26	1302.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:15 PM	38	1302.50	XCSE
GENMAB A/S	01-Apr-2025	13:31:15 PM	26	1302.00	XCSE
GENMAB A/S	01-Apr-2025	13:31:15 PM	34	1302.00	XCSE
GENMAB A/S	01-Apr-2025	13:31:28 PM	85	1302.00	XCSE
GENMAB A/S	01-Apr-2025	13:32:01 PM	80	1303.00	XCSE
GENMAB A/S	01-Apr-2025	13:38:38 PM	10	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:38:38 PM	15	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:39:09 PM	12	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:39:11 PM	83	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:39:11 PM	25	1307.00	TQEX
GENMAB A/S	01-Apr-2025	13:39:11 PM	67	1307.50	CEUX
GENMAB A/S	01-Apr-2025	13:39:39 PM	82	1306.00	XCSE
GENMAB A/S	01-Apr-2025	13:39:39 PM	38	1306.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	13:39:39 PM	7	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:39:39 PM	27	1306.50	XCSE
GENMAB A/S	01-Apr-2025	13:39:39 PM	36	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:39:39 PM	28	1306.50	AQEU
GENMAB A/S	01-Apr-2025	13:39:39 PM	71	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:39:39 PM	8	1306.00	CEUX
GENMAB A/S	01-Apr-2025	13:40:14 PM	26	1306.50	TQEX
GENMAB A/S	01-Apr-2025	13:42:17 PM	10	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:42:17 PM	75	1307.00	XCSE
GENMAB A/S	01-Apr-2025	13:42:17 PM	84	1307.00	CEUX
GENMAB A/S	01-Apr-2025	13:44:34 PM	27	1309.00	XCSE
GENMAB A/S	01-Apr-2025	13:44:34 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	13:44:34 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	13:44:34 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	13:44:34 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	13:45:33 PM	32	1309.00	CEUX
GENMAB A/S	01-Apr-2025	13:50:02 PM	28	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:50:56 PM	13	1310.50	AQEU
GENMAB A/S	01-Apr-2025	13:50:56 PM	7	1310.50	AQEU
GENMAB A/S	01-Apr-2025	13:50:56 PM	16	1310.50	AQEU
GENMAB A/S	01-Apr-2025	13:51:55 PM	43	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:51:55 PM	30	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:51:58 PM	13	1311.00	CEUX
GENMAB A/S	01-Apr-2025	13:54:13 PM	36	1311.00	CEUX
GENMAB A/S	01-Apr-2025	13:54:20 PM	82	1310.00	XCSE
GENMAB A/S	01-Apr-2025	13:54:20 PM	32	1310.50	CEUX
GENMAB A/S	01-Apr-2025	13:55:50 PM	81	1310.50	XCSE
GENMAB A/S	01-Apr-2025	13:55:58 PM	18	1310.50	CEUX
GENMAB A/S	01-Apr-2025	13:56:49 PM	38	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:56:49 PM	20	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:56:49 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:56:49 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	13:56:49 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	14:01:14 PM	51	1316.50	TQEX
GENMAB A/S	01-Apr-2025	14:01:14 PM	66	1317.50	AQEU
GENMAB A/S	01-Apr-2025	14:01:14 PM	57	1314.00	CEUX
GENMAB A/S	01-Apr-2025	14:01:14 PM	31	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:01:14 PM	51	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:01:15 PM	13	1317.00	XCSE
GENMAB A/S	01-Apr-2025	14:01:15 PM	70	1317.00	XCSE
GENMAB A/S	01-Apr-2025	14:01:15 PM	24	1317.00	XCSE
GENMAB A/S	01-Apr-2025	14:01:15 PM	64	1316.50	AQEU
GENMAB A/S	01-Apr-2025	14:01:15 PM	36	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:01:15 PM	63	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:01:16 PM	86	1316.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	14:01:16 PM	37	1316.00	TQEX
GENMAB A/S	01-Apr-2025	14:01:16 PM	10	1315.50	AQEU
GENMAB A/S	01-Apr-2025	14:01:16 PM	79	1315.50	CEUX
GENMAB A/S	01-Apr-2025	14:02:08 PM	84	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:08 PM	84	1315.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:08 PM	50	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:08 PM	18	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:08 PM	40	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:08 PM	25	1316.00	TQEX
GENMAB A/S	01-Apr-2025	14:02:08 PM	23	1315.00	TQEX
GENMAB A/S	01-Apr-2025	14:02:08 PM	39	1315.50	AQEU
GENMAB A/S	01-Apr-2025	14:02:08 PM	85	1316.00	CEUX
GENMAB A/S	01-Apr-2025	14:02:08 PM	84	1315.00	CEUX
GENMAB A/S	01-Apr-2025	14:02:09 PM	79	1315.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	37	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	11	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	24	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	10	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	9	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	10	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	38	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:16 PM	15	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	81	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	23	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	12	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	9	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	12	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	24	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	11	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	17	1316.00	XCSE
GENMAB A/S	01-Apr-2025	14:02:29 PM	10	1315.50	AQEU
GENMAB A/S	01-Apr-2025	14:02:29 PM	15	1315.50	AQEU
GENMAB A/S	01-Apr-2025	14:03:12 PM	1	1315.00	XCSE
GENMAB A/S	01-Apr-2025	14:03:12 PM	44	1315.00	XCSE
GENMAB A/S	01-Apr-2025	14:03:12 PM	34	1315.00	XCSE
GENMAB A/S	01-Apr-2025	14:03:12 PM	22	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:03:12 PM	12	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:03:12 PM	61	1315.00	CEUX
GENMAB A/S	01-Apr-2025	14:03:12 PM	19	1315.00	CEUX
GENMAB A/S	01-Apr-2025	14:04:32 PM	42	1315.00	TQEX
GENMAB A/S	01-Apr-2025	14:05:08 PM	38	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:05:08 PM	22	1315.50	XCSE
GENMAB A/S	01-Apr-2025	14:05:08 PM	34	1315.00	AQEU
GENMAB A/S	01-Apr-2025	14:07:36 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:36 PM	30	1321.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	14:07:36 PM	40	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:36 PM	12	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:36 PM	10	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:36 PM	10	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:36 PM	30	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:36 PM	46	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:53 PM	83	1320.50	XCSE
GENMAB A/S	01-Apr-2025	14:07:53 PM	17	1320.50	AQEU
GENMAB A/S	01-Apr-2025	14:07:53 PM	83	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:07:55 PM	13	1320.50	AQEU
GENMAB A/S	01-Apr-2025	14:09:00 PM	82	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:09:00 PM	26	1319.50	AQEU
GENMAB A/S	01-Apr-2025	14:09:00 PM	82	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:09:10 PM	85	1318.50	XCSE
GENMAB A/S	01-Apr-2025	14:09:10 PM	33	1318.50	AQEU
GENMAB A/S	01-Apr-2025	14:09:10 PM	86	1318.50	CEUX
GENMAB A/S	01-Apr-2025	14:09:32 PM	2	1317.50	TQEX
GENMAB A/S	01-Apr-2025	14:09:32 PM	21	1317.50	TQEX
GENMAB A/S	01-Apr-2025	14:10:55 PM	81	1317.00	XCSE
GENMAB A/S	01-Apr-2025	14:10:55 PM	29	1317.00	AQEU
GENMAB A/S	01-Apr-2025	14:10:55 PM	18	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:10:55 PM	65	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:13:18 PM	83	1317.00	XCSE
GENMAB A/S	01-Apr-2025	14:13:18 PM	64	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:14:45 PM	6	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:15:18 PM	56	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:17:14 PM	25	1319.50	TQEX
GENMAB A/S	01-Apr-2025	14:17:14 PM	26	1319.50	AQEU
GENMAB A/S	01-Apr-2025	14:17:14 PM	80	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:17:15 PM	35	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:17:15 PM	50	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:17:15 PM	7	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:17:15 PM	28	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:18:33 PM	17	1321.00	XCSE
GENMAB A/S	01-Apr-2025	14:18:33 PM	38	1321.00	XCSE
GENMAB A/S	01-Apr-2025	14:18:33 PM	82	1320.50	XCSE
GENMAB A/S	01-Apr-2025	14:18:33 PM	35	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:18:46 PM	23	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:20:18 PM	33	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:20:18 PM	48	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:20:18 PM	32	1321.50	TQEX
GENMAB A/S	01-Apr-2025	14:21:05 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:05 PM	30	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:05 PM	11	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:05 PM	12	1321.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	14:21:05 PM	12	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:05 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:05 PM	9	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:05 PM	36	1321.50	AQEU
GENMAB A/S	01-Apr-2025	14:21:05 PM	25	1321.00	CEUX
GENMAB A/S	01-Apr-2025	14:21:12 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	30	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	9	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	31	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	12	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	11	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	11	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:12 PM	1	1321.00	CEUX
GENMAB A/S	01-Apr-2025	14:21:12 PM	68	1321.00	CEUX
GENMAB A/S	01-Apr-2025	14:21:27 PM	82	1320.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:27 PM	45	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:21:57 PM	6	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:57 PM	75	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:21:57 PM	54	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:22:27 PM	86	1320.50	XCSE
GENMAB A/S	01-Apr-2025	14:22:27 PM	1	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:22:27 PM	18	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:22:27 PM	9	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:23:30 PM	23	1319.50	TQEX
GENMAB A/S	01-Apr-2025	14:23:30 PM	24	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:23:41 PM	25	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:25:01 PM	83	1319.00	XCSE
GENMAB A/S	01-Apr-2025	14:26:25 PM	23	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:26:25 PM	14	1319.50	XCSE
GENMAB A/S	01-Apr-2025	14:26:41 PM	86	1318.00	XCSE
GENMAB A/S	01-Apr-2025	14:26:41 PM	32	1318.00	TQEX
GENMAB A/S	01-Apr-2025	14:26:41 PM	31	1318.50	CEUX
GENMAB A/S	01-Apr-2025	14:27:54 PM	68	1317.00	XCSE
GENMAB A/S	01-Apr-2025	14:27:54 PM	30	1317.00	CEUX
GENMAB A/S	01-Apr-2025	14:28:42 PM	59	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:29:40 PM	42	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:29:40 PM	22	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:30:08 PM	44	1320.50	TQEX
GENMAB A/S	01-Apr-2025	14:30:08 PM	19	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:30:08 PM	42	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:30:33 PM	30	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:32:22 PM	56	1320.50	CEUX
GENMAB A/S	01-Apr-2025	14:32:54 PM	52	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:32:54 PM	91	1320.00	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	14:32:54 PM	15	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:32:54 PM	2	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:32:58 PM	25	1319.50	AQEU
GENMAB A/S	01-Apr-2025	14:32:58 PM	36	1319.50	CEUX
GENMAB A/S	01-Apr-2025	14:33:05 PM	91	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:33:05 PM	10	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:34:06 PM	34	1320.50	XCSE
GENMAB A/S	01-Apr-2025	14:34:25 PM	65	1320.00	XCSE
GENMAB A/S	01-Apr-2025	14:36:57 PM	33	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:36:57 PM	45	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:36:57 PM	19	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:36:57 PM	11	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:36:57 PM	32	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:36:57 PM	50	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:37:17 PM	86	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:37:17 PM	45	1322.00	TQEX
GENMAB A/S	01-Apr-2025	14:38:19 PM	18	1321.50	CEUX
GENMAB A/S	01-Apr-2025	14:38:23 PM	10	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:38:23 PM	38	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:38:23 PM	10	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:38:23 PM	31	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:38:23 PM	19	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:40:44 PM	79	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:40:44 PM	38	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:40:44 PM	2	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:40:44 PM	70	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:41:24 PM	38	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:24 PM	50	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:41:24 PM	30	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:41:29 PM	4	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:45 PM	3	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:46 PM	12	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:46 PM	11	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:55 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:55 PM	38	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:41:55 PM	7	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:43:15 PM	18	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:43:15 PM	65	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:45:36 PM	10	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:45:36 PM	10	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:45:36 PM	38	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:45:36 PM	11	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:46:53 PM	11	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:47:50 PM	31	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:47:50 PM	50	1323.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	14:47:50 PM	12	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:47:50 PM	14	1323.50	TQEX
GENMAB A/S	01-Apr-2025	14:47:50 PM	15	1323.50	TQEX
GENMAB A/S	01-Apr-2025	14:47:50 PM	43	1323.50	AQEU
GENMAB A/S	01-Apr-2025	14:48:15 PM	69	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:48:15 PM	38	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:48:15 PM	19	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:48:15 PM	31	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:48:15 PM	26	1322.50	TQEX
GENMAB A/S	01-Apr-2025	14:48:15 PM	32	1323.00	CEUX
GENMAB A/S	01-Apr-2025	14:48:15 PM	79	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:48:17 PM	27	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:48:17 PM	47	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:48:17 PM	34	1322.50	AQEU
GENMAB A/S	01-Apr-2025	14:48:17 PM	81	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:49:09 PM	79	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:50:27 PM	3	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:52:17 PM	5	1323.50	CEUX
GENMAB A/S	01-Apr-2025	14:52:17 PM	79	1323.50	CEUX
GENMAB A/S	01-Apr-2025	14:52:28 PM	12	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:52:28 PM	12	1323.50	XCSE
GENMAB A/S	01-Apr-2025	14:52:51 PM	66	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:52:51 PM	16	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:52:51 PM	38	1323.00	XCSE
GENMAB A/S	01-Apr-2025	14:52:51 PM	29	1322.50	TQEX
GENMAB A/S	01-Apr-2025	14:52:51 PM	84	1322.50	CEUX
GENMAB A/S	01-Apr-2025	14:53:26 PM	5	1322.50	XCSE
GENMAB A/S	01-Apr-2025	14:54:34 PM	83	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:54:34 PM	10	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:54:34 PM	11	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:54:34 PM	12	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:54:34 PM	23	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:54:34 PM	12	1322.00	XCSE
GENMAB A/S	01-Apr-2025	14:55:15 PM	39	1321.50	CEUX
GENMAB A/S	01-Apr-2025	14:55:16 PM	26	1321.50	CEUX
GENMAB A/S	01-Apr-2025	14:55:17 PM	40	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:55:17 PM	10	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:55:17 PM	7	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:55:17 PM	14	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:55:17 PM	12	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:55:17 PM	11	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:55:22 PM	1	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:56:21 PM	8	1321.50	CEUX
GENMAB A/S	01-Apr-2025	14:56:21 PM	43	1321.50	CEUX
GENMAB A/S	01-Apr-2025	14:57:06 PM	31	1321.50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	14:57:25 PM	35	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:57:25 PM	1	1321.50	XCSE
GENMAB A/S	01-Apr-2025	14:58:21 PM	84	1321.00	XCSE
GENMAB A/S	01-Apr-2025	14:58:21 PM	1	1321.00	TQEX
GENMAB A/S	01-Apr-2025	14:58:21 PM	24	1321.00	TQEX
GENMAB A/S	01-Apr-2025	14:58:34 PM	80	1321.00	XCSE
GENMAB A/S	01-Apr-2025	14:58:34 PM	38	1321.00	XCSE
GENMAB A/S	01-Apr-2025	14:58:34 PM	35	1321.00	AQEU
GENMAB A/S	01-Apr-2025	15:00:26 PM	32	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:01:14 PM	8	1322.00	XCSE
GENMAB A/S	01-Apr-2025	15:02:19 PM	6	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:01 PM	75	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:03 PM	27	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:03 PM	9	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:03 PM	12	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:03 PM	53	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:03 PM	33	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:03 PM	35	1321.00	TQEX
GENMAB A/S	01-Apr-2025	15:03:03 PM	5	1321.50	CEUX
GENMAB A/S	01-Apr-2025	15:03:03 PM	6	1321.50	CEUX
GENMAB A/S	01-Apr-2025	15:03:03 PM	5	1321.50	CEUX
GENMAB A/S	01-Apr-2025	15:03:03 PM	69	1321.00	CEUX
GENMAB A/S	01-Apr-2025	15:03:03 PM	4	1321.00	CEUX
GENMAB A/S	01-Apr-2025	15:03:03 PM	11	1321.00	CEUX
GENMAB A/S	01-Apr-2025	15:03:04 PM	38	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	9	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	11	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	50	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	20	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	11	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	29	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	12	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	36	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	9	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	12	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	38	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:04 PM	4	1320.50	XCSE
GENMAB A/S	01-Apr-2025	15:03:11 PM	1	1320.00	TQEX
GENMAB A/S	01-Apr-2025	15:03:11 PM	22	1320.00	TQEX
GENMAB A/S	01-Apr-2025	15:03:11 PM	85	1320.00	CEUX
GENMAB A/S	01-Apr-2025	15:03:15 PM	79	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:05:34 PM	24	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:05:34 PM	8	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:06:50 PM	86	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:06:50 PM	24	1321.50	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:06:50 PM	2	1321.50	TQEX
GENMAB A/S	01-Apr-2025	15:06:50 PM	23	1321.50	AQEU
GENMAB A/S	01-Apr-2025	15:06:50 PM	81	1321.50	CEUX
GENMAB A/S	01-Apr-2025	15:06:51 PM	42	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:06:51 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:06:51 PM	26	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:06:51 PM	2	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:06:51 PM	8	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:07:17 PM	28	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:07:17 PM	26	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:07:17 PM	10	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:07:17 PM	9	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:07:17 PM	11	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:08:33 PM	10	1322.00	XCSE
GENMAB A/S	01-Apr-2025	15:08:57 PM	81	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:08:58 PM	15	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:08:58 PM	28	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:09:04 PM	3	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:09:04 PM	22	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:09:10 PM	10	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:09:16 PM	9	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:10:26 PM	20	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:10:26 PM	10	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:11:09 PM	25	1324.00	TQEX
GENMAB A/S	01-Apr-2025	15:11:26 PM	10	1324.00	XCSE
GENMAB A/S	01-Apr-2025	15:11:38 PM	25	1324.00	XCSE
GENMAB A/S	01-Apr-2025	15:11:38 PM	28	1324.00	CEUX
GENMAB A/S	01-Apr-2025	15:12:47 PM	14	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:12:47 PM	3	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:12:49 PM	25	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:13:02 PM	23	1324.50	TQEX
GENMAB A/S	01-Apr-2025	15:13:02 PM	31	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:13:02 PM	49	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:13:28 PM	36	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:13:40 PM	36	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:14:04 PM	18	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:14:20 PM	38	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:20 PM	10	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:20 PM	45	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:20 PM	12	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:20 PM	3	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:20 PM	71	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:14:21 PM	6	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	10	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	45	1324.50	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:14:21 PM	9	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	38	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	12	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	38	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	12	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	12	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	34	1324.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	79	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:21 PM	23	1324.00	TQEX
GENMAB A/S	01-Apr-2025	15:14:21 PM	14	1324.50	AQEU
GENMAB A/S	01-Apr-2025	15:14:21 PM	12	1324.50	AQEU
GENMAB A/S	01-Apr-2025	15:14:21 PM	68	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:14:21 PM	17	1324.50	CEUX
GENMAB A/S	01-Apr-2025	15:14:21 PM	82	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:14:42 PM	82	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:42 PM	50	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:42 PM	19	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:14:42 PM	38	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:14:42 PM	1	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:14:42 PM	23	1323.00	TQEX
GENMAB A/S	01-Apr-2025	15:14:42 PM	29	1323.00	AQEU
GENMAB A/S	01-Apr-2025	15:15:59 PM	9	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:15:59 PM	10	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:16:29 PM	2	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:17:04 PM	8	1323.00	CEUX
GENMAB A/S	01-Apr-2025	15:18:20 PM	9	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:18:20 PM	10	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:18:20 PM	10	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:18:20 PM	20	1323.50	AQEU
GENMAB A/S	01-Apr-2025	15:18:20 PM	10	1323.50	AQEU
GENMAB A/S	01-Apr-2025	15:18:51 PM	44	1323.50	XCSE
GENMAB A/S	01-Apr-2025	15:18:51 PM	32	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:19:38 PM	15	1323.50	CEUX
GENMAB A/S	01-Apr-2025	15:19:39 PM	86	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	70	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	29	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	9	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	31	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	10	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	9	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	12	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:39 PM	18	1323.00	CEUX
GENMAB A/S	01-Apr-2025	15:19:39 PM	60	1323.00	CEUX
GENMAB A/S	01-Apr-2025	15:19:39 PM	72	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:19:40 PM	9	1322.50	XCSE

100

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:19:40 PM	10	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	10	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	29	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	11	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	9	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	38	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	11	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:40 PM	29	1322.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:58 PM	71	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:58 PM	11	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:19:58 PM	31	1321.50	TQEX
GENMAB A/S	01-Apr-2025	15:19:58 PM	2	1321.50	TQEX
GENMAB A/S	01-Apr-2025	15:21:25 PM	82	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:21:52 PM	86	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:21:52 PM	59	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:21:52 PM	18	1323.00	CEUX
GENMAB A/S	01-Apr-2025	15:21:52 PM	65	1323.00	CEUX
GENMAB A/S	01-Apr-2025	15:22:26 PM	33	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:26 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:26 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:26 PM	12	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:26 PM	9	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:26 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:27 PM	11	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:27 PM	12	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:27 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:28 PM	11	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:28 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:29 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:29 PM	13	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:35 PM	11	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:35 PM	12	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:35 PM	10	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:35 PM	34	1323.00	XCSE
GENMAB A/S	01-Apr-2025	15:22:39 PM	28	1322.50	TQEX
GENMAB A/S	01-Apr-2025	15:25:17 PM	22	1322.50	TQEX
GENMAB A/S	01-Apr-2025	15:25:17 PM	5	1322.50	TQEX
GENMAB A/S	01-Apr-2025	15:25:17 PM	20	1322.50	CEUX
GENMAB A/S	01-Apr-2025	15:26:04 PM	81	1322.00	XCSE
GENMAB A/S	01-Apr-2025	15:26:04 PM	82	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:26:05 PM	36	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:26:05 PM	26	1322.00	CEUX
GENMAB A/S	01-Apr-2025	15:26:30 PM	86	1321.00	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	38	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	30	1321.50	XCSE

101

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:26:30 PM	3	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	9	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	5	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	5	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	4	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	9	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	5	1321.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	11	1320.00	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	38	1320.00	XCSE
GENMAB A/S	01-Apr-2025	15:26:30 PM	23	1321.50	TQEX
GENMAB A/S	01-Apr-2025	15:26:30 PM	5	1320.50	TQEX
GENMAB A/S	01-Apr-2025	15:26:30 PM	20	1320.50	TQEX
GENMAB A/S	01-Apr-2025	15:26:30 PM	15	1321.50	AQEU
GENMAB A/S	01-Apr-2025	15:26:30 PM	3	1321.50	AQEU
GENMAB A/S	01-Apr-2025	15:26:30 PM	3	1321.50	AQEU
GENMAB A/S	01-Apr-2025	15:26:30 PM	2	1321.50	AQEU
GENMAB A/S	01-Apr-2025	15:26:30 PM	83	1321.00	CEUX
GENMAB A/S	01-Apr-2025	15:26:30 PM	33	1319.50	CEUX
GENMAB A/S	01-Apr-2025	15:26:31 PM	1	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:32 PM	40	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:32 PM	39	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:32 PM	66	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:32 PM	38	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:26:32 PM	52	1319.50	CEUX
GENMAB A/S	01-Apr-2025	15:27:00 PM	2	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:00 PM	3	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:00 PM	30	1319.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:24 PM	5	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:27:38 PM	9	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	85	1318.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	6	1318.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	38	1318.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	9	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	38	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	5	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	62	1318.50	XCSE
GENMAB A/S	01-Apr-2025	15:27:41 PM	23	1318.50	AQEU
GENMAB A/S	01-Apr-2025	15:27:41 PM	86	1318.50	CEUX
GENMAB A/S	01-Apr-2025	15:28:00 PM	85	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:28:26 PM	23	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:28:26 PM	43	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:28:34 PM	18	1319.00	CEUX
GENMAB A/S	01-Apr-2025	15:29:30 PM	36	1319.00	CEUX
GENMAB A/S	01-Apr-2025	15:29:31 PM	23	1319.00	CEUX

102

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:29:46 PM	9	1319.50	CEUX
GENMAB A/S	01-Apr-2025	15:29:46 PM	13	1319.50	CEUX
GENMAB A/S	01-Apr-2025	15:29:46 PM	86	1319.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:00 PM	83	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:00 PM	31	1318.50	TQEX
GENMAB A/S	01-Apr-2025	15:30:00 PM	27	1319.50	TQEX
GENMAB A/S	01-Apr-2025	15:30:00 PM	85	1318.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:00 PM	82	1319.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:00 PM	65	1318.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:05 PM	30	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	38	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	10	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	10	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	8	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	38	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	11	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	33	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:05 PM	17	1318.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:15 PM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:15 PM	38	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:15 PM	12	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:15 PM	9	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:15 PM	33	1319.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:25 PM	81	1318.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:32 PM	18	1317.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:32 PM	62	1317.50	CEUX
GENMAB A/S	01-Apr-2025	15:30:36 PM	83	1317.00	XCSE
GENMAB A/S	01-Apr-2025	15:30:36 PM	29	1317.00	TQEX
GENMAB A/S	01-Apr-2025	15:30:36 PM	2	1317.00	TQEX
GENMAB A/S	01-Apr-2025	15:30:51 PM	44	1317.50	XCSE
GENMAB A/S	01-Apr-2025	15:30:51 PM	12	1317.50	XCSE
GENMAB A/S	01-Apr-2025	15:30:51 PM	50	1317.50	XCSE
GENMAB A/S	01-Apr-2025	15:30:51 PM	2	1317.50	XCSE
GENMAB A/S	01-Apr-2025	15:30:51 PM	20	1318.00	TQEX
GENMAB A/S	01-Apr-2025	15:31:02 PM	80	1317.00	XCSE
GENMAB A/S	01-Apr-2025	15:31:02 PM	34	1317.00	CEUX
GENMAB A/S	01-Apr-2025	15:31:02 PM	49	1317.00	CEUX
GENMAB A/S	01-Apr-2025	15:31:05 PM	86	1316.00	XCSE
GENMAB A/S	01-Apr-2025	15:31:05 PM	39	1316.00	CEUX
GENMAB A/S	01-Apr-2025	15:31:05 PM	24	1316.00	CEUX
GENMAB A/S	01-Apr-2025	15:31:17 PM	24	1315.50	XCSE
GENMAB A/S	01-Apr-2025	15:31:18 PM	29	1315.50	XCSE

103

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:31:21 PM	43	1315.00	CEUX
GENMAB A/S	01-Apr-2025	15:31:27 PM	84	1314.50	XCSE
GENMAB A/S	01-Apr-2025	15:31:27 PM	31	1315.00	XCSE
GENMAB A/S	01-Apr-2025	15:31:27 PM	30	1315.00	XCSE
GENMAB A/S	01-Apr-2025	15:31:27 PM	10	1315.00	XCSE
GENMAB A/S	01-Apr-2025	15:31:27 PM	37	1315.00	XCSE
GENMAB A/S	01-Apr-2025	15:31:50 PM	80	1314.50	XCSE
GENMAB A/S	01-Apr-2025	15:31:50 PM	81	1313.50	XCSE
GENMAB A/S	01-Apr-2025	15:31:50 PM	37	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:31:50 PM	46	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:31:50 PM	27	1314.50	TQEX
GENMAB A/S	01-Apr-2025	15:31:50 PM	1	1314.50	TQEX
GENMAB A/S	01-Apr-2025	15:31:50 PM	8	1313.50	TQEX
GENMAB A/S	01-Apr-2025	15:31:50 PM	20	1313.50	TQEX
GENMAB A/S	01-Apr-2025	15:31:50 PM	38	1314.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	21	1314.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	16	1314.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	4	1313.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	38	1313.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	25	1313.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	5	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:50 PM	51	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:31:54 PM	5	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:32:16 PM	16	1316.00	CEUX
GENMAB A/S	01-Apr-2025	15:32:16 PM	47	1316.00	CEUX
GENMAB A/S	01-Apr-2025	15:32:43 PM	86	1315.50	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	38	1315.50	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	22	1315.50	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	47	1315.50	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	1	1315.50	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	58	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	25	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	2	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:32:43 PM	24	1314.50	TQEX
GENMAB A/S	01-Apr-2025	15:32:43 PM	67	1315.00	CEUX
GENMAB A/S	01-Apr-2025	15:32:43 PM	35	1314.00	CEUX
GENMAB A/S	01-Apr-2025	15:32:43 PM	18	1314.00	CEUX
GENMAB A/S	01-Apr-2025	15:32:44 PM	10	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:32:56 PM	61	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:33:04 PM	27	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:33:52 PM	17	1312.00	TQEX
GENMAB A/S	01-Apr-2025	15:33:52 PM	6	1312.00	TQEX
GENMAB A/S	01-Apr-2025	15:33:53 PM	79	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:07 PM	55	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:34:07 PM	38	1311.00	XCSE

104

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:34:07 PM	15	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:34:07 PM	22	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:07 PM	57	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:07 PM	24	1311.00	TQEX
GENMAB A/S	01-Apr-2025	15:34:07 PM	50	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:34:16 PM	23	1310.00	TQEX
GENMAB A/S	01-Apr-2025	15:34:29 PM	84	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:29 PM	26	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:29 PM	26	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:29 PM	11	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:29 PM	12	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:34:29 PM	83	1310.50	CEUX
GENMAB A/S	01-Apr-2025	15:36:01 PM	82	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	38	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	25	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	11	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	10	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	12	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	12	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:02 PM	25	1313.50	TQEX
GENMAB A/S	01-Apr-2025	15:36:02 PM	79	1313.50	CEUX
GENMAB A/S	01-Apr-2025	15:36:02 PM	20	1313.50	CEUX
GENMAB A/S	01-Apr-2025	15:36:05 PM	82	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:05 PM	10	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:36:06 PM	24	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:06 PM	44	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:06 PM	12	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:06 PM	25	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:06 PM	4	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:06 PM	23	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:36:06 PM	25	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:36:06 PM	8	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:36:06 PM	14	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:36:37 PM	20	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:37 PM	50	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:37 PM	9	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:37 PM	8	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:37 PM	21	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:48 PM	9	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:48 PM	38	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:48 PM	9	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:49 PM	9	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:49 PM	38	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:49 PM	44	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:49 PM	9	1314.00	XCSE

105

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:36:50 PM	38	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:50 PM	44	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:50 PM	9	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:50 PM	85	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:36:51 PM	25	1312.50	TQEX
GENMAB A/S	01-Apr-2025	15:36:51 PM	19	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:36:51 PM	63	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:37:15 PM	84	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:15 PM	26	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:15 PM	60	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:15 PM	9	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:15 PM	26	1311.50	TQEX
GENMAB A/S	01-Apr-2025	15:37:15 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:37:15 PM	80	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:37:34 PM	24	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:34 PM	38	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:34 PM	46	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:37:34 PM	81	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:37:39 PM	54	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:37:39 PM	28	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:37:53 PM	12	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:37:53 PM	10	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:37:53 PM	9	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:37:53 PM	26	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	80	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	11	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	12	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	12	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	38	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	10	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	9	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	12	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	38	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:38:28 PM	23	1312.50	TQEX
GENMAB A/S	01-Apr-2025	15:38:28 PM	2	1312.50	TQEX
GENMAB A/S	01-Apr-2025	15:38:28 PM	79	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:39:16 PM	40	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:39:16 PM	35	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:39:16 PM	33	1312.50	XCSE
GENMAB A/S	01-Apr-2025	15:39:46 PM	82	1313.50	XCSE
GENMAB A/S	01-Apr-2025	15:39:46 PM	26	1313.50	TQEX
GENMAB A/S	01-Apr-2025	15:39:54 PM	33	1313.50	XCSE
GENMAB A/S	01-Apr-2025	15:39:54 PM	16	1313.50	CEUX
GENMAB A/S	01-Apr-2025	15:40:02 PM	33	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:02 PM	12	1313.00	XCSE

106

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:40:02 PM	38	1313.50	XCSE
GENMAB A/S	01-Apr-2025	15:40:02 PM	25	1313.50	XCSE
GENMAB A/S	01-Apr-2025	15:40:02 PM	24	1312.50	TQEX
GENMAB A/S	01-Apr-2025	15:40:02 PM	84	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:40:03 PM	23	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:03 PM	53	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:03 PM	9	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:03 PM	11	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:03 PM	10	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:27 PM	11	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:40:27 PM	69	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	24	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	31	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	3	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	10	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	11	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	34	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	31	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	9	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:10 PM	27	1313.50	TQEX
GENMAB A/S	01-Apr-2025	15:41:15 PM	12	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:15 PM	12	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:15 PM	38	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:15 PM	8	1314.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:16 PM	30	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:16 PM	49	1313.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:16 PM	79	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:41:16 PM	10	1313.00	CEUX
GENMAB A/S	01-Apr-2025	15:41:42 PM	82	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:41:42 PM	82	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:41:42 PM	36	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:41:45 PM	32	1312.50	CEUX
GENMAB A/S	01-Apr-2025	15:42:18 PM	37	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:42:19 PM	80	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:42:19 PM	25	1312.00	TQEX
GENMAB A/S	01-Apr-2025	15:42:19 PM	3	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:42:19 PM	77	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:42:50 PM	27	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:42:50 PM	5	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:43:26 PM	14	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:44:14 PM	60	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:44:14 PM	21	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:44:14 PM	45	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:44:14 PM	83	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:45:21 PM	86	1309.50	XCSE

107

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:45:21 PM	70	1309.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:21 PM	20	1309.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:21 PM	18	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:45:21 PM	80	1309.50	CEUX
GENMAB A/S	01-Apr-2025	15:45:22 PM	41	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:45:22 PM	83	1309.00	CEUX
GENMAB A/S	01-Apr-2025	15:45:27 PM	2	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:45:44 PM	83	1308.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:44 PM	83	1308.50	CEUX
GENMAB A/S	01-Apr-2025	15:45:44 PM	2	1308.50	CEUX
GENMAB A/S	01-Apr-2025	15:45:58 PM	41	1308.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:58 PM	10	1308.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:58 PM	12	1308.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:58 PM	10	1308.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:58 PM	35	1308.50	XCSE
GENMAB A/S	01-Apr-2025	15:45:58 PM	23	1308.00	TQEX
GENMAB A/S	01-Apr-2025	15:45:58 PM	31	1307.50	CEUX
GENMAB A/S	01-Apr-2025	15:46:45 PM	13	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:46:45 PM	72	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:46:45 PM	71	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:46:45 PM	21	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:46:45 PM	16	1309.00	XCSE
GENMAB A/S	01-Apr-2025	15:46:45 PM	83	1309.00	CEUX
GENMAB A/S	01-Apr-2025	15:47:35 PM	80	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:47:35 PM	80	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:47:55 PM	47	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:47:55 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:47:55 PM	41	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:47:55 PM	31	1309.50	TQEX
GENMAB A/S	01-Apr-2025	15:48:09 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	41	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	31	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	6	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	74	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:09 PM	1	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	51	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	8	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	4	1311.50	XCSE

108

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:48:10 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	3	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	41	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:10 PM	1	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	74	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	16	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	41	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:11 PM	35	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:48:16 PM	30	1311.50	TQEX
GENMAB A/S	01-Apr-2025	15:49:26 PM	82	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:26 PM	42	1311.00	AQEU
GENMAB A/S	01-Apr-2025	15:49:26 PM	10	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:49:26 PM	36	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:49:27 PM	15	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	58	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:49:27 PM	24	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:49:27 PM	4	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:49:27 PM	28	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:49:28 PM	13	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:49:28 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:49:28 PM	5	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:49:28 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:49:28 PM	18	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:49:28 PM	80	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:49:54 PM	24	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:50:17 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:50:17 PM	74	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:50:17 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:50:17 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:50:17 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:50:17 PM	28	1311.00	TQEX
GENMAB A/S	01-Apr-2025	15:50:17 PM	79	1311.00	CEUX

109

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:50:17 PM	36	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:50:17 PM	5	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:50:17 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:50:17 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:50:18 PM	35	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:26 PM	19	1310.50	AQEU
GENMAB A/S	01-Apr-2025	15:51:26 PM	5	1310.50	AQEU
GENMAB A/S	01-Apr-2025	15:51:27 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:27 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:27 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:27 PM	1	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:27 PM	58	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:27 PM	15	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:51:27 PM	24	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:51:27 PM	1	1310.50	CEUX
GENMAB A/S	01-Apr-2025	15:51:27 PM	22	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:51:27 PM	13	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:15 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:52:15 PM	51	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:52:15 PM	16	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:52:16 PM	108	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:52:16 PM	25	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:52:26 PM	80	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:52:26 PM	40	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:52:26 PM	9	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:52:26 PM	86	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:26 PM	15	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:26 PM	6	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:26 PM	5	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:26 PM	5	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:26 PM	8	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:26 PM	28	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:52:27 PM	5	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:53:01 PM	10	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:53:01 PM	36	1310.50	CEUX
GENMAB A/S	01-Apr-2025	15:53:06 PM	36	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:53:06 PM	37	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:53:06 PM	35	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:53:06 PM	20	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:53:06 PM	23	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:54:54 PM	7	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:54:54 PM	86	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:55:26 PM	9	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:55:26 PM	3	1311.50	CEUX
GENMAB A/S	01-Apr-2025	15:55:48 PM	41	1311.50	XCSE

110

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:55:48 PM	15	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:48 PM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:48 PM	14	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:48 PM	33	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:48 PM	25	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:55:49 PM	44	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:49 PM	15	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:55:50 PM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	38	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	25	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	15	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:55:50 PM	24	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:55:50 PM	10	1310.50	CEUX
GENMAB A/S	01-Apr-2025	15:55:50 PM	36	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:55:51 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:55:51 PM	38	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:55:51 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:14 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:14 PM	6	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:14 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:14 PM	6	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:15 PM	69	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:27 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:29 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:34 PM	13	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:40 PM	10	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:40 PM	11	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:40 PM	10	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:40 PM	17	1312.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:40 PM	65	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:40 PM	19	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:40 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:40 PM	56	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:40 PM	25	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:41 PM	63	1311.50	XCSE

111

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:56:41 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:41 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:41 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:41 PM	15	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:41 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:41 PM	32	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	44	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	29	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	32	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:42 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:56:46 PM	80	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:56:46 PM	31	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:56:46 PM	84	1311.00	CEUX
GENMAB A/S	01-Apr-2025	15:56:46 PM	20	1310.50	CEUX
GENMAB A/S	01-Apr-2025	15:57:37 PM	30	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:58:30 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:30 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:30 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:30 PM	6	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:30 PM	50	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:30 PM	14	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:31 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:31 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:31 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:31 PM	30	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:31 PM	46	1311.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:31 PM	20	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:58:31 PM	3	1310.50	TQEX
GENMAB A/S	01-Apr-2025	15:58:31 PM	27	1310.50	AQEU
GENMAB A/S	01-Apr-2025	15:58:54 PM	85	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:58:54 PM	11	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:58:54 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:58:54 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:58:54 PM	37	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:58:54 PM	36	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:54 PM	38	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:58:54 PM	20	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:58:54 PM	27	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:58:54 PM	20	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:58:54 PM	5	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:58:54 PM	6	1310.00	CEUX

112

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	15:58:54 PM	5	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:58:55 PM	11	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:55 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:55 PM	10	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:55 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:55 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:55 PM	10	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:58:55 PM	30	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:59:18 PM	4	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:59:19 PM	86	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:19 PM	27	1310.00	TQEX
GENMAB A/S	01-Apr-2025	15:59:19 PM	81	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:59:26 PM	65	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	1	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	49	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	30	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	18	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	11	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	1	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:26 PM	5	1310.00	CEUX
GENMAB A/S	01-Apr-2025	15:59:27 PM	9	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:27 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:27 PM	11	1310.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	10	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	10	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	50	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	1	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	15:59:59 PM	6	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	12	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	10	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	26	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	36	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:00:00 PM	3	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:00:01 PM	81	1309.00	XCSE

113

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:00:01 PM	24	1309.00	TQEX
GENMAB A/S	01-Apr-2025	16:00:01 PM	85	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:00:03 PM	86	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:00:03 PM	23	1307.50	TQEX
GENMAB A/S	01-Apr-2025	16:00:03 PM	83	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:00:20 PM	50	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:00:48 PM	41	1308.50	TQEX
GENMAB A/S	01-Apr-2025	16:00:48 PM	25	1308.50	AQEU
GENMAB A/S	01-Apr-2025	16:00:48 PM	75	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:00:48 PM	7	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:01:01 PM	14	1308.50	AQEU
GENMAB A/S	01-Apr-2025	16:01:14 PM	32	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:01:14 PM	10	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:01:14 PM	18	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:01:26 PM	26	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:01:27 PM	23	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:02:04 PM	82	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:02:04 PM	23	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:02:04 PM	36	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:02:25 PM	20	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:02:25 PM	61	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:02:25 PM	30	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:02:25 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:02:25 PM	41	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:02:25 PM	26	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:02:25 PM	36	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:02:25 PM	81	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:02:25 PM	62	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:02:26 PM	1	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:02:26 PM	1	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:03:03 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:03:30 PM	86	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:03:30 PM	36	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:03:30 PM	80	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:03:40 PM	35	1311.00	TQEX
GENMAB A/S	01-Apr-2025	16:03:40 PM	83	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:03:41 PM	5	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:03:41 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:03:41 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:03:41 PM	28	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:03:42 PM	83	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:04:14 PM	39	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:04:14 PM	45	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:04:14 PM	52	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:04:39 PM	41	1311.50	TQEX

114

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:05:02 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:03 PM	27	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:03 PM	9	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:05 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:06 PM	36	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:10 PM	36	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:05:10 PM	66	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:05:11 PM	19	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:05:11 PM	61	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:05:11 PM	28	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:05:19 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:05:27 PM	4	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:05:38 PM	41	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:05:38 PM	36	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:05:52 PM	85	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:52 PM	31	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:52 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:52 PM	20	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:52 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:52 PM	6	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:52 PM	86	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:52 PM	27	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:53 PM	3	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	39	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	20	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	37	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	4	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	36	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	39	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	13	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	19	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:53 PM	16	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:05:58 PM	54	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:05:58 PM	4	1310.00	AQEU
GENMAB A/S	01-Apr-2025	16:05:58 PM	25	1310.00	AQEU
GENMAB A/S	01-Apr-2025	16:05:58 PM	64	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:06:13 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:06:13 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:06:13 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:06:13 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:06:13 PM	11	1311.00	XCSE

115

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:06:16 PM	85	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:07:02 PM	3	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:07:02 PM	51	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:07:02 PM	29	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:07:02 PM	15	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:07:26 PM	11	1310.00	AQEU
GENMAB A/S	01-Apr-2025	16:07:26 PM	12	1310.00	AQEU
GENMAB A/S	01-Apr-2025	16:07:26 PM	81	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:07:31 PM	84	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:07:44 PM	14	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:07:44 PM	28	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:08:25 PM	26	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:08:25 PM	36	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:08:25 PM	27	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:09:26 PM	36	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:09:43 PM	36	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:09:43 PM	82	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:09:44 PM	25	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:09:44 PM	9	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:09:44 PM	4	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:09:59 PM	22	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:09:59 PM	18	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:10:36 PM	36	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:10:36 PM	5	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:10:36 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:11:26 PM	38	1311.00	TQEX
GENMAB A/S	01-Apr-2025	16:11:26 PM	85	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:11:40 PM	27	1313.50	TQEX
GENMAB A/S	01-Apr-2025	16:11:40 PM	25	1313.50	CEUX
GENMAB A/S	01-Apr-2025	16:11:40 PM	5	1314.00	CEUX
GENMAB A/S	01-Apr-2025	16:11:40 PM	5	1314.00	CEUX
GENMAB A/S	01-Apr-2025	16:11:40 PM	61	1313.50	CEUX
GENMAB A/S	01-Apr-2025	16:12:19 PM	81	1313.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:19 PM	34	1313.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:19 PM	32	1313.00	CEUX
GENMAB A/S	01-Apr-2025	16:12:23 PM	31	1313.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:23 PM	6	1313.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:23 PM	22	1313.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:23 PM	3	1312.50	TQEX
GENMAB A/S	01-Apr-2025	16:12:23 PM	25	1312.50	TQEX
GENMAB A/S	01-Apr-2025	16:12:23 PM	9	1312.50	CEUX
GENMAB A/S	01-Apr-2025	16:12:23 PM	70	1312.50	CEUX
GENMAB A/S	01-Apr-2025	16:12:28 PM	33	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:28 PM	5	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:28 PM	43	1312.00	XCSE

116

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:12:28 PM	41	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:28 PM	22	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:12:44 PM	28	1311.50	TQEX
GENMAB A/S	01-Apr-2025	16:12:44 PM	51	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:12:44 PM	33	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:12:59 PM	80	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:08 PM	108	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:08 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:27 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:27 PM	13	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:27 PM	30	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:27 PM	24	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:13:28 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:07 PM	41	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:07 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:07 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:07 PM	80	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:07 PM	37	1310.50	TQEX
GENMAB A/S	01-Apr-2025	16:14:07 PM	32	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:14:07 PM	86	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:14:08 PM	23	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:08 PM	41	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:08 PM	21	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:08 PM	9	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:08 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:08 PM	4	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:09 PM	21	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:09 PM	41	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:09 PM	69	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:14:11 PM	80	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	50	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	22	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	23	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	12	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	12	1308.50	XCSE

117

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:14:11 PM	19	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	1	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	11	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	12	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	41	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:11 PM	4	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:14:13 PM	23	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:14:20 PM	33	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:20 PM	1	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:14:20 PM	47	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:15:09 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:15:09 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:15:09 PM	10	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:15:09 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:15:12 PM	12	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:15:12 PM	85	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:15:40 PM	80	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:15:48 PM	79	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:15:48 PM	22	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:15:48 PM	14	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:16:27 PM	2	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:17:10 PM	43	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:17:10 PM	36	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:18:05 PM	18	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:18:05 PM	34	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:18:07 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:18:07 PM	36	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:18:07 PM	41	1307.50	AQEU
GENMAB A/S	01-Apr-2025	16:18:16 PM	17	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:18:29 PM	35	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:18:29 PM	18	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:18:49 PM	39	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:18:49 PM	32	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:19:04 PM	32	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:19:04 PM	41	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:19:28 PM	82	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:19:30 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:19:30 PM	17	1307.50	XCSE

118

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:19:40 PM	30	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:19:50 PM	38	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:19:51 PM	4	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:04 PM	6	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:08 PM	39	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	6	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	22	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	33	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:08 PM	37	1307.00	TQEX
GENMAB A/S	01-Apr-2025	16:20:09 PM	5	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:09 PM	6	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:09 PM	21	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:10 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:10 PM	34	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:10 PM	47	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:10 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:10 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:10 PM	5	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:13 PM	8	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:13 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:13 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:13 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:13 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:13 PM	36	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:13 PM	1	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:24 PM	65	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:20:39 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:39 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:39 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:40 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:40 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:44 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	15	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	31	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	21	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	31	1307.50	XCSE

119

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:20:56 PM	13	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	7	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	73	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:20:56 PM	37	1307.00	TQEX
GENMAB A/S	01-Apr-2025	16:20:56 PM	32	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:20:56 PM	73	1306.50	CEUX
GENMAB A/S	01-Apr-2025	16:21:22 PM	79	1305.50	XCSE
GENMAB A/S	01-Apr-2025	16:21:22 PM	53	1305.50	CEUX
GENMAB A/S	01-Apr-2025	16:21:22 PM	7	1305.50	CEUX
GENMAB A/S	01-Apr-2025	16:21:46 PM	85	1305.00	XCSE
GENMAB A/S	01-Apr-2025	16:21:46 PM	52	1305.50	XCSE
GENMAB A/S	01-Apr-2025	16:21:46 PM	41	1305.50	XCSE
GENMAB A/S	01-Apr-2025	16:21:46 PM	15	1305.50	XCSE
GENMAB A/S	01-Apr-2025	16:21:46 PM	32	1305.00	CEUX
GENMAB A/S	01-Apr-2025	16:21:47 PM	81	1305.00	XCSE
GENMAB A/S	01-Apr-2025	16:22:45 PM	9	1305.00	XCSE
GENMAB A/S	01-Apr-2025	16:23:52 PM	86	1306.00	XCSE
GENMAB A/S	01-Apr-2025	16:24:27 PM	83	1306.00	XCSE
GENMAB A/S	01-Apr-2025	16:24:27 PM	80	1306.00	CEUX
GENMAB A/S	01-Apr-2025	16:24:39 PM	3	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:24:39 PM	7	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:24:48 PM	13	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:25:25 PM	18	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:25:25 PM	18	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:25:29 PM	79	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:25:29 PM	83	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:25:30 PM	25	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:25:30 PM	31	1308.00	AQEU
GENMAB A/S	01-Apr-2025	16:26:25 PM	36	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:26:42 PM	1	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:26:42 PM	10	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:26:59 PM	41	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:26:59 PM	14	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:26:59 PM	31	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:26:59 PM	22	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:26:59 PM	29	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:26:59 PM	26	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:27:25 PM	3	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:27:25 PM	76	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:27:25 PM	43	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:27:25 PM	14	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:27:25 PM	58	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	21	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	6	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	36	1307.50	CEUX

120

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:27:25 PM	5	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	6	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	6	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	5	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:25 PM	9	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:27:26 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:27:26 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	27	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	13	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	31	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:10 PM	26	1307.00	TQEX
GENMAB A/S	01-Apr-2025	16:28:10 PM	36	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:28:11 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	9	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	35	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:11 PM	2	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:12 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:12 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:12 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:12 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:12 PM	32	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:12 PM	43	1306.50	CEUX
GENMAB A/S	01-Apr-2025	16:28:15 PM	1	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	1	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	83	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	29	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	41	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	12	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	10	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	11	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	5	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:28:15 PM	37	1306.50	CEUX
GENMAB A/S	01-Apr-2025	16:28:23 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:23 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:23 PM	7	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:47 PM	15	1307.50	XCSE

121

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:28:47 PM	65	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:47 PM	39	1307.50	TQEX
GENMAB A/S	01-Apr-2025	16:28:47 PM	25	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:28:55 PM	27	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:55 PM	39	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:28:55 PM	18	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:29:02 PM	16	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:29:33 PM	75	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:29:33 PM	12	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:29:33 PM	26	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:29:33 PM	10	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:29:33 PM	10	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:29:33 PM	41	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:29:33 PM	36	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:29:33 PM	84	1306.50	CEUX
GENMAB A/S	01-Apr-2025	16:29:56 PM	85	1305.50	XCSE
GENMAB A/S	01-Apr-2025	16:30:10 PM	86	1305.00	CEUX
GENMAB A/S	01-Apr-2025	16:30:13 PM	61	1305.00	CEUX
GENMAB A/S	01-Apr-2025	16:30:15 PM	61	1304.50	XCSE
GENMAB A/S	01-Apr-2025	16:30:16 PM	82	1304.00	CEUX
GENMAB A/S	01-Apr-2025	16:31:19 PM	10	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:31:19 PM	11	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:31:21 PM	10	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:31:21 PM	41	1306.50	XCSE
GENMAB A/S	01-Apr-2025	16:31:24 PM	84	1306.00	XCSE
GENMAB A/S	01-Apr-2025	16:31:24 PM	34	1306.00	TQEX
GENMAB A/S	01-Apr-2025	16:31:24 PM	69	1306.00	CEUX
GENMAB A/S	01-Apr-2025	16:31:26 PM	15	1306.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:00 PM	41	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:00 PM	38	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:00 PM	15	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:08 PM	10	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:08 PM	41	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:09 PM	34	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:32:41 PM	36	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:32:42 PM	13	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:32:52 PM	18	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:32:57 PM	36	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:05 PM	46	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:07 PM	12	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:33:07 PM	41	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:33:07 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:33:07 PM	33	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:33:10 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:33:10 PM	41	1308.00	XCSE

122

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:33:25 PM	33	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:33:25 PM	11	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:33:25 PM	12	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:33:25 PM	41	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:33:26 PM	6	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:33:48 PM	7	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:48 PM	6	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:48 PM	6	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:48 PM	9	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:53 PM	79	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:33:53 PM	23	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:33:53 PM	22	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:34:05 PM	36	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:16 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:16 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:16 PM	21	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:16 PM	41	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:16 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:16 PM	17	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:35 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:35 PM	41	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:35 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:35 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:35 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:35 PM	15	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:45 PM	11	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:34:45 PM	14	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:34:45 PM	81	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:34:55 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:55 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:55 PM	41	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:55 PM	33	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:34:55 PM	15	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:35:26 PM	10	1307.50	XCSE
GENMAB A/S	01-Apr-2025	16:35:26 PM	16	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:36:25 PM	82	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:36:25 PM	19	1307.00	TQEX
GENMAB A/S	01-Apr-2025	16:36:25 PM	83	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:36:26 PM	15	1307.00	TQEX
GENMAB A/S	01-Apr-2025	16:36:26 PM	34	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:36:26 PM	25	1307.00	AQEU
GENMAB A/S	01-Apr-2025	16:36:26 PM	8	1307.00	AQEU
GENMAB A/S	01-Apr-2025	16:37:25 PM	31	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:37:25 PM	36	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:37:26 PM	18	1307.00	XCSE

123

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:37:26 PM	2	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:37:26 PM	34	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:37:27 PM	23	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:37:27 PM	32	1307.00	XCSE
GENMAB A/S	01-Apr-2025	16:37:27 PM	15	1307.00	CEUX
GENMAB A/S	01-Apr-2025	16:38:12 PM	4	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:38:16 PM	18	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:38:28 PM	86	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:38:28 PM	27	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:38:28 PM	84	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:38:28 PM	36	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:38:28 PM	6	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:38:28 PM	32	1308.00	AQEU
GENMAB A/S	01-Apr-2025	16:38:29 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:39:45 PM	56	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:39:45 PM	41	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:39:45 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:39:45 PM	36	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:39:45 PM	79	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:39:45 PM	37	1309.00	AQEU
GENMAB A/S	01-Apr-2025	16:39:46 PM	60	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:39:46 PM	26	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:39:46 PM	45	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:40:01 PM	41	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:40:01 PM	31	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:40:01 PM	21	1308.50	TQEX
GENMAB A/S	01-Apr-2025	16:40:01 PM	9	1308.50	TQEX
GENMAB A/S	01-Apr-2025	16:40:01 PM	30	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:40:01 PM	36	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:40:01 PM	5	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:40:01 PM	6	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:40:06 PM	9	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:40:35 PM	18	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:26 PM	52	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:28 PM	17	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:29 PM	23	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:31 PM	85	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:41:31 PM	85	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:31 PM	36	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:31 PM	45	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:41:34 PM	5	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:42:03 PM	57	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:42:03 PM	25	1308.50	TQEX
GENMAB A/S	01-Apr-2025	16:42:21 PM	25	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:42:21 PM	86	1308.00	CEUX

124

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:42:21 PM	20	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:42:25 PM	55	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:42:25 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:42:25 PM	15	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:42:25 PM	5	1308.00	CEUX
GENMAB A/S	01-Apr-2025	16:43:16 PM	37	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:16 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:16 PM	19	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:16 PM	18	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:43:17 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	30	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	50	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	30	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	12	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:17 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:19 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:19 PM	18	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:19 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:19 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:19 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:21 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:21 PM	16	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:21 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	12	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:22 PM	12	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:23 PM	3	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:23 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:23 PM	15	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:24 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:24 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:24 PM	29	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:25 PM	10	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:25 PM	52	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:25 PM	29	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:43:58 PM	8	1310.50	CEUX

125

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:43:58 PM	36	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:43:59 PM	13	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:44:02 PM	16	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:44:03 PM	80	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:44:05 PM	86	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:44:20 PM	52	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:44:20 PM	30	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:44:20 PM	26	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:44:20 PM	85	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:44:20 PM	17	1310.00	TQEX
GENMAB A/S	01-Apr-2025	16:44:20 PM	31	1310.00	TQEX
GENMAB A/S	01-Apr-2025	16:45:02 PM	40	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:02 PM	18	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:02 PM	86	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:03 PM	36	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:03 PM	14	1309.50	AQEU
GENMAB A/S	01-Apr-2025	16:45:05 PM	9	1309.50	AQEU
GENMAB A/S	01-Apr-2025	16:45:07 PM	81	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:07 PM	32	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:07 PM	34	1309.00	TQEX
GENMAB A/S	01-Apr-2025	16:45:07 PM	20	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:07 PM	21	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:12 PM	34	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	52	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	22	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	8	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:12 PM	41	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:12 PM	43	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:27 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:27 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:27 PM	30	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:27 PM	5	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:27 PM	6	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:27 PM	6	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:45:28 PM	30	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	52	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	26	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	4	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:28 PM	13	1308.50	CEUX

126

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:45:28 PM	7	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:28 PM	14	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:28 PM	42	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:29 PM	30	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	30	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:29 PM	29	1308.50	CEUX
GENMAB A/S	01-Apr-2025	16:45:42 PM	84	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:42 PM	14	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:42 PM	11	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:42 PM	9	1308.00	XCSE
GENMAB A/S	01-Apr-2025	16:45:42 PM	29	1308.00	TQEX
GENMAB A/S	01-Apr-2025	16:45:42 PM	2	1307.50	CEUX
GENMAB A/S	01-Apr-2025	16:46:03 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:46:03 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:46:03 PM	11	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:46:04 PM	9	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:46:04 PM	12	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:46:04 PM	10	1309.00	XCSE
GENMAB A/S	01-Apr-2025	16:46:12 PM	1	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:46:12 PM	22	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:46:43 PM	44	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:46:43 PM	30	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	9	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	27	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	34	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	78	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	6	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:47:03 PM	25	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:47:14 PM	23	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:47:14 PM	9	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:47:14 PM	71	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:47:14 PM	35	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:47:22 PM	40	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:47:25 PM	6	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:47:36 PM	9	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:47:44 PM	9	1310.00	XCSE

127

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:47:44 PM	36	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:47:44 PM	2	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:47:44 PM	27	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:48:05 PM	80	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:05 PM	52	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:05 PM	11	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:05 PM	26	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:05 PM	11	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:05 PM	8	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:05 PM	23	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:48:05 PM	29	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:48:05 PM	50	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:48:08 PM	82	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:08 PM	31	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:48:08 PM	61	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:48:08 PM	23	1309.50	AQEU
GENMAB A/S	01-Apr-2025	16:48:10 PM	11	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	10	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	9	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	52	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	26	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	61	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	12	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:10 PM	23	1310.00	XCSE
GENMAB A/S	01-Apr-2025	16:48:11 PM	30	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:11 PM	54	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:14 PM	10	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:14 PM	9	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:14 PM	9	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:14 PM	32	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:48:25 PM	9	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:48:38 PM	10	1308.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:38 PM	4	1309.00	AQEU
GENMAB A/S	01-Apr-2025	16:48:38 PM	1	1309.00	AQEU
GENMAB A/S	01-Apr-2025	16:48:47 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:47 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:48:47 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:49:02 PM	85	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:49:02 PM	31	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:49:02 PM	12	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:06 PM	79	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:49:06 PM	65	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:09 PM	9	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:24 PM	9	1309.50	CEUX

128

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:49:26 PM	34	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:49:26 PM	52	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:49:43 PM	25	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:49:43 PM	9	1309.00	CEUX
GENMAB A/S	01-Apr-2025	16:49:43 PM	19	1309.00	AQEU
GENMAB A/S	01-Apr-2025	16:49:49 PM	5	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:49 PM	21	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:50 PM	36	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:51 PM	34	1309.50	TQEX
GENMAB A/S	01-Apr-2025	16:49:51 PM	15	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:51 PM	55	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:49:51 PM	31	1309.50	CEUX
GENMAB A/S	01-Apr-2025	16:50:01 PM	52	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	19	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	11	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	4	1309.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	24	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:01 PM	84	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:02 PM	108	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:02 PM	108	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:02 PM	32	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:50:16 PM	85	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:50:16 PM	23	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:16 PM	52	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:16 PM	19	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:16 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:16 PM	5	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:50:16 PM	18	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:50:17 PM	1	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:50:47 PM	38	1311.00	TQEX
GENMAB A/S	01-Apr-2025	16:50:47 PM	5	1311.00	TQEX
GENMAB A/S	01-Apr-2025	16:51:25 PM	78	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:25 PM	8	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:25 PM	35	1311.00	TQEX
GENMAB A/S	01-Apr-2025	16:51:25 PM	10	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:51:25 PM	1	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:51:26 PM	26	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:26 PM	59	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:49 PM	29	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:51:49 PM	5	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:51:49 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:51:49 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:51:55 PM	5	1312.00	XCSE

129

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:51:55 PM	9	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:55 PM	41	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:55 PM	31	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:55 PM	22	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:51:55 PM	7	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:51:55 PM	16	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:51:55 PM	28	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:51:55 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:51:55 PM	79	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:00 PM	27	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:00 PM	6	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:00 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:00 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:00 PM	6	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:01 PM	3	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	9	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	10	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	52	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	2	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	32	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	46	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	52	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	10	1312.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:01 PM	21	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:01 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:01 PM	5	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:01 PM	6	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:02 PM	31	1312.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:02 PM	1	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:02 PM	60	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:02 PM	30	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:04 PM	45	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:06 PM	47	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:06 PM	9	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:06 PM	10	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:06 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:06 PM	30	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:06 PM	86	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:06 PM	1	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:06 PM	2	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:06 PM	30	1310.50	AQEU
GENMAB A/S	01-Apr-2025	16:52:10 PM	82	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:10 PM	24	1310.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:11 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	52	1311.00	XCSE

130

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:52:11 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	6	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	52	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	12	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:11 PM	1	1310.50	AQEU
GENMAB A/S	01-Apr-2025	16:52:12 PM	10	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:14 PM	15	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:21 PM	11	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:25 PM	23	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:25 PM	34	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	22	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	11	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	12	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	1	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	1	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:26 PM	2	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:26 PM	12	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:26 PM	1	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:26 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:26 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:26 PM	6	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:52:26 PM	35	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:31 PM	37	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:34 PM	27	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:37 PM	13	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:37 PM	22	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:37 PM	5	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:37 PM	15	1311.50	AQEU
GENMAB A/S	01-Apr-2025	16:52:37 PM	8	1311.50	AQEU
GENMAB A/S	01-Apr-2025	16:52:41 PM	23	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:41 PM	46	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:52:41 PM	29	1311.00	TQEX
GENMAB A/S	01-Apr-2025	16:52:41 PM	23	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:43 PM	28	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:43 PM	24	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:52:46 PM	32	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:52:56 PM	25	1310.50	AQEU
GENMAB A/S	01-Apr-2025	16:53:01 PM	26	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:53:01 PM	30	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:53:01 PM	23	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:04 PM	26	1311.00	XCSE

131

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	01-Apr-2025	16:53:12 PM	1	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:12 PM	38	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:12 PM	25	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:12 PM	23	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:12 PM	5	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:12 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:12 PM	6	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:12 PM	17	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:25 PM	4	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	21	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	9	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	11	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	51	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	23	1310.50	XCSE
GENMAB A/S	01-Apr-2025	16:53:25 PM	8	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:25 PM	51	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:25 PM	2	1311.00	AQEU
GENMAB A/S	01-Apr-2025	16:53:25 PM	2	1311.00	AQEU
GENMAB A/S	01-Apr-2025	16:53:25 PM	15	1311.00	AQEU
GENMAB A/S	01-Apr-2025	16:53:26 PM	1	1310.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:39 PM	31	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:55 PM	37	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:55 PM	10	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:55 PM	19	1311.00	CEUX
GENMAB A/S	01-Apr-2025	16:53:55 PM	20	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:53:55 PM	9	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:53:59 PM	24	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:53:59 PM	13	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:54:03 PM	5	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:54:04 PM	18	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:54:10 PM	18	1311.50	CEUX
GENMAB A/S	01-Apr-2025	16:54:22 PM	33	1311.00	XCSE
GENMAB A/S	01-Apr-2025	16:54:22 PM	25	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:54:23 PM	19	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:54:23 PM	14	1311.50	XCSE
GENMAB A/S	01-Apr-2025	16:54:26 PM	31	1311.50	AQEU
GENMAB A/S	01-Apr-2025	16:54:47 PM	9	1311.50	AQEU
GENMAB A/S	01-Apr-2025	16:54:48 PM	18	1311.50	AQEU
GENMAB A/S	02-Apr-2025	09:21:59 AM	16	1272.50	CEUX
GENMAB A/S	02-Apr-2025	09:22:15 AM	54	1272.50	CEUX
GENMAB A/S	02-Apr-2025	09:22:16 AM	2	1274.50	XCSE
GENMAB A/S	02-Apr-2025	09:22:16 AM	22	1274.50	CEUX
GENMAB A/S	02-Apr-2025	09:22:16 AM	27	1274.50	CEUX
GENMAB A/S	02-Apr-2025	09:22:53 AM	68	1276.50	XCSE

132

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	09:23:10 AM	69	1277.00	TQEX
GENMAB A/S	02-Apr-2025	09:23:11 AM	78	1277.00	AQEU
GENMAB A/S	02-Apr-2025	09:23:12 AM	50	1276.50	XCSE
GENMAB A/S	02-Apr-2025	09:23:19 AM	74	1276.00	TQEX
GENMAB A/S	02-Apr-2025	09:23:19 AM	66	1276.00	AQEU
GENMAB A/S	02-Apr-2025	09:23:19 AM	38	1276.00	CEUX
GENMAB A/S	02-Apr-2025	09:23:48 AM	26	1278.00	AQEU
GENMAB A/S	02-Apr-2025	09:24:52 AM	1	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:24:52 AM	82	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:24:52 AM	23	1278.00	AQEU
GENMAB A/S	02-Apr-2025	09:24:52 AM	69	1278.00	CEUX
GENMAB A/S	02-Apr-2025	09:25:41 AM	86	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:25:42 AM	24	1280.00	TQEX
GENMAB A/S	02-Apr-2025	09:25:43 AM	38	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:25:43 AM	15	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:25:50 AM	76	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:26:07 AM	80	1280.00	XCSE
GENMAB A/S	02-Apr-2025	09:26:08 AM	14	1279.50	CEUX
GENMAB A/S	02-Apr-2025	09:26:13 AM	68	1279.50	CEUX
GENMAB A/S	02-Apr-2025	09:26:15 AM	82	1279.00	XCSE
GENMAB A/S	02-Apr-2025	09:26:15 AM	26	1279.00	TQEX
GENMAB A/S	02-Apr-2025	09:26:15 AM	82	1278.50	CEUX
GENMAB A/S	02-Apr-2025	09:26:16 AM	81	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:28:15 AM	16	1281.50	XCSE
GENMAB A/S	02-Apr-2025	09:28:15 AM	39	1281.50	XCSE
GENMAB A/S	02-Apr-2025	09:28:16 AM	39	1281.50	XCSE
GENMAB A/S	02-Apr-2025	09:28:26 AM	19	1282.50	XCSE
GENMAB A/S	02-Apr-2025	09:28:26 AM	19	1282.50	XCSE
GENMAB A/S	02-Apr-2025	09:28:55 AM	1	1281.50	XCSE
GENMAB A/S	02-Apr-2025	09:28:57 AM	84	1283.00	XCSE
GENMAB A/S	02-Apr-2025	09:28:57 AM	80	1282.50	CEUX
GENMAB A/S	02-Apr-2025	09:29:02 AM	84	1281.50	XCSE
GENMAB A/S	02-Apr-2025	09:29:02 AM	58	1281.50	CEUX
GENMAB A/S	02-Apr-2025	09:29:04 AM	20	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:29:04 AM	49	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:29:04 AM	18	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:29:04 AM	45	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:29:04 AM	17	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:29:50 AM	13	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:29:51 AM	84	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:29:51 AM	10	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:30:03 AM	82	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:30:03 AM	75	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:30:03 AM	12	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:30:03 AM	25	1279.00	CEUX

133

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	09:30:03 AM	6	1278.00	CEUX
GENMAB A/S	02-Apr-2025	09:30:38 AM	7	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:30:38 AM	26	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:30:38 AM	23	1279.00	CEUX
GENMAB A/S	02-Apr-2025	09:31:24 AM	26	1280.50	TQEX
GENMAB A/S	02-Apr-2025	09:31:30 AM	17	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:31:34 AM	20	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:32:02 AM	43	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:32:02 AM	40	1281.00	CEUX
GENMAB A/S	02-Apr-2025	09:33:31 AM	25	1281.50	TQEX
GENMAB A/S	02-Apr-2025	09:35:45 AM	87	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:45 AM	40	1286.00	CEUX
GENMAB A/S	02-Apr-2025	09:35:45 AM	47	1286.00	CEUX
GENMAB A/S	02-Apr-2025	09:35:47 AM	65	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:47 AM	24	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:47 AM	20	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:47 AM	30	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:47 AM	24	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:47 AM	39	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:47 AM	16	1286.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:51 AM	86	1285.00	XCSE
GENMAB A/S	02-Apr-2025	09:35:51 AM	41	1285.00	TQEX
GENMAB A/S	02-Apr-2025	09:35:51 AM	27	1285.00	AQEU
GENMAB A/S	02-Apr-2025	09:35:51 AM	84	1285.00	CEUX
GENMAB A/S	02-Apr-2025	09:36:37 AM	84	1283.50	XCSE
GENMAB A/S	02-Apr-2025	09:36:37 AM	25	1283.50	TQEX
GENMAB A/S	02-Apr-2025	09:36:37 AM	29	1284.00	CEUX
GENMAB A/S	02-Apr-2025	09:36:37 AM	58	1284.00	CEUX
GENMAB A/S	02-Apr-2025	09:37:12 AM	31	1283.00	TQEX
GENMAB A/S	02-Apr-2025	09:37:12 AM	6	1283.00	TQEX
GENMAB A/S	02-Apr-2025	09:37:15 AM	81	1282.00	XCSE
GENMAB A/S	02-Apr-2025	09:37:15 AM	55	1282.50	CEUX
GENMAB A/S	02-Apr-2025	09:37:17 AM	1	1281.00	CEUX
GENMAB A/S	02-Apr-2025	09:37:25 AM	43	1281.00	CEUX
GENMAB A/S	02-Apr-2025	09:37:27 AM	84	1280.50	XCSE
GENMAB A/S	02-Apr-2025	09:37:56 AM	86	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:37:56 AM	28	1279.50	CEUX
GENMAB A/S	02-Apr-2025	09:38:22 AM	79	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:38:22 AM	1	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:38:50 AM	23	1278.50	CEUX
GENMAB A/S	02-Apr-2025	09:39:29 AM	85	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:39:36 AM	29	1279.50	TQEX
GENMAB A/S	02-Apr-2025	09:39:36 AM	35	1279.50	CEUX
GENMAB A/S	02-Apr-2025	09:39:52 AM	85	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:39:52 AM	20	1279.50	TQEX

134

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	09:40:38 AM	80	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:40:38 AM	18	1278.50	CEUX
GENMAB A/S	02-Apr-2025	09:40:38 AM	18	1278.50	CEUX
GENMAB A/S	02-Apr-2025	09:42:05 AM	81	1282.00	XCSE
GENMAB A/S	02-Apr-2025	09:42:05 AM	40	1281.50	CEUX
GENMAB A/S	02-Apr-2025	09:42:06 AM	21	1281.50	TQEX
GENMAB A/S	02-Apr-2025	09:42:06 AM	7	1281.50	CEUX
GENMAB A/S	02-Apr-2025	09:42:26 AM	1	1281.00	XCSE
GENMAB A/S	02-Apr-2025	09:42:26 AM	82	1281.00	XCSE
GENMAB A/S	02-Apr-2025	09:42:26 AM	29	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:43:00 AM	4	1281.00	XCSE
GENMAB A/S	02-Apr-2025	09:43:56 AM	53	1281.00	XCSE
GENMAB A/S	02-Apr-2025	09:44:05 AM	17	1280.50	CEUX
GENMAB A/S	02-Apr-2025	09:44:27 AM	80	1280.00	XCSE
GENMAB A/S	02-Apr-2025	09:44:27 AM	26	1280.00	TQEX
GENMAB A/S	02-Apr-2025	09:44:27 AM	47	1279.50	CEUX
GENMAB A/S	02-Apr-2025	09:44:39 AM	28	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:46:00 AM	24	1279.50	TQEX
GENMAB A/S	02-Apr-2025	09:46:00 AM	71	1279.50	CEUX
GENMAB A/S	02-Apr-2025	09:48:12 AM	52	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:48:12 AM	80	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:48:12 AM	29	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:48:12 AM	34	1278.50	CEUX
GENMAB A/S	02-Apr-2025	09:48:25 AM	55	1278.00	XCSE
GENMAB A/S	02-Apr-2025	09:49:16 AM	39	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:49:16 AM	30	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:49:16 AM	15	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:49:16 AM	3	1278.50	XCSE
GENMAB A/S	02-Apr-2025	09:50:01 AM	84	1277.00	XCSE
GENMAB A/S	02-Apr-2025	09:50:01 AM	25	1277.00	TQEX
GENMAB A/S	02-Apr-2025	09:50:01 AM	54	1277.00	CEUX
GENMAB A/S	02-Apr-2025	09:51:50 AM	76	1276.50	XCSE
GENMAB A/S	02-Apr-2025	09:51:50 AM	4	1276.50	XCSE
GENMAB A/S	02-Apr-2025	09:51:50 AM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	09:51:50 AM	15	1277.00	XCSE
GENMAB A/S	02-Apr-2025	09:51:50 AM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	09:51:50 AM	17	1277.00	XCSE
GENMAB A/S	02-Apr-2025	09:51:50 AM	83	1277.00	CEUX
GENMAB A/S	02-Apr-2025	09:52:17 AM	85	1275.50	XCSE
GENMAB A/S	02-Apr-2025	09:52:17 AM	30	1275.50	XCSE
GENMAB A/S	02-Apr-2025	09:52:17 AM	25	1275.50	XCSE
GENMAB A/S	02-Apr-2025	09:52:17 AM	25	1276.00	XCSE
GENMAB A/S	02-Apr-2025	09:52:17 AM	23	1276.00	TQEX
GENMAB A/S	02-Apr-2025	09:52:17 AM	57	1276.00	CEUX
GENMAB A/S	02-Apr-2025	09:52:17 AM	24	1275.00	CEUX

135

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	09:52:27 AM	56	1275.00	CEUX
GENMAB A/S	02-Apr-2025	09:54:01 AM	80	1274.00	XCSE
GENMAB A/S	02-Apr-2025	09:54:34 AM	23	1273.50	TQEX
GENMAB A/S	02-Apr-2025	09:54:34 AM	18	1273.50	CEUX
GENMAB A/S	02-Apr-2025	09:54:34 AM	55	1273.50	CEUX
GENMAB A/S	02-Apr-2025	09:54:38 AM	82	1273.00	XCSE
GENMAB A/S	02-Apr-2025	09:55:08 AM	22	1272.50	CEUX
GENMAB A/S	02-Apr-2025	09:56:41 AM	86	1274.00	XCSE
GENMAB A/S	02-Apr-2025	09:57:33 AM	83	1275.00	XCSE
GENMAB A/S	02-Apr-2025	09:57:33 AM	85	1274.00	XCSE
GENMAB A/S	02-Apr-2025	09:57:33 AM	23	1274.50	TQEX
GENMAB A/S	02-Apr-2025	09:57:33 AM	31	1275.50	CEUX
GENMAB A/S	02-Apr-2025	09:57:33 AM	53	1275.50	CEUX
GENMAB A/S	02-Apr-2025	09:57:33 AM	86	1274.50	CEUX
GENMAB A/S	02-Apr-2025	09:57:34 AM	83	1274.00	XCSE
GENMAB A/S	02-Apr-2025	09:58:35 AM	29	1277.50	CEUX
GENMAB A/S	02-Apr-2025	09:58:35 AM	21	1277.50	CEUX
GENMAB A/S	02-Apr-2025	09:59:38 AM	31	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:59:38 AM	20	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:59:38 AM	4	1279.50	XCSE
GENMAB A/S	02-Apr-2025	09:59:47 AM	20	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:00:00 AM	33	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:00:00 AM	81	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:00:00 AM	32	1280.00	TQEX
GENMAB A/S	02-Apr-2025	10:00:00 AM	55	1279.50	CEUX
GENMAB A/S	02-Apr-2025	10:00:05 AM	81	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:00:05 AM	38	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:01:39 AM	83	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:01:39 AM	82	1277.50	XCSE
GENMAB A/S	02-Apr-2025	10:01:39 AM	4	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:01:39 AM	28	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:01:39 AM	37	1277.50	CEUX
GENMAB A/S	02-Apr-2025	10:01:39 AM	43	1276.50	CEUX
GENMAB A/S	02-Apr-2025	10:01:41 AM	18	1276.00	XCSE
GENMAB A/S	02-Apr-2025	10:01:41 AM	69	1276.00	XCSE
GENMAB A/S	02-Apr-2025	10:03:05 AM	23	1276.00	CEUX
GENMAB A/S	02-Apr-2025	10:04:12 AM	27	1276.00	TQEX
GENMAB A/S	02-Apr-2025	10:04:12 AM	32	1276.00	CEUX
GENMAB A/S	02-Apr-2025	10:04:45 AM	50	1276.00	XCSE
GENMAB A/S	02-Apr-2025	10:04:45 AM	15	1276.00	XCSE
GENMAB A/S	02-Apr-2025	10:05:00 AM	34	1275.50	XCSE
GENMAB A/S	02-Apr-2025	10:05:00 AM	24	1275.50	XCSE
GENMAB A/S	02-Apr-2025	10:05:09 AM	23	1275.00	CEUX
GENMAB A/S	02-Apr-2025	10:06:25 AM	47	1277.50	XCSE
GENMAB A/S	02-Apr-2025	10:06:25 AM	17	1277.50	XCSE

136

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	10:06:43 AM	80	1277.50	XCSE
GENMAB A/S	02-Apr-2025	10:06:44 AM	23	1277.00	TQEX
GENMAB A/S	02-Apr-2025	10:06:44 AM	14	1277.00	CEUX
GENMAB A/S	02-Apr-2025	10:06:44 AM	34	1277.00	CEUX
GENMAB A/S	02-Apr-2025	10:06:44 AM	26	1277.00	AQEU
GENMAB A/S	02-Apr-2025	10:07:01 AM	87	1276.00	XCSE
GENMAB A/S	02-Apr-2025	10:07:01 AM	57	1276.00	CEUX
GENMAB A/S	02-Apr-2025	10:07:05 AM	23	1275.50	AQEU
GENMAB A/S	02-Apr-2025	10:07:16 AM	33	1275.00	CEUX
GENMAB A/S	02-Apr-2025	10:07:16 AM	22	1275.00	CEUX
GENMAB A/S	02-Apr-2025	10:07:24 AM	87	1274.50	XCSE
GENMAB A/S	02-Apr-2025	10:09:11 AM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	10:09:11 AM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	10:09:11 AM	15	1276.50	XCSE
GENMAB A/S	02-Apr-2025	10:09:41 AM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	10:10:14 AM	35	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:10:37 AM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:10:37 AM	39	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:10:37 AM	37	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:10:42 AM	84	1276.50	XCSE
GENMAB A/S	02-Apr-2025	10:10:42 AM	26	1276.50	TQEX
GENMAB A/S	02-Apr-2025	10:10:42 AM	66	1276.50	CEUX
GENMAB A/S	02-Apr-2025	10:10:52 AM	82	1275.50	XCSE
GENMAB A/S	02-Apr-2025	10:10:52 AM	25	1275.50	TQEX
GENMAB A/S	02-Apr-2025	10:10:52 AM	49	1275.50	CEUX
GENMAB A/S	02-Apr-2025	10:15:19 AM	80	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	25	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	19	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	13	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	30	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	22	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	87	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:19 AM	45	1277.00	TQEX
GENMAB A/S	02-Apr-2025	10:15:19 AM	72	1277.00	CEUX
GENMAB A/S	02-Apr-2025	10:15:26 AM	85	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:15:53 AM	87	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:15:53 AM	75	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:15:53 AM	5	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:16:44 AM	83	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:16:44 AM	84	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:16:44 AM	52	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:16:44 AM	87	1277.50	CEUX
GENMAB A/S	02-Apr-2025	10:16:44 AM	39	1276.50	CEUX
GENMAB A/S	02-Apr-2025	10:16:44 AM	24	1277.50	AQEU
GENMAB A/S	02-Apr-2025	10:18:51 AM	47	1277.50	CEUX

137

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	10:22:40 AM	22	1277.50	CEUX
GENMAB A/S	02-Apr-2025	10:23:12 AM	25	1278.50	TQEX
GENMAB A/S	02-Apr-2025	10:23:12 AM	83	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:23:12 AM	2	1278.50	CEUX
GENMAB A/S	02-Apr-2025	10:23:13 AM	26	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:23:13 AM	28	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:23:13 AM	30	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:23:13 AM	25	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:23:13 AM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:23:21 AM	77	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:23:21 AM	7	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:23:21 AM	80	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:23:21 AM	23	1277.00	XCSE
GENMAB A/S	02-Apr-2025	10:23:21 AM	32	1277.50	TQEX
GENMAB A/S	02-Apr-2025	10:23:21 AM	60	1277.50	CEUX
GENMAB A/S	02-Apr-2025	10:23:22 AM	83	1276.00	XCSE
GENMAB A/S	02-Apr-2025	10:23:22 AM	30	1275.50	XCSE
GENMAB A/S	02-Apr-2025	10:23:22 AM	32	1276.00	TQEX
GENMAB A/S	02-Apr-2025	10:23:22 AM	46	1276.50	CEUX
GENMAB A/S	02-Apr-2025	10:23:22 AM	72	1275.00	CEUX
GENMAB A/S	02-Apr-2025	10:23:22 AM	23	1276.00	CEUX
GENMAB A/S	02-Apr-2025	10:23:22 AM	23	1276.00	AQEU
GENMAB A/S	02-Apr-2025	10:23:22 AM	27	1275.50	AQEU
GENMAB A/S	02-Apr-2025	10:26:19 AM	37	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:26:20 AM	2	1278.00	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	3	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	78	1278.50	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	43	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	13	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	12	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	41	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:27:17 AM	44	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:27:58 AM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:28 AM	22	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:28 AM	24	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:32 AM	35	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:59 AM	29	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:29:59 AM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:29:59 AM	47	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:59 AM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:59 AM	6	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:29:59 AM	25	1279.50	AQEU
GENMAB A/S	02-Apr-2025	10:30:00 AM	46	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:30:00 AM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:30:00 AM	11	1280.00	XCSE

138

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	10:30:00 AM	24	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:30:00 AM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:30:03 AM	29	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:30:03 AM	57	1279.00	XCSE
GENMAB A/S	02-Apr-2025	10:30:03 AM	19	1279.00	CEUX
GENMAB A/S	02-Apr-2025	10:30:03 AM	49	1279.00	CEUX
GENMAB A/S	02-Apr-2025	10:32:24 AM	39	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:32:24 AM	30	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:32:24 AM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:32:24 AM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:32:24 AM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:32:24 AM	34	1279.00	TQEX
GENMAB A/S	02-Apr-2025	10:35:02 AM	81	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:35:02 AM	45	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:35:02 AM	39	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:35:02 AM	25	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:35:02 AM	28	1280.00	TQEX
GENMAB A/S	02-Apr-2025	10:35:02 AM	82	1280.00	CEUX
GENMAB A/S	02-Apr-2025	10:35:02 AM	24	1280.00	AQEU
GENMAB A/S	02-Apr-2025	10:35:11 AM	2	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:35:11 AM	34	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:35:11 AM	30	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:35:11 AM	16	1280.00	XCSE
GENMAB A/S	02-Apr-2025	10:36:21 AM	38	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:39:03 AM	87	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:39:03 AM	12	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:39:03 AM	11	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:39:03 AM	13	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:39:03 AM	24	1281.00	TQEX
GENMAB A/S	02-Apr-2025	10:39:03 AM	18	1281.00	CEUX
GENMAB A/S	02-Apr-2025	10:39:03 AM	63	1281.00	CEUX
GENMAB A/S	02-Apr-2025	10:39:03 AM	21	1280.00	CEUX
GENMAB A/S	02-Apr-2025	10:39:03 AM	61	1280.00	CEUX
GENMAB A/S	02-Apr-2025	10:39:03 AM	23	1280.00	AQEU
GENMAB A/S	02-Apr-2025	10:39:04 AM	11	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:39:04 AM	39	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:39:04 AM	14	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:39:04 AM	13	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:39:04 AM	32	1280.50	XCSE
GENMAB A/S	02-Apr-2025	10:39:39 AM	12	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:39:39 AM	73	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:39:42 AM	10	1282.50	AQEU
GENMAB A/S	02-Apr-2025	10:43:01 AM	82	1284.50	XCSE
GENMAB A/S	02-Apr-2025	10:43:01 AM	60	1284.50	XCSE
GENMAB A/S	02-Apr-2025	10:43:01 AM	12	1284.50	XCSE

139

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	10:43:01 AM	23	1285.00	XCSE
GENMAB A/S	02-Apr-2025	10:43:01 AM	14	1285.00	XCSE
GENMAB A/S	02-Apr-2025	10:43:01 AM	22	1285.00	XCSE
GENMAB A/S	02-Apr-2025	10:43:01 AM	12	1285.00	XCSE
GENMAB A/S	02-Apr-2025	10:43:02 AM	28	1285.00	XCSE
GENMAB A/S	02-Apr-2025	10:43:10 AM	86	1284.50	XCSE
GENMAB A/S	02-Apr-2025	10:43:10 AM	20	1284.50	AQEU
GENMAB A/S	02-Apr-2025	10:43:10 AM	14	1284.50	AQEU
GENMAB A/S	02-Apr-2025	10:43:35 AM	23	1284.00	TQEX
GENMAB A/S	02-Apr-2025	10:43:35 AM	4	1284.00	CEUX
GENMAB A/S	02-Apr-2025	10:43:35 AM	79	1284.00	CEUX
GENMAB A/S	02-Apr-2025	10:44:00 AM	35	1283.50	XCSE
GENMAB A/S	02-Apr-2025	10:44:00 AM	6	1283.50	XCSE
GENMAB A/S	02-Apr-2025	10:44:00 AM	45	1283.50	XCSE
GENMAB A/S	02-Apr-2025	10:44:40 AM	20	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:45:08 AM	21	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:45:56 AM	23	1283.00	TQEX
GENMAB A/S	02-Apr-2025	10:45:56 AM	43	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:46:05 AM	37	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:46:05 AM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:46:16 AM	85	1282.50	XCSE
GENMAB A/S	02-Apr-2025	10:47:40 AM	43	1282.50	XCSE
GENMAB A/S	02-Apr-2025	10:47:41 AM	23	1282.50	TQEX
GENMAB A/S	02-Apr-2025	10:48:31 AM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:48:31 AM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:49:12 AM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:49:12 AM	59	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:49:12 AM	37	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:50:55 AM	83	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:50:55 AM	29	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:50:55 AM	51	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:51:01 AM	3	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:52:06 AM	22	1282.00	TQEX
GENMAB A/S	02-Apr-2025	10:52:06 AM	23	1282.00	TQEX
GENMAB A/S	02-Apr-2025	10:52:25 AM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:52:25 AM	11	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:52:25 AM	1	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:52:25 AM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:52:25 AM	32	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:52:26 AM	46	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:52:26 AM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:53:01 AM	32	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:53:02 AM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:56:45 AM	36	1281.50	CEUX
GENMAB A/S	02-Apr-2025	10:56:56 AM	25	1282.00	XCSE

140

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	10:56:56 AM	14	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:56:56 AM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:56:56 AM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:56:56 AM	36	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:56:56 AM	7	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:56:56 AM	7	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:06 AM	30	1282.50	TQEX
GENMAB A/S	02-Apr-2025	10:59:06 AM	4	1282.50	TQEX
GENMAB A/S	02-Apr-2025	10:59:10 AM	26	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:10 AM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:10 AM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:10 AM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:10 AM	39	1283.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:10 AM	7	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:10 AM	7	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:10 AM	6	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:10 AM	25	1283.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:24 AM	83	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:24 AM	39	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:24 AM	18	1282.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:24 AM	80	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:24 AM	33	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:24 AM	25	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:24 AM	84	1282.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:24 AM	81	1281.00	CEUX
GENMAB A/S	02-Apr-2025	10:59:24 AM	25	1282.00	AQEU
GENMAB A/S	02-Apr-2025	10:59:24 AM	27	1281.00	AQEU
GENMAB A/S	02-Apr-2025	10:59:25 AM	81	1281.00	XCSE
GENMAB A/S	02-Apr-2025	10:59:25 AM	23	1281.00	AQEU
GENMAB A/S	02-Apr-2025	10:59:26 AM	8	1279.50	XCSE
GENMAB A/S	02-Apr-2025	10:59:26 AM	83	1279.50	CEUX
GENMAB A/S	02-Apr-2025	10:59:27 AM	7	1279.50	XCSE
GENMAB A/S	02-Apr-2025	11:00:08 AM	87	1281.00	CEUX
GENMAB A/S	02-Apr-2025	11:00:08 AM	23	1281.00	AQEU
GENMAB A/S	02-Apr-2025	11:00:10 AM	86	1280.50	XCSE
GENMAB A/S	02-Apr-2025	11:00:10 AM	2	1280.00	CEUX
GENMAB A/S	02-Apr-2025	11:00:10 AM	65	1280.00	CEUX
GENMAB A/S	02-Apr-2025	11:00:10 AM	14	1280.00	CEUX
GENMAB A/S	02-Apr-2025	11:00:45 AM	71	1279.50	XCSE
GENMAB A/S	02-Apr-2025	11:01:41 AM	81	1278.50	XCSE
GENMAB A/S	02-Apr-2025	11:01:41 AM	73	1279.00	CEUX
GENMAB A/S	02-Apr-2025	11:01:41 AM	9	1279.00	CEUX
GENMAB A/S	02-Apr-2025	11:01:42 AM	63	1278.00	CEUX
GENMAB A/S	02-Apr-2025	11:02:59 AM	22	1277.00	CEUX
GENMAB A/S	02-Apr-2025	11:06:48 AM	84	1280.00	XCSE

141

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	11:06:48 AM	1	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:06:48 AM	13	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:06:48 AM	29	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:06:48 AM	23	1280.00	TQEX
GENMAB A/S	02-Apr-2025	11:06:48 AM	59	1280.00	CEUX
GENMAB A/S	02-Apr-2025	11:06:48 AM	18	1280.00	AQEU
GENMAB A/S	02-Apr-2025	11:06:48 AM	5	1280.00	AQEU
GENMAB A/S	02-Apr-2025	11:08:04 AM	62	1280.50	XCSE
GENMAB A/S	02-Apr-2025	11:08:04 AM	15	1280.50	XCSE
GENMAB A/S	02-Apr-2025	11:08:04 AM	32	1280.50	XCSE
GENMAB A/S	02-Apr-2025	11:08:05 AM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:08:05 AM	43	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:08:05 AM	23	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:08:05 AM	12	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:10:58 AM	20	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:11:35 AM	87	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:11:35 AM	43	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:11:35 AM	9	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:11:35 AM	3	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:11:35 AM	26	1281.50	TQEX
GENMAB A/S	02-Apr-2025	11:11:44 AM	10	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:11:47 AM	3	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:11:55 AM	13	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:11:56 AM	11	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:11:59 AM	14	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:11:59 AM	12	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	12	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	12	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	43	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	14	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	13	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	11	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	2	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	10	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	87	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:12:03 AM	83	1282.00	CEUX
GENMAB A/S	02-Apr-2025	11:12:23 AM	1	1281.50	TQEX
GENMAB A/S	02-Apr-2025	11:12:23 AM	22	1281.50	TQEX
GENMAB A/S	02-Apr-2025	11:12:29 AM	6	1281.00	XCSE
GENMAB A/S	02-Apr-2025	11:12:48 AM	78	1281.00	XCSE
GENMAB A/S	02-Apr-2025	11:12:48 AM	84	1281.00	CEUX
GENMAB A/S	02-Apr-2025	11:13:02 AM	24	1280.50	TQEX
GENMAB A/S	02-Apr-2025	11:13:06 AM	83	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:13:06 AM	76	1280.00	CEUX
GENMAB A/S	02-Apr-2025	11:13:45 AM	86	1279.00	XCSE

142

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	11:13:55 AM	4	1279.00	AQEU
GENMAB A/S	02-Apr-2025	11:15:00 AM	37	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:15:00 AM	50	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:15:14 AM	18	1279.50	CEUX
GENMAB A/S	02-Apr-2025	11:17:10 AM	83	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:17:10 AM	23	1280.00	TQEX
GENMAB A/S	02-Apr-2025	11:17:10 AM	25	1280.00	AQEU
GENMAB A/S	02-Apr-2025	11:17:11 AM	7	1279.50	CEUX
GENMAB A/S	02-Apr-2025	11:17:37 AM	72	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:19:13 AM	70	1278.50	CEUX
GENMAB A/S	02-Apr-2025	11:19:24 AM	12	1278.00	AQEU
GENMAB A/S	02-Apr-2025	11:20:53 AM	18	1278.00	AQEU
GENMAB A/S	02-Apr-2025	11:20:56 AM	3	1278.00	AQEU
GENMAB A/S	02-Apr-2025	11:22:34 AM	44	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:22:34 AM	44	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:22:34 AM	28	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:22:34 AM	13	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:22:51 AM	12	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:22:51 AM	3	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:22:51 AM	8	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:24:40 AM	40	1279.00	XCSE
GENMAB A/S	02-Apr-2025	11:26:00 AM	35	1278.50	XCSE
GENMAB A/S	02-Apr-2025	11:26:02 AM	62	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:26:33 AM	82	1279.50	XCSE
GENMAB A/S	02-Apr-2025	11:26:33 AM	30	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:26:33 AM	30	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:26:33 AM	43	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:26:33 AM	6	1280.00	XCSE
GENMAB A/S	02-Apr-2025	11:26:33 AM	26	1279.50	TQEX
GENMAB A/S	02-Apr-2025	11:26:33 AM	82	1279.50	CEUX
GENMAB A/S	02-Apr-2025	11:26:33 AM	32	1279.50	CEUX
GENMAB A/S	02-Apr-2025	11:27:53 AM	33	1278.50	XCSE
GENMAB A/S	02-Apr-2025	11:27:58 AM	13	1278.50	XCSE
GENMAB A/S	02-Apr-2025	11:27:58 AM	44	1278.50	TQEX
GENMAB A/S	02-Apr-2025	11:27:58 AM	50	1278.50	CEUX
GENMAB A/S	02-Apr-2025	11:27:58 AM	32	1278.50	CEUX
GENMAB A/S	02-Apr-2025	11:28:37 AM	3	1278.00	AQEU
GENMAB A/S	02-Apr-2025	11:28:51 AM	44	1278.50	XCSE
GENMAB A/S	02-Apr-2025	11:28:51 AM	43	1278.50	XCSE
GENMAB A/S	02-Apr-2025	11:29:28 AM	23	1279.00	AQEU
GENMAB A/S	02-Apr-2025	11:32:36 AM	12	1281.00	CEUX
GENMAB A/S	02-Apr-2025	11:32:36 AM	1	1281.00	CEUX
GENMAB A/S	02-Apr-2025	11:33:51 AM	81	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:33:51 AM	81	1281.50	XCSE
GENMAB A/S	02-Apr-2025	11:33:51 AM	29	1282.00	TQEX

143

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	11:33:51 AM	84	1282.50	CEUX
GENMAB A/S	02-Apr-2025	11:33:51 AM	36	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:34:15 AM	18	1282.50	CEUX
GENMAB A/S	02-Apr-2025	11:34:15 AM	65	1282.50	CEUX
GENMAB A/S	02-Apr-2025	11:34:41 AM	83	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:35:40 AM	43	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:35:40 AM	5	1282.00	XCSE
GENMAB A/S	02-Apr-2025	11:35:40 AM	85	1281.50	CEUX
GENMAB A/S	02-Apr-2025	11:36:26 AM	44	1282.50	XCSE
GENMAB A/S	02-Apr-2025	11:36:26 AM	8	1282.00	CEUX
GENMAB A/S	02-Apr-2025	11:41:53 AM	18	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:41:53 AM	68	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:42:21 AM	31	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:21 AM	15	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:21 AM	43	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:22 AM	12	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:22 AM	43	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:22 AM	14	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:22 AM	37	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:22 AM	21	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:22 AM	12	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:50 AM	48	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:42:50 AM	48	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:43:22 AM	29	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:43:22 AM	15	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:43:23 AM	29	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:43:23 AM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:43:54 AM	43	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:43:54 AM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:43:54 AM	40	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:44:01 AM	23	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:44:31 AM	21	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:44:31 AM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:44:31 AM	12	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:44:31 AM	19	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:45:41 AM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:45:41 AM	37	1283.00	XCSE
GENMAB A/S	02-Apr-2025	11:46:07 AM	36	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:46:07 AM	23	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:46:12 AM	85	1284.00	CEUX
GENMAB A/S	02-Apr-2025	11:48:41 AM	25	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:48:41 AM	30	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:50:31 AM	1	1285.00	XCSE
GENMAB A/S	02-Apr-2025	11:50:31 AM	2	1285.00	XCSE
GENMAB A/S	02-Apr-2025	11:50:31 AM	84	1285.00	CEUX

144

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	11:50:34 AM	25	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:50:34 AM	22	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:50:38 AM	25	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:50:41 AM	25	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:50:41 AM	3	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:51:01 AM	31	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:51:02 AM	31	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:51:02 AM	31	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:51:03 AM	27	1285.50	XCSE
GENMAB A/S	02-Apr-2025	11:51:03 AM	82	1285.00	CEUX
GENMAB A/S	02-Apr-2025	11:51:21 AM	38	1285.00	XCSE
GENMAB A/S	02-Apr-2025	11:52:00 AM	29	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:52:00 AM	51	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:52:00 AM	42	1284.50	TQEX
GENMAB A/S	02-Apr-2025	11:55:51 AM	21	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:51 AM	37	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:51 AM	12	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:51 AM	30	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:52 AM	1	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:58 AM	14	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:58 AM	3	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:55:58 AM	37	1284.50	XCSE
GENMAB A/S	02-Apr-2025	11:56:00 AM	1	1284.00	CEUX
GENMAB A/S	02-Apr-2025	11:56:00 AM	82	1284.00	CEUX
GENMAB A/S	02-Apr-2025	11:56:27 AM	12	1284.00	XCSE
GENMAB A/S	02-Apr-2025	11:56:28 AM	84	1283.50	XCSE
GENMAB A/S	02-Apr-2025	11:56:28 AM	34	1283.50	TQEX
GENMAB A/S	02-Apr-2025	11:56:31 AM	1	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:56:31 AM	79	1283.00	CEUX
GENMAB A/S	02-Apr-2025	11:59:57 AM	25	1283.50	TQEX
GENMAB A/S	02-Apr-2025	12:02:04 PM	82	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:02:04 PM	41	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:02:04 PM	43	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:02:06 PM	25	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:02:06 PM	20	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:02:06 PM	85	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:02:06 PM	29	1282.50	TQEX
GENMAB A/S	02-Apr-2025	12:02:06 PM	80	1282.50	CEUX
GENMAB A/S	02-Apr-2025	12:02:18 PM	80	1281.50	XCSE
GENMAB A/S	02-Apr-2025	12:02:27 PM	26	1281.50	AQEU
GENMAB A/S	02-Apr-2025	12:02:27 PM	85	1281.50	CEUX
GENMAB A/S	02-Apr-2025	12:03:23 PM	86	1281.50	XCSE
GENMAB A/S	02-Apr-2025	12:03:23 PM	26	1281.50	AQEU
GENMAB A/S	02-Apr-2025	12:03:23 PM	51	1281.50	CEUX
GENMAB A/S	02-Apr-2025	12:03:23 PM	14	1281.50	CEUX

145

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	12:04:38 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:04:38 PM	4	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:04:38 PM	7	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:04:51 PM	46	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:04:51 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:04:51 PM	5	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:05:26 PM	23	1282.50	AQEU
GENMAB A/S	02-Apr-2025	12:05:26 PM	8	1282.00	CEUX
GENMAB A/S	02-Apr-2025	12:05:27 PM	2	1282.50	AQEU
GENMAB A/S	02-Apr-2025	12:08:45 PM	49	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:19 PM	13	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:20 PM	11	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:20 PM	22	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:21 PM	13	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:22 PM	11	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:22 PM	25	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:23 PM	1	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:25 PM	14	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:09:33 PM	8	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:10:25 PM	72	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:10:25 PM	24	1283.00	TQEX
GENMAB A/S	02-Apr-2025	12:10:25 PM	87	1283.00	CEUX
GENMAB A/S	02-Apr-2025	12:10:31 PM	11	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:10:31 PM	24	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:10:31 PM	12	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:10:31 PM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:10:31 PM	16	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:11:54 PM	40	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:12:11 PM	25	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:12:41 PM	19	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:12:41 PM	8	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:13:11 PM	13	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:13:11 PM	1	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:13:11 PM	43	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:14:54 PM	21	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:14:54 PM	2	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:14:55 PM	43	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:14:55 PM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:15:59 PM	29	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:20:08 PM	52	1285.00	CEUX
GENMAB A/S	02-Apr-2025	12:20:08 PM	1	1285.00	CEUX
GENMAB A/S	02-Apr-2025	12:20:08 PM	1	1285.00	CEUX
GENMAB A/S	02-Apr-2025	12:20:11 PM	82	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:11 PM	5	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:12 PM	24	1284.50	XCSE

146

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	12:20:12 PM	13	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:27 PM	2	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:27 PM	25	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:40 PM	11	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:40 PM	12	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:40 PM	14	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:41 PM	12	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:41 PM	13	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:42 PM	12	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:42 PM	12	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:20:45 PM	11	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:21:03 PM	13	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:21:03 PM	2	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:21:06 PM	11	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:21:21 PM	54	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:21:27 PM	2	1284.50	CEUX
GENMAB A/S	02-Apr-2025	12:21:27 PM	21	1284.50	CEUX
GENMAB A/S	02-Apr-2025	12:22:12 PM	7	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:22:50 PM	23	1284.50	CEUX
GENMAB A/S	02-Apr-2025	12:22:51 PM	25	1284.50	AQEU
GENMAB A/S	02-Apr-2025	12:23:27 PM	32	1284.50	CEUX
GENMAB A/S	02-Apr-2025	12:25:28 PM	2	1284.50	CEUX
GENMAB A/S	02-Apr-2025	12:25:56 PM	22	1285.00	TQEX
GENMAB A/S	02-Apr-2025	12:26:00 PM	86	1285.00	XCSE
GENMAB A/S	02-Apr-2025	12:26:00 PM	33	1285.00	TQEX
GENMAB A/S	02-Apr-2025	12:26:00 PM	36	1285.00	CEUX
GENMAB A/S	02-Apr-2025	12:27:41 PM	53	1285.50	XCSE
GENMAB A/S	02-Apr-2025	12:27:41 PM	14	1285.50	XCSE
GENMAB A/S	02-Apr-2025	12:27:41 PM	13	1285.50	XCSE
GENMAB A/S	02-Apr-2025	12:28:02 PM	1	1285.50	XCSE
GENMAB A/S	02-Apr-2025	12:28:07 PM	31	1284.00	TQEX
GENMAB A/S	02-Apr-2025	12:28:07 PM	87	1285.00	CEUX
GENMAB A/S	02-Apr-2025	12:28:07 PM	53	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:28:08 PM	4	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:28:38 PM	26	1284.00	TQEX
GENMAB A/S	02-Apr-2025	12:29:30 PM	86	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:29:55 PM	2	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:29:55 PM	43	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:32:25 PM	4	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:32:27 PM	79	1284.50	XCSE
GENMAB A/S	02-Apr-2025	12:32:27 PM	82	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:32:27 PM	25	1284.00	TQEX
GENMAB A/S	02-Apr-2025	12:32:27 PM	82	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:33:01 PM	20	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:33:01 PM	43	1283.50	XCSE

147

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	12:33:03 PM	34	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:33:03 PM	13	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:33:04 PM	30	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:33:25 PM	35	1283.00	TQEX
GENMAB A/S	02-Apr-2025	12:33:25 PM	85	1283.00	CEUX
GENMAB A/S	02-Apr-2025	12:33:48 PM	25	1283.00	AQEU
GENMAB A/S	02-Apr-2025	12:35:22 PM	37	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:35:22 PM	1	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:35:22 PM	43	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:35:22 PM	39	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:35:41 PM	5	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:35:41 PM	48	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:35:41 PM	18	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:36:09 PM	83	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:37:47 PM	2	1282.50	CEUX
GENMAB A/S	02-Apr-2025	12:37:47 PM	23	1282.50	CEUX
GENMAB A/S	02-Apr-2025	12:37:47 PM	33	1282.50	CEUX
GENMAB A/S	02-Apr-2025	12:40:07 PM	34	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:40:21 PM	30	1283.50	TQEX
GENMAB A/S	02-Apr-2025	12:40:27 PM	10	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:41:38 PM	23	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:38 PM	57	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:38 PM	6	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:38 PM	23	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:38 PM	7	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:39 PM	11	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:39 PM	43	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:41:39 PM	12	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:42:11 PM	2	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:42:11 PM	30	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:42:11 PM	13	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:42:11 PM	32	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:42:37 PM	4	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:42:37 PM	9	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:42:37 PM	29	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:42:37 PM	7	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:43:01 PM	25	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:43:49 PM	13	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:44:37 PM	1	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:44:37 PM	4	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:44:37 PM	11	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:47:26 PM	3	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:48:26 PM	4	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:49:26 PM	5	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:50:01 PM	54	1283.00	XCSE

148

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	12:50:33 PM	3	1283.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:26 PM	4	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:28 PM	11	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:30 PM	27	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:30 PM	27	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:30 PM	36	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:30 PM	8	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:31 PM	27	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:33 PM	36	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:34 PM	36	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:45 PM	36	1284.00	CEUX
GENMAB A/S	02-Apr-2025	12:51:49 PM	22	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	21	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	37	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	27	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	2	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	9	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	14	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	43	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	37	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:49 PM	6	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:50 PM	5	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:50 PM	12	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:50 PM	14	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:51:50 PM	27	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:52:11 PM	13	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:52:11 PM	43	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:52:11 PM	33	1284.00	XCSE
GENMAB A/S	02-Apr-2025	12:53:26 PM	4	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:53:26 PM	36	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:53:27 PM	23	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:53:47 PM	1	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:54:24 PM	1	1283.50	XCSE
GENMAB A/S	02-Apr-2025	12:54:24 PM	26	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:54:24 PM	3	1283.00	AQEU
GENMAB A/S	02-Apr-2025	12:54:24 PM	32	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:54:57 PM	3	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:54:57 PM	20	1283.50	CEUX
GENMAB A/S	02-Apr-2025	12:55:07 PM	25	1283.00	TQEX
GENMAB A/S	02-Apr-2025	12:55:07 PM	20	1283.00	AQEU
GENMAB A/S	02-Apr-2025	12:55:07 PM	83	1283.00	CEUX
GENMAB A/S	02-Apr-2025	12:55:09 PM	12	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:55:09 PM	11	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:55:09 PM	37	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:55:09 PM	2	1283.00	XCSE

149

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	12:55:09 PM	34	1283.00	XCSE
GENMAB A/S	02-Apr-2025	12:55:41 PM	12	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:55:51 PM	3	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:55:51 PM	13	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:56:05 PM	84	1282.00	XCSE
GENMAB A/S	02-Apr-2025	12:56:05 PM	26	1282.00	TQEX
GENMAB A/S	02-Apr-2025	12:56:05 PM	81	1282.00	CEUX
GENMAB A/S	02-Apr-2025	12:56:50 PM	84	1282.50	XCSE
GENMAB A/S	02-Apr-2025	12:56:50 PM	32	1282.50	TQEX
GENMAB A/S	02-Apr-2025	12:56:50 PM	83	1282.50	CEUX
GENMAB A/S	02-Apr-2025	12:56:51 PM	3	1281.50	CEUX
GENMAB A/S	02-Apr-2025	12:56:51 PM	81	1281.50	CEUX
GENMAB A/S	02-Apr-2025	12:58:58 PM	9	1281.00	XCSE
GENMAB A/S	02-Apr-2025	12:58:58 PM	71	1281.00	XCSE
GENMAB A/S	02-Apr-2025	12:59:01 PM	80	1280.50	CEUX
GENMAB A/S	02-Apr-2025	12:59:47 PM	83	1279.50	XCSE
GENMAB A/S	02-Apr-2025	13:02:05 PM	40	1280.50	XCSE
GENMAB A/S	02-Apr-2025	13:02:56 PM	23	1280.00	AQEU
GENMAB A/S	02-Apr-2025	13:02:57 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:02:57 PM	12	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:02:57 PM	1	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:02:57 PM	12	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:02:58 PM	83	1279.50	XCSE
GENMAB A/S	02-Apr-2025	13:02:58 PM	26	1279.50	TQEX
GENMAB A/S	02-Apr-2025	13:02:58 PM	75	1279.00	CEUX
GENMAB A/S	02-Apr-2025	13:07:35 PM	14	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:39 PM	16	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:40 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:41 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:41 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:44 PM	14	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:44 PM	11	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:07:44 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	48	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	33	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	43	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	37	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	3	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:05 PM	82	1283.00	CEUX
GENMAB A/S	02-Apr-2025	13:13:06 PM	14	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:07 PM	13	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:13:26 PM	8	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:00 PM	109	1283.00	XCSE

150

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	13:15:00 PM	26	1282.50	TQEX
GENMAB A/S	02-Apr-2025	13:15:04 PM	80	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:05 PM	12	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:23 PM	25	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:23 PM	43	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:23 PM	23	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:23 PM	82	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:15:23 PM	32	1282.50	TQEX
GENMAB A/S	02-Apr-2025	13:15:23 PM	24	1281.50	TQEX
GENMAB A/S	02-Apr-2025	13:15:23 PM	87	1282.00	CEUX
GENMAB A/S	02-Apr-2025	13:16:50 PM	67	1281.00	XCSE
GENMAB A/S	02-Apr-2025	13:17:34 PM	15	1281.00	XCSE
GENMAB A/S	02-Apr-2025	13:18:25 PM	9	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:18:58 PM	16	1282.50	XCSE
GENMAB A/S	02-Apr-2025	13:19:02 PM	38	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:19:02 PM	20	1282.50	CEUX
GENMAB A/S	02-Apr-2025	13:19:03 PM	60	1282.50	CEUX
GENMAB A/S	02-Apr-2025	13:19:18 PM	87	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:19:18 PM	82	1281.50	CEUX
GENMAB A/S	02-Apr-2025	13:19:41 PM	78	1280.50	CEUX
GENMAB A/S	02-Apr-2025	13:19:41 PM	5	1280.50	CEUX
GENMAB A/S	02-Apr-2025	13:19:58 PM	20	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:19:58 PM	67	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:19:58 PM	28	1280.00	TQEX
GENMAB A/S	02-Apr-2025	13:20:34 PM	81	1280.50	XCSE
GENMAB A/S	02-Apr-2025	13:22:03 PM	43	1280.00	CEUX
GENMAB A/S	02-Apr-2025	13:22:03 PM	18	1280.00	CEUX
GENMAB A/S	02-Apr-2025	13:22:05 PM	85	1279.50	XCSE
GENMAB A/S	02-Apr-2025	13:23:34 PM	21	1279.50	TQEX
GENMAB A/S	02-Apr-2025	13:26:00 PM	47	1279.50	XCSE
GENMAB A/S	02-Apr-2025	13:26:38 PM	31	1279.00	CEUX
GENMAB A/S	02-Apr-2025	13:26:38 PM	52	1279.00	CEUX
GENMAB A/S	02-Apr-2025	13:26:40 PM	30	1279.00	AQEU
GENMAB A/S	02-Apr-2025	13:27:10 PM	33	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:27:10 PM	48	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:27:10 PM	26	1279.00	XCSE
GENMAB A/S	02-Apr-2025	13:27:10 PM	12	1279.00	AQEU
GENMAB A/S	02-Apr-2025	13:29:21 PM	42	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:29:21 PM	54	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:29:21 PM	24	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:29:21 PM	5	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:29:22 PM	23	1277.50	AQEU
GENMAB A/S	02-Apr-2025	13:29:22 PM	43	1277.50	CEUX
GENMAB A/S	02-Apr-2025	13:29:22 PM	11	1277.50	CEUX
GENMAB A/S	02-Apr-2025	13:29:25 PM	21	1277.50	TQEX

151

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	13:29:25 PM	13	1277.50	CEUX
GENMAB A/S	02-Apr-2025	13:29:25 PM	17	1277.50	CEUX
GENMAB A/S	02-Apr-2025	13:29:30 PM	27	1277.00	XCSE
GENMAB A/S	02-Apr-2025	13:29:30 PM	54	1277.00	XCSE
GENMAB A/S	02-Apr-2025	13:30:07 PM	39	1276.50	CEUX
GENMAB A/S	02-Apr-2025	13:30:07 PM	9	1276.50	CEUX
GENMAB A/S	02-Apr-2025	13:30:26 PM	50	1276.00	XCSE
GENMAB A/S	02-Apr-2025	13:30:26 PM	36	1276.00	XCSE
GENMAB A/S	02-Apr-2025	13:34:25 PM	5	1275.50	AQEU
GENMAB A/S	02-Apr-2025	13:34:36 PM	18	1275.50	AQEU
GENMAB A/S	02-Apr-2025	13:34:36 PM	11	1275.00	CEUX
GENMAB A/S	02-Apr-2025	13:34:36 PM	73	1275.00	CEUX
GENMAB A/S	02-Apr-2025	13:35:27 PM	21	1275.00	XCSE
GENMAB A/S	02-Apr-2025	13:35:27 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	13:35:27 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	13:36:38 PM	85	1276.50	XCSE
GENMAB A/S	02-Apr-2025	13:36:38 PM	28	1276.50	TQEX
GENMAB A/S	02-Apr-2025	13:36:38 PM	84	1277.00	CEUX
GENMAB A/S	02-Apr-2025	13:36:38 PM	43	1276.00	CEUX
GENMAB A/S	02-Apr-2025	13:36:38 PM	37	1276.00	CEUX
GENMAB A/S	02-Apr-2025	13:38:27 PM	5	1276.50	XCSE
GENMAB A/S	02-Apr-2025	13:39:23 PM	3	1276.50	XCSE
GENMAB A/S	02-Apr-2025	13:40:58 PM	27	1278.00	CEUX
GENMAB A/S	02-Apr-2025	13:40:58 PM	47	1278.00	CEUX
GENMAB A/S	02-Apr-2025	13:41:08 PM	84	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	30	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	12	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	37	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	13	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	11	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	6	1278.00	XCSE
GENMAB A/S	02-Apr-2025	13:41:19 PM	17	1277.50	TQEX
GENMAB A/S	02-Apr-2025	13:41:19 PM	6	1277.50	TQEX
GENMAB A/S	02-Apr-2025	13:41:26 PM	6	1277.50	XCSE
GENMAB A/S	02-Apr-2025	13:43:56 PM	40	1278.00	CEUX
GENMAB A/S	02-Apr-2025	13:43:57 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:43:57 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:43:57 PM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:43:59 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:00 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:00 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:05 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:12 PM	40	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:13 PM	13	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:13 PM	13	1278.50	XCSE

152

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	13:44:13 PM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:23 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:41 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:41 PM	31	1278.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:42 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	13:44:42 PM	25	1278.00	TQEX
GENMAB A/S	02-Apr-2025	13:44:42 PM	24	1278.00	AQEU
GENMAB A/S	02-Apr-2025	13:44:42 PM	28	1278.00	CEUX
GENMAB A/S	02-Apr-2025	13:45:18 PM	39	1280.50	CEUX
GENMAB A/S	02-Apr-2025	13:45:18 PM	24	1280.50	CEUX
GENMAB A/S	02-Apr-2025	13:45:50 PM	84	1280.00	XCSE
GENMAB A/S	02-Apr-2025	13:48:18 PM	42	1281.00	XCSE
GENMAB A/S	02-Apr-2025	13:48:33 PM	35	1281.50	CEUX
GENMAB A/S	02-Apr-2025	13:49:41 PM	38	1281.00	XCSE
GENMAB A/S	02-Apr-2025	13:50:30 PM	44	1281.50	TQEX
GENMAB A/S	02-Apr-2025	13:50:30 PM	30	1281.50	CEUX
GENMAB A/S	02-Apr-2025	13:50:30 PM	18	1281.50	CEUX
GENMAB A/S	02-Apr-2025	13:52:24 PM	29	1281.00	AQEU
GENMAB A/S	02-Apr-2025	13:52:30 PM	46	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:52:30 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:52:30 PM	11	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:52:30 PM	14	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:52:30 PM	25	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:52:47 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:47 PM	37	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:47 PM	14	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:47 PM	14	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:47 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:47 PM	20	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:48 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:48 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:48 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:48 PM	37	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:52:48 PM	30	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:53:26 PM	12	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:53:26 PM	15	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:53:27 PM	2	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:53:27 PM	15	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:53:51 PM	11	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:53:51 PM	9	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:54:32 PM	1	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:54:33 PM	82	1282.00	XCSE
GENMAB A/S	02-Apr-2025	13:54:34 PM	80	1285.50	XCSE
GENMAB A/S	02-Apr-2025	13:54:34 PM	84	1286.00	CEUX
GENMAB A/S	02-Apr-2025	13:54:35 PM	42	1285.00	TQEX

153

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	13:54:39 PM	36	1285.00	AQEU
GENMAB A/S	02-Apr-2025	13:54:39 PM	19	1284.50	CEUX
GENMAB A/S	02-Apr-2025	13:54:39 PM	5	1284.50	CEUX
GENMAB A/S	02-Apr-2025	13:55:10 PM	80	1284.00	XCSE
GENMAB A/S	02-Apr-2025	13:55:10 PM	39	1284.00	AQEU
GENMAB A/S	02-Apr-2025	13:55:10 PM	59	1284.50	CEUX
GENMAB A/S	02-Apr-2025	13:55:10 PM	86	1283.50	CEUX
GENMAB A/S	02-Apr-2025	13:55:35 PM	83	1283.00	XCSE
GENMAB A/S	02-Apr-2025	13:55:35 PM	18	1283.00	AQEU
GENMAB A/S	02-Apr-2025	13:55:35 PM	17	1283.00	AQEU
GENMAB A/S	02-Apr-2025	13:55:42 PM	80	1281.50	XCSE
GENMAB A/S	02-Apr-2025	13:55:42 PM	86	1282.50	CEUX
GENMAB A/S	02-Apr-2025	13:58:25 PM	10	1281.50	AQEU
GENMAB A/S	02-Apr-2025	13:59:26 PM	6	1281.50	AQEU
GENMAB A/S	02-Apr-2025	13:59:26 PM	2	1281.50	AQEU
GENMAB A/S	02-Apr-2025	13:59:27 PM	3	1281.50	AQEU
GENMAB A/S	02-Apr-2025	13:59:46 PM	1	1281.50	AQEU
GENMAB A/S	02-Apr-2025	14:00:26 PM	65	1282.00	XCSE
GENMAB A/S	02-Apr-2025	14:00:26 PM	21	1282.00	XCSE
GENMAB A/S	02-Apr-2025	14:00:34 PM	1	1282.00	XCSE
GENMAB A/S	02-Apr-2025	14:01:27 PM	5	1281.50	XCSE
GENMAB A/S	02-Apr-2025	14:01:27 PM	8	1281.50	XCSE
GENMAB A/S	02-Apr-2025	14:01:27 PM	24	1281.50	TQEX
GENMAB A/S	02-Apr-2025	14:01:27 PM	3	1281.50	AQEU
GENMAB A/S	02-Apr-2025	14:02:02 PM	62	1281.50	XCSE
GENMAB A/S	02-Apr-2025	14:02:02 PM	19	1281.50	XCSE
GENMAB A/S	02-Apr-2025	14:02:26 PM	7	1281.50	XCSE
GENMAB A/S	02-Apr-2025	14:03:09 PM	23	1281.00	CEUX
GENMAB A/S	02-Apr-2025	14:03:12 PM	84	1280.50	XCSE
GENMAB A/S	02-Apr-2025	14:03:12 PM	12	1281.00	XCSE
GENMAB A/S	02-Apr-2025	14:03:12 PM	39	1281.00	XCSE
GENMAB A/S	02-Apr-2025	14:03:12 PM	14	1281.00	XCSE
GENMAB A/S	02-Apr-2025	14:03:12 PM	9	1281.00	XCSE
GENMAB A/S	02-Apr-2025	14:03:23 PM	12	1280.00	TQEX
GENMAB A/S	02-Apr-2025	14:03:25 PM	10	1280.00	AQEU
GENMAB A/S	02-Apr-2025	14:03:25 PM	20	1280.00	AQEU
GENMAB A/S	02-Apr-2025	14:03:27 PM	28	1279.50	CEUX
GENMAB A/S	02-Apr-2025	14:03:29 PM	82	1279.00	XCSE
GENMAB A/S	02-Apr-2025	14:05:27 PM	8	1278.50	AQEU
GENMAB A/S	02-Apr-2025	14:05:37 PM	18	1278.50	AQEU
GENMAB A/S	02-Apr-2025	14:07:26 PM	25	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:07:26 PM	10	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:07:26 PM	21	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:07:26 PM	22	1278.50	TQEX
GENMAB A/S	02-Apr-2025	14:07:27 PM	81	1278.50	XCSE

154

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	14:07:27 PM	1	1278.50	AQEU
GENMAB A/S	02-Apr-2025	14:07:31 PM	36	1278.50	AQEU
GENMAB A/S	02-Apr-2025	14:08:05 PM	24	1278.00	CEUX
GENMAB A/S	02-Apr-2025	14:08:26 PM	19	1278.00	CEUX
GENMAB A/S	02-Apr-2025	14:08:49 PM	33	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:08:49 PM	7	1278.50	CEUX
GENMAB A/S	02-Apr-2025	14:08:49 PM	2	1278.50	CEUX
GENMAB A/S	02-Apr-2025	14:08:52 PM	46	1278.50	CEUX
GENMAB A/S	02-Apr-2025	14:08:52 PM	25	1278.50	CEUX
GENMAB A/S	02-Apr-2025	14:08:57 PM	52	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:00 PM	35	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:00 PM	26	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	5	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:04 PM	35	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:16 PM	17	1278.00	AQEU
GENMAB A/S	02-Apr-2025	14:09:16 PM	13	1278.00	AQEU
GENMAB A/S	02-Apr-2025	14:09:21 PM	44	1278.00	XCSE
GENMAB A/S	02-Apr-2025	14:09:21 PM	11	1278.00	XCSE
GENMAB A/S	02-Apr-2025	14:09:21 PM	8	1278.00	XCSE
GENMAB A/S	02-Apr-2025	14:09:34 PM	81	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:09:34 PM	52	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:09:34 PM	31	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:10:00 PM	27	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:10:00 PM	51	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:10:02 PM	2	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:10:23 PM	4	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:11:31 PM	18	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:11:31 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:12:08 PM	27	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:12:51 PM	47	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:12:51 PM	5	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:13:08 PM	1	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:13:17 PM	30	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:13:17 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:13:18 PM	51	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:14:25 PM	15	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:14:41 PM	71	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:14:41 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:14:41 PM	65	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:16:10 PM	80	1278.50	XCSE

155

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	14:16:27 PM	42	1279.00	XCSE
GENMAB A/S	02-Apr-2025	14:16:27 PM	14	1279.00	XCSE
GENMAB A/S	02-Apr-2025	14:16:27 PM	11	1279.00	XCSE
GENMAB A/S	02-Apr-2025	14:16:33 PM	46	1279.00	XCSE
GENMAB A/S	02-Apr-2025	14:16:56 PM	23	1279.00	AQEU
GENMAB A/S	02-Apr-2025	14:17:18 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:17:18 PM	6	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:17:18 PM	38	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:17:26 PM	32	1279.00	CEUX
GENMAB A/S	02-Apr-2025	14:18:01 PM	1	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:18:01 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:18:01 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:18:01 PM	34	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:18:01 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	14:18:01 PM	32	1279.00	CEUX
GENMAB A/S	02-Apr-2025	14:18:25 PM	80	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:18:25 PM	82	1278.50	CEUX
GENMAB A/S	02-Apr-2025	14:21:00 PM	39	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:21:00 PM	9	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:21:00 PM	37	1278.50	XCSE
GENMAB A/S	02-Apr-2025	14:21:00 PM	30	1278.00	TQEX
GENMAB A/S	02-Apr-2025	14:21:00 PM	20	1278.00	AQEU
GENMAB A/S	02-Apr-2025	14:21:00 PM	7	1278.00	AQEU
GENMAB A/S	02-Apr-2025	14:21:00 PM	23	1278.00	CEUX
GENMAB A/S	02-Apr-2025	14:21:05 PM	39	1278.00	TQEX
GENMAB A/S	02-Apr-2025	14:21:22 PM	24	1278.00	AQEU
GENMAB A/S	02-Apr-2025	14:21:26 PM	9	1278.00	CEUX
GENMAB A/S	02-Apr-2025	14:21:34 PM	25	1278.00	XCSE
GENMAB A/S	02-Apr-2025	14:21:34 PM	84	1277.50	XCSE
GENMAB A/S	02-Apr-2025	14:21:54 PM	82	1277.50	CEUX
GENMAB A/S	02-Apr-2025	14:22:09 PM	20	1277.00	TQEX
GENMAB A/S	02-Apr-2025	14:22:09 PM	8	1277.00	TQEX
GENMAB A/S	02-Apr-2025	14:22:10 PM	72	1276.50	CEUX
GENMAB A/S	02-Apr-2025	14:22:10 PM	8	1276.50	CEUX
GENMAB A/S	02-Apr-2025	14:22:21 PM	43	1277.00	XCSE
GENMAB A/S	02-Apr-2025	14:22:21 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	14:22:21 PM	4	1277.00	XCSE
GENMAB A/S	02-Apr-2025	14:22:50 PM	81	1276.00	XCSE
GENMAB A/S	02-Apr-2025	14:23:00 PM	18	1275.50	TQEX
GENMAB A/S	02-Apr-2025	14:23:15 PM	8	1275.50	TQEX
GENMAB A/S	02-Apr-2025	14:23:29 PM	1	1275.00	XCSE
GENMAB A/S	02-Apr-2025	14:23:29 PM	83	1275.00	XCSE
GENMAB A/S	02-Apr-2025	14:23:29 PM	23	1274.50	TQEX
GENMAB A/S	02-Apr-2025	14:23:29 PM	81	1275.00	CEUX
GENMAB A/S	02-Apr-2025	14:24:32 PM	11	1275.00	CEUX

156

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	14:24:51 PM	25	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:25:11 PM	4	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:25:21 PM	2	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:25:57 PM	39	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:25:57 PM	20	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:25:57 PM	1	1275.00	CEUX
GENMAB A/S	02-Apr-2025	14:25:57 PM	74	1275.00	CEUX
GENMAB A/S	02-Apr-2025	14:26:21 PM	3	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:26:21 PM	57	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:26:21 PM	6	1275.50	XCSE
GENMAB A/S	02-Apr-2025	14:26:39 PM	80	1274.50	XCSE
GENMAB A/S	02-Apr-2025	14:26:39 PM	85	1273.50	XCSE
GENMAB A/S	02-Apr-2025	14:26:39 PM	43	1274.00	AQEU
GENMAB A/S	02-Apr-2025	14:26:39 PM	82	1274.00	CEUX
GENMAB A/S	02-Apr-2025	14:26:47 PM	80	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:26:47 PM	40	1273.00	CEUX
GENMAB A/S	02-Apr-2025	14:26:47 PM	46	1273.00	CEUX
GENMAB A/S	02-Apr-2025	14:27:25 PM	41	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:27:25 PM	1	1272.50	AQEU
GENMAB A/S	02-Apr-2025	14:28:03 PM	1	1272.50	AQEU
GENMAB A/S	02-Apr-2025	14:28:08 PM	13	1272.50	AQEU
GENMAB A/S	02-Apr-2025	14:28:16 PM	3	1272.50	AQEU
GENMAB A/S	02-Apr-2025	14:28:28 PM	12	1272.50	AQEU
GENMAB A/S	02-Apr-2025	14:28:30 PM	84	1272.00	CEUX
GENMAB A/S	02-Apr-2025	14:28:30 PM	1	1272.00	CEUX
GENMAB A/S	02-Apr-2025	14:29:27 PM	22	1271.50	CEUX
GENMAB A/S	02-Apr-2025	14:29:41 PM	1	1271.50	CEUX
GENMAB A/S	02-Apr-2025	14:29:41 PM	1	1271.50	CEUX
GENMAB A/S	02-Apr-2025	14:30:39 PM	82	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:32:17 PM	35	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:32:17 PM	24	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:32:17 PM	21	1271.50	CEUX
GENMAB A/S	02-Apr-2025	14:32:52 PM	50	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:32:52 PM	24	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:32:52 PM	19	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:32:52 PM	80	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:32:52 PM	9	1271.50	CEUX
GENMAB A/S	02-Apr-2025	14:35:26 PM	17	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:35:42 PM	29	1272.00	TQEX
GENMAB A/S	02-Apr-2025	14:37:01 PM	50	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:37:01 PM	37	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:37:01 PM	9	1272.00	TQEX
GENMAB A/S	02-Apr-2025	14:37:30 PM	13	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:37:30 PM	18	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:38:24 PM	2	1272.50	CEUX

157

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	14:38:30 PM	32	1272.50	CEUX
GENMAB A/S	02-Apr-2025	14:39:02 PM	19	1272.50	CEUX
GENMAB A/S	02-Apr-2025	14:39:47 PM	19	1273.00	TQEX
GENMAB A/S	02-Apr-2025	14:39:47 PM	6	1273.00	TQEX
GENMAB A/S	02-Apr-2025	14:40:03 PM	28	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:03 PM	19	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:03 PM	1	1273.50	CEUX
GENMAB A/S	02-Apr-2025	14:40:03 PM	11	1273.50	CEUX
GENMAB A/S	02-Apr-2025	14:40:03 PM	30	1273.50	CEUX
GENMAB A/S	02-Apr-2025	14:40:03 PM	12	1273.50	CEUX
GENMAB A/S	02-Apr-2025	14:40:18 PM	11	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:18 PM	11	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	24	1273.50	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	15	1273.50	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	24	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	13	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	33	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	16	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	25	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	9	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	11	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	12	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	11	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	9	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:22 PM	43	1273.50	CEUX
GENMAB A/S	02-Apr-2025	14:40:22 PM	38	1273.50	CEUX
GENMAB A/S	02-Apr-2025	14:40:23 PM	6	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:24 PM	39	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:24 PM	11	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:40:24 PM	14	1274.00	XCSE
GENMAB A/S	02-Apr-2025	14:41:00 PM	86	1273.00	XCSE
GENMAB A/S	02-Apr-2025	14:41:00 PM	25	1273.00	TQEX
GENMAB A/S	02-Apr-2025	14:41:00 PM	61	1272.50	CEUX
GENMAB A/S	02-Apr-2025	14:41:15 PM	4	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:41:15 PM	79	1272.00	XCSE
GENMAB A/S	02-Apr-2025	14:41:15 PM	26	1272.00	TQEX
GENMAB A/S	02-Apr-2025	14:41:21 PM	3	1271.50	CEUX
GENMAB A/S	02-Apr-2025	14:41:46 PM	81	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:41:58 PM	62	1270.50	CEUX
GENMAB A/S	02-Apr-2025	14:41:58 PM	21	1270.50	CEUX
GENMAB A/S	02-Apr-2025	14:42:21 PM	80	1272.50	XCSE
GENMAB A/S	02-Apr-2025	14:42:21 PM	6	1273.00	CEUX
GENMAB A/S	02-Apr-2025	14:42:21 PM	74	1273.00	CEUX
GENMAB A/S	02-Apr-2025	14:43:26 PM	43	1272.00	CEUX
GENMAB A/S	02-Apr-2025	14:43:26 PM	41	1272.00	CEUX

158

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	14:43:37 PM	85	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:44:09 PM	86	1271.00	CEUX
GENMAB A/S	02-Apr-2025	14:44:09 PM	1	1271.00	CEUX
GENMAB A/S	02-Apr-2025	14:44:12 PM	84	1270.50	XCSE
GENMAB A/S	02-Apr-2025	14:44:12 PM	30	1270.50	TQEX
GENMAB A/S	02-Apr-2025	14:44:25 PM	11	1270.00	CEUX
GENMAB A/S	02-Apr-2025	14:44:25 PM	34	1270.00	CEUX
GENMAB A/S	02-Apr-2025	14:46:44 PM	51	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:47:33 PM	33	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:47:36 PM	1	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:49:09 PM	41	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:49:10 PM	45	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:49:11 PM	64	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:49:11 PM	14	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:49:11 PM	31	1271.50	XCSE
GENMAB A/S	02-Apr-2025	14:49:12 PM	84	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:49:13 PM	39	1270.50	CEUX
GENMAB A/S	02-Apr-2025	14:49:13 PM	5	1270.50	CEUX
GENMAB A/S	02-Apr-2025	14:50:24 PM	11	1270.00	TQEX
GENMAB A/S	02-Apr-2025	14:50:25 PM	81	1270.00	XCSE
GENMAB A/S	02-Apr-2025	14:50:25 PM	2	1270.00	TQEX
GENMAB A/S	02-Apr-2025	14:50:26 PM	9	1270.00	TQEX
GENMAB A/S	02-Apr-2025	14:50:28 PM	3	1270.00	TQEX
GENMAB A/S	02-Apr-2025	14:51:31 PM	47	1269.50	CEUX
GENMAB A/S	02-Apr-2025	14:51:50 PM	84	1269.00	XCSE
GENMAB A/S	02-Apr-2025	14:51:50 PM	11	1269.00	TQEX
GENMAB A/S	02-Apr-2025	14:51:50 PM	16	1269.00	TQEX
GENMAB A/S	02-Apr-2025	14:51:50 PM	10	1268.50	CEUX
GENMAB A/S	02-Apr-2025	14:51:50 PM	15	1268.50	CEUX
GENMAB A/S	02-Apr-2025	14:51:50 PM	1	1268.50	CEUX
GENMAB A/S	02-Apr-2025	14:52:21 PM	31	1269.50	CEUX
GENMAB A/S	02-Apr-2025	14:52:21 PM	3	1269.50	CEUX
GENMAB A/S	02-Apr-2025	14:52:50 PM	9	1269.50	CEUX
GENMAB A/S	02-Apr-2025	14:52:50 PM	37	1269.50	CEUX
GENMAB A/S	02-Apr-2025	14:53:11 PM	46	1270.00	XCSE
GENMAB A/S	02-Apr-2025	14:53:11 PM	41	1270.00	XCSE
GENMAB A/S	02-Apr-2025	14:53:11 PM	12	1270.00	XCSE
GENMAB A/S	02-Apr-2025	14:53:11 PM	6	1270.00	XCSE
GENMAB A/S	02-Apr-2025	14:55:52 PM	23	1270.50	AQEU
GENMAB A/S	02-Apr-2025	14:56:26 PM	35	1270.50	XCSE
GENMAB A/S	02-Apr-2025	14:56:27 PM	1	1270.50	XCSE
GENMAB A/S	02-Apr-2025	14:56:40 PM	82	1270.00	CEUX
GENMAB A/S	02-Apr-2025	14:56:43 PM	10	1270.50	XCSE
GENMAB A/S	02-Apr-2025	14:56:43 PM	15	1270.50	XCSE
GENMAB A/S	02-Apr-2025	14:56:43 PM	41	1270.50	XCSE

159

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	14:57:06 PM	33	1270.00	XCSE
GENMAB A/S	02-Apr-2025	14:57:08 PM	44	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:57:08 PM	11	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:57:08 PM	54	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:57:08 PM	43	1270.50	CEUX
GENMAB A/S	02-Apr-2025	14:57:27 PM	11	1270.50	AQEU
GENMAB A/S	02-Apr-2025	14:58:19 PM	29	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:58:19 PM	51	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:58:19 PM	14	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:58:19 PM	51	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:58:40 PM	69	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:59:01 PM	2	1270.50	AQEU
GENMAB A/S	02-Apr-2025	14:59:21 PM	31	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:59:21 PM	18	1271.00	XCSE
GENMAB A/S	02-Apr-2025	14:59:21 PM	2	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:01:08 PM	27	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:01:17 PM	10	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:01:17 PM	78	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:01:17 PM	10	1271.00	CEUX
GENMAB A/S	02-Apr-2025	15:01:17 PM	16	1271.00	CEUX
GENMAB A/S	02-Apr-2025	15:01:21 PM	41	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:01:21 PM	27	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:01:21 PM	86	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:01:21 PM	34	1271.00	TQEX
GENMAB A/S	02-Apr-2025	15:01:21 PM	10	1270.50	AQEU
GENMAB A/S	02-Apr-2025	15:01:21 PM	39	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:01:21 PM	2	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:01:26 PM	9	1270.00	TQEX
GENMAB A/S	02-Apr-2025	15:01:36 PM	52	1270.00	XCSE
GENMAB A/S	02-Apr-2025	15:01:36 PM	14	1270.00	TQEX
GENMAB A/S	02-Apr-2025	15:01:37 PM	64	1269.50	CEUX
GENMAB A/S	02-Apr-2025	15:01:37 PM	20	1269.50	CEUX
GENMAB A/S	02-Apr-2025	15:04:28 PM	83	1270.50	XCSE
GENMAB A/S	02-Apr-2025	15:04:28 PM	30	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:04:28 PM	52	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:04:29 PM	26	1270.50	XCSE
GENMAB A/S	02-Apr-2025	15:04:45 PM	27	1270.50	XCSE
GENMAB A/S	02-Apr-2025	15:05:26 PM	7	1270.50	XCSE
GENMAB A/S	02-Apr-2025	15:05:27 PM	40	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:05:27 PM	4	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:05:27 PM	34	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:05:27 PM	36	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:05:27 PM	1	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:05:27 PM	43	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:06:10 PM	3	1270.50	XCSE

160

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:06:10 PM	28	1270.00	TQEX
GENMAB A/S	02-Apr-2025	15:06:25 PM	15	1270.00	AQEU
GENMAB A/S	02-Apr-2025	15:07:27 PM	3	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:07:28 PM	29	1271.00	TQEX
GENMAB A/S	02-Apr-2025	15:07:28 PM	23	1271.00	AQEU
GENMAB A/S	02-Apr-2025	15:08:03 PM	8	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:08:59 PM	80	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:08:59 PM	23	1271.00	TQEX
GENMAB A/S	02-Apr-2025	15:09:28 PM	3	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:28 PM	27	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:28 PM	6	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:28 PM	7	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:28 PM	6	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:37 PM	33	1272.00	TQEX
GENMAB A/S	02-Apr-2025	15:09:37 PM	13	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:37 PM	10	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:37 PM	4	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:37 PM	21	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:09:40 PM	16	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:40 PM	27	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:40 PM	33	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:46 PM	12	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:46 PM	2	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:47 PM	14	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:47 PM	22	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:47 PM	11	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:47 PM	39	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:47 PM	23	1272.00	XCSE
GENMAB A/S	02-Apr-2025	15:09:47 PM	29	1271.50	CEUX
GENMAB A/S	02-Apr-2025	15:09:47 PM	57	1271.50	CEUX
GENMAB A/S	02-Apr-2025	15:09:54 PM	10	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:09:57 PM	4	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:00 PM	3	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:00 PM	2	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	87	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	11	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	36	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	9	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	30	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	23	1271.50	XCSE
GENMAB A/S	02-Apr-2025	15:10:02 PM	23	1271.00	AQEU
GENMAB A/S	02-Apr-2025	15:10:08 PM	9	1270.00	AQEU
GENMAB A/S	02-Apr-2025	15:10:08 PM	77	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:10:43 PM	87	1269.50	CEUX
GENMAB A/S	02-Apr-2025	15:10:55 PM	80	1269.50	XCSE

161

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:11:07 PM	43	1269.50	CEUX
GENMAB A/S	02-Apr-2025	15:11:07 PM	11	1269.50	CEUX
GENMAB A/S	02-Apr-2025	15:13:26 PM	12	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:13:26 PM	51	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:13:26 PM	46	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:13:27 PM	6	1269.00	AQEU
GENMAB A/S	02-Apr-2025	15:14:25 PM	37	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:25 PM	14	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:25 PM	51	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:25 PM	7	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:26 PM	51	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:26 PM	11	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:26 PM	6	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:14:35 PM	18	1269.00	AQEU
GENMAB A/S	02-Apr-2025	15:15:04 PM	15	1269.00	TQEX
GENMAB A/S	02-Apr-2025	15:15:04 PM	8	1269.00	TQEX
GENMAB A/S	02-Apr-2025	15:15:05 PM	8	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:16:26 PM	5	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:16:28 PM	6	1269.50	XCSE
GENMAB A/S	02-Apr-2025	15:17:26 PM	24	1269.00	TQEX
GENMAB A/S	02-Apr-2025	15:17:26 PM	14	1269.00	AQEU
GENMAB A/S	02-Apr-2025	15:17:26 PM	10	1269.00	AQEU
GENMAB A/S	02-Apr-2025	15:17:26 PM	85	1269.00	CEUX
GENMAB A/S	02-Apr-2025	15:17:27 PM	51	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:17:27 PM	6	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:17:27 PM	32	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:17:27 PM	83	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:18:21 PM	36	1269.00	CEUX
GENMAB A/S	02-Apr-2025	15:18:26 PM	3	1269.00	CEUX
GENMAB A/S	02-Apr-2025	15:18:39 PM	23	1269.50	AQEU
GENMAB A/S	02-Apr-2025	15:18:57 PM	36	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:18:57 PM	6	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:18:57 PM	36	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:18:57 PM	11	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:18:57 PM	12	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:19:03 PM	84	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	51	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	30	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	14	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	14	1269.00	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	20	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	60	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:03 PM	23	1269.00	TQEX
GENMAB A/S	02-Apr-2025	15:19:03 PM	85	1269.00	CEUX
GENMAB A/S	02-Apr-2025	15:19:05 PM	16	1268.50	XCSE

162

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:19:08 PM	11	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:08 PM	4	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:11 PM	4	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:11 PM	3	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:14 PM	48	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:14 PM	4	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:14 PM	2	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:21 PM	4	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:21 PM	39	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:21 PM	2	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:21 PM	85	1267.50	XCSE
GENMAB A/S	02-Apr-2025	15:19:21 PM	16	1268.00	TQEX
GENMAB A/S	02-Apr-2025	15:19:21 PM	13	1268.00	TQEX
GENMAB A/S	02-Apr-2025	15:19:21 PM	82	1268.00	CEUX
GENMAB A/S	02-Apr-2025	15:19:23 PM	20	1267.00	CEUX
GENMAB A/S	02-Apr-2025	15:19:23 PM	54	1267.00	CEUX
GENMAB A/S	02-Apr-2025	15:19:23 PM	7	1267.00	CEUX
GENMAB A/S	02-Apr-2025	15:20:26 PM	13	1267.50	XCSE
GENMAB A/S	02-Apr-2025	15:20:26 PM	73	1267.00	XCSE
GENMAB A/S	02-Apr-2025	15:21:26 PM	9	1267.00	XCSE
GENMAB A/S	02-Apr-2025	15:21:26 PM	5	1267.00	AQEU
GENMAB A/S	02-Apr-2025	15:21:26 PM	24	1267.00	CEUX
GENMAB A/S	02-Apr-2025	15:22:51 PM	30	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:22:51 PM	38	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:51 PM	43	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:51 PM	30	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:51 PM	23	1268.50	TQEX
GENMAB A/S	02-Apr-2025	15:22:51 PM	25	1268.00	AQEU
GENMAB A/S	02-Apr-2025	15:22:51 PM	80	1268.50	CEUX
GENMAB A/S	02-Apr-2025	15:22:53 PM	1	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:59 PM	31	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:59 PM	17	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:59 PM	51	1268.00	XCSE
GENMAB A/S	02-Apr-2025	15:22:59 PM	23	1267.50	TQEX
GENMAB A/S	02-Apr-2025	15:22:59 PM	70	1267.50	CEUX
GENMAB A/S	02-Apr-2025	15:22:59 PM	10	1267.50	CEUX
GENMAB A/S	02-Apr-2025	15:23:12 PM	83	1267.00	XCSE
GENMAB A/S	02-Apr-2025	15:25:08 PM	37	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:08 PM	11	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:08 PM	26	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:08 PM	11	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:26 PM	7	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:27 PM	14	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:27 PM	1	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:44 PM	13	1268.50	XCSE

163

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:25:44 PM	34	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:44 PM	51	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:44 PM	3	1268.50	XCSE
GENMAB A/S	02-Apr-2025	15:25:47 PM	24	1268.50	CEUX
GENMAB A/S	02-Apr-2025	15:25:47 PM	16	1268.50	CEUX
GENMAB A/S	02-Apr-2025	15:25:47 PM	34	1268.50	CEUX
GENMAB A/S	02-Apr-2025	15:27:50 PM	23	1269.00	CEUX
GENMAB A/S	02-Apr-2025	15:27:50 PM	18	1269.00	CEUX
GENMAB A/S	02-Apr-2025	15:28:06 PM	28	1270.00	XCSE
GENMAB A/S	02-Apr-2025	15:28:07 PM	11	1270.00	XCSE
GENMAB A/S	02-Apr-2025	15:28:22 PM	36	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:28:22 PM	6	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:28:22 PM	6	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:28:22 PM	7	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:28:26 PM	11	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:29:13 PM	78	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:29:13 PM	7	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:29:22 PM	36	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:29:26 PM	5	1270.00	XCSE
GENMAB A/S	02-Apr-2025	15:29:26 PM	3	1270.00	CEUX
GENMAB A/S	02-Apr-2025	15:29:30 PM	7	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:29:30 PM	6	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:29:30 PM	34	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:29:33 PM	80	1270.50	XCSE
GENMAB A/S	02-Apr-2025	15:29:33 PM	42	1270.50	TQEX
GENMAB A/S	02-Apr-2025	15:29:33 PM	18	1270.50	AQEU
GENMAB A/S	02-Apr-2025	15:29:33 PM	26	1270.50	CEUX
GENMAB A/S	02-Apr-2025	15:29:34 PM	22	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:29:34 PM	12	1271.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:00 PM	36	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:30:00 PM	18	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:30:00 PM	21	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:30:00 PM	8	1272.00	CEUX
GENMAB A/S	02-Apr-2025	15:30:02 PM	82	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	51	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	24	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	28	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	6	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	50	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	15	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:02 PM	34	1273.00	AQEU
GENMAB A/S	02-Apr-2025	15:30:02 PM	84	1273.00	CEUX
GENMAB A/S	02-Apr-2025	15:30:04 PM	15	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:04 PM	28	1273.00	XCSE
GENMAB A/S	02-Apr-2025	15:30:06 PM	24	1273.50	AQEU

164

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:30:36 PM	38	1274.50	XCSE
GENMAB A/S	02-Apr-2025	15:30:36 PM	20	1274.50	XCSE
GENMAB A/S	02-Apr-2025	15:30:36 PM	51	1274.50	XCSE
GENMAB A/S	02-Apr-2025	15:30:37 PM	12	1274.50	XCSE
GENMAB A/S	02-Apr-2025	15:30:53 PM	10	1275.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:03 PM	81	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:03 PM	3	1275.50	AQEU
GENMAB A/S	02-Apr-2025	15:31:03 PM	24	1275.50	AQEU
GENMAB A/S	02-Apr-2025	15:31:03 PM	36	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:31:04 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:04 PM	12	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:04 PM	14	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:04 PM	51	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:04 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:04 PM	51	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:05 PM	24	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:05 PM	59	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:05 PM	49	1275.00	TQEX
GENMAB A/S	02-Apr-2025	15:31:05 PM	25	1275.50	AQEU
GENMAB A/S	02-Apr-2025	15:31:05 PM	85	1275.00	CEUX
GENMAB A/S	02-Apr-2025	15:31:05 PM	35	1275.00	CEUX
GENMAB A/S	02-Apr-2025	15:31:05 PM	36	1275.50	CEUX
GENMAB A/S	02-Apr-2025	15:31:05 PM	6	1275.50	CEUX
GENMAB A/S	02-Apr-2025	15:31:05 PM	7	1275.50	CEUX
GENMAB A/S	02-Apr-2025	15:31:07 PM	30	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:07 PM	51	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:07 PM	15	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:07 PM	13	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:07 PM	32	1275.00	CEUX
GENMAB A/S	02-Apr-2025	15:31:07 PM	54	1275.00	CEUX
GENMAB A/S	02-Apr-2025	15:31:18 PM	7	1275.00	AQEU
GENMAB A/S	02-Apr-2025	15:31:27 PM	7	1275.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:27 PM	51	1275.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:27 PM	16	1275.00	AQEU
GENMAB A/S	02-Apr-2025	15:31:39 PM	2	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:39 PM	59	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:39 PM	18	1276.00	TQEX
GENMAB A/S	02-Apr-2025	15:31:39 PM	26	1276.00	TQEX
GENMAB A/S	02-Apr-2025	15:31:44 PM	38	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:45 PM	32	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:45 PM	51	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:45 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:45 PM	13	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:45 PM	2	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	9	1277.50	XCSE

165

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:31:46 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	51	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	13	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	28	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	13	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	32	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:46 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	46	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	49	1277.50	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	27	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	51	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	8	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	5	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	51	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	28	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:48 PM	31	1277.00	TQEX
GENMAB A/S	02-Apr-2025	15:31:48 PM	84	1276.50	CEUX
GENMAB A/S	02-Apr-2025	15:31:49 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:49 PM	28	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:49 PM	51	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:49 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:31:49 PM	5	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:00 PM	22	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:00 PM	70	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:00 PM	29	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:00 PM	10	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:00 PM	29	1276.00	TQEX
GENMAB A/S	02-Apr-2025	15:32:01 PM	82	1275.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:01 PM	29	1275.00	TQEX
GENMAB A/S	02-Apr-2025	15:32:01 PM	86	1275.00	CEUX
GENMAB A/S	02-Apr-2025	15:32:02 PM	86	1274.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:02 PM	82	1274.00	CEUX
GENMAB A/S	02-Apr-2025	15:32:08 PM	43	1277.00	CEUX
GENMAB A/S	02-Apr-2025	15:32:08 PM	36	1277.00	CEUX
GENMAB A/S	02-Apr-2025	15:32:19 PM	38	1278.00	CEUX

166

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:32:31 PM	45	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:31 PM	44	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:32:31 PM	87	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:32:31 PM	14	1279.50	TQEX
GENMAB A/S	02-Apr-2025	15:32:31 PM	15	1279.50	TQEX
GENMAB A/S	02-Apr-2025	15:32:31 PM	24	1279.50	AQEU
GENMAB A/S	02-Apr-2025	15:32:37 PM	79	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:32:46 PM	77	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:03 PM	19	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:33:03 PM	52	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:33:03 PM	13	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:33:17 PM	30	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:17 PM	51	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:32 PM	87	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:33:32 PM	51	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:32 PM	24	1281.00	AQEU
GENMAB A/S	02-Apr-2025	15:33:39 PM	29	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:33:39 PM	57	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:33:39 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:33:39 PM	27	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:39 PM	51	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:39 PM	20	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:33:39 PM	23	1280.50	TQEX
GENMAB A/S	02-Apr-2025	15:33:39 PM	23	1279.50	TQEX
GENMAB A/S	02-Apr-2025	15:33:39 PM	28	1280.00	AQEU
GENMAB A/S	02-Apr-2025	15:33:39 PM	23	1279.50	AQEU
GENMAB A/S	02-Apr-2025	15:33:39 PM	23	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:33:39 PM	64	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:33:42 PM	87	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:33:42 PM	61	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:33:42 PM	19	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:34:11 PM	6	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:34:26 PM	7	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:34:26 PM	9	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:33 PM	82	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:34:33 PM	45	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:34:33 PM	50	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:34:33 PM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:34:33 PM	8	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:33 PM	44	1279.50	TQEX
GENMAB A/S	02-Apr-2025	15:34:33 PM	35	1279.00	AQEU
GENMAB A/S	02-Apr-2025	15:34:33 PM	84	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:34:45 PM	39	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	26	1278.50	XCSE

167

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:34:45 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	12	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:45 PM	24	1278.00	CEUX
GENMAB A/S	02-Apr-2025	15:34:51 PM	1	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:51 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:34:51 PM	13	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:35:01 PM	25	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:35:01 PM	15	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:35:01 PM	6	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:35:01 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:35:01 PM	39	1278.50	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	85	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	30	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	30	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	2	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	25	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:35:30 PM	23	1279.50	TQEX
GENMAB A/S	02-Apr-2025	15:35:30 PM	86	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:35:31 PM	15	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:27 PM	8	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:29 PM	12	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:29 PM	16	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:29 PM	3	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:29 PM	1	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:29 PM	72	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:29 PM	13	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:36:30 PM	22	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	14	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	11	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	13	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	15	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	34	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	13	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:30 PM	10	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:34 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:34 PM	6	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:34 PM	17	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:36:34 PM	29	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:36:34 PM	40	1281.00	XCSE

168

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:36:46 PM	85	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:37:14 PM	44	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:37:14 PM	65	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:37:29 PM	5	1282.50	TQEX
GENMAB A/S	02-Apr-2025	15:37:29 PM	20	1282.50	TQEX
GENMAB A/S	02-Apr-2025	15:37:29 PM	82	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:37:30 PM	23	1282.50	AQEU
GENMAB A/S	02-Apr-2025	15:37:33 PM	86	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:37:51 PM	39	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:37:51 PM	9	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:37:51 PM	23	1281.50	TQEX
GENMAB A/S	02-Apr-2025	15:37:51 PM	80	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:38:39 PM	85	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:38:39 PM	19	1281.50	TQEX
GENMAB A/S	02-Apr-2025	15:38:39 PM	82	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:38:56 PM	38	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:38:56 PM	29	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:38:56 PM	2	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:38:56 PM	39	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:39:01 PM	27	1281.50	TQEX
GENMAB A/S	02-Apr-2025	15:39:01 PM	85	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:39:27 PM	85	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:39:27 PM	2	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:39:27 PM	21	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:39:30 PM	35	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:02 PM	2	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:40:26 PM	10	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	39	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	5	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	28	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	37	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	87	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	39	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	14	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	13	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	12	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:37 PM	24	1281.00	TQEX
GENMAB A/S	02-Apr-2025	15:40:37 PM	1	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	10	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	13	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	2	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	43	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	84	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	66	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:40:37 PM	15	1280.50	CEUX

169

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:40:38 PM	41	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:39 PM	46	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:40:39 PM	39	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:40:39 PM	14	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:40:39 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:40:39 PM	23	1280.00	TQEX
GENMAB A/S	02-Apr-2025	15:40:39 PM	23	1280.50	AQEU
GENMAB A/S	02-Apr-2025	15:40:39 PM	83	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:40:41 PM	60	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:40:45 PM	27	1279.50	AQEU
GENMAB A/S	02-Apr-2025	15:41:00 PM	2	1282.50	AQEU
GENMAB A/S	02-Apr-2025	15:41:00 PM	22	1282.50	AQEU
GENMAB A/S	02-Apr-2025	15:41:01 PM	38	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:41:07 PM	46	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:41:07 PM	73	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:41:08 PM	3	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:41:08 PM	39	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:41:26 PM	23	1281.00	TQEX
GENMAB A/S	02-Apr-2025	15:41:26 PM	23	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:41:41 PM	85	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:41:41 PM	39	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:41:41 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:41:41 PM	13	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:41:41 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:41:42 PM	51	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:41:42 PM	11	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:42:10 PM	83	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:42:11 PM	26	1280.50	AQEU
GENMAB A/S	02-Apr-2025	15:42:27 PM	28	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:42:27 PM	2	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:42:27 PM	13	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:42:27 PM	40	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:42:34 PM	10	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:42:35 PM	8	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:04 PM	23	1281.00	TQEX
GENMAB A/S	02-Apr-2025	15:43:04 PM	19	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:43:04 PM	49	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:43:09 PM	87	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:09 PM	39	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:09 PM	20	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:09 PM	39	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:43:09 PM	11	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:43:09 PM	33	1280.50	AQEU
GENMAB A/S	02-Apr-2025	15:43:37 PM	84	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:37 PM	45	1280.50	XCSE

170

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:43:37 PM	24	1280.50	AQEU
GENMAB A/S	02-Apr-2025	15:43:37 PM	48	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:43:38 PM	51	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:38 PM	30	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:43:38 PM	24	1279.50	TQEX
GENMAB A/S	02-Apr-2025	15:43:56 PM	15	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:43:56 PM	37	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:44:14 PM	21	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:44:15 PM	22	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:44:15 PM	38	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:44:22 PM	13	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:44:22 PM	39	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:44:22 PM	13	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:44:22 PM	12	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:44:22 PM	30	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:44:22 PM	2	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:44:25 PM	1	1279.50	CEUX
GENMAB A/S	02-Apr-2025	15:44:28 PM	83	1279.50	CEUX
GENMAB A/S	02-Apr-2025	15:44:41 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:16 PM	44	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:16 PM	45	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:16 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:16 PM	23	1280.50	TQEX
GENMAB A/S	02-Apr-2025	15:45:48 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:48 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:48 PM	44	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	83	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	39	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	11	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	30	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	4	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:45:55 PM	18	1280.00	AQEU
GENMAB A/S	02-Apr-2025	15:45:55 PM	10	1280.00	AQEU
GENMAB A/S	02-Apr-2025	15:45:55 PM	22	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:45:55 PM	56	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:46:02 PM	9	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:46:27 PM	69	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:46:28 PM	41	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:46:28 PM	33	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:46:28 PM	9	1281.00	CEUX
GENMAB A/S	02-Apr-2025	15:46:57 PM	80	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:46:57 PM	6	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:46:57 PM	17	1280.50	TQEX

171

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:46:57 PM	7	1280.50	TQEX
GENMAB A/S	02-Apr-2025	15:47:14 PM	18	1280.00	CEUX
GENMAB A/S	02-Apr-2025	15:47:22 PM	25	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:47:22 PM	15	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:47:22 PM	10	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:47:35 PM	39	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:47:36 PM	46	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:10 PM	35	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:48:10 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:48:10 PM	37	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:48:10 PM	7	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:48:10 PM	82	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:48:11 PM	14	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	13	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	39	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	27	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	16	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	13	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	14	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:11 PM	82	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:12 PM	34	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:12 PM	11	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:12 PM	39	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:12 PM	14	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:12 PM	11	1283.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:25 PM	44	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:31 PM	37	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:48:31 PM	28	1282.50	TQEX
GENMAB A/S	02-Apr-2025	15:48:31 PM	67	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:48:31 PM	13	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:49:12 PM	84	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:12 PM	39	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:12 PM	29	1281.50	TQEX
GENMAB A/S	02-Apr-2025	15:49:12 PM	81	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:49:26 PM	4	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:27 PM	11	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:27 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:27 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:28 PM	14	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:31 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:49:40 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:03 PM	68	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:03 PM	30	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	66	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	16	1281.50	XCSE

172

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:50:04 PM	39	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	9	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	11	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	24	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:50:04 PM	23	1281.50	TQEX
GENMAB A/S	02-Apr-2025	15:50:04 PM	80	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:50:04 PM	5	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:50:19 PM	18	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:50:21 PM	11	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:21 PM	12	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:32 PM	30	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:32 PM	39	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:32 PM	13	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:32 PM	11	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:32 PM	16	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:32 PM	28	1282.00	TQEX
GENMAB A/S	02-Apr-2025	15:50:32 PM	67	1282.00	CEUX
GENMAB A/S	02-Apr-2025	15:50:58 PM	6	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:58 PM	39	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:58 PM	23	1282.00	TQEX
GENMAB A/S	02-Apr-2025	15:50:59 PM	11	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:59 PM	12	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:59 PM	39	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:59 PM	14	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:59 PM	13	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:50:59 PM	20	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:51:03 PM	16	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:51:13 PM	20	1282.00	TQEX
GENMAB A/S	02-Apr-2025	15:51:14 PM	19	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:51:41 PM	52	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:51:41 PM	8	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:51:41 PM	2	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:51:41 PM	1	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:51:41 PM	91	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:51:42 PM	52	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:51:42 PM	1	1282.50	XCSE
GENMAB A/S	02-Apr-2025	15:51:43 PM	17	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:51:59 PM	11	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:51:59 PM	39	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:51:59 PM	24	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:01 PM	39	1284.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:01 PM	11	1284.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:01 PM	37	1284.00	XCSE

173

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:53:01 PM	1	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:01 PM	15	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:01 PM	64	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:01 PM	23	1283.00	TQEX
GENMAB A/S	02-Apr-2025	15:53:01 PM	23	1283.50	AQEU
GENMAB A/S	02-Apr-2025	15:53:01 PM	25	1283.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:01 PM	23	1283.00	CEUX
GENMAB A/S	02-Apr-2025	15:53:01 PM	25	1283.00	CEUX
GENMAB A/S	02-Apr-2025	15:53:03 PM	32	1283.00	CEUX
GENMAB A/S	02-Apr-2025	15:53:10 PM	38	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:10 PM	49	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:11 PM	45	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:12 PM	11	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:12 PM	22	1283.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:14 PM	20	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:14 PM	9	1282.50	TQEX
GENMAB A/S	02-Apr-2025	15:53:14 PM	14	1282.50	TQEX
GENMAB A/S	02-Apr-2025	15:53:14 PM	80	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:14 PM	7	1282.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:23 PM	24	1282.00	AQEU
GENMAB A/S	02-Apr-2025	15:53:26 PM	39	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:26 PM	21	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:26 PM	13	1282.00	XCSE
GENMAB A/S	02-Apr-2025	15:53:26 PM	85	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:53:26 PM	28	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:26 PM	59	1281.50	CEUX
GENMAB A/S	02-Apr-2025	15:53:32 PM	24	1281.00	AQEU
GENMAB A/S	02-Apr-2025	15:53:50 PM	24	1281.00	TQEX
GENMAB A/S	02-Apr-2025	15:53:53 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:53:55 PM	17	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:53:59 PM	27	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:53:59 PM	12	1281.50	XCSE
GENMAB A/S	02-Apr-2025	15:54:00 PM	12	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:54:00 PM	1	1281.00	XCSE
GENMAB A/S	02-Apr-2025	15:54:00 PM	16	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:54:02 PM	25	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:54:05 PM	16	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:54:10 PM	23	1280.50	XCSE
GENMAB A/S	02-Apr-2025	15:54:10 PM	87	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:54:24 PM	28	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:54:51 PM	17	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:54:51 PM	23	1280.00	AQEU
GENMAB A/S	02-Apr-2025	15:54:51 PM	56	1280.50	CEUX
GENMAB A/S	02-Apr-2025	15:55:00 PM	19	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:00 PM	39	1280.00	XCSE

174

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:55:00 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:00 PM	14	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:00 PM	26	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:17 PM	18	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:17 PM	35	1279.50	AQEU
GENMAB A/S	02-Apr-2025	15:55:27 PM	12	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	39	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	13	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	11	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	28	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	6	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	28	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:27 PM	9	1280.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:36 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:36 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:36 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:36 PM	39	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:36 PM	24	1279.50	AQEU
GENMAB A/S	02-Apr-2025	15:55:39 PM	10	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:55:41 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:41 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:41 PM	19	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:41 PM	39	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:41 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:41 PM	15	1279.50	XCSE
GENMAB A/S	02-Apr-2025	15:55:41 PM	44	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:55:59 PM	3	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:59 PM	35	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:59 PM	20	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:59 PM	10	1279.00	XCSE
GENMAB A/S	02-Apr-2025	15:55:59 PM	26	1279.00	TQEX
GENMAB A/S	02-Apr-2025	15:55:59 PM	15	1278.50	AQEU
GENMAB A/S	02-Apr-2025	15:55:59 PM	9	1278.50	AQEU
GENMAB A/S	02-Apr-2025	15:55:59 PM	26	1279.00	CEUX
GENMAB A/S	02-Apr-2025	15:56:05 PM	19	1278.50	AQEU
GENMAB A/S	02-Apr-2025	15:56:05 PM	8	1278.50	AQEU
GENMAB A/S	02-Apr-2025	15:56:05 PM	83	1278.50	CEUX
GENMAB A/S	02-Apr-2025	15:56:17 PM	20	1278.00	XCSE
GENMAB A/S	02-Apr-2025	15:56:17 PM	19	1278.00	XCSE
GENMAB A/S	02-Apr-2025	15:56:17 PM	20	1278.00	XCSE
GENMAB A/S	02-Apr-2025	15:56:17 PM	22	1278.00	XCSE
GENMAB A/S	02-Apr-2025	15:56:17 PM	4	1278.00	TQEX
GENMAB A/S	02-Apr-2025	15:56:17 PM	17	1278.00	TQEX
GENMAB A/S	02-Apr-2025	15:56:17 PM	3	1278.00	TQEX
GENMAB A/S	02-Apr-2025	15:56:18 PM	70	1277.50	CEUX

175

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:56:18 PM	9	1277.50	CEUX
GENMAB A/S	02-Apr-2025	15:56:21 PM	81	1276.50	XCSE
GENMAB A/S	02-Apr-2025	15:56:21 PM	23	1277.00	TQEX
GENMAB A/S	02-Apr-2025	15:56:21 PM	28	1277.00	AQEU
GENMAB A/S	02-Apr-2025	15:56:21 PM	20	1276.00	AQEU
GENMAB A/S	02-Apr-2025	15:56:21 PM	4	1276.00	AQEU
GENMAB A/S	02-Apr-2025	15:56:21 PM	15	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:56:21 PM	24	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:56:25 PM	3	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:56:27 PM	15	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:56:42 PM	10	1276.50	AQEU
GENMAB A/S	02-Apr-2025	15:56:58 PM	22	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:56:58 PM	19	1277.50	AQEU
GENMAB A/S	02-Apr-2025	15:56:58 PM	14	1277.50	AQEU
GENMAB A/S	02-Apr-2025	15:57:00 PM	2	1277.50	AQEU
GENMAB A/S	02-Apr-2025	15:57:19 PM	65	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:57:19 PM	60	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:57:19 PM	39	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:57:19 PM	10	1277.00	XCSE
GENMAB A/S	02-Apr-2025	15:57:19 PM	9	1277.00	CEUX
GENMAB A/S	02-Apr-2025	15:57:19 PM	70	1277.00	CEUX
GENMAB A/S	02-Apr-2025	15:57:24 PM	8	1276.50	AQEU
GENMAB A/S	02-Apr-2025	15:57:52 PM	4	1276.50	AQEU
GENMAB A/S	02-Apr-2025	15:57:59 PM	7	1276.50	AQEU
GENMAB A/S	02-Apr-2025	15:58:26 PM	9	1276.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:01 PM	30	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:59:26 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:26 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:26 PM	44	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:26 PM	39	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:26 PM	43	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:32 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:32 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:32 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:33 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:33 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:33 PM	14	1276.00	XCSE
GENMAB A/S	02-Apr-2025	15:59:33 PM	23	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:33 PM	46	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:35 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:35 PM	2	1275.50	XCSE
GENMAB A/S	02-Apr-2025	15:59:37 PM	24	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:59:37 PM	21	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:59:37 PM	53	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:59:37 PM	6	1276.00	CEUX

176

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	15:59:37 PM	5	1276.00	CEUX
GENMAB A/S	02-Apr-2025	15:59:59 PM	31	1275.00	TQEX
GENMAB A/S	02-Apr-2025	15:59:59 PM	31	1275.00	AQEU
GENMAB A/S	02-Apr-2025	15:59:59 PM	80	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:00:01 PM	14	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:00:09 PM	9	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:00:14 PM	54	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:14 PM	9	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:14 PM	32	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:14 PM	14	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:26 PM	5	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:00:27 PM	86	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:00:28 PM	8	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:00:40 PM	2	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:40 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:40 PM	24	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:00:40 PM	35	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:00:40 PM	34	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:00:40 PM	86	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:00:41 PM	1	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:53 PM	6	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:00:59 PM	31	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:01:00 PM	44	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:01:19 PM	5	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:01:28 PM	6	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:01:28 PM	24	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:01:28 PM	23	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:01:30 PM	7	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:01:30 PM	17	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:01:35 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:01:35 PM	18	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:05 PM	24	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:05 PM	58	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:05 PM	39	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:05 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:05 PM	40	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:02:05 PM	41	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:02:05 PM	3	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:02:15 PM	39	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:15 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:15 PM	46	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:15 PM	6	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:02:15 PM	13	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:02:27 PM	87	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:27 PM	43	1275.50	CEUX

177

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:02:27 PM	39	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:02:32 PM	39	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:32 PM	11	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:32 PM	23	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:02:33 PM	10	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:33 PM	39	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:34 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:34 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	14	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	11	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:35 PM	39	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	11	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	82	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	1	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	14	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	11	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:36 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	14	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	14	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	11	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	12	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	2	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	86	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:02:37 PM	16	1274.50	TQEX
GENMAB A/S	02-Apr-2025	16:02:37 PM	85	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:03:07 PM	80	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:07 PM	29	1277.00	TQEX
GENMAB A/S	02-Apr-2025	16:03:07 PM	32	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:03:09 PM	53	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:03:09 PM	15	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:03:21 PM	5	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:21 PM	39	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:21 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:21 PM	21	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:21 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:21 PM	10	1277.00	XCSE

178

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:03:21 PM	9	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:03:21 PM	41	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:03:25 PM	11	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:03:27 PM	19	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:03:41 PM	39	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:41 PM	14	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:41 PM	15	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:51 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:03:51 PM	10	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:04:19 PM	19	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:19 PM	23	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	30	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	9	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	39	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	6	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:52 PM	23	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:04:53 PM	7	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	39	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:04:53 PM	15	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:05:08 PM	10	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:05:08 PM	25	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:05:13 PM	22	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:14 PM	12	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:23 PM	15	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:25 PM	11	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:26 PM	13	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:28 PM	10	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:41 PM	8	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:41 PM	14	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:42 PM	11	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:42 PM	39	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:42 PM	14	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:42 PM	14	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:05:47 PM	19	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:05:47 PM	30	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:05:47 PM	6	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:05:47 PM	49	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:06:27 PM	38	1278.00	XCSE

179

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:06:27 PM	86	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:06:37 PM	52	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:06:37 PM	4	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:06:37 PM	10	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:06:37 PM	9	1277.50	TQEX
GENMAB A/S	02-Apr-2025	16:06:37 PM	21	1277.50	TQEX
GENMAB A/S	02-Apr-2025	16:06:37 PM	33	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:06:37 PM	82	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:07:07 PM	46	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:07:16 PM	12	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:07:17 PM	43	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:07:17 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:07:17 PM	25	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:07:34 PM	22	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:08:25 PM	28	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:08:25 PM	37	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:08:25 PM	36	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:08:31 PM	36	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:08:31 PM	35	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:08:32 PM	86	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:32 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:32 PM	39	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:32 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:32 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:32 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:32 PM	32	1276.50	TQEX
GENMAB A/S	02-Apr-2025	16:08:32 PM	23	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:08:32 PM	76	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:08:33 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	39	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	31	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	15	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	68	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:08:33 PM	32	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:08:33 PM	40	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:08:33 PM	19	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:08:56 PM	6	1274.50	AQEU
GENMAB A/S	02-Apr-2025	16:09:04 PM	66	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:04 PM	17	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:04 PM	20	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:04 PM	16	1274.50	AQEU
GENMAB A/S	02-Apr-2025	16:09:04 PM	1	1274.50	AQEU
GENMAB A/S	02-Apr-2025	16:09:04 PM	31	1274.50	CEUX

180

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:09:04 PM	53	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:09:07 PM	81	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:14 PM	49	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:14 PM	37	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:14 PM	35	1274.00	AQEU
GENMAB A/S	02-Apr-2025	16:09:27 PM	39	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:27 PM	43	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:09:27 PM	36	1274.50	TQEX
GENMAB A/S	02-Apr-2025	16:09:27 PM	4	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:09:27 PM	40	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:09:27 PM	63	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:09:27 PM	16	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:10:11 PM	77	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:10:11 PM	9	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:10:23 PM	81	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:10:23 PM	44	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:10:23 PM	40	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:10:23 PM	2	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:10:23 PM	42	1274.00	AQEU
GENMAB A/S	02-Apr-2025	16:10:26 PM	61	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:10:26 PM	19	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:10:48 PM	34	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:10:48 PM	14	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:11:28 PM	12	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:28 PM	48	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:28 PM	47	1274.00	AQEU
GENMAB A/S	02-Apr-2025	16:11:30 PM	30	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:30 PM	12	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:30 PM	48	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:30 PM	13	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:35 PM	4	1273.50	TQEX
GENMAB A/S	02-Apr-2025	16:11:35 PM	19	1273.50	TQEX
GENMAB A/S	02-Apr-2025	16:11:35 PM	53	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:11:41 PM	45	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:41 PM	23	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:11:51 PM	51	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:12:03 PM	49	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:12:03 PM	6	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:12:11 PM	6	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:12:11 PM	48	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:12:11 PM	55	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:12:31 PM	37	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:12:31 PM	28	1273.50	CEUX
GENMAB A/S	02-Apr-2025	16:13:05 PM	15	1274.00	TQEX
GENMAB A/S	02-Apr-2025	16:13:05 PM	46	1274.00	AQEU

181

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:13:14 PM	68	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:13:14 PM	13	1274.00	XCSE
GENMAB A/S	02-Apr-2025	16:13:14 PM	8	1274.00	TQEX
GENMAB A/S	02-Apr-2025	16:13:18 PM	48	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:18 PM	23	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:13:18 PM	1	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:13:28 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:28 PM	2	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:28 PM	48	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:28 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:28 PM	11	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:28 PM	9	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:28 PM	15	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:13:44 PM	42	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:13:52 PM	23	1276.00	TQEX
GENMAB A/S	02-Apr-2025	16:14:05 PM	30	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:14:05 PM	3	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:14:05 PM	1	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:14:05 PM	13	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:14:16 PM	13	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:16 PM	15	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:16 PM	11	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:16 PM	11	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:16 PM	59	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:20 PM	48	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:20 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:20 PM	14	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:20 PM	14	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:24 PM	80	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:14:24 PM	16	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:14:24 PM	52	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:14:34 PM	42	1274.50	AQEU
GENMAB A/S	02-Apr-2025	16:14:56 PM	42	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:56 PM	40	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:56 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:14:56 PM	6	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:15:04 PM	36	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:15:18 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:15:18 PM	48	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:15:44 PM	38	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:16:14 PM	41	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:16:14 PM	29	1276.50	TQEX
GENMAB A/S	02-Apr-2025	16:16:24 PM	41	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:16:26 PM	7	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:16:41 PM	79	1277.00	XCSE

182

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:16:42 PM	10	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:44 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:46 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:56 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:56 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:56 PM	17	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:56 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:56 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:59 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:16:59 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:03 PM	59	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:20 PM	17	1277.00	TQEX
GENMAB A/S	02-Apr-2025	16:17:26 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:26 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:26 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:26 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:26 PM	53	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:26 PM	8	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:26 PM	32	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:26 PM	35	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:26 PM	3	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:26 PM	7	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:26 PM	7	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:17:44 PM	84	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:17:44 PM	82	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:17:44 PM	5	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:17:44 PM	40	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:17:58 PM	85	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:17:58 PM	25	1278.00	TQEX
GENMAB A/S	02-Apr-2025	16:17:58 PM	35	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:17:58 PM	87	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:18:00 PM	35	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:18:25 PM	80	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:18:25 PM	86	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:18:30 PM	56	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:18:33 PM	19	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:19:05 PM	42	1277.00	TQEX
GENMAB A/S	02-Apr-2025	16:19:05 PM	34	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:19:05 PM	34	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:19:08 PM	33	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:19:11 PM	36	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:19:11 PM	13	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:19:12 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:19:12 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:19:12 PM	13	1277.00	XCSE

183

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:19:12 PM	24	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:19:12 PM	47	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:09 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:20:09 PM	34	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:41 PM	45	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:41 PM	6	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:41 PM	28	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:20:42 PM	48	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	30	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:42 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:43 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:43 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:43 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:43 PM	49	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:20:52 PM	33	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:20:52 PM	37	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:21:01 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:21:01 PM	30	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:01 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:01 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:01 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:01 PM	29	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:21 PM	77	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:21 PM	4	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:21 PM	4	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:21:21 PM	19	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:21:21 PM	45	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:21:54 PM	41	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:21:54 PM	29	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:22:00 PM	13	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:22:12 PM	7	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:22:15 PM	9	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:22:26 PM	86	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:22:26 PM	36	1277.00	TQEX
GENMAB A/S	02-Apr-2025	16:22:26 PM	28	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:22:26 PM	29	1276.00	AQEU
GENMAB A/S	02-Apr-2025	16:22:26 PM	80	1277.00	CEUX

184

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:22:30 PM	32	1276.50	AQEU
GENMAB A/S	02-Apr-2025	16:22:32 PM	42	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:22:49 PM	27	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:23:08 PM	80	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:23:08 PM	36	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:23:08 PM	47	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:23:09 PM	33	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:23:21 PM	44	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:23:21 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:23:21 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:23:21 PM	86	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:23:21 PM	24	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:23:35 PM	43	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:23:44 PM	29	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:23:44 PM	4	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:24:24 PM	43	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:24:24 PM	36	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:24:49 PM	71	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:24:51 PM	80	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:24:51 PM	17	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:24:51 PM	14	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:24:51 PM	84	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:24:54 PM	23	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:25:05 PM	3	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:05 PM	15	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:05 PM	43	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:25:06 PM	15	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	15	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	10	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:14 PM	24	1276.50	TQEX
GENMAB A/S	02-Apr-2025	16:25:14 PM	23	1276.50	AQEU
GENMAB A/S	02-Apr-2025	16:25:14 PM	25	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:25:15 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:15 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:25:16 PM	31	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:25:44 PM	31	1277.50	AQEU
GENMAB A/S	02-Apr-2025	16:26:03 PM	82	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:14 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:14 PM	30	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:14 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:14 PM	14	1277.00	XCSE

185

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:26:14 PM	3	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:14 PM	23	1276.50	AQEU
GENMAB A/S	02-Apr-2025	16:26:14 PM	36	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:26:21 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:26:21 PM	48	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:21 PM	12	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:21 PM	12	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:24 PM	87	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:26:24 PM	36	1277.50	TQEX
GENMAB A/S	02-Apr-2025	16:26:24 PM	20	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:26:24 PM	11	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:26:24 PM	36	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:27:02 PM	48	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:02 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:02 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:02 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:14 PM	25	1279.00	AQEU
GENMAB A/S	02-Apr-2025	16:27:14 PM	62	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:27:21 PM	48	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:21 PM	37	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:21 PM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:21 PM	2	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:51 PM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:51 PM	48	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:27:51 PM	34	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:28:24 PM	60	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:28:24 PM	27	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:28:25 PM	15	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:28:25 PM	15	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:28:35 PM	50	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:28:35 PM	24	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:28:42 PM	2	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:29:14 PM	22	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:29:24 PM	36	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:29:24 PM	32	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:29:25 PM	18	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:29:25 PM	28	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:29:25 PM	53	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:29:25 PM	36	1277.50	TQEX
GENMAB A/S	02-Apr-2025	16:29:25 PM	5	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:29:26 PM	13	1277.00	CEUX
GENMAB A/S	02-Apr-2025	16:29:34 PM	23	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:29:34 PM	22	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:29:49 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:29:49 PM	48	1278.50	XCSE

186

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:29:49 PM	9	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:29:57 PM	36	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:29:57 PM	10	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:30:14 PM	41	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:30:14 PM	2	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:30:22 PM	81	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:30:22 PM	38	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:30:22 PM	12	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:30:22 PM	57	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:30:25 PM	30	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:30:25 PM	48	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:30:25 PM	13	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:30:25 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:30:25 PM	7	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:30:25 PM	14	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:30:25 PM	9	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:30:41 PM	23	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:31:05 PM	85	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:31:05 PM	81	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:31:27 PM	78	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:31:27 PM	31	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:31:27 PM	73	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:31:28 PM	40	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:31:28 PM	26	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:31:28 PM	39	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:31:29 PM	28	1277.00	AQEU
GENMAB A/S	02-Apr-2025	16:31:41 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:31:41 PM	23	1277.50	AQEU
GENMAB A/S	02-Apr-2025	16:31:46 PM	28	1277.00	TQEX
GENMAB A/S	02-Apr-2025	16:31:51 PM	46	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:31:51 PM	46	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:11 PM	26	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:11 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:11 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:11 PM	13	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:11 PM	6	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:20 PM	87	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:20 PM	27	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:20 PM	56	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:20 PM	24	1276.50	AQEU
GENMAB A/S	02-Apr-2025	16:32:20 PM	32	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:32:20 PM	51	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:32:20 PM	45	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:32:20 PM	55	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:32:40 PM	7	1275.50	XCSE

187

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:32:40 PM	7	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:40 PM	8	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:40 PM	2	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:32:47 PM	35	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:32:47 PM	32	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:32:48 PM	24	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:33:15 PM	53	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:33:15 PM	20	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:33:39 PM	20	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:33:41 PM	18	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:33:42 PM	3	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:33:42 PM	5	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:33:53 PM	1	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:33:53 PM	31	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:33:53 PM	32	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:34:25 PM	27	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:34:25 PM	23	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:34:27 PM	28	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:34:40 PM	11	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:34:40 PM	12	1275.50	TQEX
GENMAB A/S	02-Apr-2025	16:34:41 PM	9	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:34:41 PM	53	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:34:50 PM	39	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:34:50 PM	45	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:12 PM	23	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:35:19 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:19 PM	26	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:19 PM	35	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:35:19 PM	36	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:35:19 PM	32	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:35:19 PM	19	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:35:20 PM	48	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:20 PM	12	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:20 PM	13	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:20 PM	13	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:20 PM	23	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:20 PM	63	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:20 PM	13	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:44 PM	23	1274.00	AQEU
GENMAB A/S	02-Apr-2025	16:35:44 PM	40	1274.00	CEUX
GENMAB A/S	02-Apr-2025	16:35:54 PM	22	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:54 PM	11	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:54 PM	23	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:54 PM	13	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:54 PM	11	1275.50	XCSE

188

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:35:54 PM	29	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:54 PM	18	1275.00	TQEX
GENMAB A/S	02-Apr-2025	16:35:54 PM	17	1275.00	TQEX
GENMAB A/S	02-Apr-2025	16:35:54 PM	15	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:35:54 PM	23	1275.00	AQEU
GENMAB A/S	02-Apr-2025	16:35:54 PM	43	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:35:54 PM	11	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:35:55 PM	10	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:35:55 PM	75	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:36:11 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:36:11 PM	33	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:36:11 PM	53	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:36:13 PM	33	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:36:14 PM	46	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:36:22 PM	83	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:36:34 PM	23	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:36:44 PM	2	1275.50	AQEU
GENMAB A/S	02-Apr-2025	16:37:27 PM	42	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:37:48 PM	25	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:38:04 PM	32	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:38:11 PM	73	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:38:24 PM	27	1275.00	TQEX
GENMAB A/S	02-Apr-2025	16:38:24 PM	3	1275.00	TQEX
GENMAB A/S	02-Apr-2025	16:38:24 PM	35	1274.50	AQEU
GENMAB A/S	02-Apr-2025	16:38:25 PM	22	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:38:27 PM	9	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:27 PM	16	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:38:35 PM	8	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:38:35 PM	48	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:38:35 PM	12	1274.50	XCSE
GENMAB A/S	02-Apr-2025	16:38:35 PM	30	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:35 PM	15	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:35 PM	4	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:35 PM	40	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:38:35 PM	14	1274.50	CEUX
GENMAB A/S	02-Apr-2025	16:38:36 PM	45	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	44	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	11	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	9	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	4	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	13	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	7	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	18	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	48	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:38:36 PM	12	1275.00	XCSE

189

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:39:08 PM	23	1275.00	TQEX
GENMAB A/S	02-Apr-2025	16:39:08 PM	16	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:39:13 PM	16	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:39:21 PM	38	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:39:21 PM	40	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:40:01 PM	49	1275.00	XCSE
GENMAB A/S	02-Apr-2025	16:40:01 PM	18	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:40:01 PM	17	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:40:01 PM	17	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:40:01 PM	60	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:40:01 PM	40	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:40:01 PM	7	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:40:01 PM	6	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:40:06 PM	20	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:40:11 PM	26	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:40:26 PM	22	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:40:32 PM	11	1275.50	XCSE
GENMAB A/S	02-Apr-2025	16:40:54 PM	38	1275.00	TQEX
GENMAB A/S	02-Apr-2025	16:40:54 PM	44	1275.00	CEUX
GENMAB A/S	02-Apr-2025	16:40:55 PM	34	1275.50	CEUX
GENMAB A/S	02-Apr-2025	16:41:10 PM	6	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	9	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	17	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	10	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	33	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	34	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	12	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	9	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	3	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:10 PM	25	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:41:10 PM	29	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:41:11 PM	10	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	10	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	12	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	14	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:12 PM	14	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:13 PM	14	1276.00	XCSE

190

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:41:13 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:13 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:13 PM	11	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:14 PM	12	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:14 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:14 PM	13	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:14 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:18 PM	28	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:18 PM	29	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:18 PM	48	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:18 PM	4	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:18 PM	42	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:41:18 PM	9	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:41:18 PM	60	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:41:19 PM	16	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	48	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	11	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	8	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	2	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	13	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	48	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	12	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:19 PM	5	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:41:34 PM	40	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:41:34 PM	29	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:42:03 PM	9	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:42:03 PM	48	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:42:03 PM	12	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:42:05 PM	45	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:42:23 PM	45	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:42:26 PM	41	1276.50	AQEU
GENMAB A/S	02-Apr-2025	16:42:44 PM	14	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:42:44 PM	54	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:42:44 PM	62	1276.00	CEUX
GENMAB A/S	02-Apr-2025	16:43:25 PM	50	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:43:25 PM	6	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:43:26 PM	33	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:43:27 PM	31	1276.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:27 PM	10	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:27 PM	25	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:27 PM	9	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:27 PM	14	1276.50	XCSE

191

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:43:27 PM	48	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:27 PM	3	1276.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:27 PM	25	1276.00	TQEX
GENMAB A/S	02-Apr-2025	16:43:29 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:29 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:29 PM	11	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:29 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:29 PM	52	1276.50	CEUX
GENMAB A/S	02-Apr-2025	16:43:29 PM	47	1276.50	AQEU
GENMAB A/S	02-Apr-2025	16:43:32 PM	2	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:32 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:32 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:32 PM	14	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:33 PM	12	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:33 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:33 PM	13	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:33 PM	48	1277.00	XCSE
GENMAB A/S	02-Apr-2025	16:43:36 PM	14	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:36 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:43:36 PM	11	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:07 PM	48	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:07 PM	33	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:07 PM	16	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:07 PM	9	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:07 PM	3	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:07 PM	47	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:44:07 PM	29	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:44:07 PM	6	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:44:07 PM	35	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:44:07 PM	6	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:44:08 PM	23	1278.00	TQEX
GENMAB A/S	02-Apr-2025	16:44:08 PM	15	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:44:12 PM	38	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:12 PM	30	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:12 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:12 PM	15	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:12 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:12 PM	4	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:14 PM	43	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:14 PM	12	1279.00	TQEX
GENMAB A/S	02-Apr-2025	16:44:14 PM	3	1279.00	TQEX
GENMAB A/S	02-Apr-2025	16:44:14 PM	10	1279.00	TQEX
GENMAB A/S	02-Apr-2025	16:44:23 PM	43	1279.00	AQEU
GENMAB A/S	02-Apr-2025	16:44:24 PM	4	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:44 PM	16	1280.00	TQEX

192

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:44:44 PM	7	1280.00	TQEX
GENMAB A/S	02-Apr-2025	16:44:44 PM	27	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:44:50 PM	23	1281.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	84	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	48	1281.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	30	1281.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	14	1281.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	13	1281.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	4	1281.00	XCSE
GENMAB A/S	02-Apr-2025	16:44:52 PM	25	1280.00	TQEX
GENMAB A/S	02-Apr-2025	16:44:52 PM	46	1280.50	CEUX
GENMAB A/S	02-Apr-2025	16:44:52 PM	31	1280.00	AQEU
GENMAB A/S	02-Apr-2025	16:44:53 PM	84	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:44:53 PM	45	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:18 PM	23	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:45:18 PM	26	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:45:18 PM	51	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:18 PM	34	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:28 PM	82	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:45:28 PM	37	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:32 PM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:32 PM	24	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:46 PM	2	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:46 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:46 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:46 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:46 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:51 PM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:51 PM	10	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:51 PM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:51 PM	2	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:51 PM	9	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:51 PM	2	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:45:57 PM	23	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:57 PM	6	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:57 PM	7	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:57 PM	2	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:45:57 PM	12	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:46:01 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:01 PM	10	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:06 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:06 PM	13	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:06 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:06 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:11 PM	16	1279.50	XCSE

193

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:46:11 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:11 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:11 PM	6	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:17 PM	50	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:46:17 PM	3	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:46:21 PM	44	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:21 PM	10	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:21 PM	5	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:46:29 PM	15	1279.50	AQEU
GENMAB A/S	02-Apr-2025	16:46:30 PM	34	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:00 PM	50	1281.50	CEUX
GENMAB A/S	02-Apr-2025	16:47:00 PM	40	1281.50	CEUX
GENMAB A/S	02-Apr-2025	16:47:00 PM	19	1281.50	CEUX
GENMAB A/S	02-Apr-2025	16:47:01 PM	14	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	13	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	12	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	56	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	9	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	11	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	11	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	10	1281.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	14	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	29	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:47:03 PM	27	1280.50	TQEX
GENMAB A/S	02-Apr-2025	16:47:03 PM	2	1280.50	TQEX
GENMAB A/S	02-Apr-2025	16:47:03 PM	77	1280.50	CEUX
GENMAB A/S	02-Apr-2025	16:47:03 PM	40	1280.50	AQEU
GENMAB A/S	02-Apr-2025	16:47:03 PM	15	1280.50	AQEU
GENMAB A/S	02-Apr-2025	16:47:03 PM	2	1280.50	AQEU
GENMAB A/S	02-Apr-2025	16:47:03 PM	2	1280.50	AQEU
GENMAB A/S	02-Apr-2025	16:47:03 PM	2	1280.50	AQEU
GENMAB A/S	02-Apr-2025	16:47:05 PM	35	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:47:12 PM	23	1279.50	TQEX
GENMAB A/S	02-Apr-2025	16:47:35 PM	32	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:47:35 PM	15	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:47:35 PM	32	1279.00	AQEU
GENMAB A/S	02-Apr-2025	16:48:05 PM	45	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	43	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:48:12 PM	18	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:48:12 PM	37	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:12 PM	18	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	1	1278.50	CEUX

194

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:48:12 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:12 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:15 PM	5	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:15 PM	35	1278.00	TQEX
GENMAB A/S	02-Apr-2025	16:48:15 PM	31	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:48:15 PM	32	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:48:17 PM	13	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:18 PM	13	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:18 PM	14	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:18 PM	11	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:18 PM	48	1278.00	XCSE
GENMAB A/S	02-Apr-2025	16:48:31 PM	31	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:48:40 PM	33	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:48:51 PM	20	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:03 PM	27	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:49:03 PM	50	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:49:05 PM	47	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:06 PM	7	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:49:06 PM	19	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:49:28 PM	10	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	10	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	12	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	48	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	29	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	52	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	10	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	47	1279.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:28 PM	4	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:28 PM	4	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:28 PM	50	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:28 PM	9	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:37 PM	31	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:49:39 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:49:39 PM	48	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:49:40 PM	10	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:49:47 PM	32	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:49:52 PM	31	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:49:52 PM	50	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:49:53 PM	34	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:53 PM	75	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:49:53 PM	24	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:49:54 PM	15	1280.00	AQEU
GENMAB A/S	02-Apr-2025	16:49:55 PM	16	1280.00	AQEU
GENMAB A/S	02-Apr-2025	16:50:05 PM	21	1279.50	XCSE

195

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:50:05 PM	43	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:50:13 PM	109	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:13 PM	35	1280.00	AQEU
GENMAB A/S	02-Apr-2025	16:50:14 PM	10	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	10	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	48	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	14	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	12	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	14	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	1	1280.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:14 PM	27	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:50:17 PM	109	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:50:18 PM	109	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:50:18 PM	40	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:50:20 PM	42	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:50:24 PM	57	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:50:29 PM	26	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:50:31 PM	49	1280.00	XCSE
GENMAB A/S	02-Apr-2025	16:50:34 PM	63	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:50:34 PM	22	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:50:34 PM	22	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:50:46 PM	25	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:51:03 PM	46	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:51:03 PM	7	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:51:03 PM	11	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:51:07 PM	45	1280.00	CEUX
GENMAB A/S	02-Apr-2025	16:51:08 PM	10	1279.50	TQEX
GENMAB A/S	02-Apr-2025	16:51:11 PM	46	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:21 PM	31	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:21 PM	5	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:21 PM	31	1279.50	TQEX
GENMAB A/S	02-Apr-2025	16:51:21 PM	22	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:51:21 PM	17	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:51:24 PM	4	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:51:24 PM	19	1279.50	CEUX
GENMAB A/S	02-Apr-2025	16:51:35 PM	60	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:35 PM	4	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:35 PM	11	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:35 PM	14	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:51:35 PM	40	1279.50	TQEX
GENMAB A/S	02-Apr-2025	16:51:35 PM	24	1279.00	AQEU
GENMAB A/S	02-Apr-2025	16:51:36 PM	12	1279.50	XCSE
GENMAB A/S	02-Apr-2025	16:52:03 PM	9	1279.00	CEUX
GENMAB A/S	02-Apr-2025	16:52:03 PM	2	1279.00	AQEU
GENMAB A/S	02-Apr-2025	16:52:03 PM	2	1279.00	AQEU

196

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for March 31 – April 2, 2025

GENMAB A/S	02-Apr-2025	16:52:11 PM	30	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:52:11 PM	28	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:52:39 PM	50	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:52:45 PM	75	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:52:45 PM	13	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:52:45 PM	11	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:52:45 PM	10	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:52:45 PM	33	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:53:10 PM	14	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:53:10 PM	75	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:53:10 PM	13	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:53:10 PM	7	1278.50	XCSE
GENMAB A/S	02-Apr-2025	16:53:10 PM	3	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:53:10 PM	4	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:53:10 PM	4	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:53:10 PM	15	1278.50	TQEX
GENMAB A/S	02-Apr-2025	16:53:10 PM	50	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:53:10 PM	6	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:53:10 PM	7	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:53:10 PM	15	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:53:10 PM	2	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:53:10 PM	2	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:53:10 PM	2	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:53:10 PM	15	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:53:10 PM	2	1278.50	AQEU
GENMAB A/S	02-Apr-2025	16:53:12 PM	23	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:53:14 PM	50	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:53:26 PM	109	1278.50	CEUX
GENMAB A/S	02-Apr-2025	16:53:36 PM	34	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:53:37 PM	25	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:53:44 PM	24	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:53:56 PM	25	1277.50	TQEX
GENMAB A/S	02-Apr-2025	16:54:16 PM	6	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:54:17 PM	23	1277.50	XCSE
GENMAB A/S	02-Apr-2025	16:54:22 PM	16	1277.50	CEUX
GENMAB A/S	02-Apr-2025	16:54:24 PM	50	1278.00	CEUX
GENMAB A/S	02-Apr-2025	16:54:38 PM	15	1278.00	AQEU
GENMAB A/S	02-Apr-2025	16:54:48 PM	48	1277.50	XCSE

197