Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

Issuer	Date	Time CEST	Price (DKK)	Quantity	Venue
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	23	XCSE
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	23	XCSE
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	16	XCSE
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	23	XCSE
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	9	XCSE
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	20	CEUX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	6	CEUX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	4	TQEX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	4	TQEX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	4	TQEX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	4	TQEX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	15	CEUX
GENMAB A/S	15/04/2024	9:01:58 AM	2,089.00	18	CEUX
GENMAB A/S	15/04/2024	9:02:53 AM	2,089.00	37	AQEU
GENMAB A/S	15/04/2024	9:07:21 AM	2,099.00	7	CEUX
GENMAB A/S	15/04/2024	9:07:21 AM	2,099.00	36	CEUX
GENMAB A/S	15/04/2024	9:08:23 AM	2,098.00	50	XCSE
GENMAB A/S	15/04/2024	9:08:23 AM	2,097.00	18	AQEU
GENMAB A/S	15/04/2024	9:08:23 AM	2,097.00	30	AQEU
GENMAB A/S	15/04/2024	9:12:38 AM	2,081.00	36	XCSE
GENMAB A/S	15/04/2024	9:14:55 AM	2,084.00	40	XCSE
GENMAB A/S	15/04/2024	9:14:56 AM	2,084.00	35	CEUX
GENMAB A/S	15/04/2024	9:15:20 AM	2,083.00	36	CEUX
GENMAB A/S	15/04/2024	9:17:38 AM	2,087.00	9	XCSE
GENMAB A/S	15/04/2024	9:17:38 AM	2,087.00	32	XCSE
GENMAB A/S	15/04/2024	9:17:38 AM	2,087.00	39	XCSE
GENMAB A/S	15/04/2024	9:24:20 AM	2,087.00	74	XCSE
GENMAB A/S	15/04/2024	9:24:22 AM	2,085.00	53	AQEU
GENMAB A/S	15/04/2024	9:24:22 AM	2,085.00	16	AQEU
GENMAB A/S	15/04/2024	9:25:11 AM	2,084.00	35	CEUX
GENMAB A/S	15/04/2024	9:25:11 AM	2,083.00	56	XCSE
GENMAB A/S	15/04/2024	9:25:11 AM	2,083.00	8	XCSE
GENMAB A/S	15/04/2024	9:25:11 AM	2,083.00	27	XCSE
GENMAB A/S	15/04/2024	9:25:12 AM	2,082.00	47	CEUX
GENMAB A/S	15/04/2024	9:25:12 AM	2,082.00	54	TQEX
GENMAB A/S	15/04/2024	9:30:07 AM	2,067.00	38	XCSE
GENMAB A/S	15/04/2024	9:30:09 AM	2,066.00	1	CEUX
GENMAB A/S	15/04/2024	9:35:31 AM	2,065.00	55	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	9:39:59 AM	2,069.00	36	AQEU
GENMAB A/S	15/04/2024	9:40:29 AM	2,067.00	14	CEUX
GENMAB A/S	15/04/2024	9:40:29 AM	2,067.00	41	CEUX
GENMAB A/S	15/04/2024	9:40:29 AM	2,066.00	54	CEUX
GENMAB A/S	15/04/2024	9:40:29 AM	2,065.00	58	XCSE
GENMAB A/S	15/04/2024	9:40:29 AM	2,065.00	28	XCSE
GENMAB A/S	15/04/2024	9:40:29 AM	2,065.00	15	XCSE
GENMAB A/S	15/04/2024	9:40:29 AM	2,065.00	1	XCSE
GENMAB A/S	15/04/2024	9:47:11 AM	2,066.00	56	CEUX
GENMAB A/S	15/04/2024	9:52:33 AM	2,070.00	30	XCSE
GENMAB A/S	15/04/2024	9:52:33 AM	2,070.00	11	XCSE
GENMAB A/S	15/04/2024	9:52:33 AM	2,069.00	43	TQEX
GENMAB A/S	15/04/2024	9:52:33 AM	2,069.00	18	TQEX
GENMAB A/S	15/04/2024	9:54:26 AM	2,068.00	42	CEUX
GENMAB A/S	15/04/2024	9:54:26 AM	2,068.00	19	CEUX
GENMAB A/S	15/04/2024	9:57:09 AM	2,065.00	36	CEUX
GENMAB A/S	15/04/2024	9:58:43 AM	2,063.00	24	CEUX
GENMAB A/S	15/04/2024	9:58:43 AM	2,063.00	12	CEUX
GENMAB A/S	15/04/2024	9:58:45 AM	2,063.00	26	XCSE
GENMAB A/S	15/04/2024	10:01:45 AM	2,062.00	11	CEUX
GENMAB A/S	15/04/2024	10:01:45 AM	2,062.00	8	CEUX
GENMAB A/S	15/04/2024	10:01:45 AM	2,062.00	26	CEUX
GENMAB A/S	15/04/2024	10:03:24 AM	2,063.00	17	CEUX
GENMAB A/S	15/04/2024	10:03:24 AM	2,063.00	62	CEUX
GENMAB A/S	15/04/2024	10:05:37 AM	2,060.00	13	CEUX
GENMAB A/S	15/04/2024	10:05:37 AM	2,060.00	31	CEUX
GENMAB A/S	15/04/2024	10:05:38 AM	2,059.00	43	XCSE
GENMAB A/S	15/04/2024	10:05:38 AM	2,059.00	41	XCSE
GENMAB A/S	15/04/2024	10:12:59 AM	2,053.00	35	XCSE
GENMAB A/S	15/04/2024	10:12:59 AM	2,053.00	12	CEUX
GENMAB A/S	15/04/2024	10:12:59 AM	2,053.00	27	CEUX
GENMAB A/S	15/04/2024	10:12:59 AM	2,053.00	36	CEUX
GENMAB A/S	15/04/2024	10:17:20 AM	2,052.00	49	XCSE
GENMAB A/S	15/04/2024	10:20:25 AM	2,051.00	30	CEUX
GENMAB A/S	15/04/2024	10:20:25 AM	2,051.00	30	CEUX
GENMAB A/S	15/04/2024	10:20:25 AM	2,051.00	26	CEUX
GENMAB A/S	15/04/2024	10:21:12 AM	2,046.00	40	CEUX
GENMAB A/S	15/04/2024	10:27:14 AM	2,051.00	44	CEUX
GENMAB A/S	15/04/2024	10:29:37 AM	2,051.00	43	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	10:34:01 AM	2,054.00	46	CEUX
GENMAB A/S	15/04/2024	10:38:06 AM	2,057.00	17	CEUX
GENMAB A/S	15/04/2024	10:38:06 AM	2,057.00	3	CEUX
GENMAB A/S	15/04/2024	10:38:06 AM	2,057.00	7	CEUX
GENMAB A/S	15/04/2024	10:38:06 AM	2,057.00	10	XCSE
GENMAB A/S	15/04/2024	10:38:52 AM	2,056.00	25	XCSE
GENMAB A/S	15/04/2024	10:38:52 AM	2,056.00	53	XCSE
GENMAB A/S	15/04/2024	10:38:52 AM	2,056.00	25	XCSE
GENMAB A/S	15/04/2024	10:38:52 AM	2,056.00	25	XCSE
GENMAB A/S	15/04/2024	10:38:52 AM	2,056.00	10	XCSE
GENMAB A/S	15/04/2024	10:44:56 AM	2,053.00	68	CEUX
GENMAB A/S	15/04/2024	10:49:31 AM	2,051.00	39	CEUX
GENMAB A/S	15/04/2024	10:49:31 AM	2,051.00	38	XCSE
GENMAB A/S	15/04/2024	10:55:29 AM	2,058.00	41	CEUX
GENMAB A/S	15/04/2024	10:55:29 AM	2,058.00	2	CEUX
GENMAB A/S	15/04/2024	10:58:50 AM	2,060.00	8	CEUX
GENMAB A/S	15/04/2024	10:58:50 AM	2,060.00	18	CEUX
GENMAB A/S	15/04/2024	10:58:50 AM	2,060.00	13	CEUX
GENMAB A/S	15/04/2024	10:59:37 AM	2,059.00	44	XCSE
GENMAB A/S	15/04/2024	11:01:17 AM	2,055.00	44	XCSE
GENMAB A/S	15/04/2024	11:01:17 AM	2,055.00	44	XCSE
GENMAB A/S	15/04/2024	11:01:18 AM	2,055.00	2	XCSE
GENMAB A/S	15/04/2024	11:09:19 AM	2,054.00	21	CEUX
GENMAB A/S	15/04/2024	11:09:19 AM	2,054.00	18	CEUX
GENMAB A/S	15/04/2024	11:09:19 AM	2,054.00	40	XCSE
GENMAB A/S	15/04/2024	11:10:24 AM	2,057.00	1	CEUX
GENMAB A/S	15/04/2024	11:10:24 AM	2,057.00	1	CEUX
GENMAB A/S	15/04/2024	11:11:28 AM	2,057.00	34	CEUX
GENMAB A/S	15/04/2024	11:13:48 AM	2,055.00	33	XCSE
GENMAB A/S	15/04/2024	11:13:48 AM	2,055.00	1	XCSE
GENMAB A/S	15/04/2024	11:16:33 AM	2,054.00	36	CEUX
GENMAB A/S	15/04/2024	11:20:52 AM	2,055.00	34	AQEU
GENMAB A/S	15/04/2024	11:20:52 AM	2,055.00	7	AQEU
GENMAB A/S	15/04/2024	11:23:30 AM	2,055.00	7	AQEU
GENMAB A/S	15/04/2024	11:23:30 AM	2,055.00	45	CEUX
GENMAB A/S	15/04/2024	11:23:30 AM	2,055.00	6	TQEX
GENMAB A/S	15/04/2024	11:23:30 AM	2,055.00	49	XCSE
GENMAB A/S	15/04/2024	11:23:30 AM	2,055.00	36	XCSE
GENMAB A/S	15/04/2024	11:23:30 AM	2,054.00	37	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	11:31:06 AM	2,047.00	34	CEUX
GENMAB A/S	15/04/2024	11:31:07 AM	2,046.00	34	XCSE
GENMAB A/S	15/04/2024	11:31:07 AM	2,046.00	1	XCSE
GENMAB A/S	15/04/2024	11:31:07 AM	2,046.00	34	XCSE
GENMAB A/S	15/04/2024	11:36:32 AM	2,053.00	7	AQEU
GENMAB A/S	15/04/2024	11:36:32 AM	2,053.00	49	CEUX
GENMAB A/S	15/04/2024	11:36:32 AM	2,053.00	8	TQEX
GENMAB A/S	15/04/2024	11:36:32 AM	2,053.00	54	XCSE
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	27	XCSE
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	49	XCSE
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	7	AQEU
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	44	CEUX
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	6	TQEX
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	27	XCSE
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	41	XCSE
GENMAB A/S	15/04/2024	11:41:28 AM	2,051.00	11	XCSE
GENMAB A/S	15/04/2024	11:46:44 AM	2,057.00	17	XCSE
GENMAB A/S	15/04/2024	11:46:44 AM	2,057.00	23	XCSE
GENMAB A/S	15/04/2024	11:46:44 AM	2,057.00	2	XCSE
GENMAB A/S	15/04/2024	11:47:43 AM	2,057.00	30	XCSE
GENMAB A/S	15/04/2024	11:47:43 AM	2,057.00	8	XCSE
GENMAB A/S	15/04/2024	11:48:26 AM	2,055.00	8	XCSE
GENMAB A/S	15/04/2024	11:48:26 AM	2,055.00	8	XCSE
GENMAB A/S	15/04/2024	11:48:26 AM	2,055.00	2	CEUX
GENMAB A/S	15/04/2024	11:48:26 AM	2,055.00	4	TQEX
GENMAB A/S	15/04/2024	11:48:26 AM	2,055.00	7	CEUX
GENMAB A/S	15/04/2024	11:50:17 AM	2,061.00	17	CEUX
GENMAB A/S	15/04/2024	11:50:18 AM	2,060.00	61	XCSE
GENMAB A/S	15/04/2024	11:50:18 AM	2,060.00	11	XCSE
GENMAB A/S	15/04/2024	11:50:18 AM	2,060.00	33	XCSE
GENMAB A/S	15/04/2024	11:50:18 AM	2,060.00	34	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	20	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	27	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	20	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	10	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	10	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	14	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	10	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	3	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	10	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	10	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	2	TQEX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	2	TQEX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	2	TQEX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	4	TQEX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	10	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	37	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	30	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	33	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	17	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,058.00	2	XCSE
GENMAB A/S	15/04/2024	11:51:52 AM	2,057.00	42	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,057.00	15	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,057.00	27	CEUX
GENMAB A/S	15/04/2024	11:51:52 AM	2,057.00	1	CEUX
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	36	CEUX
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	36	CEUX
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	39	XCSE
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	36	CEUX
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	36	CEUX
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	29	CEUX
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	39	XCSE
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	39	XCSE
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	39	XCSE
GENMAB A/S	15/04/2024	12:01:49 PM	2,060.00	36	XCSE
GENMAB A/S	15/04/2024	12:06:23 PM	2,060.00	11	AQEU
GENMAB A/S	15/04/2024	12:06:23 PM	2,060.00	72	CEUX
GENMAB A/S	15/04/2024	12:06:23 PM	2,060.00	80	XCSE
GENMAB A/S	15/04/2024	12:06:23 PM	2,059.00	28	CEUX
GENMAB A/S	15/04/2024	12:06:23 PM	2,059.00	52	CEUX
GENMAB A/S	15/04/2024	12:17:05 PM	2,063.00	27	XCSE
GENMAB A/S	15/04/2024	12:17:05 PM	2,063.00	9	XCSE
GENMAB A/S	15/04/2024	12:18:07 PM	2,062.00	39	CEUX
GENMAB A/S	15/04/2024	12:18:59 PM	2,062.00	30	XCSE
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	84	TQEX
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	7	AQEU
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	10	AQEU
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	68	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	10	TQEX
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	38	XCSE
GENMAB A/S	15/04/2024	12:19:11 PM	2,060.00	11	XCSE
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	29	XCSE
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	16	XCSE
GENMAB A/S	15/04/2024	12:19:11 PM	2,061.00	30	XCSE
GENMAB A/S	15/04/2024	12:28:49 PM	2,061.00	4	CEUX
GENMAB A/S	15/04/2024	12:28:49 PM	2,061.00	3	CEUX
GENMAB A/S	15/04/2024	12:28:49 PM	2,061.00	1	XCSE
GENMAB A/S	15/04/2024	12:28:49 PM	2,061.00	57	CEUX
GENMAB A/S	15/04/2024	12:28:49 PM	2,061.00	15	CEUX
GENMAB A/S	15/04/2024	12:28:49 PM	2,060.00	9	TQEX
GENMAB A/S	15/04/2024	12:28:49 PM	2,060.00	24	CEUX
GENMAB A/S	15/04/2024	12:28:49 PM	2,060.00	13	XCSE
GENMAB A/S	15/04/2024	12:28:49 PM	2,060.00	32	XCSE
GENMAB A/S	15/04/2024	12:28:49 PM	2,060.00	21	XCSE
GENMAB A/S	15/04/2024	12:28:49 PM	2,060.00	33	CEUX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	30	CEUX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	67	CEUX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	30	CEUX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	30	CEUX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	5	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	11	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	5	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	11	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	5	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	11	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	17	CEUX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	3	TQEX
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	22	XCSE
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	11	XCSE
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	75	XCSE
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	33	XCSE
GENMAB A/S	15/04/2024	12:32:35 PM	2,060.00	51	XCSE
GENMAB A/S	15/04/2024	12:38:19 PM	2,056.00	7	AQEU
GENMAB A/S	15/04/2024	12:38:19 PM	2,056.00	49	CEUX
GENMAB A/S	15/04/2024	12:38:19 PM	2,056.00	8	TQEX
GENMAB A/S	15/04/2024	12:38:19 PM	2,056.00	11	XCSE
GENMAB A/S	15/04/2024	12:38:19 PM	2,056.00	44	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	12:38:20 PM	2,055.00	1	CEUX
GENMAB A/S	15/04/2024	12:38:22 PM	2,055.00	12	CEUX
GENMAB A/S	15/04/2024	12:38:22 PM	2,055.00	56	CEUX
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	18	XCSE
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	97	XCSE
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	3	AQEU
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	12	AQEU
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	104	CEUX
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	10	TQEX
GENMAB A/S	15/04/2024	12:46:23 PM	2,059.00	6	TQEX
GENMAB A/S	15/04/2024	12:51:09 PM	2,059.00	39	CEUX
GENMAB A/S	15/04/2024	12:51:09 PM	2,059.00	26	CEUX
GENMAB A/S	15/04/2024	12:51:09 PM	2,059.00	20	CEUX
GENMAB A/S	15/04/2024	12:51:52 PM	2,058.00	85	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	26	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	23	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	3	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	30	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	11	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	19	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	3	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	1	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	3	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	11	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	12	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	11	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	23	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	23	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	12	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	11	XCSE
GENMAB A/S	15/04/2024	12:55:05 PM	2,056.00	2	XCSE
GENMAB A/S	15/04/2024	1:05:37 PM	2,059.00	7	CEUX
GENMAB A/S	15/04/2024	1:07:31 PM	2,060.00	11	XCSE
GENMAB A/S	15/04/2024	1:07:31 PM	2,060.00	11	XCSE
GENMAB A/S	15/04/2024	1:07:32 PM	2,060.00	1	XCSE
GENMAB A/S	15/04/2024	1:08:41 PM	2,061.00	25	XCSE
GENMAB A/S	15/04/2024	1:08:41 PM	2,061.00	159	XCSE
GENMAB A/S	15/04/2024	1:08:42 PM	2,061.00	10	AQEU
GENMAB A/S	15/04/2024	1:08:42 PM	2,061.00	13	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	1:08:42 PM	2,061.00	18	CEUX
GENMAB A/S	15/04/2024	1:08:42 PM	2,061.00	69	CEUX
GENMAB A/S	15/04/2024	1:08:42 PM	2,061.00	78	CEUX
GENMAB A/S	15/04/2024	1:08:42 PM	2,061.00	26	TQEX
GENMAB A/S	15/04/2024	1:17:38 PM	2,064.00	34	XCSE
GENMAB A/S	15/04/2024	1:17:38 PM	2,064.00	7	XCSE
GENMAB A/S	15/04/2024	1:17:38 PM	2,064.00	4	XCSE
GENMAB A/S	15/04/2024	1:17:38 PM	2,064.00	33	XCSE
GENMAB A/S	15/04/2024	1:17:51 PM	2,064.00	37	XCSE
GENMAB A/S	15/04/2024	1:17:51 PM	2,064.00	1	XCSE
GENMAB A/S	15/04/2024	1:18:26 PM	2,064.00	4	XCSE
GENMAB A/S	15/04/2024	1:18:26 PM	2,064.00	1	XCSE
GENMAB A/S	15/04/2024	1:18:26 PM	2,064.00	33	XCSE
GENMAB A/S	15/04/2024	1:18:26 PM	2,064.00	1	XCSE
GENMAB A/S	15/04/2024	1:18:50 PM	2,063.00	40	XCSE
GENMAB A/S	15/04/2024	1:18:50 PM	2,063.00	55	XCSE
GENMAB A/S	15/04/2024	1:18:50 PM	2,063.00	74	CEUX
GENMAB A/S	15/04/2024	1:18:50 PM	2,063.00	12	CEUX
GENMAB A/S	15/04/2024	1:18:50 PM	2,063.00	8	TQEX
GENMAB A/S	15/04/2024	1:18:50 PM	2,063.00	6	TQEX
GENMAB A/S	15/04/2024	1:19:45 PM	2,064.00	38	AQEU
GENMAB A/S	15/04/2024	1:25:28 PM	2,064.00	38	XCSE
GENMAB A/S	15/04/2024	1:26:30 PM	2,063.00	7	CEUX
GENMAB A/S	15/04/2024	1:26:30 PM	2,063.00	15	CEUX
GENMAB A/S	15/04/2024	1:27:03 PM	2,064.00	1	TQEX
GENMAB A/S	15/04/2024	1:27:03 PM	2,064.00	8	TQEX
GENMAB A/S	15/04/2024	1:27:03 PM	2,064.00	28	TQEX
GENMAB A/S	15/04/2024	1:27:56 PM	2,064.00	41	XCSE
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	19	AQEU
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	75	CEUX
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	37	CEUX
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	19	TQEX
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	1	TQEX
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	83	XCSE
GENMAB A/S	15/04/2024	1:27:56 PM	2,063.00	65	XCSE
GENMAB A/S	15/04/2024	1:31:07 PM	2,065.00	9	XCSE
GENMAB A/S	15/04/2024	1:31:40 PM	2,065.00	1	XCSE
GENMAB A/S	15/04/2024	1:36:33 PM	2,065.00	8	CEUX
GENMAB A/S	15/04/2024	1:36:33 PM	2,065.00	32	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	1:36:33 PM	2,065.00	10	TQEX
GENMAB A/S	15/04/2024	1:38:48 PM	2,065.00	38	XCSE
GENMAB A/S	15/04/2024	1:39:51 PM	2,065.00	37	AQEU
GENMAB A/S	15/04/2024	1:40:48 PM	2,064.00	81	XCSE
GENMAB A/S	15/04/2024	1:40:48 PM	2,064.00	21	XCSE
GENMAB A/S	15/04/2024	1:40:48 PM	2,064.00	2	XCSE
GENMAB A/S	15/04/2024	1:40:48 PM	2,064.00	4	XCSE
GENMAB A/S	15/04/2024	1:40:48 PM	2,064.00	2	XCSE
GENMAB A/S	15/04/2024	1:40:49 PM	2,064.00	27	XCSE
GENMAB A/S	15/04/2024	1:40:49 PM	2,064.00	27	XCSE
GENMAB A/S	15/04/2024	1:40:49 PM	2,064.00	27	XCSE
GENMAB A/S	15/04/2024	1:40:49 PM	2,064.00	13	XCSE
GENMAB A/S	15/04/2024	1:47:21 PM	2,066.00	30	XCSE
GENMAB A/S	15/04/2024	1:47:21 PM	2,066.00	6	TQEX
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	33	XCSE
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	96	XCSE
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	17	AQEU
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	62	CEUX
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	54	CEUX
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	9	TQEX
GENMAB A/S	15/04/2024	1:48:44 PM	2,066.00	9	TQEX
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	25	XCSE
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	40	XCSE
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	26	XCSE
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	16	XCSE
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	24	CEUX
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	14	CEUX
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	10	CEUX
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	4	CEUX
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	13	CEUX
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	10	XCSE
GENMAB A/S	15/04/2024	1:55:28 PM	2,063.00	43	XCSE
GENMAB A/S	15/04/2024	2:03:23 PM	2,064.00	41	XCSE
GENMAB A/S	15/04/2024	2:04:48 PM	2,064.00	3	XCSE
GENMAB A/S	15/04/2024	2:05:16 PM	2,064.00	35	XCSE
GENMAB A/S	15/04/2024	2:06:59 PM	2,065.00	76	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	1	AQEU
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	9	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	1	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	9	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	1	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	9	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	1	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	9	XCSE
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	9	XCSE
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:07:08 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	22	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	22	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	22	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	22	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	9	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	1	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	22	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	11	CEUX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	10	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	7	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	3	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	1	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	7	TQEX
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	7	AQEU
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	23	XCSE
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	8	XCSE
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	15	XCSE
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	11	XCSE
GENMAB A/S	15/04/2024	2:10:49 PM	2,064.00	7	AQEU
GENMAB A/S	15/04/2024	2:15:05 PM	2,062.00	46	XCSE
GENMAB A/S	15/04/2024	2:21:44 PM	2,065.00	8	TQEX
GENMAB A/S	15/04/2024	2:21:44 PM	2,065.00	7	TQEX
GENMAB A/S	15/04/2024	2:21:44 PM	2,065.00	14	TQEX
GENMAB A/S	15/04/2024	2:21:44 PM	2,065.00	6	XCSE
GENMAB A/S	15/04/2024	2:22:43 PM	2,065.00	7	TQEX
GENMAB A/S	15/04/2024	2:22:43 PM	2,065.00	3	XCSE
GENMAB A/S	15/04/2024	2:22:43 PM	2,065.00	28	XCSE
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	21	AQEU
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	75	CEUX
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	75	CEUX
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	23	TQEX
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	53	XCSE
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	67	XCSE
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	42	XCSE
GENMAB A/S	15/04/2024	2:23:09 PM	2,064.00	4	XCSE
GENMAB A/S	15/04/2024	2:29:26 PM	2,062.00	20	XCSE
GENMAB A/S	15/04/2024	2:29:26 PM	2,062.00	69	XCSE
GENMAB A/S	15/04/2024	2:30:03 PM	2,059.00	28	XCSE
GENMAB A/S	15/04/2024	2:33:43 PM	2,063.00	45	XCSE
GENMAB A/S	15/04/2024	2:33:43 PM	2,063.00	41	CEUX
GENMAB A/S	15/04/2024	2:33:43 PM	2,063.00	6	TQEX
GENMAB A/S	15/04/2024	2:33:43 PM	2,063.00	6	XCSE
GENMAB A/S	15/04/2024	2:37:05 PM	2,066.00	91	XCSE
GENMAB A/S	15/04/2024	2:40:23 PM	2,065.00	74	XCSE
GENMAB A/S	15/04/2024	2:40:23 PM	2,065.00	3	TQEX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	2	AQEU
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	6	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	16	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	7	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	16	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	1	TQEX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	17	XCSE
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	4	XCSE
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	13	XCSE
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	11	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	13	XCSE
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	16	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	3	AQEU
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	16	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	6	CEUX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:42:17 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	2:44:00 PM	2,065.00	14	CEUX
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	17	AQEU
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	114	CEUX
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	3	CEUX
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	2	CEUX
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	18	TQEX
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	43	XCSE
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	75	XCSE
GENMAB A/S	15/04/2024	2:45:59 PM	2,065.00	15	XCSE
GENMAB A/S	15/04/2024	2:55:51 PM	2,064.00	54	XCSE
GENMAB A/S	15/04/2024	2:55:51 PM	2,064.00	18	XCSE
GENMAB A/S	15/04/2024	2:56:44 PM	2,064.00	39	XCSE
GENMAB A/S	15/04/2024	2:57:33 PM	2,064.00	15	CEUX
GENMAB A/S	15/04/2024	2:57:33 PM	2,064.00	14	CEUX
GENMAB A/S	15/04/2024	2:57:33 PM	2,064.00	8	XCSE
GENMAB A/S	15/04/2024	2:58:34 PM	2,064.00	35	XCSE
GENMAB A/S	15/04/2024	2:59:18 PM	2,064.00	16	CEUX
GENMAB A/S	15/04/2024	2:59:18 PM	2,064.00	10	CEUX
GENMAB A/S	15/04/2024	2:59:18 PM	2,064.00	16	XCSE
GENMAB A/S	15/04/2024	3:00:20 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	3:00:20 PM	2,064.00	23	XCSE
GENMAB A/S	15/04/2024	3:00:24 PM	2,063.00	2	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	3:01:24 PM	2,064.00	38	CEUX
GENMAB A/S	15/04/2024	3:02:12 PM	2,064.00	11	CEUX
GENMAB A/S	15/04/2024	3:02:12 PM	2,064.00	19	CEUX
GENMAB A/S	15/04/2024	3:02:12 PM	2,064.00	5	CEUX
GENMAB A/S	15/04/2024	3:03:06 PM	2,064.00	14	CEUX
GENMAB A/S	15/04/2024	3:03:06 PM	2,064.00	16	CEUX
GENMAB A/S	15/04/2024	3:03:06 PM	2,064.00	9	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	46	CEUX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	7	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	1	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	7	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	49	XCSE
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	50	XCSE
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	7	AQEU
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	46	CEUX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	8	CEUX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	7	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	2	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	7	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	1	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	7	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	1	TQEX
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	1	XCSE
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	6	XCSE
GENMAB A/S	15/04/2024	3:04:00 PM	2,063.00	31	XCSE
GENMAB A/S	15/04/2024	3:04:06 PM	2,062.00	48	XCSE
GENMAB A/S	15/04/2024	3:04:06 PM	2,062.00	48	XCSE
GENMAB A/S	15/04/2024	3:04:06 PM	2,062.00	7	XCSE
GENMAB A/S	15/04/2024	3:11:14 PM	2,061.00	1	TQEX
GENMAB A/S	15/04/2024	3:11:14 PM	2,061.00	10	CEUX
GENMAB A/S	15/04/2024	3:11:14 PM	2,061.00	3	TQEX
GENMAB A/S	15/04/2024	3:11:14 PM	2,061.00	10	XCSE
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	10	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	10	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	10	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	10	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	5	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	4	TQEX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	10	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	80	XCSE
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	10	XCSE
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	2	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	4	TQEX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	4	TQEX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	25	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	25	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	25	CEUX
GENMAB A/S	15/04/2024	3:12:21 PM	2,061.00	18	CEUX
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	23	XCSE
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	54	XCSE
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	10	AQEU
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	69	CEUX
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	55	CEUX
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	29	CEUX
GENMAB A/S	15/04/2024	3:17:23 PM	2,060.00	11	TQEX
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	9	CEUX
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	4	TQEX
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	9	CEUX
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	4	TQEX
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	9	XCSE
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	9	XCSE
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	9	CEUX
GENMAB A/S	15/04/2024	3:22:08 PM	2,063.00	2	TQEX
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	75	CEUX
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	18	CEUX
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	8	TQEX
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	77	XCSE
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	25	XCSE
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	13	AQEU
GENMAB A/S	15/04/2024	3:24:19 PM	2,062.00	6	TQEX
GENMAB A/S	15/04/2024	3:26:15 PM	2,062.00	23	CEUX
GENMAB A/S	15/04/2024	3:26:15 PM	2,062.00	23	CEUX
GENMAB A/S	15/04/2024	3:26:16 PM	2,062.00	23	CEUX
GENMAB A/S	15/04/2024	3:26:16 PM	2,062.00	8	CEUX
GENMAB A/S	15/04/2024	3:26:16 PM	2,062.00	3	CEUX
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	10	CEUX
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	18	CEUX
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	30	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	3	TQEX
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	3	TQEX
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	9	AQEU
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	3	TQEX
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	5	XCSE
GENMAB A/S	15/04/2024	3:27:52 PM	2,061.00	60	XCSE
GENMAB A/S	15/04/2024	3:33:49 PM	2,063.00	42	XCSE
GENMAB A/S	15/04/2024	3:33:49 PM	2,063.00	42	XCSE
GENMAB A/S	15/04/2024	3:33:49 PM	2,063.00	27	XCSE
GENMAB A/S	15/04/2024	3:33:49 PM	2,063.00	27	XCSE
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	7	AQEU
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	7	AQEU
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	23	CEUX
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	25	CEUX
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	48	CEUX
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	7	TQEX
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	8	TQEX
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	52	XCSE
GENMAB A/S	15/04/2024	3:39:56 PM	2,070.00	53	XCSE
GENMAB A/S	15/04/2024	3:42:08 PM	2,072.00	4	TQEX
GENMAB A/S	15/04/2024	3:42:08 PM	2,072.00	9	CEUX
GENMAB A/S	15/04/2024	3:42:08 PM	2,072.00	9	CEUX
GENMAB A/S	15/04/2024	3:42:08 PM	2,072.00	4	TQEX
GENMAB A/S	15/04/2024	3:42:08 PM	2,072.00	8	XCSE
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	105	XCSE
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	11	XCSE
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	68	CEUX
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	15	TQEX
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	23	CEUX
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	13	CEUX
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	15	AQEU
GENMAB A/S	15/04/2024	3:42:31 PM	2,071.00	1	TQEX
GENMAB A/S	15/04/2024	3:43:14 PM	2,070.00	2	CEUX
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	13	AQEU
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	88	CEUX
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	13	TQEX
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	13	TQEX
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	49	XCSE
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	48	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	48	XCSE
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	28	XCSE
GENMAB A/S	15/04/2024	3:45:02 PM	2,070.00	88	CEUX
GENMAB A/S	15/04/2024	3:46:29 PM	2,066.00	3	AQEU
GENMAB A/S	15/04/2024	3:46:29 PM	2,066.00	14	AQEU
GENMAB A/S	15/04/2024	3:46:29 PM	2,066.00	3	CEUX
GENMAB A/S	15/04/2024	3:46:29 PM	2,066.00	4	CEUX
GENMAB A/S	15/04/2024	3:46:29 PM	2,066.00	11	CEUX
GENMAB A/S	15/04/2024	3:51:59 PM	2,064.00	4	CEUX
GENMAB A/S	15/04/2024	3:51:59 PM	2,064.00	11	CEUX
GENMAB A/S	15/04/2024	3:52:01 PM	2,064.00	1	CEUX
GENMAB A/S	15/04/2024	3:53:10 PM	2,066.00	35	CEUX
GENMAB A/S	15/04/2024	3:53:36 PM	2,066.00	26	CEUX
GENMAB A/S	15/04/2024	3:53:36 PM	2,066.00	14	CEUX
GENMAB A/S	15/04/2024	3:54:07 PM	2,066.00	20	CEUX
GENMAB A/S	15/04/2024	3:54:07 PM	2,066.00	5	CEUX
GENMAB A/S	15/04/2024	3:54:07 PM	2,066.00	9	CEUX
GENMAB A/S	15/04/2024	3:54:39 PM	2,066.00	5	AQEU
GENMAB A/S	15/04/2024	3:54:39 PM	2,066.00	11	CEUX
GENMAB A/S	15/04/2024	3:54:39 PM	2,066.00	7	CEUX
GENMAB A/S	15/04/2024	3:54:39 PM	2,066.00	16	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	9	AQEU
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	1	AQEU
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	13	AQEU
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	28	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	33	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	11	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	1	AQEU
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	13	AQEU
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	11	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	1	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	9	TQEX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	18	TQEX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	11	CEUX
GENMAB A/S	15/04/2024	3:54:55 PM	2,065.00	3	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	10	AQEU
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	14	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	53	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	18	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	10	AQEU
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	41	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	30	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	12	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	11	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	11	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	1	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	11	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	1	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	5	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	79	XCSE
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	79	XCSE
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	12	XCSE
GENMAB A/S	15/04/2024	3:55:27 PM	2,066.00	4	AQEU
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	40	XCSE
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	36	XCSE
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	4	AQEU
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	50	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	11	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	7	AQEU
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	7	TQEX
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	10	CEUX
GENMAB A/S	15/04/2024	3:55:27 PM	2,065.00	1	CEUX
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	9	AQEU
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	60	CEUX
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	9	TQEX
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	51	XCSE
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	67	XCSE
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	51	XCSE
GENMAB A/S	15/04/2024	4:02:01 PM	2,066.00	46	XCSE
GENMAB A/S	15/04/2024	4:06:21 PM	2,061.00	60	CEUX
GENMAB A/S	15/04/2024	4:08:53 PM	2,064.00	11	CEUX
GENMAB A/S	15/04/2024	4:09:22 PM	2,064.00	15	AQEU
GENMAB A/S	15/04/2024	4:09:22 PM	2,064.00	11	CEUX
GENMAB A/S	15/04/2024	4:09:22 PM	2,064.00	83	CEUX
GENMAB A/S	15/04/2024	4:09:22 PM	2,064.00	16	TQEX
GENMAB A/S	15/04/2024	4:09:22 PM	2,064.00	117	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	4:10:28 PM	2,064.00	75	XCSE
GENMAB A/S	15/04/2024	4:10:28 PM	2,064.00	10	AQEU
GENMAB A/S	15/04/2024	4:10:28 PM	2,064.00	68	CEUX
GENMAB A/S	15/04/2024	4:10:28 PM	2,064.00	7	TQEX
GENMAB A/S	15/04/2024	4:10:28 PM	2,064.00	3	TQEX
GENMAB A/S	15/04/2024	4:13:35 PM	2,063.00	6	XCSE
GENMAB A/S	15/04/2024	4:13:35 PM	2,063.00	14	XCSE
GENMAB A/S	15/04/2024	4:13:35 PM	2,063.00	23	XCSE
GENMAB A/S	15/04/2024	4:13:35 PM	2,063.00	11	XCSE
GENMAB A/S	15/04/2024	4:13:35 PM	2,063.00	11	XCSE
GENMAB A/S	15/04/2024	4:13:35 PM	2,063.00	4	XCSE
GENMAB A/S	15/04/2024	4:13:36 PM	2,063.00	13	XCSE
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	23	XCSE
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	14	XCSE
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	10	AQEU
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	14	AQEU
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	10	AQEU
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	4	AQEU
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	30	CEUX
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	38	CEUX
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	30	CEUX
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	6	CEUX
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	10	TQEX
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	38	XCSE
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	23	XCSE
GENMAB A/S	15/04/2024	4:16:04 PM	2,065.00	33	XCSE
GENMAB A/S	15/04/2024	4:18:22 PM	2,066.00	12	XCSE
GENMAB A/S	15/04/2024	4:18:23 PM	2,066.00	21	XCSE
GENMAB A/S	15/04/2024	4:18:23 PM	2,066.00	4	TQEX
GENMAB A/S	15/04/2024	4:18:55 PM	2,066.00	8	CEUX
GENMAB A/S	15/04/2024	4:18:55 PM	2,066.00	7	XCSE
GENMAB A/S	15/04/2024	4:19:57 PM	2,066.00	11	AQEU
GENMAB A/S	15/04/2024	4:19:57 PM	2,066.00	75	CEUX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	10	AQEU
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	6	AQEU
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	10	AQEU
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	4	AQEU
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	38	CEUX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	31	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	12	CEUX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	11	TQEX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	11	TQEX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	11	TQEX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	77	XCSE
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	10	AQEU
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	1	AQEU
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	57	CEUX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	69	CEUX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	6	TQEX
GENMAB A/S	15/04/2024	4:21:11 PM	2,067.00	77	XCSE
GENMAB A/S	15/04/2024	4:21:12 PM	2,067.00	2	CEUX
GENMAB A/S	15/04/2024	4:22:32 PM	2,066.00	88	CEUX
GENMAB A/S	15/04/2024	4:22:32 PM	2,066.00	15	TQEX
GENMAB A/S	15/04/2024	4:22:32 PM	2,066.00	114	XCSE
GENMAB A/S	15/04/2024	4:25:23 PM	2,066.00	2	CEUX
GENMAB A/S	15/04/2024	4:26:17 PM	2,066.00	16	CEUX
GENMAB A/S	15/04/2024	4:27:25 PM	2,068.00	16	CEUX
GENMAB A/S	15/04/2024	4:27:25 PM	2,068.00	4	TQEX
GENMAB A/S	15/04/2024	4:27:31 PM	2,068.00	16	CEUX
GENMAB A/S	15/04/2024	4:27:31 PM	2,068.00	4	TQEX
GENMAB A/S	15/04/2024	4:27:31 PM	2,068.00	3	XCSE
GENMAB A/S	15/04/2024	4:27:31 PM	2,068.00	13	XCSE
GENMAB A/S	15/04/2024	4:27:31 PM	2,068.00	16	CEUX
GENMAB A/S	15/04/2024	4:27:31 PM	2,068.00	16	CEUX
GENMAB A/S	15/04/2024	4:29:37 PM	2,066.00	52	XCSE
GENMAB A/S	15/04/2024	4:29:37 PM	2,066.00	19	XCSE
GENMAB A/S	15/04/2024	4:29:37 PM	2,066.00	52	XCSE
GENMAB A/S	15/04/2024	4:29:37 PM	2,066.00	22	XCSE
GENMAB A/S	15/04/2024	4:29:37 PM	2,066.00	8	XCSE
GENMAB A/S	15/04/2024	4:29:40 PM	2,065.00	18	CEUX
GENMAB A/S	15/04/2024	4:29:40 PM	2,065.00	4	TQEX
GENMAB A/S	15/04/2024	4:29:40 PM	2,065.00	43	XCSE
GENMAB A/S	15/04/2024	4:29:40 PM	2,065.00	19	XCSE
GENMAB A/S	15/04/2024	4:33:53 PM	2,066.00	10	AQEU
GENMAB A/S	15/04/2024	4:33:53 PM	2,066.00	68	CEUX
GENMAB A/S	15/04/2024	4:33:53 PM	2,066.00	10	TQEX
GENMAB A/S	15/04/2024	4:33:53 PM	2,066.00	75	XCSE
GENMAB A/S	15/04/2024	4:35:14 PM	2,067.00	25	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	4:35:14 PM	2,067.00	94	XCSE
GENMAB A/S	15/04/2024	4:35:14 PM	2,067.00	15	AQEU
GENMAB A/S	15/04/2024	4:35:14 PM	2,067.00	52	CEUX
GENMAB A/S	15/04/2024	4:35:14 PM	2,067.00	54	CEUX
GENMAB A/S	15/04/2024	4:35:14 PM	2,067.00	17	TQEX
GENMAB A/S	15/04/2024	4:37:10 PM	2,067.00	71	CEUX
GENMAB A/S	15/04/2024	4:37:10 PM	2,067.00	12	TQEX
GENMAB A/S	15/04/2024	4:37:10 PM	2,067.00	80	XCSE
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	3	AQEU
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	8	AQEU
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	63	CEUX
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	12	CEUX
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	11	TQEX
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	32	XCSE
GENMAB A/S	15/04/2024	4:40:01 PM	2,065.00	50	XCSE
GENMAB A/S	15/04/2024	4:44:41 PM	2,066.00	26	XCSE
GENMAB A/S	15/04/2024	4:44:53 PM	2,066.00	35	XCSE
GENMAB A/S	15/04/2024	4:45:05 PM	2,065.00	178	CEUX
GENMAB A/S	15/04/2024	4:45:05 PM	2,065.00	42	TQEX
GENMAB A/S	15/04/2024	4:45:05 PM	2,065.00	11	TQEX
GENMAB A/S	15/04/2024	4:45:23 PM	2,065.00	97	CEUX
GENMAB A/S	15/04/2024	4:45:23 PM	2,065.00	27	XCSE
GENMAB A/S	15/04/2024	4:45:23 PM	2,065.00	279	XCSE
GENMAB A/S	15/04/2024	4:45:23 PM	2,065.00	30	XCSE
GENMAB A/S	15/04/2024	4:45:23 PM	2,065.00	9	TQEX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	10	CEUX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	8	CEUX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	11	XCSE
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	11	XCSE
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	18	XCSE
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	2	CEUX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	10	CEUX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	8	CEUX
GENMAB A/S	15/04/2024	4:46:25 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:46:26 PM	2,064.00	16	XCSE
GENMAB A/S	15/04/2024	4:46:26 PM	2,064.00	10	XCSE
GENMAB A/S	15/04/2024	4:47:41 PM	2,064.00	15	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	4:47:41 PM	2,064.00	1	CEUX
GENMAB A/S	15/04/2024	4:47:44 PM	2,064.00	15	XCSE
GENMAB A/S	15/04/2024	4:47:44 PM	2,064.00	55	XCSE
GENMAB A/S	15/04/2024	4:49:42 PM	2,065.00	108	XCSE
GENMAB A/S	15/04/2024	4:49:44 PM	2,065.00	57	XCSE
GENMAB A/S	15/04/2024	4:49:44 PM	2,065.00	39	XCSE
GENMAB A/S	15/04/2024	4:50:08 PM	2,065.00	16	CEUX
GENMAB A/S	15/04/2024	4:51:17 PM	2,064.00	16	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	36	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	3	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	10	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	1	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	13	CEUX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	4	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	7	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	5	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	7	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	12	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	9	XCSE
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	14	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	7	AQEU
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	7	TQEX
GENMAB A/S	15/04/2024	4:51:24 PM	2,064.00	19	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	24	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	25	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	71	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	7	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	64	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	24	XCSE
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	22	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	22	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	22	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	20	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	4	TQEX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	4	TQEX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	2	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	22	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	22	CEUX
GENMAB A/S	16/04/2024	9:00:18 AM	2,060.00	2	CEUX
GENMAB A/S	16/04/2024	9:00:24 AM	2,058.00	56	CEUX
GENMAB A/S	16/04/2024	9:00:24 AM	2,058.00	5	CEUX
GENMAB A/S	16/04/2024	9:00:24 AM	2,058.00	70	CEUX
GENMAB A/S	16/04/2024	9:00:24 AM	2,058.00	3	CEUX
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	21	CEUX
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	21	CEUX
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	2	CEUX
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	21	XCSE
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	7	XCSE
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	19	XCSE
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	30	XCSE
GENMAB A/S	16/04/2024	9:05:11 AM	2,058.00	15	XCSE
GENMAB A/S	16/04/2024	9:07:25 AM	2,058.00	57	TQEX
GENMAB A/S	16/04/2024	9:07:25 AM	2,058.00	35	TQEX
GENMAB A/S	16/04/2024	9:07:25 AM	2,058.00	89	TQEX
GENMAB A/S	16/04/2024	9:07:25 AM	2,058.00	44	XCSE
GENMAB A/S	16/04/2024	9:11:38 AM	2,059.00	71	TQEX
GENMAB A/S	16/04/2024	9:11:38 AM	2,059.00	4	TQEX
GENMAB A/S	16/04/2024	9:11:38 AM	2,059.00	79	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,061.00	47	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,061.00	2	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,061.00	7	AQEU
GENMAB A/S	16/04/2024	9:12:24 AM	2,061.00	45	CEUX
GENMAB A/S	16/04/2024	9:12:24 AM	2,061.00	6	TQEX
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	16	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	27	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	4	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	27	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	16	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	11	XCSE
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	26	TQEX
GENMAB A/S	16/04/2024	9:12:24 AM	2,060.00	12	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,061.00	7	AQEU
GENMAB A/S	16/04/2024	9:15:19 AM	2,061.00	44	CEUX
GENMAB A/S	16/04/2024	9:15:19 AM	2,061.00	2	TQEX
GENMAB A/S	16/04/2024	9:15:19 AM	2,061.00	51	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	9:15:19 AM	2,061.00	6	TQEX
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	44	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	21	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	29	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	29	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	15	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	14	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	36	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	12	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,060.00	5	XCSE
GENMAB A/S	16/04/2024	9:15:19 AM	2,061.00	48	XCSE
GENMAB A/S	16/04/2024	9:19:19 AM	2,060.00	79	XCSE
GENMAB A/S	16/04/2024	9:19:19 AM	2,060.00	37	AQEU
GENMAB A/S	16/04/2024	9:22:13 AM	2,065.00	66	CEUX
GENMAB A/S	16/04/2024	9:22:13 AM	2,065.00	23	CEUX
GENMAB A/S	16/04/2024	9:25:54 AM	2,067.00	76	CEUX
GENMAB A/S	16/04/2024	9:25:54 AM	2,067.00	10	CEUX
GENMAB A/S	16/04/2024	9:27:46 AM	2,063.00	6	CEUX
GENMAB A/S	16/04/2024	9:29:44 AM	2,066.00	45	TQEX
GENMAB A/S	16/04/2024	9:29:44 AM	2,066.00	21	TQEX
GENMAB A/S	16/04/2024	9:29:44 AM	2,066.00	15	TQEX
GENMAB A/S	16/04/2024	9:30:30 AM	2,066.00	75	XCSE
GENMAB A/S	16/04/2024	9:30:30 AM	2,066.00	4	AQEU
GENMAB A/S	16/04/2024	9:30:30 AM	2,066.00	6	AQEU
GENMAB A/S	16/04/2024	9:30:30 AM	2,066.00	68	CEUX
GENMAB A/S	16/04/2024	9:30:30 AM	2,066.00	10	TQEX
GENMAB A/S	16/04/2024	9:35:06 AM	2,066.00	7	AQEU
GENMAB A/S	16/04/2024	9:35:06 AM	2,066.00	48	CEUX
GENMAB A/S	16/04/2024	9:35:06 AM	2,066.00	8	TQEX
GENMAB A/S	16/04/2024	9:35:06 AM	2,066.00	39	XCSE
GENMAB A/S	16/04/2024	9:35:06 AM	2,066.00	15	XCSE
GENMAB A/S	16/04/2024	9:35:42 AM	2,066.00	7	AQEU
GENMAB A/S	16/04/2024	9:35:42 AM	2,066.00	32	CEUX
GENMAB A/S	16/04/2024	9:35:42 AM	2,066.00	16	CEUX
GENMAB A/S	16/04/2024	9:35:42 AM	2,066.00	7	TQEX
GENMAB A/S	16/04/2024	9:35:42 AM	2,066.00	52	XCSE
GENMAB A/S	16/04/2024	9:35:43 AM	2,064.00	34	XCSE
GENMAB A/S	16/04/2024	9:35:43 AM	2,064.00	21	XCSE
GENMAB A/S	16/04/2024	9:40:11 AM	2,063.00	40	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	9:40:11 AM	2,063.00	35	XCSE
GENMAB A/S	16/04/2024	9:40:11 AM	2,063.00	67	CEUX
GENMAB A/S	16/04/2024	9:40:11 AM	2,063.00	10	AQEU
GENMAB A/S	16/04/2024	9:40:11 AM	2,063.00	10	TQEX
GENMAB A/S	16/04/2024	9:43:06 AM	2,065.00	13	AQEU
GENMAB A/S	16/04/2024	9:43:06 AM	2,065.00	71	CEUX
GENMAB A/S	16/04/2024	9:43:06 AM	2,065.00	103	XCSE
GENMAB A/S	16/04/2024	9:43:06 AM	2,065.00	22	CEUX
GENMAB A/S	16/04/2024	9:49:50 AM	2,070.00	1	TQEX
GENMAB A/S	16/04/2024	9:56:24 AM	2,076.00	11	XCSE
GENMAB A/S	16/04/2024	9:56:24 AM	2,076.00	11	XCSE
GENMAB A/S	16/04/2024	9:56:24 AM	2,076.00	20	XCSE
GENMAB A/S	16/04/2024	9:56:24 AM	2,076.00	2	AQEU
GENMAB A/S	16/04/2024	9:56:24 AM	2,076.00	10	AQEU
GENMAB A/S	16/04/2024	9:56:24 AM	2,076.00	11	CEUX
GENMAB A/S	16/04/2024	9:56:36 AM	2,077.00	5	AQEU
GENMAB A/S	16/04/2024	9:56:36 AM	2,077.00	15	AQEU
GENMAB A/S	16/04/2024	9:56:36 AM	2,077.00	139	CEUX
GENMAB A/S	16/04/2024	9:56:36 AM	2,077.00	156	XCSE
GENMAB A/S	16/04/2024	10:04:28 AM	2,077.00	7	AQEU
GENMAB A/S	16/04/2024	10:04:28 AM	2,077.00	14	TQEX
GENMAB A/S	16/04/2024	10:04:28 AM	2,077.00	7	XCSE
GENMAB A/S	16/04/2024	10:04:28 AM	2,077.00	6	XCSE
GENMAB A/S	16/04/2024	10:05:08 AM	2,076.00	14	CEUX
GENMAB A/S	16/04/2024	10:05:08 AM	2,076.00	7	CEUX
GENMAB A/S	16/04/2024	10:05:08 AM	2,076.00	11	TQEX
GENMAB A/S	16/04/2024	10:05:15 AM	2,075.00	40	CEUX
GENMAB A/S	16/04/2024	10:05:15 AM	2,075.00	6	TQEX
GENMAB A/S	16/04/2024	10:05:15 AM	2,075.00	6	AQEU
GENMAB A/S	16/04/2024	10:05:15 AM	2,075.00	44	XCSE
GENMAB A/S	16/04/2024	10:05:18 AM	2,074.00	43	XCSE
GENMAB A/S	16/04/2024	10:05:18 AM	2,074.00	65	XCSE
GENMAB A/S	16/04/2024	10:05:18 AM	2,074.00	21	XCSE
GENMAB A/S	16/04/2024	10:05:18 AM	2,074.00	43	XCSE
GENMAB A/S	16/04/2024	10:05:18 AM	2,074.00	2	XCSE
GENMAB A/S	16/04/2024	10:06:16 AM	2,072.00	44	XCSE
GENMAB A/S	16/04/2024	10:06:16 AM	2,072.00	44	XCSE
GENMAB A/S	16/04/2024	10:06:16 AM	2,072.00	1	XCSE
GENMAB A/S	16/04/2024	10:10:42 AM	2,073.00	90	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	10:10:46 AM	2,072.00	76	CEUX
GENMAB A/S	16/04/2024	10:10:46 AM	2,072.00	12	CEUX
GENMAB A/S	16/04/2024	10:10:46 AM	2,072.00	42	XCSE
GENMAB A/S	16/04/2024	10:10:46 AM	2,072.00	42	XCSE
GENMAB A/S	16/04/2024	10:10:46 AM	2,072.00	5	XCSE
GENMAB A/S	16/04/2024	10:15:47 AM	2,068.00	45	XCSE
GENMAB A/S	16/04/2024	10:15:47 AM	2,068.00	45	XCSE
GENMAB A/S	16/04/2024	10:16:22 AM	2,067.00	12	XCSE
GENMAB A/S	16/04/2024	10:16:22 AM	2,067.00	34	XCSE
GENMAB A/S	16/04/2024	10:16:28 AM	2,067.00	21	XCSE
GENMAB A/S	16/04/2024	10:16:28 AM	2,067.00	21	XCSE
GENMAB A/S	16/04/2024	10:16:28 AM	2,067.00	21	XCSE
GENMAB A/S	16/04/2024	10:16:28 AM	2,067.00	18	XCSE
GENMAB A/S	16/04/2024	10:16:28 AM	2,067.00	14	XCSE
GENMAB A/S	16/04/2024	10:16:33 AM	2,066.00	41	TQEX
GENMAB A/S	16/04/2024	10:16:33 AM	2,066.00	12	TQEX
GENMAB A/S	16/04/2024	10:22:53 AM	2,065.00	23	CEUX
GENMAB A/S	16/04/2024	10:22:53 AM	2,065.00	14	CEUX
GENMAB A/S	16/04/2024	10:22:53 AM	2,065.00	23	CEUX
GENMAB A/S	16/04/2024	10:22:53 AM	2,065.00	14	CEUX
GENMAB A/S	16/04/2024	10:22:53 AM	2,065.00	1	CEUX
GENMAB A/S	16/04/2024	10:22:53 AM	2,065.00	73	XCSE
GENMAB A/S	16/04/2024	10:22:54 AM	2,064.00	47	XCSE
GENMAB A/S	16/04/2024	10:22:54 AM	2,064.00	47	XCSE
GENMAB A/S	16/04/2024	10:22:54 AM	2,064.00	40	XCSE
GENMAB A/S	16/04/2024	10:30:08 AM	2,060.00	43	XCSE
GENMAB A/S	16/04/2024	10:30:08 AM	2,059.00	33	CEUX
GENMAB A/S	16/04/2024	10:30:08 AM	2,059.00	75	XCSE
GENMAB A/S	16/04/2024	10:30:08 AM	2,059.00	9	XCSE
GENMAB A/S	16/04/2024	10:30:08 AM	2,059.00	18	CEUX
GENMAB A/S	16/04/2024	10:34:31 AM	2,069.00	7	XCSE
GENMAB A/S	16/04/2024	10:34:31 AM	2,069.00	36	XCSE
GENMAB A/S	16/04/2024	10:35:57 AM	2,069.00	36	CEUX
GENMAB A/S	16/04/2024	10:35:57 AM	2,069.00	14	CEUX
GENMAB A/S	16/04/2024	10:35:57 AM	2,068.00	81	XCSE
GENMAB A/S	16/04/2024	10:35:57 AM	2,068.00	10	XCSE
GENMAB A/S	16/04/2024	10:35:58 AM	2,067.00	45	XCSE
GENMAB A/S	16/04/2024	10:35:58 AM	2,067.00	86	XCSE
GENMAB A/S	16/04/2024	10:35:58 AM	2,067.00	45	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	10:43:28 AM	2,068.00	21	XCSE
GENMAB A/S	16/04/2024	10:43:28 AM	2,068.00	58	XCSE
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	10	XCSE
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	10	CEUX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	10	CEUX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	3	CEUX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	4	TQEX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	10	XCSE
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	26	XCSE
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	10	CEUX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	10	CEUX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	4	TQEX
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	25	XCSE
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	25	XCSE
GENMAB A/S	16/04/2024	10:45:02 AM	2,068.00	20	XCSE
GENMAB A/S	16/04/2024	10:49:20 AM	2,062.00	16	XCSE
GENMAB A/S	16/04/2024	10:51:33 AM	2,063.00	24	XCSE
GENMAB A/S	16/04/2024	10:51:45 AM	2,063.00	24	XCSE
GENMAB A/S	16/04/2024	10:51:45 AM	2,063.00	20	XCSE
GENMAB A/S	16/04/2024	10:51:45 AM	2,063.00	13	CEUX
GENMAB A/S	16/04/2024	10:51:45 AM	2,063.00	54	CEUX
GENMAB A/S	16/04/2024	10:53:13 AM	2,063.00	47	XCSE
GENMAB A/S	16/04/2024	10:53:13 AM	2,062.00	50	XCSE
GENMAB A/S	16/04/2024	10:53:13 AM	2,062.00	50	XCSE
GENMAB A/S	16/04/2024	10:53:13 AM	2,062.00	20	XCSE
GENMAB A/S	16/04/2024	10:53:13 AM	2,062.00	13	XCSE
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	25	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	27	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	25	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	27	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	11	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	25	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	2	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,063.00	6	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,062.00	75	XCSE
GENMAB A/S	16/04/2024	11:00:00 AM	2,062.00	4	XCSE
GENMAB A/S	16/04/2024	11:00:00 AM	2,062.00	21	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,062.00	56	CEUX
GENMAB A/S	16/04/2024	11:00:00 AM	2,062.00	78	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	11:07:31 AM	2,061.00	94	XCSE
GENMAB A/S	16/04/2024	11:07:31 AM	2,061.00	12	AQEU
GENMAB A/S	16/04/2024	11:07:31 AM	2,061.00	85	CEUX
GENMAB A/S	16/04/2024	11:07:31 AM	2,061.00	13	TQEX
GENMAB A/S	16/04/2024	11:07:31 AM	2,060.00	24	XCSE
GENMAB A/S	16/04/2024	11:07:31 AM	2,060.00	49	XCSE
GENMAB A/S	16/04/2024	11:13:53 AM	2,062.00	20	XCSE
GENMAB A/S	16/04/2024	11:13:53 AM	2,062.00	4	XCSE
GENMAB A/S	16/04/2024	11:13:53 AM	2,062.00	24	XCSE
GENMAB A/S	16/04/2024	11:13:53 AM	2,062.00	30	XCSE
GENMAB A/S	16/04/2024	11:13:53 AM	2,062.00	24	XCSE
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	7	AQEU
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	36	CEUX
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	10	CEUX
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	37	XCSE
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	16	XCSE
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	33	XCSE
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	28	XCSE
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	8	AQEU
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	23	CEUX
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	8	XCSE
GENMAB A/S	16/04/2024	11:19:36 AM	2,062.00	22	XCSE
GENMAB A/S	16/04/2024	11:19:37 AM	2,062.00	22	XCSE
GENMAB A/S	16/04/2024	11:19:37 AM	2,062.00	22	XCSE
GENMAB A/S	16/04/2024	11:19:37 AM	2,062.00	13	XCSE
GENMAB A/S	16/04/2024	11:29:17 AM	2,061.00	1	AQEU
GENMAB A/S	16/04/2024	11:29:17 AM	2,061.00	7	AQEU
GENMAB A/S	16/04/2024	11:29:37 AM	2,061.00	7	AQEU
GENMAB A/S	16/04/2024	11:29:37 AM	2,061.00	1	TQEX
GENMAB A/S	16/04/2024	11:29:59 AM	2,062.00	28	XCSE
GENMAB A/S	16/04/2024	11:29:59 AM	2,062.00	11	XCSE
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	64	XCSE
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	3	AQEU
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	58	CEUX
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	36	CEUX
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	8	TQEX
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	1	TQEX
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	2	TQEX
GENMAB A/S	16/04/2024	11:29:59 AM	2,061.00	8	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	11:30:01 AM	2,060.00	68	CEUX
GENMAB A/S	16/04/2024	11:30:01 AM	2,060.00	17	CEUX
GENMAB A/S	16/04/2024	11:30:01 AM	2,060.00	50	CEUX
GENMAB A/S	16/04/2024	11:34:15 AM	2,059.00	37	XCSE
GENMAB A/S	16/04/2024	11:34:15 AM	2,059.00	74	XCSE
GENMAB A/S	16/04/2024	11:40:10 AM	2,063.00	23	XCSE
GENMAB A/S	16/04/2024	11:40:10 AM	2,063.00	23	XCSE
GENMAB A/S	16/04/2024	11:40:15 AM	2,063.00	23	XCSE
GENMAB A/S	16/04/2024	11:40:15 AM	2,063.00	23	XCSE
GENMAB A/S	16/04/2024	11:40:15 AM	2,063.00	23	XCSE
GENMAB A/S	16/04/2024	11:40:15 AM	2,063.00	10	XCSE
GENMAB A/S	16/04/2024	11:43:24 AM	2,063.00	2	AQEU
GENMAB A/S	16/04/2024	11:43:24 AM	2,063.00	3	CEUX
GENMAB A/S	16/04/2024	11:43:31 AM	2,063.00	8	XCSE
GENMAB A/S	16/04/2024	11:43:31 AM	2,063.00	4	TQEX
GENMAB A/S	16/04/2024	11:44:02 AM	2,063.00	18	CEUX
GENMAB A/S	16/04/2024	11:44:02 AM	2,063.00	8	XCSE
GENMAB A/S	16/04/2024	11:44:02 AM	2,063.00	2	AQEU
GENMAB A/S	16/04/2024	11:44:02 AM	2,063.00	16	CEUX
GENMAB A/S	16/04/2024	11:44:02 AM	2,063.00	12	CEUX
GENMAB A/S	16/04/2024	11:44:02 AM	2,063.00	7	CEUX
GENMAB A/S	16/04/2024	11:44:04 AM	2,063.00	22	XCSE
GENMAB A/S	16/04/2024	11:44:04 AM	2,063.00	22	XCSE
GENMAB A/S	16/04/2024	11:44:04 AM	2,063.00	22	XCSE
GENMAB A/S	16/04/2024	11:44:04 AM	2,063.00	11	XCSE
GENMAB A/S	16/04/2024	11:44:04 AM	2,063.00	11	XCSE
GENMAB A/S	16/04/2024	11:44:04 AM	2,063.00	9	XCSE
GENMAB A/S	16/04/2024	11:49:12 AM	2,063.00	46	XCSE
GENMAB A/S	16/04/2024	11:49:12 AM	2,063.00	25	XCSE
GENMAB A/S	16/04/2024	11:49:34 AM	2,062.00	64	XCSE
GENMAB A/S	16/04/2024	11:52:08 AM	2,060.00	67	CEUX
GENMAB A/S	16/04/2024	11:52:57 AM	2,060.00	70	CEUX
GENMAB A/S	16/04/2024	11:53:45 AM	2,058.00	74	XCSE
GENMAB A/S	16/04/2024	11:59:07 AM	2,061.00	46	XCSE
GENMAB A/S	16/04/2024	11:59:07 AM	2,061.00	6	AQEU
GENMAB A/S	16/04/2024	11:59:07 AM	2,061.00	42	CEUX
GENMAB A/S	16/04/2024	11:59:07 AM	2,061.00	7	TQEX
GENMAB A/S	16/04/2024	12:04:57 PM	2,062.00	68	XCSE
GENMAB A/S	16/04/2024	12:04:57 PM	2,062.00	61	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	12:04:57 PM	2,062.00	9	CEUX
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	2	AQEU
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	6	AQEU
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	55	CEUX
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	9	TQEX
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	42	XCSE
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	19	XCSE
GENMAB A/S	16/04/2024	12:10:45 PM	2,059.00	70	XCSE
GENMAB A/S	16/04/2024	12:18:56 PM	2,076.00	1	AQEU
GENMAB A/S	16/04/2024	12:18:56 PM	2,076.00	7	AQEU
GENMAB A/S	16/04/2024	12:18:59 PM	2,076.00	37	AQEU
GENMAB A/S	16/04/2024	12:18:59 PM	2,075.00	64	XCSE
GENMAB A/S	16/04/2024	12:18:59 PM	2,075.00	35	CEUX
GENMAB A/S	16/04/2024	12:18:59 PM	2,075.00	58	CEUX
GENMAB A/S	16/04/2024	12:18:59 PM	2,075.00	9	TQEX
GENMAB A/S	16/04/2024	12:18:59 PM	2,075.00	9	CEUX
GENMAB A/S	16/04/2024	12:20:41 PM	2,075.00	65	XCSE
GENMAB A/S	16/04/2024	12:20:41 PM	2,075.00	68	CEUX
GENMAB A/S	16/04/2024	12:20:41 PM	2,075.00	6	CEUX
GENMAB A/S	16/04/2024	12:28:29 PM	2,080.00	25	CEUX
GENMAB A/S	16/04/2024	12:28:29 PM	2,080.00	25	CEUX
GENMAB A/S	16/04/2024	12:28:29 PM	2,080.00	19	CEUX
GENMAB A/S	16/04/2024	12:33:32 PM	2,079.00	19	TQEX
GENMAB A/S	16/04/2024	12:33:32 PM	2,079.00	4	TQEX
GENMAB A/S	16/04/2024	12:33:32 PM	2,079.00	19	TQEX
GENMAB A/S	16/04/2024	12:33:32 PM	2,079.00	23	TQEX
GENMAB A/S	16/04/2024	12:33:32 PM	2,079.00	23	TQEX
GENMAB A/S	16/04/2024	12:36:32 PM	2,080.00	41	XCSE
GENMAB A/S	16/04/2024	12:36:37 PM	2,080.00	24	XCSE
GENMAB A/S	16/04/2024	12:37:02 PM	2,080.00	59	CEUX
GENMAB A/S	16/04/2024	12:37:02 PM	2,080.00	6	CEUX
GENMAB A/S	16/04/2024	12:37:02 PM	2,080.00	3	CEUX
GENMAB A/S	16/04/2024	12:37:02 PM	2,080.00	12	CEUX
GENMAB A/S	16/04/2024	12:41:44 PM	2,083.00	44	XCSE
GENMAB A/S	16/04/2024	12:41:44 PM	2,083.00	27	XCSE
GENMAB A/S	16/04/2024	12:41:44 PM	2,083.00	25	XCSE
GENMAB A/S	16/04/2024	12:41:44 PM	2,083.00	2	XCSE
GENMAB A/S	16/04/2024	12:41:44 PM	2,083.00	9	XCSE
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	3	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	36	CEUX
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	41	CEUX
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	24	CEUX
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	6	AQEU
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	7	AQEU
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	24	CEUX
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	6	TQEX
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	44	XCSE
GENMAB A/S	16/04/2024	12:48:47 PM	2,084.00	21	CEUX
GENMAB A/S	16/04/2024	12:57:09 PM	2,083.00	26	XCSE
GENMAB A/S	16/04/2024	12:57:09 PM	2,083.00	26	XCSE
GENMAB A/S	16/04/2024	12:57:09 PM	2,083.00	26	XCSE
GENMAB A/S	16/04/2024	12:57:09 PM	2,083.00	26	XCSE
GENMAB A/S	16/04/2024	12:57:09 PM	2,083.00	26	XCSE
GENMAB A/S	16/04/2024	12:57:09 PM	2,083.00	10	XCSE
GENMAB A/S	16/04/2024	1:02:00 PM	2,082.00	6	AQEU
GENMAB A/S	16/04/2024	1:02:00 PM	2,082.00	10	CEUX
GENMAB A/S	16/04/2024	1:02:00 PM	2,082.00	33	CEUX
GENMAB A/S	16/04/2024	1:02:00 PM	2,082.00	7	TQEX
GENMAB A/S	16/04/2024	1:02:00 PM	2,082.00	47	XCSE
GENMAB A/S	16/04/2024	1:02:00 PM	2,081.00	43	XCSE
GENMAB A/S	16/04/2024	1:02:00 PM	2,081.00	9	XCSE
GENMAB A/S	16/04/2024	1:09:38 PM	2,077.00	25	CEUX
GENMAB A/S	16/04/2024	1:13:32 PM	2,076.00	40	XCSE
GENMAB A/S	16/04/2024	1:13:32 PM	2,076.00	50	XCSE
GENMAB A/S	16/04/2024	1:13:32 PM	2,076.00	49	XCSE
GENMAB A/S	16/04/2024	1:13:39 PM	2,075.00	51	XCSE
GENMAB A/S	16/04/2024	1:13:39 PM	2,075.00	79	CEUX
GENMAB A/S	16/04/2024	1:26:33 PM	2,080.00	10	CEUX
GENMAB A/S	16/04/2024	1:26:33 PM	2,080.00	27	CEUX
GENMAB A/S	16/04/2024	1:26:37 PM	2,080.00	39	XCSE
GENMAB A/S	16/04/2024	1:28:06 PM	2,080.00	9	CEUX
GENMAB A/S	16/04/2024	1:28:06 PM	2,080.00	30	XCSE
GENMAB A/S	16/04/2024	1:29:35 PM	2,080.00	11	CEUX
GENMAB A/S	16/04/2024	1:29:35 PM	2,080.00	29	XCSE
GENMAB A/S	16/04/2024	1:30:10 PM	2,079.00	30	XCSE
GENMAB A/S	16/04/2024	1:30:10 PM	2,079.00	10	CEUX
GENMAB A/S	16/04/2024	1:30:10 PM	2,079.00	10	CEUX
GENMAB A/S	16/04/2024	1:30:10 PM	2,079.00	4	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	1:31:33 PM	2,080.00	26	XCSE
GENMAB A/S	16/04/2024	1:31:33 PM	2,080.00	26	XCSE
GENMAB A/S	16/04/2024	1:31:33 PM	2,080.00	9	XCSE
GENMAB A/S	16/04/2024	1:31:33 PM	2,080.00	24	XCSE
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	26	XCSE
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	14	XCSE
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	4	AQEU
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	4	AQEU
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	4	AQEU
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	11	CEUX
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	13	CEUX
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	14	CEUX
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	13	CEUX
GENMAB A/S	16/04/2024	1:31:39 PM	2,080.00	13	CEUX
GENMAB A/S	16/04/2024	1:38:53 PM	2,083.00	21	XCSE
GENMAB A/S	16/04/2024	1:38:53 PM	2,083.00	15	XCSE
GENMAB A/S	16/04/2024	1:38:53 PM	2,083.00	6	XCSE
GENMAB A/S	16/04/2024	1:38:53 PM	2,083.00	21	XCSE
GENMAB A/S	16/04/2024	1:38:53 PM	2,083.00	21	XCSE
GENMAB A/S	16/04/2024	1:38:57 PM	2,083.00	25	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	21	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	3	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	21	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	1	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	21	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	1	XCSE
GENMAB A/S	16/04/2024	1:48:09 PM	2,085.00	21	XCSE
GENMAB A/S	16/04/2024	1:49:11 PM	2,085.00	53	CEUX
GENMAB A/S	16/04/2024	2:12:48 PM	2,085.00	48	TQEX
GENMAB A/S	16/04/2024	2:26:05 PM	2,085.00	1	XCSE
GENMAB A/S	16/04/2024	2:26:27 PM	2,085.00	81	XCSE
GENMAB A/S	16/04/2024	2:29:39 PM	2,082.00	48	XCSE
GENMAB A/S	16/04/2024	2:29:39 PM	2,082.00	27	XCSE
GENMAB A/S	16/04/2024	2:29:39 PM	2,082.00	20	XCSE
GENMAB A/S	16/04/2024	2:29:57 PM	2,079.00	39	CEUX
GENMAB A/S	16/04/2024	2:39:27 PM	2,081.00	49	CEUX
GENMAB A/S	16/04/2024	2:39:27 PM	2,081.00	25	CEUX
GENMAB A/S	16/04/2024	2:42:18 PM	2,080.00	2	XCSE
GENMAB A/S	16/04/2024	2:42:18 PM	2,080.00	16	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	2:42:18 PM	2,080.00	16	XCSE
GENMAB A/S	16/04/2024	2:42:18 PM	2,080.00	8	CEUX
GENMAB A/S	16/04/2024	2:46:06 PM	2,083.00	29	TQEX
GENMAB A/S	16/04/2024	2:46:56 PM	2,083.00	7	AQEU
GENMAB A/S	16/04/2024	2:47:02 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:47:14 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:47:25 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:47:38 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:47:49 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:48:41 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:49:06 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:49:21 PM	2,083.00	7	TQEX
GENMAB A/S	16/04/2024	2:50:10 PM	2,081.00	95	XCSE
GENMAB A/S	16/04/2024	2:50:10 PM	2,081.00	14	TQEX
GENMAB A/S	16/04/2024	2:50:10 PM	2,081.00	12	AQEU
GENMAB A/S	16/04/2024	2:50:10 PM	2,081.00	75	CEUX
GENMAB A/S	16/04/2024	2:50:10 PM	2,081.00	11	CEUX
GENMAB A/S	16/04/2024	2:50:10 PM	2,080.00	39	CEUX
GENMAB A/S	16/04/2024	2:50:10 PM	2,080.00	40	CEUX
GENMAB A/S	16/04/2024	2:55:57 PM	2,077.00	102	XCSE
GENMAB A/S	16/04/2024	2:55:57 PM	2,077.00	13	AQEU
GENMAB A/S	16/04/2024	2:55:57 PM	2,077.00	92	CEUX
GENMAB A/S	16/04/2024	2:55:57 PM	2,077.00	14	TQEX
GENMAB A/S	16/04/2024	2:55:57 PM	2,076.00	78	CEUX
GENMAB A/S	16/04/2024	2:55:57 PM	2,076.00	74	CEUX
GENMAB A/S	16/04/2024	2:58:18 PM	2,064.00	44	CEUX
GENMAB A/S	16/04/2024	3:00:07 PM	2,061.00	49	CEUX
GENMAB A/S	16/04/2024	3:06:02 PM	2,056.00	22	CEUX
GENMAB A/S	16/04/2024	3:06:45 PM	2,056.00	10	XCSE
GENMAB A/S	16/04/2024	3:06:45 PM	2,056.00	53	XCSE
GENMAB A/S	16/04/2024	3:06:53 PM	2,054.00	15	XCSE
GENMAB A/S	16/04/2024	3:09:49 PM	2,050.00	61	CEUX
GENMAB A/S	16/04/2024	3:11:06 PM	2,048.00	49	XCSE
GENMAB A/S	16/04/2024	3:11:06 PM	2,048.00	49	XCSE
GENMAB A/S	16/04/2024	3:15:38 PM	2,057.00	35	XCSE
GENMAB A/S	16/04/2024	3:16:34 PM	2,056.00	2	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,056.00	56	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,056.00	9	TQEX
GENMAB A/S	16/04/2024	3:16:34 PM	2,056.00	64	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	21	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	19	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	21	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	19	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	2	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	2	CEUX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	4	TQEX
GENMAB A/S	16/04/2024	3:16:34 PM	2,055.00	4	TQEX
GENMAB A/S	16/04/2024	3:20:31 PM	2,056.00	8	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,056.00	96	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,056.00	13	AQEU
GENMAB A/S	16/04/2024	3:20:31 PM	2,056.00	93	CEUX
GENMAB A/S	16/04/2024	3:20:31 PM	2,056.00	15	TQEX
GENMAB A/S	16/04/2024	3:20:31 PM	2,055.00	42	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,055.00	42	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,055.00	19	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,054.00	43	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,054.00	43	XCSE
GENMAB A/S	16/04/2024	3:20:31 PM	2,054.00	21	CEUX
GENMAB A/S	16/04/2024	3:22:40 PM	2,050.00	54	XCSE
GENMAB A/S	16/04/2024	3:22:40 PM	2,050.00	54	CEUX
GENMAB A/S	16/04/2024	3:22:40 PM	2,050.00	4	CEUX
GENMAB A/S	16/04/2024	3:22:41 PM	2,050.00	8	CEUX
GENMAB A/S	16/04/2024	3:23:47 PM	2,046.00	45	XCSE
GENMAB A/S	16/04/2024	3:23:47 PM	2,046.00	1	XCSE
GENMAB A/S	16/04/2024	3:29:22 PM	2,041.00	48	XCSE
GENMAB A/S	16/04/2024	3:30:01 PM	2,040.00	6	AQEU
GENMAB A/S	16/04/2024	3:30:01 PM	2,040.00	45	XCSE
GENMAB A/S	16/04/2024	3:30:01 PM	2,040.00	39	CEUX
GENMAB A/S	16/04/2024	3:30:01 PM	2,040.00	8	CEUX
GENMAB A/S	16/04/2024	3:30:01 PM	2,039.00	2	AQEU
GENMAB A/S	16/04/2024	3:30:01 PM	2,039.00	22	AQEU
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	3	CEUX
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	6	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	1	AQEU
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	6	CEUX
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:16 PM	2,041.00	1	AQEU
GENMAB A/S	16/04/2024	3:33:17 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:17 PM	2,041.00	1	AQEU
GENMAB A/S	16/04/2024	3:33:17 PM	2,041.00	3	CEUX
GENMAB A/S	16/04/2024	3:33:17 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:17 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	1	AQEU
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	6	CEUX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	1	AQEU
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	8	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	1	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	2	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	3	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	1	AQEU
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	9	CEUX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	5	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	1	TQEX
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	7	AQEU
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	30	XCSE
GENMAB A/S	16/04/2024	3:33:21 PM	2,041.00	13	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	120	XCSE
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	3	TQEX
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	14	TQEX
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	4	AQEU
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	4	AQEU
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	7	AQEU
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	75	CEUX
GENMAB A/S	16/04/2024	3:35:30 PM	2,039.00	33	CEUX
GENMAB A/S	16/04/2024	3:35:31 PM	2,037.00	23	XCSE
GENMAB A/S	16/04/2024	3:35:31 PM	2,037.00	21	CEUX
GENMAB A/S	16/04/2024	3:35:31 PM	2,037.00	3	AQEU
GENMAB A/S	16/04/2024	3:35:31 PM	2,037.00	5	TQEX
GENMAB A/S	16/04/2024	3:35:31 PM	2,037.00	23	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	1	AQEU
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	CEUX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	CEUX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	5	TQEX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	5	TQEX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	1	AQEU
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	CEUX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	5	TQEX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	CEUX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	5	TQEX
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	10	XCSE
GENMAB A/S	16/04/2024	3:36:39 PM	2,038.00	18	CEUX
GENMAB A/S	16/04/2024	3:36:40 PM	2,037.00	20	XCSE
GENMAB A/S	16/04/2024	3:36:40 PM	2,037.00	73	CEUX
GENMAB A/S	16/04/2024	3:38:34 PM	2,031.00	1	AQEU
GENMAB A/S	16/04/2024	3:38:34 PM	2,031.00	1	AQEU
GENMAB A/S	16/04/2024	3:38:34 PM	2,031.00	1	AQEU
GENMAB A/S	16/04/2024	3:38:35 PM	2,031.00	1	AQEU
GENMAB A/S	16/04/2024	3:38:42 PM	2,031.00	3	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:38:42 PM	2,031.00	3	AQEU
GENMAB A/S	16/04/2024	3:38:42 PM	2,031.00	67	CEUX
GENMAB A/S	16/04/2024	3:38:42 PM	2,031.00	2	TQEX
GENMAB A/S	16/04/2024	3:38:42 PM	2,031.00	8	TQEX
GENMAB A/S	16/04/2024	3:38:42 PM	2,031.00	75	XCSE
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	22	XCSE
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	3	AQEU
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	3	AQEU
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	20	CEUX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	20	CEUX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	5	TQEX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	3	AQEU
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	5	CEUX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	5	TQEX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	22	XCSE
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	3	CEUX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	47	CEUX
GENMAB A/S	16/04/2024	3:38:56 PM	2,027.00	14	CEUX
GENMAB A/S	16/04/2024	3:39:28 PM	2,023.00	19	CEUX
GENMAB A/S	16/04/2024	3:40:19 PM	2,019.00	19	XCSE
GENMAB A/S	16/04/2024	3:40:20 PM	2,019.00	19	XCSE
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	3	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	1	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	1	AQEU
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	1	XCSE
GENMAB A/S	16/04/2024	3:42:33 PM	2,028.00	1	AQEU
GENMAB A/S	16/04/2024	3:42:34 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:42:37 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	23	XCSE
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	3	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	3	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	AQEU
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	4	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	4	TQEX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	2	AQEU
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	2	AQEU
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	6	AQEU
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	12	AQEU
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	2	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	9	CEUX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	1	TQEX
GENMAB A/S	16/04/2024	3:43:08 PM	2,028.00	2	TQEX
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	50	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	12	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	38	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	3	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	12	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	5	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	5	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	5	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	2	XCSE
GENMAB A/S	16/04/2024	3:43:34 PM	2,024.00	3	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	21	XCSE
GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	6	XCSE
GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	6	XCSE
GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	21	XCSE
GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	21	XCSE
GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	6	XCSE
GENMAB A/S	16/04/2024	3:45:41 PM	2,027.00	1	XCSE
GENMAB A/S	16/04/2024	3:45:43 PM	2,027.00	27	XCSE
GENMAB A/S	16/04/2024	3:45:43 PM	2,027.00	6	XCSE
GENMAB A/S	16/04/2024	3:45:43 PM	2,027.00	7	XCSE
GENMAB A/S	16/04/2024	3:45:43 PM	2,027.00	7	XCSE
GENMAB A/S	16/04/2024	3:45:43 PM	2,027.00	7	XCSE
GENMAB A/S	16/04/2024	3:45:43 PM	2,027.00	8	XCSE
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	16	XCSE
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	3	AQEU
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	3	AQEU
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	16	XCSE
GENMAB A/S	16/04/2024	3:46:30 PM	2,028.00	16	XCSE
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	9	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	9	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	9	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	9	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	3	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	9	XCSE
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	9	XCSE
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	22	XCSE
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	24	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	24	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	2	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	22	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	2	CEUX
GENMAB A/S	16/04/2024	3:48:02 PM	2,029.00	6	CEUX
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	9	XCSE
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	1	AQEU
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	4	AQEU
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	10	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	9	XCSE
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	1	AQEU
GENMAB A/S	16/04/2024	3:48:29 PM	2,028.00	2	CEUX
GENMAB A/S	16/04/2024	3:48:31 PM	2,028.00	1	AQEU
GENMAB A/S	16/04/2024	3:48:31 PM	2,028.00	8	CEUX
GENMAB A/S	16/04/2024	3:48:31 PM	2,028.00	5	TQEX
GENMAB A/S	16/04/2024	3:48:31 PM	2,028.00	9	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	98	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	26	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	15	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	11	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	20	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	11	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	31	XCSE
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	13	AQEU
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	88	CEUX
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	13	TQEX
GENMAB A/S	16/04/2024	3:50:37 PM	2,031.00	5	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	18	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	8	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	4	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	7	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	6	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	4	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	4	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	30	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	5	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	CEUX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	2	TQEX
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	9	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	30	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	23	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	23	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	24	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	23	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	1	XCSE
GENMAB A/S	16/04/2024	3:53:20 PM	2,035.00	3	XCSE
GENMAB A/S	16/04/2024	3:55:24 PM	2,034.00	8	AQEU
GENMAB A/S	16/04/2024	3:55:24 PM	2,034.00	54	CEUX
GENMAB A/S	16/04/2024	3:55:24 PM	2,034.00	8	TQEX
GENMAB A/S	16/04/2024	3:55:24 PM	2,034.00	60	XCSE
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	49	XCSE
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	26	XCSE
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	23	XCSE
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	7	XCSE
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	5	TQEX
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	7	AQEU
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	44	CEUX
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	2	CEUX
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	1	TQEX
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	8	TQEX
GENMAB A/S	16/04/2024	3:57:49 PM	2,042.00	49	XCSE
GENMAB A/S	16/04/2024	3:57:50 PM	2,042.00	60	XCSE
GENMAB A/S	16/04/2024	3:58:50 PM	2,044.00	21	XCSE
GENMAB A/S	16/04/2024	3:58:50 PM	2,044.00	21	XCSE
GENMAB A/S	16/04/2024	3:58:50 PM	2,044.00	21	XCSE
GENMAB A/S	16/04/2024	3:58:50 PM	2,044.00	39	XCSE
GENMAB A/S	16/04/2024	3:59:00 PM	2,044.00	7	AQEU
GENMAB A/S	16/04/2024	3:59:00 PM	2,044.00	8	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	3:59:00 PM	2,044.00	8	TQEX
GENMAB A/S	16/04/2024	3:59:00 PM	2,044.00	56	XCSE
GENMAB A/S	16/04/2024	3:59:00 PM	2,044.00	42	CEUX
GENMAB A/S	16/04/2024	3:59:15 PM	2,041.00	47	XCSE
GENMAB A/S	16/04/2024	3:59:15 PM	2,041.00	21	XCSE
GENMAB A/S	16/04/2024	3:59:15 PM	2,041.00	30	XCSE
GENMAB A/S	16/04/2024	3:59:15 PM	2,041.00	51	XCSE
GENMAB A/S	16/04/2024	3:59:15 PM	2,041.00	24	XCSE
GENMAB A/S	16/04/2024	3:59:15 PM	2,041.00	3	XCSE
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	22	XCSE
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	22	XCSE
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	1	TQEX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	3	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	3	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	3	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	3	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	3	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	8	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	20	CEUX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	12	CEUX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	20	CEUX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	7	CEUX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	4	TQEX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	5	TQEX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	16	TQEX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	8	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	19	XCSE
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	8	AQEU
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	7	TQEX
GENMAB A/S	16/04/2024	4:02:03 PM	2,042.00	8	AQEU
GENMAB A/S	16/04/2024	4:02:14 PM	2,038.00	44	XCSE
GENMAB A/S	16/04/2024	4:02:14 PM	2,038.00	55	XCSE
GENMAB A/S	16/04/2024	4:02:14 PM	2,038.00	14	XCSE
GENMAB A/S	16/04/2024	4:04:04 PM	2,040.00	24	XCSE
GENMAB A/S	16/04/2024	4:04:04 PM	2,040.00	24	XCSE
GENMAB A/S	16/04/2024	4:04:04 PM	2,040.00	24	XCSE
GENMAB A/S	16/04/2024	4:04:05 PM	2,040.00	24	XCSE
GENMAB A/S	16/04/2024	4:04:05 PM	2,040.00	24	XCSE
GENMAB A/S	16/04/2024	4:07:07 PM	2,041.00	9	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:07:21 PM	2,042.00	5	AQEU
GENMAB A/S	16/04/2024	4:07:25 PM	2,042.00	7	AQEU
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	5	AQEU
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	40	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	5	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	26	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	27	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	31	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	24	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	31	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	31	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	1	CEUX
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	27	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	7	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	22	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	29	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	5	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	22	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	2	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	34	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	22	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	48	XCSE
GENMAB A/S	16/04/2024	4:07:54 PM	2,042.00	2	XCSE
GENMAB A/S	16/04/2024	4:08:36 PM	2,042.00	9	XCSE
GENMAB A/S	16/04/2024	4:08:54 PM	2,043.00	64	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	56	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	28	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	28	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	24	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	30	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	16	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,044.00	8	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,043.00	42	XCSE
GENMAB A/S	16/04/2024	4:09:55 PM	2,043.00	44	XCSE
GENMAB A/S	16/04/2024	4:12:02 PM	2,046.00	76	CEUX
GENMAB A/S	16/04/2024	4:12:02 PM	2,046.00	11	TQEX
GENMAB A/S	16/04/2024	4:12:02 PM	2,046.00	83	XCSE
GENMAB A/S	16/04/2024	4:12:02 PM	2,046.00	11	AQEU
GENMAB A/S	16/04/2024	4:13:20 PM	2,044.00	63	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:13:20 PM	2,044.00	8	AQEU
GENMAB A/S	16/04/2024	4:13:20 PM	2,044.00	56	CEUX
GENMAB A/S	16/04/2024	4:13:20 PM	2,044.00	9	TQEX
GENMAB A/S	16/04/2024	4:13:21 PM	2,043.00	48	XCSE
GENMAB A/S	16/04/2024	4:13:21 PM	2,043.00	52	XCSE
GENMAB A/S	16/04/2024	4:13:21 PM	2,043.00	32	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	22	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	22	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	22	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	22	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	22	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	22	XCSE
GENMAB A/S	16/04/2024	4:16:10 PM	2,048.00	4	XCSE
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	10	XCSE
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	5	TQEX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	4	TQEX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	5	TQEX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	5	TQEX
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	10	XCSE
GENMAB A/S	16/04/2024	4:16:55 PM	2,047.00	29	XCSE
GENMAB A/S	16/04/2024	4:16:56 PM	2,047.00	25	XCSE
GENMAB A/S	16/04/2024	4:16:58 PM	2,047.00	3	XCSE
GENMAB A/S	16/04/2024	4:18:15 PM	2,047.00	70	XCSE
GENMAB A/S	16/04/2024	4:18:15 PM	2,047.00	63	CEUX
GENMAB A/S	16/04/2024	4:18:23 PM	2,047.00	9	XCSE
GENMAB A/S	16/04/2024	4:18:23 PM	2,047.00	1	AQEU
GENMAB A/S	16/04/2024	4:18:23 PM	2,047.00	5	CEUX
GENMAB A/S	16/04/2024	4:18:23 PM	2,047.00	9	XCSE
GENMAB A/S	16/04/2024	4:19:19 PM	2,046.00	59	CEUX
GENMAB A/S	16/04/2024	4:19:19 PM	2,046.00	9	TQEX
GENMAB A/S	16/04/2024	4:19:19 PM	2,046.00	66	XCSE
GENMAB A/S	16/04/2024	4:19:19 PM	2,046.00	9	CEUX
GENMAB A/S	16/04/2024	4:20:54 PM	2,045.00	10	AQEU
GENMAB A/S	16/04/2024	4:20:54 PM	2,045.00	72	CEUX
GENMAB A/S	16/04/2024	4:20:54 PM	2,045.00	11	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:20:54 PM	2,045.00	79	XCSE
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	23	XCSE
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	21	XCSE
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	19	XCSE
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	3	AQEU
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	2	AQEU
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	2	AQEU
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	21	CEUX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	21	CEUX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	15	CEUX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	4	CEUX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	21	CEUX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	5	TQEX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	5	TQEX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	5	TQEX
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	23	XCSE
GENMAB A/S	16/04/2024	4:20:55 PM	2,044.00	14	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	7	AQEU
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	37	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	33	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	2	AQEU
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	10	CEUX
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	7	CEUX
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	9	CEUX
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	16	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	20	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	16	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	20	XCSE
GENMAB A/S	16/04/2024	4:25:25 PM	2,045.00	16	XCSE
GENMAB A/S	16/04/2024	4:25:26 PM	2,045.00	16	XCSE
GENMAB A/S	16/04/2024	4:26:17 PM	2,044.00	2	AQEU
GENMAB A/S	16/04/2024	4:26:17 PM	2,044.00	17	CEUX
GENMAB A/S	16/04/2024	4:26:17 PM	2,044.00	5	TQEX
GENMAB A/S	16/04/2024	4:26:17 PM	2,044.00	17	XCSE
GENMAB A/S	16/04/2024	4:26:17 PM	2,044.00	56	XCSE
GENMAB A/S	16/04/2024	4:26:17 PM	2,044.00	17	CEUX
GENMAB A/S	16/04/2024	4:27:17 PM	2,046.00	10	XCSE
GENMAB A/S	16/04/2024	4:27:17 PM	2,046.00	11	CEUX
GENMAB A/S	16/04/2024	4:27:17 PM	2,046.00	11	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:28:38 PM	2,047.00	39	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,048.00	9	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,048.00	14	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,048.00	12	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,048.00	3	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	11	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	13	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	33	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	3	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	2	AQEU
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	21	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	3	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	21	XCSE
GENMAB A/S	16/04/2024	4:29:00 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:02 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:02 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:29:02 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	2	AQEU
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	11	XCSE
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	37	XCSE
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	33	XCSE
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	4	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	10	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	1	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	11	XCSE
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	1	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	23	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	8	CEUX
GENMAB A/S	16/04/2024	4:30:00 PM	2,047.00	6	CEUX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	9	AQEU
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	9	AQEU
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	1	AQEU
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	9	AQEU
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	11	AQEU
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	60	CEUX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	11	CEUX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	9	TQEX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	7	TQEX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	9	TQEX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	15	TQEX
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	67	XCSE
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	11	XCSE
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	56	XCSE
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	11	XCSE
GENMAB A/S	16/04/2024	4:31:46 PM	2,046.00	45	CEUX
GENMAB A/S	16/04/2024	4:31:47 PM	2,046.00	67	XCSE
GENMAB A/S	16/04/2024	4:34:47 PM	2,056.00	26	CEUX
GENMAB A/S	16/04/2024	4:34:47 PM	2,056.00	35	CEUX
GENMAB A/S	16/04/2024	4:34:47 PM	2,056.00	56	CEUX
GENMAB A/S	16/04/2024	4:34:47 PM	2,056.00	18	TQEX
GENMAB A/S	16/04/2024	4:34:47 PM	2,056.00	17	AQEU
GENMAB A/S	16/04/2024	4:34:47 PM	2,056.00	130	XCSE
GENMAB A/S	16/04/2024	4:37:02 PM	2,056.00	85	XCSE
GENMAB A/S	16/04/2024	4:37:02 PM	2,056.00	11	AQEU
GENMAB A/S	16/04/2024	4:37:02 PM	2,056.00	52	CEUX
GENMAB A/S	16/04/2024	4:37:02 PM	2,056.00	24	CEUX
GENMAB A/S	16/04/2024	4:37:02 PM	2,056.00	12	TQEX
GENMAB A/S	16/04/2024	4:37:02 PM	2,055.00	3	AQEU
GENMAB A/S	16/04/2024	4:37:04 PM	2,056.00	18	TQEX
GENMAB A/S	16/04/2024	4:37:04 PM	2,056.00	17	AQEU
GENMAB A/S	16/04/2024	4:37:04 PM	2,056.00	120	CEUX
GENMAB A/S	16/04/2024	4:39:23 PM	2,058.00	1	AQEU
GENMAB A/S	16/04/2024	4:39:23 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:39:23 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:39:23 PM	2,058.00	4	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:39:52 PM	2,058.00	1	AQEU
GENMAB A/S	16/04/2024	4:39:52 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:39:52 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:39:52 PM	2,058.00	7	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	1	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	6	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	XCSE
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	132	XCSE
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	1	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	7	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	1	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	21	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	9	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	13	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	1	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	8	CEUX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	1	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	7	AQEU
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:32 PM	2,058.00	4	TQEX
GENMAB A/S	16/04/2024	4:40:33 PM	2,058.00	11	CEUX
GENMAB A/S	16/04/2024	4:43:49 PM	2,059.00	13	CEUX
GENMAB A/S	16/04/2024	4:43:55 PM	2,060.00	5	AQEU
GENMAB A/S	16/04/2024	4:43:55 PM	2,060.00	16	AQEU
GENMAB A/S	16/04/2024	4:43:55 PM	2,060.00	14	AQEU
GENMAB A/S	16/04/2024	4:44:10 PM	2,060.00	5	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:44:13 PM	2,060.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:17 PM	2,060.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:19 PM	2,060.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:19 PM	2,060.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	37	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	33	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	33	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	16	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	30	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	33	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	4	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	44	CEUX
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	16	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	33	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	37	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,059.00	11	XCSE
GENMAB A/S	16/04/2024	4:44:19 PM	2,058.00	41	CEUX
GENMAB A/S	16/04/2024	4:44:20 PM	2,058.00	90	XCSE
GENMAB A/S	16/04/2024	4:44:20 PM	2,058.00	20	XCSE
GENMAB A/S	16/04/2024	4:44:20 PM	2,058.00	20	XCSE
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	20	XCSE
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	19	CEUX
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	65	CEUX
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	8	CEUX
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	11	CEUX
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	20	XCSE
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	3	AQEU
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	19	CEUX
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	18	CEUX
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	3	XCSE
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	7	AQEU
GENMAB A/S	16/04/2024	4:44:21 PM	2,058.00	12	XCSE
GENMAB A/S	16/04/2024	4:48:03 PM	2,046.00	47	XCSE
GENMAB A/S	16/04/2024	4:48:04 PM	2,046.00	47	XCSE
GENMAB A/S	16/04/2024	4:48:04 PM	2,046.00	36	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:48:23 PM	2,045.00	9	XCSE
GENMAB A/S	16/04/2024	4:48:33 PM	2,046.00	2	AQEU
GENMAB A/S	16/04/2024	4:48:35 PM	2,046.00	12	CEUX
GENMAB A/S	16/04/2024	4:48:35 PM	2,046.00	3	CEUX
GENMAB A/S	16/04/2024	4:48:35 PM	2,046.00	15	CEUX
GENMAB A/S	16/04/2024	4:48:40 PM	2,046.00	15	CEUX
GENMAB A/S	16/04/2024	4:48:40 PM	2,046.00	4	TQEX
GENMAB A/S	16/04/2024	4:48:55 PM	2,046.00	2	AQEU
GENMAB A/S	16/04/2024	4:48:55 PM	2,046.00	15	CEUX
GENMAB A/S	16/04/2024	4:48:55 PM	2,046.00	2	TQEX
GENMAB A/S	16/04/2024	4:49:58 PM	2,046.00	15	CEUX
GENMAB A/S	16/04/2024	4:49:58 PM	2,046.00	6	TQEX
GENMAB A/S	16/04/2024	4:49:59 PM	2,046.00	15	CEUX
GENMAB A/S	16/04/2024	4:49:59 PM	2,046.00	6	TQEX
GENMAB A/S	16/04/2024	4:49:59 PM	2,046.00	15	CEUX
GENMAB A/S	16/04/2024	4:50:15 PM	2,046.00	14	XCSE
GENMAB A/S	16/04/2024	4:50:15 PM	2,046.00	14	XCSE
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	9	AQEU
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	59	CEUX
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	9	TQEX
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	66	XCSE
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	50	XCSE
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	24	XCSE
GENMAB A/S	16/04/2024	4:51:08 PM	2,047.00	24	CEUX
GENMAB A/S	16/04/2024	4:51:17 PM	2,047.00	35	CEUX
GENMAB A/S	16/04/2024	4:51:22 PM	2,046.00	76	XCSE
GENMAB A/S	16/04/2024	4:51:29 PM	2,045.00	8	CEUX
GENMAB A/S	16/04/2024	4:51:29 PM	2,045.00	8	CEUX
GENMAB A/S	16/04/2024	4:51:29 PM	2,045.00	5	TQEX
GENMAB A/S	16/04/2024	4:51:29 PM	2,045.00	8	XCSE
GENMAB A/S	16/04/2024	4:51:35 PM	2,045.00	2	AQEU
GENMAB A/S	16/04/2024	4:51:36 PM	2,045.00	17	CEUX
GENMAB A/S	16/04/2024	4:51:36 PM	2,045.00	18	XCSE
GENMAB A/S	16/04/2024	4:51:41 PM	2,045.00	2	AQEU
GENMAB A/S	16/04/2024	4:51:41 PM	2,045.00	17	CEUX
GENMAB A/S	16/04/2024	4:51:41 PM	2,045.00	17	CEUX
GENMAB A/S	16/04/2024	4:51:41 PM	2,045.00	18	XCSE
GENMAB A/S	16/04/2024	4:51:41 PM	2,045.00	38	XCSE
GENMAB A/S	16/04/2024	4:52:04 PM	2,045.00	5	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	16/04/2024	4:52:50 PM	2,046.00	18	AQEU
GENMAB A/S	16/04/2024	4:52:50 PM	2,046.00	127	CEUX
GENMAB A/S	16/04/2024	4:52:50 PM	2,046.00	19	TQEX
GENMAB A/S	16/04/2024	4:54:26 PM	2,049.00	26	XCSE
GENMAB A/S	16/04/2024	4:54:26 PM	2,049.00	43	XCSE
GENMAB A/S	16/04/2024	4:54:26 PM	2,049.00	26	XCSE
GENMAB A/S	16/04/2024	4:54:26 PM	2,049.00	26	XCSE
GENMAB A/S	16/04/2024	4:54:27 PM	2,049.00	19	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	7	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	7	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	19	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	19	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	10	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	25	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	25	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	25	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	14	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	8	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	19	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	3	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	18	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	8	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	11	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	19	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	7	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	8	CEUX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	3	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	3	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	2	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	2	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	4	TQEX
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	25	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	22	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	25	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	16	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	6	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	3	XCSE
GENMAB A/S	17/04/2024	9:00:22 AM	2,055.00	13	XCSE
GENMAB A/S	17/04/2024	9:01:50 AM	2,059.00	42	CEUX
GENMAB A/S	17/04/2024	9:06:57 AM	2,069.00	2	CEUX
GENMAB A/S	17/04/2024	9:07:31 AM	2,066.00	89	XCSE
GENMAB A/S	17/04/2024	9:07:33 AM	2,062.00	42	CEUX
GENMAB A/S	17/04/2024	9:07:33 AM	2,062.00	38	CEUX
GENMAB A/S	17/04/2024	9:07:33 AM	2,062.00	34	CEUX
GENMAB A/S	17/04/2024	9:07:34 AM	2,061.00	75	XCSE
GENMAB A/S	17/04/2024	9:07:34 AM	2,061.00	8	XCSE
GENMAB A/S	17/04/2024	9:07:34 AM	2,061.00	67	XCSE
GENMAB A/S	17/04/2024	9:07:34 AM	2,061.00	10	XCSE
GENMAB A/S	17/04/2024	9:11:29 AM	2,057.00	37	CEUX
GENMAB A/S	17/04/2024	9:11:29 AM	2,056.00	13	CEUX
GENMAB A/S	17/04/2024	9:11:29 AM	2,056.00	78	CEUX
GENMAB A/S	17/04/2024	9:11:29 AM	2,056.00	38	TQEX
GENMAB A/S	17/04/2024	9:11:29 AM	2,056.00	44	TQEX
GENMAB A/S	17/04/2024	9:11:29 AM	2,056.00	6	TQEX
GENMAB A/S	17/04/2024	9:11:29 AM	2,056.00	5	TQEX
GENMAB A/S	17/04/2024	9:17:14 AM	2,057.00	24	XCSE
GENMAB A/S	17/04/2024	9:17:14 AM	2,057.00	13	XCSE
GENMAB A/S	17/04/2024	9:17:14 AM	2,057.00	24	XCSE
GENMAB A/S	17/04/2024	9:17:14 AM	2,057.00	30	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	9:17:14 AM	2,057.00	2	XCSE
GENMAB A/S	17/04/2024	9:18:42 AM	2,058.00	55	XCSE
GENMAB A/S	17/04/2024	9:18:42 AM	2,058.00	50	CEUX
GENMAB A/S	17/04/2024	9:18:42 AM	2,058.00	8	TQEX
GENMAB A/S	17/04/2024	9:19:37 AM	2,057.00	81	CEUX
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	41	CEUX
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	20	CEUX
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	25	CEUX
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	41	CEUX
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	52	XCSE
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	52	XCSE
GENMAB A/S	17/04/2024	9:19:37 AM	2,056.00	3	CEUX
GENMAB A/S	17/04/2024	9:25:30 AM	2,056.00	26	CEUX
GENMAB A/S	17/04/2024	9:25:30 AM	2,056.00	8	CEUX
GENMAB A/S	17/04/2024	9:27:14 AM	2,053.00	43	XCSE
GENMAB A/S	17/04/2024	9:27:14 AM	2,053.00	51	XCSE
GENMAB A/S	17/04/2024	9:30:19 AM	2,055.00	26	XCSE
GENMAB A/S	17/04/2024	9:30:19 AM	2,055.00	26	XCSE
GENMAB A/S	17/04/2024	9:30:19 AM	2,055.00	26	XCSE
GENMAB A/S	17/04/2024	9:30:19 AM	2,055.00	21	XCSE
GENMAB A/S	17/04/2024	9:31:22 AM	2,056.00	44	XCSE
GENMAB A/S	17/04/2024	9:31:22 AM	2,056.00	6	AQEU
GENMAB A/S	17/04/2024	9:31:22 AM	2,056.00	39	CEUX
GENMAB A/S	17/04/2024	9:31:22 AM	2,056.00	6	TQEX
GENMAB A/S	17/04/2024	9:31:59 AM	2,051.00	45	XCSE
GENMAB A/S	17/04/2024	9:34:27 AM	2,050.00	24	XCSE
GENMAB A/S	17/04/2024	9:34:27 AM	2,050.00	24	XCSE
GENMAB A/S	17/04/2024	9:34:27 AM	2,050.00	24	XCSE
GENMAB A/S	17/04/2024	9:34:27 AM	2,050.00	30	XCSE
GENMAB A/S	17/04/2024	9:34:27 AM	2,050.00	14	XCSE
GENMAB A/S	17/04/2024	9:36:02 AM	2,047.00	50	XCSE
GENMAB A/S	17/04/2024	9:36:02 AM	2,047.00	10	XCSE
GENMAB A/S	17/04/2024	9:36:02 AM	2,047.00	40	XCSE
GENMAB A/S	17/04/2024	9:36:02 AM	2,047.00	7	XCSE
GENMAB A/S	17/04/2024	9:38:22 AM	2,043.00	23	XCSE
GENMAB A/S	17/04/2024	9:38:22 AM	2,043.00	23	XCSE
GENMAB A/S	17/04/2024	9:38:22 AM	2,043.00	23	XCSE
GENMAB A/S	17/04/2024	9:38:22 AM	2,043.00	25	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,044.00	24	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	9:40:29 AM	2,044.00	24	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,044.00	24	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,044.00	24	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,044.00	8	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,043.00	23	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,043.00	37	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,043.00	23	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,043.00	15	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,043.00	8	XCSE
GENMAB A/S	17/04/2024	9:40:29 AM	2,043.00	2	XCSE
GENMAB A/S	17/04/2024	9:44:38 AM	2,040.00	7	AQEU
GENMAB A/S	17/04/2024	9:44:38 AM	2,040.00	35	CEUX
GENMAB A/S	17/04/2024	9:44:38 AM	2,040.00	73	AQEU
GENMAB A/S	17/04/2024	9:44:39 AM	2,038.00	57	XCSE
GENMAB A/S	17/04/2024	9:44:39 AM	2,038.00	27	XCSE
GENMAB A/S	17/04/2024	9:44:39 AM	2,038.00	3	XCSE
GENMAB A/S	17/04/2024	9:44:39 AM	2,038.00	78	XCSE
GENMAB A/S	17/04/2024	9:48:46 AM	2,034.00	75	XCSE
GENMAB A/S	17/04/2024	9:48:46 AM	2,034.00	5	XCSE
GENMAB A/S	17/04/2024	9:53:55 AM	2,033.00	23	XCSE
GENMAB A/S	17/04/2024	9:53:55 AM	2,033.00	1	XCSE
GENMAB A/S	17/04/2024	9:53:55 AM	2,033.00	24	XCSE
GENMAB A/S	17/04/2024	9:53:55 AM	2,033.00	24	XCSE
GENMAB A/S	17/04/2024	9:53:55 AM	2,033.00	21	XCSE
GENMAB A/S	17/04/2024	9:55:26 AM	2,035.00	82	CEUX
GENMAB A/S	17/04/2024	9:59:51 AM	2,037.00	1	CEUX
GENMAB A/S	17/04/2024	9:59:51 AM	2,037.00	26	CEUX
GENMAB A/S	17/04/2024	10:00:10 AM	2,039.00	57	XCSE
GENMAB A/S	17/04/2024	10:00:10 AM	2,039.00	79	XCSE
GENMAB A/S	17/04/2024	10:00:10 AM	2,038.00	66	XCSE
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	CEUX
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	CEUX
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	CEUX
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	XCSE
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	XCSE
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	50	XCSE
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	CEUX
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	CEUX
GENMAB A/S	17/04/2024	10:03:39 AM	2,040.00	11	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	10:03:43 AM	2,038.00	63	XCSE
GENMAB A/S	17/04/2024	10:03:43 AM	2,038.00	14	XCSE
GENMAB A/S	17/04/2024	10:10:52 AM	2,037.00	20	AQEU
GENMAB A/S	17/04/2024	10:10:52 AM	2,037.00	20	TQEX
GENMAB A/S	17/04/2024	10:10:52 AM	2,037.00	2	TQEX
GENMAB A/S	17/04/2024	10:10:52 AM	2,037.00	159	XCSE
GENMAB A/S	17/04/2024	10:15:33 AM	2,036.00	21	XCSE
GENMAB A/S	17/04/2024	10:15:33 AM	2,036.00	21	XCSE
GENMAB A/S	17/04/2024	10:15:33 AM	2,036.00	85	XCSE
GENMAB A/S	17/04/2024	10:15:33 AM	2,036.00	22	XCSE
GENMAB A/S	17/04/2024	10:17:21 AM	2,029.00	54	CEUX
GENMAB A/S	17/04/2024	10:17:21 AM	2,029.00	18	CEUX
GENMAB A/S	17/04/2024	10:17:21 AM	2,030.00	24	CEUX
GENMAB A/S	17/04/2024	10:17:21 AM	2,030.00	24	CEUX
GENMAB A/S	17/04/2024	10:17:21 AM	2,030.00	15	CEUX
GENMAB A/S	17/04/2024	10:17:21 AM	2,029.00	40	XCSE
GENMAB A/S	17/04/2024	10:17:21 AM	2,029.00	24	XCSE
GENMAB A/S	17/04/2024	10:17:21 AM	2,029.00	39	CEUX
GENMAB A/S	17/04/2024	10:25:02 AM	2,026.00	66	XCSE
GENMAB A/S	17/04/2024	10:25:02 AM	2,026.00	66	TQEX
GENMAB A/S	17/04/2024	10:29:11 AM	2,032.00	34	XCSE
GENMAB A/S	17/04/2024	10:29:11 AM	2,032.00	42	XCSE
GENMAB A/S	17/04/2024	10:30:22 AM	2,031.00	52	AQEU
GENMAB A/S	17/04/2024	10:30:22 AM	2,031.00	20	AQEU
GENMAB A/S	17/04/2024	10:30:22 AM	2,030.00	70	XCSE
GENMAB A/S	17/04/2024	10:30:22 AM	2,030.00	71	XCSE
GENMAB A/S	17/04/2024	10:30:22 AM	2,030.00	35	XCSE
GENMAB A/S	17/04/2024	10:36:41 AM	2,034.00	91	XCSE
GENMAB A/S	17/04/2024	10:36:42 AM	2,033.00	1	CEUX
GENMAB A/S	17/04/2024	10:37:51 AM	2,029.00	42	XCSE
GENMAB A/S	17/04/2024	10:37:51 AM	2,029.00	14	XCSE
GENMAB A/S	17/04/2024	10:37:51 AM	2,029.00	20	XCSE
GENMAB A/S	17/04/2024	10:37:51 AM	2,029.00	8	XCSE
GENMAB A/S	17/04/2024	10:37:51 AM	2,029.00	28	XCSE
GENMAB A/S	17/04/2024	10:39:47 AM	2,029.00	29	TQEX
GENMAB A/S	17/04/2024	10:39:47 AM	2,029.00	63	TQEX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	32	XCSE
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	4	AQEU
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	1	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	5	AQEU
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	31	CEUX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	30	CEUX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	4	TQEX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	1	TQEX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	4	TQEX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	32	XCSE
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	8	CEUX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	35	CEUX
GENMAB A/S	17/04/2024	10:44:03 AM	2,030.00	19	CEUX
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	22	XCSE
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	109	XCSE
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	10	AQEU
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	7	AQEU
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	70	CEUX
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	47	CEUX
GENMAB A/S	17/04/2024	10:48:14 AM	2,029.00	18	TQEX
GENMAB A/S	17/04/2024	10:51:45 AM	2,028.00	81	XCSE
GENMAB A/S	17/04/2024	10:55:51 AM	2,026.00	22	CEUX
GENMAB A/S	17/04/2024	10:55:51 AM	2,026.00	22	CEUX
GENMAB A/S	17/04/2024	10:55:51 AM	2,026.00	22	CEUX
GENMAB A/S	17/04/2024	10:55:51 AM	2,026.00	16	CEUX
GENMAB A/S	17/04/2024	11:00:16 AM	2,026.00	40	XCSE
GENMAB A/S	17/04/2024	11:00:16 AM	2,026.00	27	XCSE
GENMAB A/S	17/04/2024	11:00:16 AM	2,026.00	43	XCSE
GENMAB A/S	17/04/2024	11:00:16 AM	2,026.00	43	XCSE
GENMAB A/S	17/04/2024	11:00:16 AM	2,026.00	44	XCSE
GENMAB A/S	17/04/2024	11:00:16 AM	2,026.00	17	XCSE
GENMAB A/S	17/04/2024	11:01:30 AM	2,025.00	25	XCSE
GENMAB A/S	17/04/2024	11:01:30 AM	2,025.00	25	XCSE
GENMAB A/S	17/04/2024	11:01:30 AM	2,025.00	38	XCSE
GENMAB A/S	17/04/2024	11:01:30 AM	2,024.00	41	CEUX
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	10	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	76	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	21	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	21	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	16	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	1	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	20	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	11:07:43 AM	2,029.00	6	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,028.00	24	CEUX
GENMAB A/S	17/04/2024	11:07:43 AM	2,028.00	46	XCSE
GENMAB A/S	17/04/2024	11:07:43 AM	2,028.00	24	CEUX
GENMAB A/S	17/04/2024	11:07:43 AM	2,028.00	24	CEUX
GENMAB A/S	17/04/2024	11:07:43 AM	2,028.00	15	CEUX
GENMAB A/S	17/04/2024	11:09:51 AM	2,021.00	1	CEUX
GENMAB A/S	17/04/2024	11:09:51 AM	2,021.00	44	CEUX
GENMAB A/S	17/04/2024	11:09:51 AM	2,021.00	1	CEUX
GENMAB A/S	17/04/2024	11:09:51 AM	2,021.00	17	CEUX
GENMAB A/S	17/04/2024	11:09:51 AM	2,021.00	28	CEUX
GENMAB A/S	17/04/2024	11:09:51 AM	2,021.00	1	CEUX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	49	XCSE
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	2	TQEX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	7	AQEU
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	7	AQEU
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	7	AQEU
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	18	CEUX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	7	CEUX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	20	CEUX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	4	TQEX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	4	TQEX
GENMAB A/S	17/04/2024	11:17:08 AM	2,019.00	49	XCSE
GENMAB A/S	17/04/2024	11:17:11 AM	2,019.00	2	AQEU
GENMAB A/S	17/04/2024	11:17:14 AM	2,018.00	27	XCSE
GENMAB A/S	17/04/2024	11:17:14 AM	2,018.00	1	XCSE
GENMAB A/S	17/04/2024	11:17:14 AM	2,018.00	14	XCSE
GENMAB A/S	17/04/2024	11:17:14 AM	2,018.00	1	XCSE
GENMAB A/S	17/04/2024	11:17:14 AM	2,018.00	42	XCSE
GENMAB A/S	17/04/2024	11:17:14 AM	2,018.00	31	XCSE
GENMAB A/S	17/04/2024	11:22:25 AM	2,009.00	58	XCSE
GENMAB A/S	17/04/2024	11:22:25 AM	2,009.00	35	XCSE
GENMAB A/S	17/04/2024	11:22:25 AM	2,009.00	89	CEUX
GENMAB A/S	17/04/2024	11:29:23 AM	2,011.00	8	XCSE
GENMAB A/S	17/04/2024	11:29:23 AM	2,011.00	71	XCSE
GENMAB A/S	17/04/2024	11:29:28 AM	2,011.00	36	CEUX
GENMAB A/S	17/04/2024	11:29:28 AM	2,011.00	31	CEUX
GENMAB A/S	17/04/2024	11:29:28 AM	2,011.00	6	TQEX
GENMAB A/S	17/04/2024	11:29:28 AM	2,011.00	39	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	11:29:29 AM	2,011.00	71	CEUX
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	CEUX
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	CEUX
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	XCSE
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	2	XCSE
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	XCSE
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	XCSE
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	CEUX
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	CEUX
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	CEUX
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	XCSE
GENMAB A/S	17/04/2024	11:37:08 AM	2,014.00	13	CEUX
GENMAB A/S	17/04/2024	11:37:09 AM	2,014.00	7	CEUX
GENMAB A/S	17/04/2024	11:37:09 AM	2,014.00	13	XCSE
GENMAB A/S	17/04/2024	11:37:09 AM	2,014.00	26	CEUX
GENMAB A/S	17/04/2024	11:40:00 AM	2,017.00	1	AQEU
GENMAB A/S	17/04/2024	11:40:00 AM	2,017.00	38	AQEU
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	10	XCSE
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	81	XCSE
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	10	XCSE
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	22	XCSE
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	2	AQEU
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	9	CEUX
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	5	TQEX
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	5	TQEX
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	14	TQEX
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	5	TQEX
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	12	TQEX
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	26	XCSE
GENMAB A/S	17/04/2024	11:41:05 AM	2,017.00	4	XCSE
GENMAB A/S	17/04/2024	11:45:14 AM	2,018.00	26	XCSE
GENMAB A/S	17/04/2024	11:45:14 AM	2,018.00	26	XCSE
GENMAB A/S	17/04/2024	11:45:14 AM	2,018.00	25	XCSE
GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	7	AQEU
GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	2	AQEU
GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	65	CEUX
GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	10	TQEX
GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	65	XCSE
GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	21	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	11:47:36 AM	2,017.00	72	XCSE
GENMAB A/S	17/04/2024	11:47:36 AM	2,016.00	10	XCSE
GENMAB A/S	17/04/2024	11:47:36 AM	2,016.00	87	XCSE
GENMAB A/S	17/04/2024	11:51:14 AM	2,017.00	84	XCSE
GENMAB A/S	17/04/2024	11:58:06 AM	2,015.00	10	CEUX
GENMAB A/S	17/04/2024	11:58:06 AM	2,015.00	3	CEUX
GENMAB A/S	17/04/2024	11:58:06 AM	2,015.00	7	CEUX
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	8	AQEU
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	47	CEUX
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	28	CEUX
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	25	CEUX
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	8	TQEX
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	38	XCSE
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	31	XCSE
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	66	XCSE
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	34	XCSE
GENMAB A/S	17/04/2024	11:59:52 AM	2,015.00	24	XCSE
GENMAB A/S	17/04/2024	11:59:54 AM	2,014.00	52	XCSE
GENMAB A/S	17/04/2024	11:59:54 AM	2,014.00	48	XCSE
GENMAB A/S	17/04/2024	12:00:03 PM	2,014.00	29	XCSE
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	7	AQEU
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	8	AQEU
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	3	TQEX
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	84	XCSE
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	53	XCSE
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	6	TQEX
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	2	CEUX
GENMAB A/S	17/04/2024	12:05:11 PM	2,015.00	1	CEUX
GENMAB A/S	17/04/2024	12:05:12 PM	2,015.00	1	CEUX
GENMAB A/S	17/04/2024	12:07:42 PM	2,014.00	2	CEUX
GENMAB A/S	17/04/2024	12:07:42 PM	2,014.00	38	CEUX
GENMAB A/S	17/04/2024	12:09:46 PM	2,011.00	85	CEUX
GENMAB A/S	17/04/2024	12:09:46 PM	2,011.00	84	XCSE
GENMAB A/S	17/04/2024	12:11:12 PM	2,004.00	43	XCSE
GENMAB A/S	17/04/2024	12:16:59 PM	2,007.00	78	XCSE
GENMAB A/S	17/04/2024	12:16:59 PM	2,006.00	6	CEUX
GENMAB A/S	17/04/2024	12:16:59 PM	2,006.00	4	CEUX
GENMAB A/S	17/04/2024	12:17:00 PM	2,006.00	65	CEUX
GENMAB A/S	17/04/2024	12:17:00 PM	2,006.00	10	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	12:17:00 PM	2,006.00	36	TQEX
GENMAB A/S	17/04/2024	12:19:52 PM	2,006.00	31	XCSE
GENMAB A/S	17/04/2024	12:19:52 PM	2,006.00	31	XCSE
GENMAB A/S	17/04/2024	12:19:52 PM	2,006.00	34	XCSE
GENMAB A/S	17/04/2024	12:19:52 PM	2,006.00	31	XCSE
GENMAB A/S	17/04/2024	12:19:52 PM	2,006.00	17	XCSE
GENMAB A/S	17/04/2024	12:25:18 PM	2,012.00	41	CEUX
GENMAB A/S	17/04/2024	12:25:18 PM	2,012.00	36	CEUX
GENMAB A/S	17/04/2024	12:25:18 PM	2,012.00	5	CEUX
GENMAB A/S	17/04/2024	12:25:18 PM	2,012.00	2	CEUX
GENMAB A/S	17/04/2024	12:25:18 PM	2,012.00	3	CEUX
GENMAB A/S	17/04/2024	12:30:25 PM	2,015.00	56	AQEU
GENMAB A/S	17/04/2024	12:30:25 PM	2,015.00	21	AQEU
GENMAB A/S	17/04/2024	12:30:25 PM	2,014.00	80	XCSE
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	38	XCSE
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	5	AQEU
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	8	AQEU
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	34	CEUX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	4	CEUX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	19	CEUX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	6	TQEX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	6	TQEX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	5	CEUX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	12	XCSE
GENMAB A/S	17/04/2024	12:33:57 PM	2,014.00	29	AQEU
GENMAB A/S	17/04/2024	12:37:28 PM	2,013.00	17	XCSE
GENMAB A/S	17/04/2024	12:37:28 PM	2,013.00	1	XCSE
GENMAB A/S	17/04/2024	12:37:28 PM	2,013.00	6	XCSE
GENMAB A/S	17/04/2024	12:37:28 PM	2,013.00	1	XCSE
GENMAB A/S	17/04/2024	12:37:28 PM	2,013.00	6	XCSE
GENMAB A/S	17/04/2024	12:39:20 PM	2,013.00	125	XCSE
GENMAB A/S	17/04/2024	12:39:20 PM	2,013.00	16	AQEU
GENMAB A/S	17/04/2024	12:39:20 PM	2,013.00	102	CEUX
GENMAB A/S	17/04/2024	12:39:20 PM	2,013.00	11	CEUX
GENMAB A/S	17/04/2024	12:39:20 PM	2,013.00	17	TQEX
GENMAB A/S	17/04/2024	12:39:20 PM	2,012.00	71	XCSE
GENMAB A/S	17/04/2024	12:39:20 PM	2,012.00	16	XCSE
GENMAB A/S	17/04/2024	12:45:17 PM	2,009.00	9	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	12:45:17 PM	2,009.00	8	CEUX
GENMAB A/S	17/04/2024	12:45:47 PM	2,009.00	9	CEUX
GENMAB A/S	17/04/2024	12:45:47 PM	2,009.00	5	TQEX
GENMAB A/S	17/04/2024	12:45:47 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	12:50:12 PM	2,010.00	1	AQEU
GENMAB A/S	17/04/2024	12:50:12 PM	2,010.00	15	AQEU
GENMAB A/S	17/04/2024	12:50:12 PM	2,010.00	7	AQEU
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	24	XCSE
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	3	AQEU
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	17	CEUX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	5	CEUX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	17	CEUX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	5	TQEX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	73	TQEX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	11	TQEX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	5	TQEX
GENMAB A/S	17/04/2024	12:50:30 PM	2,008.00	31	TQEX
GENMAB A/S	17/04/2024	12:51:42 PM	2,008.00	38	CEUX
GENMAB A/S	17/04/2024	12:51:42 PM	2,008.00	9	AQEU
GENMAB A/S	17/04/2024	12:51:42 PM	2,008.00	24	CEUX
GENMAB A/S	17/04/2024	12:51:42 PM	2,008.00	10	TQEX
GENMAB A/S	17/04/2024	12:51:42 PM	2,008.00	40	XCSE
GENMAB A/S	17/04/2024	12:51:42 PM	2,008.00	30	XCSE
GENMAB A/S	17/04/2024	12:51:42 PM	2,007.00	39	CEUX
GENMAB A/S	17/04/2024	12:51:42 PM	2,007.00	42	CEUX
GENMAB A/S	17/04/2024	12:54:31 PM	2,006.00	3	CEUX
GENMAB A/S	17/04/2024	12:55:49 PM	2,006.00	46	XCSE
GENMAB A/S	17/04/2024	12:55:49 PM	2,006.00	46	XCSE
GENMAB A/S	17/04/2024	12:55:49 PM	2,006.00	12	AQEU
GENMAB A/S	17/04/2024	12:55:49 PM	2,006.00	75	CEUX
GENMAB A/S	17/04/2024	12:55:49 PM	2,006.00	8	CEUX
GENMAB A/S	17/04/2024	12:55:49 PM	2,006.00	13	TQEX
GENMAB A/S	17/04/2024	12:58:32 PM	2,007.00	29	XCSE
GENMAB A/S	17/04/2024	12:58:32 PM	2,007.00	61	XCSE
GENMAB A/S	17/04/2024	12:58:32 PM	2,007.00	43	XCSE
GENMAB A/S	17/04/2024	12:58:32 PM	2,007.00	13	XCSE
GENMAB A/S	17/04/2024	12:58:32 PM	2,007.00	33	XCSE
GENMAB A/S	17/04/2024	1:05:35 PM	2,005.00	24	XCSE
GENMAB A/S	17/04/2024	1:05:35 PM	2,005.00	24	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	1:05:36 PM	2,005.00	2	XCSE
GENMAB A/S	17/04/2024	1:05:36 PM	2,005.00	4	XCSE
GENMAB A/S	17/04/2024	1:05:36 PM	2,005.00	8	XCSE
GENMAB A/S	17/04/2024	1:08:40 PM	2,006.00	7	AQEU
GENMAB A/S	17/04/2024	1:08:40 PM	2,006.00	48	CEUX
GENMAB A/S	17/04/2024	1:08:40 PM	2,006.00	48	CEUX
GENMAB A/S	17/04/2024	1:08:40 PM	2,006.00	28	XCSE
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	25	XCSE
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	4	AQEU
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	3	AQEU
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	4	AQEU
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	41	CEUX
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	8	TQEX
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	8	TQEX
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	32	XCSE
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	21	XCSE
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	21	XCSE
GENMAB A/S	17/04/2024	1:08:51 PM	2,006.00	22	XCSE
GENMAB A/S	17/04/2024	1:13:34 PM	2,009.00	3	CEUX
GENMAB A/S	17/04/2024	1:13:34 PM	2,009.00	61	CEUX
GENMAB A/S	17/04/2024	1:13:34 PM	2,009.00	45	CEUX
GENMAB A/S	17/04/2024	1:13:34 PM	2,009.00	120	XCSE
GENMAB A/S	17/04/2024	1:18:59 PM	2,010.00	81	XCSE
GENMAB A/S	17/04/2024	1:18:59 PM	2,010.00	72	CEUX
GENMAB A/S	17/04/2024	1:18:59 PM	2,010.00	11	TQEX
GENMAB A/S	17/04/2024	1:18:59 PM	2,010.00	11	CEUX
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	22	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	13	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	9	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	22	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	22	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	22	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	22	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	22	XCSE
GENMAB A/S	17/04/2024	1:20:58 PM	2,009.00	1	XCSE
GENMAB A/S	17/04/2024	1:23:49 PM	2,009.00	9	CEUX
GENMAB A/S	17/04/2024	1:24:59 PM	2,008.00	66	XCSE
GENMAB A/S	17/04/2024	1:24:59 PM	2,008.00	9	AQEU
GENMAB A/S	17/04/2024	1:24:59 PM	2,008.00	60	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	1:24:59 PM	2,008.00	9	TQEX
GENMAB A/S	17/04/2024	1:31:18 PM	2,007.00	74	XCSE
GENMAB A/S	17/04/2024	1:31:18 PM	2,007.00	10	AQEU
GENMAB A/S	17/04/2024	1:31:18 PM	2,007.00	66	CEUX
GENMAB A/S	17/04/2024	1:31:18 PM	2,007.00	10	TQEX
GENMAB A/S	17/04/2024	1:31:18 PM	2,006.00	83	CEUX
GENMAB A/S	17/04/2024	1:31:18 PM	2,006.00	67	XCSE
GENMAB A/S	17/04/2024	1:31:18 PM	2,006.00	9	XCSE
GENMAB A/S	17/04/2024	1:31:18 PM	2,006.00	7	XCSE
GENMAB A/S	17/04/2024	1:35:04 PM	2,003.00	62	CEUX
GENMAB A/S	17/04/2024	1:35:04 PM	2,003.00	91	XCSE
GENMAB A/S	17/04/2024	1:44:28 PM	2,004.00	35	CEUX
GENMAB A/S	17/04/2024	1:44:53 PM	2,003.00	75	CEUX
GENMAB A/S	17/04/2024	1:44:53 PM	2,003.00	4	CEUX
GENMAB A/S	17/04/2024	1:44:53 PM	2,003.00	12	TQEX
GENMAB A/S	17/04/2024	1:44:53 PM	2,003.00	89	XCSE
GENMAB A/S	17/04/2024	1:44:55 PM	2,003.00	12	XCSE
GENMAB A/S	17/04/2024	1:49:25 PM	2,006.00	40	CEUX
GENMAB A/S	17/04/2024	1:50:52 PM	2,012.00	13	CEUX
GENMAB A/S	17/04/2024	1:50:52 PM	2,012.00	26	CEUX
GENMAB A/S	17/04/2024	1:51:09 PM	2,012.00	36	CEUX
GENMAB A/S	17/04/2024	1:51:09 PM	2,012.00	2	XCSE
GENMAB A/S	17/04/2024	1:51:53 PM	2,014.00	34	XCSE
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	9	CEUX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	8	XCSE
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	8	XCSE
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	8	XCSE
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	9	CEUX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	9	CEUX
GENMAB A/S	17/04/2024	1:52:39 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	1:54:25 PM	2,016.00	15	XCSE
GENMAB A/S	17/04/2024	1:54:25 PM	2,016.00	24	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	6	AQEU
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	20	CEUX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	17	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	20	CEUX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	41	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	2	AQEU
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	37	CEUX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	37	CEUX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	4	CEUX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	41	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	5	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	22	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	14	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	26	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	4	AQEU
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	2	AQEU
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	34	XCSE
GENMAB A/S	17/04/2024	1:54:31 PM	2,014.00	7	XCSE
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	3	AQEU
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	22	CEUX
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	8	CEUX
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	18	CEUX
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	4	CEUX
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	23	XCSE
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	14	XCSE
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	9	XCSE
GENMAB A/S	17/04/2024	2:00:24 PM	2,011.00	13	XCSE
GENMAB A/S	17/04/2024	2:00:26 PM	2,011.00	38	XCSE
GENMAB A/S	17/04/2024	2:05:10 PM	2,006.00	84	XCSE
GENMAB A/S	17/04/2024	2:05:10 PM	2,006.00	75	CEUX
GENMAB A/S	17/04/2024	2:05:10 PM	2,006.00	6	CEUX
GENMAB A/S	17/04/2024	2:09:52 PM	2,008.00	32	CEUX
GENMAB A/S	17/04/2024	2:09:52 PM	2,008.00	8	CEUX
GENMAB A/S	17/04/2024	2:10:31 PM	2,006.00	17	AQEU
GENMAB A/S	17/04/2024	2:10:31 PM	2,006.00	75	CEUX
GENMAB A/S	17/04/2024	2:10:31 PM	2,006.00	42	CEUX
GENMAB A/S	17/04/2024	2:10:31 PM	2,006.00	18	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	2:10:31 PM	2,006.00	131	XCSE
GENMAB A/S	17/04/2024	2:10:41 PM	2,005.00	49	XCSE
GENMAB A/S	17/04/2024	2:10:41 PM	2,005.00	49	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	46	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	41	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	23	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	14	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	15	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	41	XCSE
GENMAB A/S	17/04/2024	2:12:09 PM	2,004.00	10	XCSE
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	11	CEUX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	7	CEUX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	4	CEUX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	7	CEUX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	10	XCSE
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	10	XCSE
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	13	XCSE
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	11	CEUX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	5	CEUX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:21:56 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:25:01 PM	2,008.00	19	CEUX
GENMAB A/S	17/04/2024	2:25:01 PM	2,008.00	17	CEUX
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	11	CEUX
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	11	CEUX
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	2	CEUX
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	10	XCSE
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	34	XCSE
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	17	XCSE
GENMAB A/S	17/04/2024	2:25:29 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	2:25:30 PM	2,007.00	12	XCSE
GENMAB A/S	17/04/2024	2:25:30 PM	2,007.00	9	XCSE
GENMAB A/S	17/04/2024	2:25:30 PM	2,007.00	6	XCSE
GENMAB A/S	17/04/2024	2:25:30 PM	2,007.00	32	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	2:27:02 PM	2,006.00	42	XCSE
GENMAB A/S	17/04/2024	2:27:02 PM	2,006.00	42	XCSE
GENMAB A/S	17/04/2024	2:27:02 PM	2,006.00	10	XCSE
GENMAB A/S	17/04/2024	2:27:02 PM	2,006.00	7	XCSE
GENMAB A/S	17/04/2024	2:27:02 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:27:02 PM	2,005.00	2	AQEU
GENMAB A/S	17/04/2024	2:27:02 PM	2,005.00	2	AQEU
GENMAB A/S	17/04/2024	2:27:02 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:27:02 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	7	AQEU
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	1	AQEU
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	7	AQEU
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	35	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	13	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	11	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	11	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	11	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	6	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	8	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	12	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	5	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	3	TQEX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	53	XCSE
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	10	XCSE
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	10	XCSE
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	25	XCSE
GENMAB A/S	17/04/2024	2:29:24 PM	2,004.00	36	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,005.00	4	CEUX
GENMAB A/S	17/04/2024	2:29:24 PM	2,004.00	8	AQEU
GENMAB A/S	17/04/2024	2:30:02 PM	2,003.00	21	XCSE
GENMAB A/S	17/04/2024	2:30:02 PM	2,003.00	21	XCSE
GENMAB A/S	17/04/2024	2:30:03 PM	2,003.00	7	XCSE
GENMAB A/S	17/04/2024	2:30:03 PM	2,003.00	10	XCSE
GENMAB A/S	17/04/2024	2:30:03 PM	2,003.00	4	XCSE
GENMAB A/S	17/04/2024	2:30:03 PM	2,003.00	43	XCSE
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	13	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	3	XCSE
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	6	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	5	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	1	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	5	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	6	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	6	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	6	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	5	AQEU
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	36	CEUX
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	17	CEUX
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	8	CEUX
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	11	CEUX
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	3	CEUX
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	22	CEUX
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	24	XCSE
GENMAB A/S	17/04/2024	2:38:21 PM	2,004.00	3	XCSE
GENMAB A/S	17/04/2024	2:40:30 PM	2,009.00	3	AQEU
GENMAB A/S	17/04/2024	2:40:30 PM	2,009.00	20	CEUX
GENMAB A/S	17/04/2024	2:40:30 PM	2,009.00	17	XCSE
GENMAB A/S	17/04/2024	2:42:21 PM	2,010.00	6	XCSE
GENMAB A/S	17/04/2024	2:42:47 PM	2,011.00	41	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	33	XCSE
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	106	XCSE
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	52	XCSE
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	11	XCSE
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	5	AQEU
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	14	AQEU
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	5	AQEU
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	36	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	33	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	62	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	13	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	23	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	23	CEUX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	6	TQEX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	14	TQEX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	5	AQEU
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	19	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	5	AQEU
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	6	TQEX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	8	TQEX
GENMAB A/S	17/04/2024	2:42:47 PM	2,010.00	21	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	17	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	17	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	12	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	17	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	18	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	34	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	18	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	4	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	18	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	30	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	17	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	17	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	2	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	9	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	8	CEUX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	5	TQEX
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	18	XCSE
GENMAB A/S	17/04/2024	2:48:10 PM	2,012.00	1	XCSE
GENMAB A/S	17/04/2024	2:51:37 PM	2,009.00	27	XCSE
GENMAB A/S	17/04/2024	2:56:22 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	2:57:38 PM	2,017.00	12	XCSE
GENMAB A/S	17/04/2024	2:58:07 PM	2,016.00	61	XCSE
GENMAB A/S	17/04/2024	2:58:07 PM	2,016.00	61	XCSE
GENMAB A/S	17/04/2024	2:58:07 PM	2,016.00	61	XCSE
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	6	XCSE
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	19	XCSE
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	8	AQEU
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	56	CEUX
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	56	CEUX
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	56	CEUX
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	1	CEUX
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	3	AQEU
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	48	CEUX
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	33	XCSE
GENMAB A/S	17/04/2024	2:58:08 PM	2,016.00	28	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	2:58:10 PM	2,015.00	20	XCSE
GENMAB A/S	17/04/2024	3:01:49 PM	2,014.00	23	XCSE
GENMAB A/S	17/04/2024	3:01:49 PM	2,014.00	22	XCSE
GENMAB A/S	17/04/2024	3:01:50 PM	2,014.00	18	XCSE
GENMAB A/S	17/04/2024	3:01:50 PM	2,014.00	5	XCSE
GENMAB A/S	17/04/2024	3:01:50 PM	2,014.00	23	XCSE
GENMAB A/S	17/04/2024	3:01:50 PM	2,014.00	3	XCSE
GENMAB A/S	17/04/2024	3:01:50 PM	2,014.00	10	XCSE
GENMAB A/S	17/04/2024	3:04:09 PM	2,015.00	14	AQEU
GENMAB A/S	17/04/2024	3:04:09 PM	2,015.00	75	CEUX
GENMAB A/S	17/04/2024	3:04:09 PM	2,015.00	24	CEUX
GENMAB A/S	17/04/2024	3:04:09 PM	2,015.00	7	AQEU
GENMAB A/S	17/04/2024	3:04:09 PM	2,015.00	49	CEUX
GENMAB A/S	17/04/2024	3:07:19 PM	2,015.00	10	AQEU
GENMAB A/S	17/04/2024	3:07:19 PM	2,015.00	70	CEUX
GENMAB A/S	17/04/2024	3:07:19 PM	2,015.00	11	TQEX
GENMAB A/S	17/04/2024	3:07:19 PM	2,015.00	43	XCSE
GENMAB A/S	17/04/2024	3:07:19 PM	2,015.00	35	XCSE
GENMAB A/S	17/04/2024	3:07:19 PM	2,014.00	26	XCSE
GENMAB A/S	17/04/2024	3:07:19 PM	2,014.00	22	XCSE
GENMAB A/S	17/04/2024	3:07:19 PM	2,014.00	26	XCSE
GENMAB A/S	17/04/2024	3:07:19 PM	2,014.00	3	CEUX
GENMAB A/S	17/04/2024	3:08:00 PM	2,015.00	40	CEUX
GENMAB A/S	17/04/2024	3:12:58 PM	2,011.00	8	CEUX
GENMAB A/S	17/04/2024	3:12:58 PM	2,011.00	5	TQEX
GENMAB A/S	17/04/2024	3:12:58 PM	2,011.00	8	XCSE
GENMAB A/S	17/04/2024	3:13:32 PM	2,011.00	5	XCSE
GENMAB A/S	17/04/2024	3:17:16 PM	2,015.00	36	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	7	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	49	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	7	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,015.00	40	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	1	AQEU
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	1	AQEU
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	1	AQEU
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	4	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	4	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	8	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	3	CEUX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	5	TQEX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	22	TQEX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	4	TQEX
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	1	AQEU
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	7	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	55	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	21	XCSE
GENMAB A/S	17/04/2024	3:17:55 PM	2,014.00	14	XCSE
GENMAB A/S	17/04/2024	3:19:09 PM	2,015.00	19	XCSE
GENMAB A/S	17/04/2024	3:20:27 PM	2,016.00	39	CEUX
GENMAB A/S	17/04/2024	3:20:27 PM	2,016.00	39	CEUX
GENMAB A/S	17/04/2024	3:20:27 PM	2,016.00	39	CEUX
GENMAB A/S	17/04/2024	3:20:27 PM	2,016.00	19	XCSE
GENMAB A/S	17/04/2024	3:20:27 PM	2,016.00	23	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	25	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	34	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	16	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	15	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	27	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	22	XCSE
GENMAB A/S	17/04/2024	3:24:45 PM	2,019.00	30	XCSE
GENMAB A/S	17/04/2024	3:25:04 PM	2,017.00	36	CEUX
GENMAB A/S	17/04/2024	3:25:04 PM	2,017.00	16	XCSE
GENMAB A/S	17/04/2024	3:29:34 PM	2,018.00	35	XCSE
GENMAB A/S	17/04/2024	3:29:34 PM	2,018.00	32	CEUX
GENMAB A/S	17/04/2024	3:29:34 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	3	AQEU
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	3	AQEU
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:01 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	8	CEUX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	8	CEUX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	6	CEUX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	3	CEUX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	23	XCSE
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	23	XCSE
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	14	XCSE
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	9	XCSE
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	22	CEUX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	23	XCSE
GENMAB A/S	17/04/2024	3:30:03 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	3	AQEU
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	20	XCSE
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	3	AQEU
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	16	AQEU
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	19	CEUX
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	5	TQEX
GENMAB A/S	17/04/2024	3:30:04 PM	2,018.00	43	XCSE
GENMAB A/S	17/04/2024	3:31:37 PM	2,017.00	18	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	3:31:37 PM	2,017.00	2	XCSE
GENMAB A/S	17/04/2024	3:31:37 PM	2,017.00	19	CEUX
GENMAB A/S	17/04/2024	3:31:37 PM	2,017.00	5	TQEX
GENMAB A/S	17/04/2024	3:31:39 PM	2,017.00	20	XCSE
GENMAB A/S	17/04/2024	3:31:39 PM	2,017.00	54	XCSE
GENMAB A/S	17/04/2024	3:31:39 PM	2,017.00	14	AQEU
GENMAB A/S	17/04/2024	3:31:39 PM	2,017.00	21	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,014.00	12	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,014.00	31	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,014.00	15	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,014.00	46	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,014.00	2	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	2	AQEU
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	2	AQEU
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	2	AQEU
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	19	AQEU
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	21	CEUX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	21	XCSE
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	21	CEUX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	12	CEUX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	5	TQEX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	14	CEUX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	3	TQEX
GENMAB A/S	17/04/2024	3:32:25 PM	2,013.00	15	XCSE
GENMAB A/S	17/04/2024	3:32:26 PM	2,013.00	33	XCSE
GENMAB A/S	17/04/2024	3:32:26 PM	2,013.00	16	XCSE
GENMAB A/S	17/04/2024	3:32:26 PM	2,013.00	16	XCSE
GENMAB A/S	17/04/2024	3:32:26 PM	2,013.00	16	XCSE
GENMAB A/S	17/04/2024	3:40:34 PM	2,015.00	52	XCSE
GENMAB A/S	17/04/2024	3:40:34 PM	2,015.00	37	XCSE
GENMAB A/S	17/04/2024	3:40:34 PM	2,015.00	81	CEUX
GENMAB A/S	17/04/2024	3:40:34 PM	2,015.00	12	TQEX
GENMAB A/S	17/04/2024	3:40:34 PM	2,015.00	12	TQEX
GENMAB A/S	17/04/2024	3:42:01 PM	2,016.00	29	XCSE
GENMAB A/S	17/04/2024	3:42:02 PM	2,016.00	8	XCSE
GENMAB A/S	17/04/2024	3:42:02 PM	2,016.00	4	XCSE
GENMAB A/S	17/04/2024	3:42:02 PM	2,016.00	25	CEUX
GENMAB A/S	17/04/2024	3:44:11 PM	2,017.00	17	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	3:44:11 PM	2,017.00	17	CEUX
GENMAB A/S	17/04/2024	3:44:11 PM	2,017.00	7	CEUX
GENMAB A/S	17/04/2024	3:44:37 PM	2,017.00	1	CEUX
GENMAB A/S	17/04/2024	3:44:37 PM	2,017.00	14	CEUX
GENMAB A/S	17/04/2024	3:44:37 PM	2,017.00	22	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	23	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	27	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	7	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	3	AQEU
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	1	AQEU
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	3	AQEU
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	1	AQEU
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	21	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	21	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	4	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	5	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	5	TQEX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	5	TQEX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	5	TQEX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	5	TQEX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	7	AQEU
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	36	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	8	TQEX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	10	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	11	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	13	CEUX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	30	XCSE
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	1	TQEX
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	26	AQEU
GENMAB A/S	17/04/2024	3:44:42 PM	2,016.00	11	AQEU
GENMAB A/S	17/04/2024	3:46:48 PM	2,016.00	36	XCSE
GENMAB A/S	17/04/2024	3:46:48 PM	2,016.00	48	CEUX
GENMAB A/S	17/04/2024	3:46:48 PM	2,016.00	30	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	3:46:48 PM	2,016.00	12	TQEX
GENMAB A/S	17/04/2024	3:46:48 PM	2,016.00	50	XCSE
GENMAB A/S	17/04/2024	3:46:48 PM	2,016.00	11	CEUX
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	39	XCSE
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	29	XCSE
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	46	XCSE
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	3	XCSE
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	9	AQEU
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	62	CEUX
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	9	TQEX
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	43	XCSE
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	6	XCSE
GENMAB A/S	17/04/2024	3:48:45 PM	2,019.00	49	XCSE
GENMAB A/S	17/04/2024	3:49:54 PM	2,017.00	11	XCSE
GENMAB A/S	17/04/2024	3:49:54 PM	2,017.00	11	XCSE
GENMAB A/S	17/04/2024	3:50:13 PM	2,019.00	21	XCSE
GENMAB A/S	17/04/2024	3:50:13 PM	2,019.00	1	XCSE
GENMAB A/S	17/04/2024	3:50:37 PM	2,020.00	50	XCSE
GENMAB A/S	17/04/2024	3:50:37 PM	2,020.00	45	CEUX
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	22	XCSE
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	66	XCSE
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	9	AQEU
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	59	CEUX
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	9	TQEX
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	22	XCSE
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	4	XCSE
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	22	XCSE
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	53	XCSE
GENMAB A/S	17/04/2024	3:52:38 PM	2,021.00	18	XCSE
GENMAB A/S	17/04/2024	3:54:24 PM	2,018.00	55	XCSE
GENMAB A/S	17/04/2024	3:54:24 PM	2,018.00	7	AQEU
GENMAB A/S	17/04/2024	3:54:24 PM	2,018.00	50	CEUX
GENMAB A/S	17/04/2024	3:54:24 PM	2,018.00	8	TQEX
GENMAB A/S	17/04/2024	3:55:04 PM	2,017.00	25	XCSE
GENMAB A/S	17/04/2024	3:55:04 PM	2,017.00	18	XCSE
GENMAB A/S	17/04/2024	3:55:04 PM	2,017.00	7	XCSE
GENMAB A/S	17/04/2024	3:55:04 PM	2,017.00	25	XCSE
GENMAB A/S	17/04/2024	3:55:04 PM	2,017.00	8	XCSE
GENMAB A/S	17/04/2024	3:55:04 PM	2,017.00	25	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	3:55:05 PM	2,017.00	25	XCSE
GENMAB A/S	17/04/2024	3:56:46 PM	2,015.00	9	AQEU
GENMAB A/S	17/04/2024	3:56:46 PM	2,015.00	28	CEUX
GENMAB A/S	17/04/2024	3:56:46 PM	2,015.00	30	CEUX
GENMAB A/S	17/04/2024	3:56:46 PM	2,015.00	9	TQEX
GENMAB A/S	17/04/2024	3:56:46 PM	2,015.00	65	XCSE
GENMAB A/S	17/04/2024	3:57:49 PM	2,014.00	28	XCSE
GENMAB A/S	17/04/2024	3:57:49 PM	2,014.00	28	XCSE
GENMAB A/S	17/04/2024	3:57:49 PM	2,014.00	4	XCSE
GENMAB A/S	17/04/2024	3:57:49 PM	2,014.00	20	XCSE
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	8	XCSE
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	13	XCSE
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	8	XCSE
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	22	XCSE
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	8	CEUX
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	8	CEUX
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	8	CEUX
GENMAB A/S	17/04/2024	3:58:32 PM	2,018.00	8	CEUX
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	11	AQEU
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	34	CEUX
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	44	CEUX
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	11	TQEX
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	1	TQEX
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	30	XCSE
GENMAB A/S	17/04/2024	3:59:24 PM	2,017.00	56	XCSE
GENMAB A/S	17/04/2024	3:59:25 PM	2,016.00	46	XCSE
GENMAB A/S	17/04/2024	4:01:58 PM	2,014.00	8	AQEU
GENMAB A/S	17/04/2024	4:01:58 PM	2,014.00	7	CEUX
GENMAB A/S	17/04/2024	4:01:58 PM	2,014.00	15	CEUX
GENMAB A/S	17/04/2024	4:01:58 PM	2,014.00	29	CEUX
GENMAB A/S	17/04/2024	4:01:58 PM	2,014.00	7	TQEX
GENMAB A/S	17/04/2024	4:01:58 PM	2,014.00	57	XCSE
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	9	XCSE
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	13	XCSE
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	38	XCSE
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	8	AQEU
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	11	CEUX
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	43	CEUX
GENMAB A/S	17/04/2024	4:03:05 PM	2,014.00	8	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:04:29 PM	2,012.00	58	XCSE
GENMAB A/S	17/04/2024	4:04:29 PM	2,012.00	8	AQEU
GENMAB A/S	17/04/2024	4:04:29 PM	2,012.00	53	CEUX
GENMAB A/S	17/04/2024	4:04:29 PM	2,012.00	8	TQEX
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	57	XCSE
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	4	AQEU
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	27	CEUX
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	7	CEUX
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	11	CEUX
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	7	CEUX
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	4	AQEU
GENMAB A/S	17/04/2024	4:05:32 PM	2,010.00	8	TQEX
GENMAB A/S	17/04/2024	4:06:08 PM	2,006.00	43	XCSE
GENMAB A/S	17/04/2024	4:06:08 PM	2,006.00	85	XCSE
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	3	AQEU
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	19	CEUX
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	19	CEUX
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	2	CEUX
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	5	TQEX
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	8	TQEX
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	18	XCSE
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	49	XCSE
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	23	XCSE
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	80	XCSE
GENMAB A/S	17/04/2024	4:06:08 PM	2,006.00	8	AQEU
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	8	AQEU
GENMAB A/S	17/04/2024	4:06:08 PM	2,007.00	12	AQEU
GENMAB A/S	17/04/2024	4:11:37 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:11:37 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	1	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	14	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	1	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	14	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	3	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	6	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	5	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	9	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	2	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	9	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	2	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	6	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	3	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	9	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	5	TQEX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	5	TQEX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	5	TQEX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	1	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	9	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	9	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	4	CEUX
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	XCSE
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	8	AQEU
GENMAB A/S	17/04/2024	4:12:05 PM	2,009.00	36	CEUX
GENMAB A/S	17/04/2024	4:13:34 PM	2,006.00	49	XCSE
GENMAB A/S	17/04/2024	4:13:34 PM	2,006.00	16	XCSE
GENMAB A/S	17/04/2024	4:13:34 PM	2,006.00	9	AQEU
GENMAB A/S	17/04/2024	4:13:34 PM	2,006.00	59	CEUX
GENMAB A/S	17/04/2024	4:13:34 PM	2,006.00	9	TQEX
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	9	AQEU
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	10	CEUX
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	51	CEUX
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	10	TQEX
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	48	XCSE
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	27	XCSE
GENMAB A/S	17/04/2024	4:14:48 PM	2,008.00	42	XCSE
GENMAB A/S	17/04/2024	4:18:31 PM	2,009.00	36	XCSE
GENMAB A/S	17/04/2024	4:18:31 PM	2,009.00	154	XCSE
GENMAB A/S	17/04/2024	4:18:31 PM	2,009.00	98	CEUX
GENMAB A/S	17/04/2024	4:18:31 PM	2,009.00	20	AQEU
GENMAB A/S	17/04/2024	4:18:31 PM	2,009.00	13	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:18:31 PM	2,009.00	26	CEUX
GENMAB A/S	17/04/2024	4:20:40 PM	2,009.00	34	XCSE
GENMAB A/S	17/04/2024	4:20:40 PM	2,009.00	31	CEUX
GENMAB A/S	17/04/2024	4:20:40 PM	2,009.00	21	CEUX
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	12	AQEU
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	4	CEUX
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	6	CEUX
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	69	CEUX
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	8	TQEX
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	4	TQEX
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	57	XCSE
GENMAB A/S	17/04/2024	4:21:35 PM	2,009.00	32	XCSE
GENMAB A/S	17/04/2024	4:24:15 PM	2,009.00	2	CEUX
GENMAB A/S	17/04/2024	4:24:15 PM	2,009.00	13	CEUX
GENMAB A/S	17/04/2024	4:25:02 PM	2,008.00	23	AQEU
GENMAB A/S	17/04/2024	4:25:02 PM	2,008.00	160	CEUX
GENMAB A/S	17/04/2024	4:25:02 PM	2,008.00	24	TQEX
GENMAB A/S	17/04/2024	4:25:02 PM	2,008.00	178	XCSE
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	12	AQEU
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	37	CEUX
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	17	CEUX
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	29	CEUX
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	13	TQEX
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	21	XCSE
GENMAB A/S	17/04/2024	4:27:53 PM	2,011.00	71	XCSE
GENMAB A/S	17/04/2024	4:27:53 PM	2,010.00	66	CEUX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	10	CEUX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	8	CEUX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	10	CEUX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	8	CEUX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	7	CEUX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	5	TQEX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	5	TQEX
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	9	XCSE
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	8	XCSE
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	34	XCSE
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	9	XCSE
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	8	XCSE
GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	9	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:30:10 PM	2,011.00	8	XCSE
GENMAB A/S	17/04/2024	4:30:12 PM	2,011.00	5	TQEX
GENMAB A/S	17/04/2024	4:30:12 PM	2,011.00	5	TQEX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	13	AQEU
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	14	AQEU
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	34	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	13	AQEU
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	3	AQEU
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	54	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	86	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	2	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	88	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	1	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	88	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	4	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	2	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	51	CEUX
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	36	XCSE
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	63	XCSE
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	149	XCSE
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	63	XCSE
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	36	XCSE
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	111	XCSE
GENMAB A/S	17/04/2024	4:31:59 PM	2,012.00	14	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	111	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	16	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	2	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	2	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	32	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	2	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	1	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	10	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	2	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	11	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	9	TQEX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	8	TQEX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	8	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	27	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	27	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	96	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	12	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	27	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	12	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	27	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	17	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	19	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	12	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	160	XCSE
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	8	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	8	AQEU
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	36	CEUX
GENMAB A/S	17/04/2024	4:39:03 PM	2,009.00	2	CEUX
GENMAB A/S	17/04/2024	4:45:11 PM	2,010.00	40	CEUX
GENMAB A/S	17/04/2024	4:45:24 PM	2,010.00	40	XCSE
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	99	XCSE
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	31	XCSE
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	221	XCSE
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	XCSE
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	55	XCSE
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	18	AQEU
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	26	AQEU
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	6	AQEU

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	1	AQEU
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	1	AQEU
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	37	AQEU
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	75	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	51	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	75	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	99	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	10	CEUX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	19	TQEX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	5	TQEX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	5	TQEX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	28	TQEX
GENMAB A/S	17/04/2024	4:46:34 PM	2,010.00	3	TQEX
GENMAB A/S	17/04/2024	4:46:34 PM	2,009.00	24	XCSE
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	16	CEUX
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	20	XCSE
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	3	CEUX
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	2	AQEU
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	8	CEUX
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	20	XCSE
GENMAB A/S	17/04/2024	4:46:35 PM	2,009.00	7	XCSE
GENMAB A/S	17/04/2024	4:50:00 PM	2,015.00	19	XCSE
GENMAB A/S	17/04/2024	4:50:00 PM	2,015.00	38	XCSE
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	9	CEUX
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	8	CEUX
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	5	TQEX
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	16	XCSE
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	34	XCSE
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	16	XCSE
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	16	XCSE
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	16	XCSE
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	2	AQEU
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	10	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	5	TQEX
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	1	TQEX
GENMAB A/S	17/04/2024	4:50:24 PM	2,015.00	7	CEUX
GENMAB A/S	17/04/2024	4:51:01 PM	2,017.00	172	XCSE
GENMAB A/S	17/04/2024	4:51:01 PM	2,017.00	22	AQEU
GENMAB A/S	17/04/2024	4:51:01 PM	2,017.00	153	CEUX
GENMAB A/S	17/04/2024	4:51:01 PM	2,017.00	24	TQEX
GENMAB A/S	17/04/2024	4:51:28 PM	2,015.00	42	XCSE
GENMAB A/S	17/04/2024	4:53:10 PM	2,014.00	20	TQEX
GENMAB A/S	17/04/2024	4:53:10 PM	2,014.00	53	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	22	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	21	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	22	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	21	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	14	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	17	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	5	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	5	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	7	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	7	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	18	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	2	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	2	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	22	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	21	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	22	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	21	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	34	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	23	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	5	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	16	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	21	TQEX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	5	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	5	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	5	CEUX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	10	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	14	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	20	TQEX
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	30	XCSE
GENMAB A/S	18/04/2024	9:00:32 AM	2,000.00	35	XCSE
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	3	AQEU
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	37	AQEU
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	20	CEUX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	20	CEUX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	20	CEUX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	20	CEUX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	13	CEUX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	5	TQEX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	37	TQEX
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	22	XCSE
GENMAB A/S	18/04/2024	9:01:39 AM	1,993.00	79	XCSE
GENMAB A/S	18/04/2024	9:05:03 AM	1,981.00	1	XCSE
GENMAB A/S	18/04/2024	9:05:03 AM	1,981.00	20	XCSE
GENMAB A/S	18/04/2024	9:05:03 AM	1,981.00	8	XCSE
GENMAB A/S	18/04/2024	9:05:03 AM	1,981.00	8	XCSE
GENMAB A/S	18/04/2024	9:06:31 AM	1,986.50	12	XCSE
GENMAB A/S	18/04/2024	9:07:12 AM	1,988.00	4	CEUX
GENMAB A/S	18/04/2024	9:07:13 AM	1,988.00	14	XCSE
GENMAB A/S	18/04/2024	9:07:13 AM	1,988.00	14	XCSE
GENMAB A/S	18/04/2024	9:07:13 AM	1,988.00	9	CEUX
GENMAB A/S	18/04/2024	9:07:13 AM	1,988.00	13	CEUX
GENMAB A/S	18/04/2024	9:07:35 AM	1,989.00	21	XCSE
GENMAB A/S	18/04/2024	9:08:13 AM	1,988.00	31	XCSE
GENMAB A/S	18/04/2024	9:08:14 AM	1,988.00	28	CEUX
GENMAB A/S	18/04/2024	9:08:14 AM	1,988.00	31	XCSE
GENMAB A/S	18/04/2024	9:08:14 AM	1,988.00	31	XCSE
GENMAB A/S	18/04/2024	9:08:14 AM	1,988.00	28	CEUX
GENMAB A/S	18/04/2024	9:08:14 AM	1,988.00	4	AQEU
GENMAB A/S	18/04/2024	9:08:18 AM	1,988.00	31	XCSE
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	31	XCSE
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	27	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	4	XCSE
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	14	XCSE
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	5	XCSE
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	4	AQEU
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	28	CEUX
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	28	CEUX
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	28	CEUX
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	4	AQEU
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	4	AQEU
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	28	CEUX
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	15	CEUX
GENMAB A/S	18/04/2024	9:08:45 AM	1,988.00	24	CEUX
GENMAB A/S	18/04/2024	9:09:15 AM	1,980.00	21	XCSE
GENMAB A/S	18/04/2024	9:09:15 AM	1,980.00	88	XCSE
GENMAB A/S	18/04/2024	9:09:15 AM	1,980.00	21	XCSE
GENMAB A/S	18/04/2024	9:09:15 AM	1,980.00	21	XCSE
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	6	TQEX
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	6	TQEX
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	6	XCSE
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	32	XCSE
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	38	XCSE
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	30	XCSE
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	6	TQEX
GENMAB A/S	18/04/2024	9:10:18 AM	1,978.50	6	TQEX
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	21	CEUX
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	13	CEUX
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	21	CEUX
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	22	XCSE
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	18	XCSE
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	13	XCSE
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	22	XCSE
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	13	XCSE
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	13	CEUX
GENMAB A/S	18/04/2024	9:12:02 AM	1,982.00	17	CEUX
GENMAB A/S	18/04/2024	9:12:27 AM	1,983.00	37	CEUX
GENMAB A/S	18/04/2024	9:12:55 AM	1,985.00	12	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	XCSE
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	56	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	XCSE
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	XCSE
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	XCSE
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	XCSE
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	5	XCSE
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	8	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	8	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	8	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	13	CEUX
GENMAB A/S	18/04/2024	9:13:58 AM	1,987.50	12	CEUX
GENMAB A/S	18/04/2024	9:14:32 AM	1,987.00	27	XCSE
GENMAB A/S	18/04/2024	9:14:32 AM	1,987.00	5	XCSE
GENMAB A/S	18/04/2024	9:14:37 AM	1,986.50	75	XCSE
GENMAB A/S	18/04/2024	9:16:08 AM	1,989.50	16	TQEX
GENMAB A/S	18/04/2024	9:16:08 AM	1,989.50	17	XCSE
GENMAB A/S	18/04/2024	9:16:08 AM	1,989.50	92	XCSE
GENMAB A/S	18/04/2024	9:16:46 AM	1,989.50	10	XCSE
GENMAB A/S	18/04/2024	9:16:46 AM	1,989.50	14	XCSE
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	27	XCSE
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	25	CEUX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	4	AQEU
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	25	CEUX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	25	CEUX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	27	XCSE
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	27	XCSE
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	26	TQEX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	30	TQEX
GENMAB A/S	18/04/2024	9:18:07 AM	1,991.50	7	TQEX
GENMAB A/S	18/04/2024	9:19:59 AM	1,993.00	64	CEUX
GENMAB A/S	18/04/2024	9:19:59 AM	1,993.00	27	CEUX
GENMAB A/S	18/04/2024	9:20:12 AM	1,993.00	17	CEUX
GENMAB A/S	18/04/2024	9:20:12 AM	1,993.00	17	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:20:12 AM	1,993.00	5	TQEX
GENMAB A/S	18/04/2024	9:20:12 AM	1,993.00	5	TQEX
GENMAB A/S	18/04/2024	9:20:12 AM	1,993.00	1	TQEX
GENMAB A/S	18/04/2024	9:20:12 AM	1,993.00	3	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	3	TQEX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	3	AQEU
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	18	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	18	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	2	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	18	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	2	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	14	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	24	CEUX
GENMAB A/S	18/04/2024	9:20:14 AM	1,992.50	18	CEUX
GENMAB A/S	18/04/2024	9:22:56 AM	1,990.50	48	CEUX
GENMAB A/S	18/04/2024	9:22:56 AM	1,990.50	8	CEUX
GENMAB A/S	18/04/2024	9:23:48 AM	1,992.50	38	AQEU
GENMAB A/S	18/04/2024	9:23:50 AM	1,992.50	1	AQEU
GENMAB A/S	18/04/2024	9:23:50 AM	1,992.50	4	AQEU
GENMAB A/S	18/04/2024	9:23:50 AM	1,992.50	3	AQEU
GENMAB A/S	18/04/2024	9:23:53 AM	1,992.50	15	AQEU
GENMAB A/S	18/04/2024	9:23:53 AM	1,992.50	4	AQEU
GENMAB A/S	18/04/2024	9:24:09 AM	1,990.50	24	XCSE
GENMAB A/S	18/04/2024	9:24:09 AM	1,990.50	5	TQEX
GENMAB A/S	18/04/2024	9:24:09 AM	1,990.50	3	AQEU
GENMAB A/S	18/04/2024	9:24:09 AM	1,990.50	24	CEUX
GENMAB A/S	18/04/2024	9:24:09 AM	1,990.50	24	XCSE
GENMAB A/S	18/04/2024	9:24:09 AM	1,990.50	24	CEUX
GENMAB A/S	18/04/2024	9:25:20 AM	1,991.00	24	XCSE
GENMAB A/S	18/04/2024	9:25:23 AM	1,991.00	22	CEUX
GENMAB A/S	18/04/2024	9:25:23 AM	1,991.00	24	XCSE
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	22	CEUX
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	24	XCSE
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	24	XCSE
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	22	CEUX
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	22	CEUX
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	3	CEUX
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	24	XCSE
GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	24	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:25:27 AM	1,991.00	16	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	25	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	50	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	2	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	2	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	23	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	2	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	2	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	23	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	4	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	24	XCSE
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	46	CEUX
GENMAB A/S	18/04/2024	9:27:16 AM	1,992.00	8	TQEX
GENMAB A/S	18/04/2024	9:28:57 AM	1,992.00	47	XCSE
GENMAB A/S	18/04/2024	9:28:57 AM	1,992.00	8	CEUX
GENMAB A/S	18/04/2024	9:28:57 AM	1,992.00	7	TQEX
GENMAB A/S	18/04/2024	9:28:57 AM	1,992.00	18	CEUX
GENMAB A/S	18/04/2024	9:28:57 AM	1,992.00	17	CEUX
GENMAB A/S	18/04/2024	9:28:57 AM	1,992.00	6	XCSE
GENMAB A/S	18/04/2024	9:29:03 AM	1,992.00	52	XCSE
GENMAB A/S	18/04/2024	9:29:30 AM	1,992.00	54	CEUX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	10	CEUX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	7	CEUX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	3	CEUX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	4	CEUX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	10	XCSE
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	10	XCSE
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	10	XCSE
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	34	XCSE
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	1	AQEU
GENMAB A/S	18/04/2024	9:32:41 AM	1,989.50	10	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	28	XCSE
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	28	XCSE
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	28	XCSE
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	25	XCSE
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	27	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	11	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	16	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	27	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	10	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	4	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	5	CEUX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	64	XCSE
GENMAB A/S	18/04/2024	9:34:18 AM	1,989.50	3	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,994.50	35	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	16	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	3	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	16	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	2	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	38	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	20	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	13	CEUX
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	12	XCSE
GENMAB A/S	18/04/2024	9:37:33 AM	1,993.50	25	XCSE
GENMAB A/S	18/04/2024	9:38:55 AM	1,993.50	26	XCSE
GENMAB A/S	18/04/2024	9:38:56 AM	1,993.50	26	XCSE
GENMAB A/S	18/04/2024	9:39:01 AM	1,993.50	26	XCSE
GENMAB A/S	18/04/2024	9:39:01 AM	1,993.50	26	XCSE
GENMAB A/S	18/04/2024	9:39:01 AM	1,993.50	5	XCSE
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	36	CEUX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	CEUX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	CEUX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	CEUX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	CEUX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	CEUX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	5	TQEX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	5	TQEX
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	XCSE
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	8	XCSE
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	16	XCSE
GENMAB A/S	18/04/2024	9:40:05 AM	1,993.00	34	CEUX
GENMAB A/S	18/04/2024	9:42:20 AM	1,992.50	38	XCSE
GENMAB A/S	18/04/2024	9:42:22 AM	1,992.50	38	XCSE
GENMAB A/S	18/04/2024	9:42:22 AM	1,992.50	25	XCSE
GENMAB A/S	18/04/2024	9:42:22 AM	1,992.50	13	XCSE
GENMAB A/S	18/04/2024	9:42:22 AM	1,992.50	2	XCSE
GENMAB A/S	18/04/2024	9:42:25 AM	1,992.00	17	AQEU
GENMAB A/S	18/04/2024	9:42:25 AM	1,992.00	36	CEUX
GENMAB A/S	18/04/2024	9:45:32 AM	1,995.50	16	CEUX
GENMAB A/S	18/04/2024	9:45:32 AM	1,995.50	2	CEUX
GENMAB A/S	18/04/2024	9:45:32 AM	1,995.50	6	CEUX
GENMAB A/S	18/04/2024	9:45:32 AM	1,995.50	7	CEUX
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.00	34	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	25	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	34	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	16	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	23	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	38	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	34	XCSE
GENMAB A/S	18/04/2024	9:45:35 AM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	9:45:58 AM	1,995.50	50	XCSE
GENMAB A/S	18/04/2024	9:45:58 AM	1,995.50	50	XCSE
GENMAB A/S	18/04/2024	9:45:58 AM	1,995.50	9	XCSE
GENMAB A/S	18/04/2024	9:45:59 AM	1,995.00	25	XCSE
GENMAB A/S	18/04/2024	9:45:59 AM	1,995.00	25	XCSE
GENMAB A/S	18/04/2024	9:45:59 AM	1,994.50	13	CEUX
GENMAB A/S	18/04/2024	9:46:00 AM	1,994.50	18	XCSE
GENMAB A/S	18/04/2024	9:48:31 AM	1,996.50	17	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	9:48:31 AM	1,996.50	17	CEUX
GENMAB A/S	18/04/2024	9:48:31 AM	1,996.50	3	TQEX
GENMAB A/S	18/04/2024	9:49:36 AM	2,000.00	74	XCSE
GENMAB A/S	18/04/2024	9:49:36 AM	2,000.00	25	XCSE
GENMAB A/S	18/04/2024	9:49:36 AM	2,000.00	25	XCSE
GENMAB A/S	18/04/2024	9:49:36 AM	2,000.00	58	XCSE
GENMAB A/S	18/04/2024	9:51:04 AM	1,999.50	8	AQEU
GENMAB A/S	18/04/2024	9:51:04 AM	1,999.50	52	CEUX
GENMAB A/S	18/04/2024	9:51:04 AM	1,999.50	4	TQEX
GENMAB A/S	18/04/2024	9:51:04 AM	1,999.50	4	TQEX
GENMAB A/S	18/04/2024	9:51:04 AM	1,999.50	57	XCSE
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.50	30	XCSE
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.50	15	XCSE
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.50	15	XCSE
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.50	30	XCSE
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.00	17	CEUX
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	9:51:04 AM	1,998.50	36	CEUX
GENMAB A/S	18/04/2024	9:55:03 AM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	9:55:03 AM	1,997.00	2	XCSE
GENMAB A/S	18/04/2024	9:56:51 AM	2,000.00	66	XCSE
GENMAB A/S	18/04/2024	9:56:51 AM	2,000.00	43	XCSE
GENMAB A/S	18/04/2024	9:56:51 AM	2,000.00	14	AQEU
GENMAB A/S	18/04/2024	9:56:51 AM	2,000.00	98	CEUX
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	5	AQEU
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	50	CEUX
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	8	TQEX
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	56	XCSE
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	27	XCSE
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	27	XCSE
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	27	XCSE
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	11	XCSE
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	5	XCSE
GENMAB A/S	18/04/2024	9:59:30 AM	1,999.00	2	AQEU
GENMAB A/S	18/04/2024	10:00:30 AM	1,996.50	20	XCSE
GENMAB A/S	18/04/2024	10:00:30 AM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	10:00:30 AM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	10:00:30 AM	1,996.50	20	XCSE
GENMAB A/S	18/04/2024	10:00:30 AM	1,996.50	2	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	10:00:30 AM	1,996.50	17	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	2	AQEU
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	9	CEUX
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	9	CEUX
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	10	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	10	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	10	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	26	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	20	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	6	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	6	XCSE
GENMAB A/S	18/04/2024	10:01:00 AM	1,998.00	7	XCSE
GENMAB A/S	18/04/2024	10:04:15 AM	1,996.00	25	XCSE
GENMAB A/S	18/04/2024	10:04:15 AM	1,996.00	25	XCSE
GENMAB A/S	18/04/2024	10:04:15 AM	1,996.00	22	XCSE
GENMAB A/S	18/04/2024	10:04:15 AM	1,996.00	3	XCSE
GENMAB A/S	18/04/2024	10:04:15 AM	1,996.00	22	XCSE
GENMAB A/S	18/04/2024	10:04:15 AM	1,996.00	25	XCSE
GENMAB A/S	18/04/2024	10:07:13 AM	1,998.50	9	CEUX
GENMAB A/S	18/04/2024	10:07:13 AM	1,998.50	5	TQEX
GENMAB A/S	18/04/2024	10:07:13 AM	1,998.50	9	XCSE
GENMAB A/S	18/04/2024	10:07:13 AM	1,998.50	1	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	6	AQEU
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	39	CEUX
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	28	CEUX
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	6	TQEX
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	44	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	37	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	1	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	5	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	39	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	7	XCSE
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	21	CEUX
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	6	TQEX
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	8	AQEU
GENMAB A/S	18/04/2024	10:08:09 AM	2,000.00	36	CEUX
GENMAB A/S	18/04/2024	10:10:38 AM	2,000.00	24	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	10:10:38 AM	2,000.00	19	XCSE
GENMAB A/S	18/04/2024	10:10:43 AM	2,000.00	25	XCSE
GENMAB A/S	18/04/2024	10:10:43 AM	2,000.00	25	XCSE
GENMAB A/S	18/04/2024	10:10:43 AM	2,000.00	25	XCSE
GENMAB A/S	18/04/2024	10:10:43 AM	2,000.00	5	XCSE
GENMAB A/S	18/04/2024	10:12:14 AM	1,998.00	66	CEUX
GENMAB A/S	18/04/2024	10:12:14 AM	1,998.00	2	CEUX
GENMAB A/S	18/04/2024	10:12:14 AM	1,998.00	10	TQEX
GENMAB A/S	18/04/2024	10:12:14 AM	1,998.00	10	AQEU
GENMAB A/S	18/04/2024	10:12:14 AM	1,998.00	76	XCSE
GENMAB A/S	18/04/2024	10:14:28 AM	1,996.50	15	XCSE
GENMAB A/S	18/04/2024	10:14:28 AM	1,996.50	7	XCSE
GENMAB A/S	18/04/2024	10:16:27 AM	1,997.50	39	CEUX
GENMAB A/S	18/04/2024	10:17:01 AM	1,997.50	41	CEUX
GENMAB A/S	18/04/2024	10:17:01 AM	1,997.00	9	CEUX
GENMAB A/S	18/04/2024	10:17:01 AM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	10:17:01 AM	1,997.00	8	XCSE
GENMAB A/S	18/04/2024	10:18:01 AM	1,996.50	118	XCSE
GENMAB A/S	18/04/2024	10:18:01 AM	1,996.50	15	AQEU
GENMAB A/S	18/04/2024	10:18:01 AM	1,996.50	75	CEUX
GENMAB A/S	18/04/2024	10:18:01 AM	1,996.50	31	CEUX
GENMAB A/S	18/04/2024	10:18:01 AM	1,996.50	17	TQEX
GENMAB A/S	18/04/2024	10:18:54 AM	1,995.00	57	XCSE
GENMAB A/S	18/04/2024	10:18:55 AM	1,995.00	23	CEUX
GENMAB A/S	18/04/2024	10:18:55 AM	1,995.00	28	CEUX
GENMAB A/S	18/04/2024	10:18:55 AM	1,995.00	7	TQEX
GENMAB A/S	18/04/2024	10:18:55 AM	1,995.00	8	CEUX
GENMAB A/S	18/04/2024	10:20:34 AM	1,993.50	8	CEUX
GENMAB A/S	18/04/2024	10:20:34 AM	1,993.50	4	TQEX
GENMAB A/S	18/04/2024	10:20:34 AM	1,993.50	8	XCSE
GENMAB A/S	18/04/2024	10:23:09 AM	1,994.50	8	CEUX
GENMAB A/S	18/04/2024	10:23:09 AM	1,994.50	6	CEUX
GENMAB A/S	18/04/2024	10:23:09 AM	1,994.50	5	TQEX
GENMAB A/S	18/04/2024	10:23:09 AM	1,994.50	8	XCSE
GENMAB A/S	18/04/2024	10:23:42 AM	1,995.00	37	CEUX
GENMAB A/S	18/04/2024	10:23:42 AM	1,995.00	2	CEUX
GENMAB A/S	18/04/2024	10:24:06 AM	1,994.50	5	XCSE
GENMAB A/S	18/04/2024	10:24:25 AM	1,995.00	37	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	58	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	58	XCSE
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	11	XCSE
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	56	XCSE
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	52	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	22	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	8	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	22	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	22	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	17	CEUX
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	15	XCSE
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	30	XCSE
GENMAB A/S	18/04/2024	10:24:51 AM	1,995.00	17	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	39	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	8	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	12	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	5	TQEX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	2	TQEX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	5	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	16	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	3	TQEX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	3	TQEX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	5	TQEX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	7	CEUX
GENMAB A/S	18/04/2024	10:30:56 AM	1,998.50	17	XCSE
GENMAB A/S	18/04/2024	10:34:25 AM	1,999.00	23	XCSE
GENMAB A/S	18/04/2024	10:34:25 AM	1,999.00	35	XCSE
GENMAB A/S	18/04/2024	10:34:25 AM	1,999.00	4	XCSE
GENMAB A/S	18/04/2024	10:34:25 AM	1,999.00	19	XCSE
GENMAB A/S	18/04/2024	10:34:25 AM	1,999.00	23	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	23	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	48	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	23	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	48	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	7	CEUX
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	8	CEUX
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	7	TQEX
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	6	TQEX
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	5	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	3	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	28	CEUX
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	14	TQEX
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	16	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	23	XCSE
GENMAB A/S	18/04/2024	10:34:28 AM	1,999.00	23	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	61	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	61	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	55	CEUX
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	54	CEUX
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	9	TQEX
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	9	TQEX
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	25	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	25	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	45	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	82	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	13	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	70	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.00	2	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	8	XCSE
GENMAB A/S	18/04/2024	10:39:08 AM	1,999.50	8	XCSE
GENMAB A/S	18/04/2024	10:48:47 AM	1,998.00	4	XCSE
GENMAB A/S	18/04/2024	10:49:13 AM	2,000.00	1	CEUX
GENMAB A/S	18/04/2024	10:49:13 AM	2,000.00	26	CEUX
GENMAB A/S	18/04/2024	10:49:13 AM	2,000.00	10	CEUX
GENMAB A/S	18/04/2024	10:49:13 AM	2,000.00	30	XCSE
GENMAB A/S	18/04/2024	10:49:13 AM	2,000.00	25	XCSE
GENMAB A/S	18/04/2024	10:49:13 AM	2,000.00	13	CEUX
GENMAB A/S	18/04/2024	10:49:17 AM	2,000.00	22	XCSE
GENMAB A/S	18/04/2024	10:49:17 AM	2,000.00	8	XCSE
GENMAB A/S	18/04/2024	10:49:17 AM	2,000.00	30	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	10:49:17 AM	2,000.00	4	CEUX
GENMAB A/S	18/04/2024	10:50:11 AM	2,000.00	41	XCSE
GENMAB A/S	18/04/2024	10:50:11 AM	2,000.00	20	XCSE
GENMAB A/S	18/04/2024	10:50:11 AM	2,000.00	30	XCSE
GENMAB A/S	18/04/2024	10:50:11 AM	2,000.00	20	XCSE
GENMAB A/S	18/04/2024	10:50:11 AM	2,000.00	26	XCSE
GENMAB A/S	18/04/2024	10:50:13 AM	1,999.00	50	XCSE
GENMAB A/S	18/04/2024	10:50:13 AM	1,999.00	50	XCSE
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	45	CEUX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	18	CEUX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	7	TQEX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	2	TQEX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	7	AQEU
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	27	CEUX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	14	CEUX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	19	TQEX
GENMAB A/S	18/04/2024	10:53:02 AM	1,998.00	27	TQEX
GENMAB A/S	18/04/2024	10:55:24 AM	1,997.50	7	AQEU
GENMAB A/S	18/04/2024	10:55:24 AM	1,997.50	12	CEUX
GENMAB A/S	18/04/2024	10:55:24 AM	1,997.50	38	CEUX
GENMAB A/S	18/04/2024	10:55:24 AM	1,997.50	8	TQEX
GENMAB A/S	18/04/2024	10:55:24 AM	1,997.50	55	XCSE
GENMAB A/S	18/04/2024	10:58:30 AM	1,996.50	46	XCSE
GENMAB A/S	18/04/2024	10:58:30 AM	1,996.50	3	XCSE
GENMAB A/S	18/04/2024	10:58:30 AM	1,996.50	29	XCSE
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	21	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	4	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	23	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	25	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	6	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	7	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	18	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	1	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	22	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	25	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	1	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	19	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	25	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	25	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	11	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	25	CEUX
GENMAB A/S	18/04/2024	11:01:52 AM	1,999.50	25	CEUX
GENMAB A/S	18/04/2024	11:04:42 AM	1,999.00	23	XCSE
GENMAB A/S	18/04/2024	11:04:42 AM	1,999.00	71	XCSE
GENMAB A/S	18/04/2024	11:05:35 AM	2,000.00	13	XCSE
GENMAB A/S	18/04/2024	11:06:00 AM	2,000.00	74	CEUX
GENMAB A/S	18/04/2024	11:06:00 AM	2,000.00	72	CEUX
GENMAB A/S	18/04/2024	11:11:01 AM	1,999.50	2	XCSE
GENMAB A/S	18/04/2024	11:12:24 AM	1,999.50	37	XCSE
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	6	AQEU
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	1	AQEU
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	34	AQEU
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	39	AQEU
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	42	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	9	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	42	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	9	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	38	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	9	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	9	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	9	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	3	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	7	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	5	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	15	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	5	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	15	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	7	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	5	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	7	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	5	TQEX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	8	XCSE
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	8	XCSE
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	87	XCSE
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	42	XCSE
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	1	CEUX
GENMAB A/S	18/04/2024	11:13:28 AM	1,999.50	12	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	11:15:45 AM	1,996.00	44	XCSE
GENMAB A/S	18/04/2024	11:15:45 AM	1,996.00	18	XCSE
GENMAB A/S	18/04/2024	11:15:45 AM	1,996.00	18	XCSE
GENMAB A/S	18/04/2024	11:15:47 AM	1,996.00	10	XCSE
GENMAB A/S	18/04/2024	11:15:47 AM	1,996.00	34	XCSE
GENMAB A/S	18/04/2024	11:15:47 AM	1,996.00	34	XCSE
GENMAB A/S	18/04/2024	11:15:50 AM	1,994.50	53	XCSE
GENMAB A/S	18/04/2024	11:15:55 AM	1,994.50	29	XCSE
GENMAB A/S	18/04/2024	11:15:55 AM	1,994.50	24	XCSE
GENMAB A/S	18/04/2024	11:15:55 AM	1,994.50	24	XCSE
GENMAB A/S	18/04/2024	11:15:55 AM	1,994.50	12	XCSE
GENMAB A/S	18/04/2024	11:22:09 AM	1,993.00	48	XCSE
GENMAB A/S	18/04/2024	11:22:09 AM	1,993.00	44	CEUX
GENMAB A/S	18/04/2024	11:22:09 AM	1,993.00	6	TQEX
GENMAB A/S	18/04/2024	11:22:09 AM	1,993.00	7	AQEU
GENMAB A/S	18/04/2024	11:22:10 AM	1,992.50	45	XCSE
GENMAB A/S	18/04/2024	11:22:10 AM	1,992.50	2	XCSE
GENMAB A/S	18/04/2024	11:26:23 AM	1,993.50	39	CEUX
GENMAB A/S	18/04/2024	11:28:30 AM	1,995.00	21	CEUX
GENMAB A/S	18/04/2024	11:28:30 AM	1,995.00	23	XCSE
GENMAB A/S	18/04/2024	11:28:53 AM	1,995.00	28	CEUX
GENMAB A/S	18/04/2024	11:28:53 AM	1,995.00	54	CEUX
GENMAB A/S	18/04/2024	11:28:53 AM	1,994.50	41	CEUX
GENMAB A/S	18/04/2024	11:28:53 AM	1,994.50	37	CEUX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	41	CEUX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	7	TQEX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	46	XCSE
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	46	XCSE
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	45	XCSE
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	16	CEUX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	13	CEUX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	12	CEUX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	2	CEUX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	7	TQEX
GENMAB A/S	18/04/2024	11:30:35 AM	1,994.50	10	TQEX
GENMAB A/S	18/04/2024	11:32:51 AM	1,994.50	15	CEUX
GENMAB A/S	18/04/2024	11:32:51 AM	1,994.50	56	CEUX
GENMAB A/S	18/04/2024	11:37:23 AM	1,995.50	26	XCSE
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	19	XCSE

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	39	XCSE
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	39	XCSE
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	34	CEUX
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	51	CEUX
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	34	CEUX
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	11	CEUX
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	9	TQEX
GENMAB A/S	18/04/2024	11:37:40 AM	1,995.50	10	XCSE
GENMAB A/S	18/04/2024	11:41:44 AM	1,997.50	37	XCSE
GENMAB A/S	18/04/2024	11:41:49 AM	1,996.50	11	XCSE
GENMAB A/S	18/04/2024	11:41:49 AM	1,996.50	11	CEUX
GENMAB A/S	18/04/2024	11:42:09 AM	1,996.50	11	XCSE
GENMAB A/S	18/04/2024	11:42:09 AM	1,996.50	1	XCSE
GENMAB A/S	18/04/2024	11:44:49 AM	1,997.50	45	XCSE
GENMAB A/S	18/04/2024	11:44:49 AM	1,997.50	1	XCSE
GENMAB A/S	18/04/2024	11:44:49 AM	1,997.50	74	XCSE
GENMAB A/S	18/04/2024	11:44:49 AM	1,997.50	6	XCSE
GENMAB A/S	18/04/2024	11:46:16 AM	1,999.50	1	CEUX
GENMAB A/S	18/04/2024	11:46:16 AM	1,999.50	6	XCSE
GENMAB A/S	18/04/2024	11:46:16 AM	1,999.50	23	XCSE
GENMAB A/S	18/04/2024	11:48:17 AM	1,999.50	9	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	9	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	32	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	36	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	52	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	9	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	27	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	77	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	9	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	66	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	16	XCSE
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	1	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	9	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	2	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	4	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	1	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	31	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	50	CEUX

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	11	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	42	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	4	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	2	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	4	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	10	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	6	CEUX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	17	TQEX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	5	TQEX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	32	TQEX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	5	TQEX
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	1	AQEU
GENMAB A/S	18/04/2024	11:51:44 AM	1,999.50	6	AQEU
GENMAB A/S	18/04/2024	12:00:25 PM	1,999.00	8	CEUX
GENMAB A/S	18/04/2024	12:00:25 PM	1,999.00	6	TQEX
GENMAB A/S	18/04/2024	12:00:25 PM	1,999.00	44	XCSE
GENMAB A/S	18/04/2024	12:00:29 PM	1,999.00	36	CEUX
GENMAB A/S	18/04/2024	12:00:33 PM	1,999.00	1	CEUX
GENMAB A/S	18/04/2024	12:01:53 PM	1,998.50	19	XCSE
GENMAB A/S	18/04/2024	12:02:40 PM	1,998.50	18	XCSE
GENMAB A/S	18/04/2024	12:02:41 PM	1,998.50	8	XCSE
GENMAB A/S	18/04/2024	12:02:41 PM	1,998.50	16	XCSE

100

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	12:04:32 PM	1,999.00	1	CEUX
GENMAB A/S	18/04/2024	12:04:32 PM	1,999.00	8	CEUX
GENMAB A/S	18/04/2024	12:04:32 PM	1,999.00	26	CEUX
GENMAB A/S	18/04/2024	12:05:12 PM	1,999.00	5	CEUX
GENMAB A/S	18/04/2024	12:05:12 PM	1,999.00	30	CEUX
GENMAB A/S	18/04/2024	12:06:01 PM	1,999.00	38	CEUX
GENMAB A/S	18/04/2024	12:06:51 PM	1,999.00	17	CEUX
GENMAB A/S	18/04/2024	12:06:51 PM	1,999.00	9	CEUX
GENMAB A/S	18/04/2024	12:06:51 PM	1,999.00	14	CEUX
GENMAB A/S	18/04/2024	12:07:32 PM	1,999.00	8	TQEX
GENMAB A/S	18/04/2024	12:07:32 PM	1,999.00	8	TQEX
GENMAB A/S	18/04/2024	12:07:32 PM	1,999.00	19	XCSE
GENMAB A/S	18/04/2024	12:07:32 PM	1,999.00	6	XCSE
GENMAB A/S	18/04/2024	12:08:23 PM	1,999.00	8	TQEX
GENMAB A/S	18/04/2024	12:08:23 PM	1,999.00	24	XCSE
GENMAB A/S	18/04/2024	12:08:23 PM	1,999.00	6	XCSE
GENMAB A/S	18/04/2024	12:08:31 PM	1,998.00	44	XCSE
GENMAB A/S	18/04/2024	12:08:31 PM	1,998.00	3	XCSE
GENMAB A/S	18/04/2024	12:08:31 PM	1,998.00	87	XCSE
GENMAB A/S	18/04/2024	12:08:31 PM	1,998.00	47	XCSE
GENMAB A/S	18/04/2024	12:08:33 PM	1,997.50	28	CEUX
GENMAB A/S	18/04/2024	12:11:29 PM	1,996.50	79	XCSE
GENMAB A/S	18/04/2024	12:11:29 PM	1,996.50	10	AQEU
GENMAB A/S	18/04/2024	12:11:29 PM	1,996.50	71	CEUX
GENMAB A/S	18/04/2024	12:11:29 PM	1,996.50	11	CEUX
GENMAB A/S	18/04/2024	12:17:09 PM	1,997.50	19	CEUX
GENMAB A/S	18/04/2024	12:17:09 PM	1,997.50	10	CEUX
GENMAB A/S	18/04/2024	12:17:15 PM	1,997.50	8	CEUX
GENMAB A/S	18/04/2024	12:17:42 PM	1,997.50	19	CEUX
GENMAB A/S	18/04/2024	12:17:48 PM	1,997.50	17	CEUX
GENMAB A/S	18/04/2024	12:18:16 PM	1,996.50	19	CEUX
GENMAB A/S	18/04/2024	12:19:00 PM	1,997.50	16	TQEX
GENMAB A/S	18/04/2024	12:19:01 PM	1,997.50	19	TQEX
GENMAB A/S	18/04/2024	12:19:34 PM	1,997.00	62	XCSE
GENMAB A/S	18/04/2024	12:19:34 PM	1,997.00	74	XCSE
GENMAB A/S	18/04/2024	12:19:34 PM	1,997.00	18	TQEX
GENMAB A/S	18/04/2024	12:22:36 PM	1,997.00	3	AQEU
GENMAB A/S	18/04/2024	12:22:36 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	12:22:36 PM	1,997.00	4	XCSE

101

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	12:22:37 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	12:22:37 PM	1,997.00	10	XCSE
GENMAB A/S	18/04/2024	12:23:23 PM	1,997.50	11	XCSE
GENMAB A/S	18/04/2024	12:24:36 PM	1,997.50	1	XCSE
GENMAB A/S	18/04/2024	12:24:56 PM	1,998.50	7	CEUX
GENMAB A/S	18/04/2024	12:24:56 PM	1,998.50	73	CEUX
GENMAB A/S	18/04/2024	12:24:56 PM	1,998.00	74	CEUX
GENMAB A/S	18/04/2024	12:24:56 PM	1,998.00	117	CEUX
GENMAB A/S	18/04/2024	12:24:56 PM	1,998.00	18	TQEX
GENMAB A/S	18/04/2024	12:24:56 PM	1,998.00	130	XCSE
GENMAB A/S	18/04/2024	12:31:29 PM	1,997.00	84	CEUX
GENMAB A/S	18/04/2024	12:31:29 PM	1,997.00	4	CEUX
GENMAB A/S	18/04/2024	12:31:29 PM	1,997.00	5	CEUX
GENMAB A/S	18/04/2024	12:31:29 PM	1,997.00	7	CEUX
GENMAB A/S	18/04/2024	12:32:19 PM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	12:32:19 PM	1,996.50	69	XCSE
GENMAB A/S	18/04/2024	12:32:20 PM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	12:32:32 PM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	12:32:32 PM	1,996.50	26	XCSE
GENMAB A/S	18/04/2024	12:37:32 PM	1,998.00	9	XCSE
GENMAB A/S	18/04/2024	12:37:32 PM	1,998.00	22	XCSE
GENMAB A/S	18/04/2024	12:37:32 PM	1,998.00	9	XCSE
GENMAB A/S	18/04/2024	12:38:19 PM	1,998.00	37	CEUX
GENMAB A/S	18/04/2024	12:39:35 PM	1,998.00	45	CEUX
GENMAB A/S	18/04/2024	12:39:35 PM	1,998.00	18	CEUX
GENMAB A/S	18/04/2024	12:40:05 PM	1,998.00	80	XCSE
GENMAB A/S	18/04/2024	12:40:05 PM	1,998.00	72	CEUX
GENMAB A/S	18/04/2024	12:40:05 PM	1,998.00	11	TQEX
GENMAB A/S	18/04/2024	12:45:08 PM	1,998.00	81	XCSE
GENMAB A/S	18/04/2024	12:45:08 PM	1,998.00	72	XCSE
GENMAB A/S	18/04/2024	12:45:08 PM	1,998.00	11	AQEU
GENMAB A/S	18/04/2024	12:45:08 PM	1,998.00	37	CEUX
GENMAB A/S	18/04/2024	12:45:08 PM	1,998.00	73	CEUX
GENMAB A/S	18/04/2024	12:45:08 PM	1,998.00	11	CEUX
GENMAB A/S	18/04/2024	12:47:05 PM	1,997.00	51	CEUX
GENMAB A/S	18/04/2024	12:50:31 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	12:50:31 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	12:50:31 PM	1,998.00	17	CEUX
GENMAB A/S	18/04/2024	12:50:31 PM	1,998.00	6	CEUX

102

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	12:51:22 PM	1,998.00	28	CEUX
GENMAB A/S	18/04/2024	12:51:22 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	12:53:12 PM	1,998.00	78	CEUX
GENMAB A/S	18/04/2024	12:53:45 PM	1,998.00	8	XCSE
GENMAB A/S	18/04/2024	12:53:45 PM	1,998.00	30	XCSE
GENMAB A/S	18/04/2024	12:54:31 PM	1,998.00	39	XCSE
GENMAB A/S	18/04/2024	12:54:41 PM	1,998.00	8	AQEU
GENMAB A/S	18/04/2024	12:54:41 PM	1,998.00	17	AQEU
GENMAB A/S	18/04/2024	12:54:41 PM	1,998.00	36	CEUX
GENMAB A/S	18/04/2024	12:54:41 PM	1,998.00	17	CEUX
GENMAB A/S	18/04/2024	12:54:41 PM	1,998.00	48	CEUX
GENMAB A/S	18/04/2024	12:54:41 PM	1,998.00	15	TQEX
GENMAB A/S	18/04/2024	12:54:41 PM	1,997.50	17	CEUX
GENMAB A/S	18/04/2024	12:54:41 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	12:58:38 PM	1,998.00	39	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	4	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	12	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	12	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	6	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	6	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	10	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	17	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	10	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	1	AQEU
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	2	AQEU
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	12	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	12	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	12	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	11	CEUX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	15	TQEX
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	10	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	29	XCSE
GENMAB A/S	18/04/2024	12:59:31 PM	1,997.50	10	CEUX
GENMAB A/S	18/04/2024	1:07:01 PM	1,997.50	12	AQEU
GENMAB A/S	18/04/2024	1:07:01 PM	1,997.50	7	AQEU
GENMAB A/S	18/04/2024	1:07:01 PM	1,997.50	39	XCSE

103

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	1:07:01 PM	1,997.50	90	XCSE
GENMAB A/S	18/04/2024	1:07:01 PM	1,997.50	68	XCSE
GENMAB A/S	18/04/2024	1:07:59 PM	1,997.50	39	CEUX
GENMAB A/S	18/04/2024	1:07:59 PM	1,997.50	6	TQEX
GENMAB A/S	18/04/2024	1:07:59 PM	1,997.50	26	XCSE
GENMAB A/S	18/04/2024	1:07:59 PM	1,997.50	26	XCSE
GENMAB A/S	18/04/2024	1:07:59 PM	1,997.50	43	XCSE
GENMAB A/S	18/04/2024	1:07:59 PM	1,997.50	10	TQEX
GENMAB A/S	18/04/2024	1:08:00 PM	1,997.50	6	CEUX
GENMAB A/S	18/04/2024	1:08:05 PM	1,997.50	17	CEUX
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.50	32	CEUX
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.50	40	CEUX
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.50	12	TQEX
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.50	74	XCSE
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.50	6	XCSE
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.00	5	XCSE
GENMAB A/S	18/04/2024	1:10:53 PM	1,999.00	63	XCSE
GENMAB A/S	18/04/2024	1:16:29 PM	1,998.50	21	XCSE
GENMAB A/S	18/04/2024	1:16:29 PM	1,998.50	20	CEUX
GENMAB A/S	18/04/2024	1:16:29 PM	1,998.50	5	TQEX
GENMAB A/S	18/04/2024	1:18:26 PM	1,998.50	20	CEUX
GENMAB A/S	18/04/2024	1:18:26 PM	1,998.50	4	TQEX
GENMAB A/S	18/04/2024	1:18:26 PM	1,998.50	21	XCSE
GENMAB A/S	18/04/2024	1:18:26 PM	1,998.50	16	XCSE
GENMAB A/S	18/04/2024	1:18:31 PM	1,998.50	25	CEUX
GENMAB A/S	18/04/2024	1:18:32 PM	1,998.00	35	CEUX
GENMAB A/S	18/04/2024	1:18:32 PM	1,998.00	24	CEUX
GENMAB A/S	18/04/2024	1:18:32 PM	1,998.00	48	XCSE
GENMAB A/S	18/04/2024	1:18:32 PM	1,998.00	36	CEUX
GENMAB A/S	18/04/2024	1:18:33 PM	1,998.00	19	XCSE
GENMAB A/S	18/04/2024	1:18:41 PM	1,998.00	11	XCSE
GENMAB A/S	18/04/2024	1:23:18 PM	1,998.00	11	XCSE
GENMAB A/S	18/04/2024	1:23:41 PM	1,998.00	20	XCSE
GENMAB A/S	18/04/2024	1:23:41 PM	1,998.00	4	XCSE
GENMAB A/S	18/04/2024	1:23:41 PM	1,998.00	14	XCSE
GENMAB A/S	18/04/2024	1:24:19 PM	1,998.50	7	CEUX
GENMAB A/S	18/04/2024	1:24:19 PM	1,998.50	5	CEUX
GENMAB A/S	18/04/2024	1:24:19 PM	1,998.50	17	CEUX
GENMAB A/S	18/04/2024	1:24:19 PM	1,998.50	12	CEUX

104

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	1:24:28 PM	1,998.00	26	XCSE
GENMAB A/S	18/04/2024	1:24:33 PM	1,998.00	26	XCSE
GENMAB A/S	18/04/2024	1:24:33 PM	1,998.00	2	XCSE
GENMAB A/S	18/04/2024	1:24:33 PM	1,998.00	5	XCSE
GENMAB A/S	18/04/2024	1:24:33 PM	1,998.00	21	XCSE
GENMAB A/S	18/04/2024	1:24:33 PM	1,998.00	26	XCSE
GENMAB A/S	18/04/2024	1:24:59 PM	1,997.50	8	XCSE
GENMAB A/S	18/04/2024	1:24:59 PM	1,997.50	2	XCSE
GENMAB A/S	18/04/2024	1:24:59 PM	1,997.50	9	CEUX
GENMAB A/S	18/04/2024	1:24:59 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	1:25:27 PM	1,997.50	42	XCSE
GENMAB A/S	18/04/2024	1:25:27 PM	1,997.50	60	XCSE
GENMAB A/S	18/04/2024	1:29:49 PM	1,998.50	34	XCSE
GENMAB A/S	18/04/2024	1:30:33 PM	1,998.50	15	CEUX
GENMAB A/S	18/04/2024	1:30:33 PM	1,998.50	1	CEUX
GENMAB A/S	18/04/2024	1:30:33 PM	1,998.50	9	CEUX
GENMAB A/S	18/04/2024	1:30:33 PM	1,998.50	6	CEUX
GENMAB A/S	18/04/2024	1:30:33 PM	1,998.50	5	XCSE
GENMAB A/S	18/04/2024	1:30:44 PM	1,998.00	12	CEUX
GENMAB A/S	18/04/2024	1:31:29 PM	1,998.50	36	XCSE
GENMAB A/S	18/04/2024	1:32:18 PM	1,998.50	21	XCSE
GENMAB A/S	18/04/2024	1:32:28 PM	1,998.50	13	XCSE
GENMAB A/S	18/04/2024	1:33:07 PM	1,998.50	23	XCSE
GENMAB A/S	18/04/2024	1:33:07 PM	1,998.50	18	XCSE
GENMAB A/S	18/04/2024	1:33:57 PM	1,998.50	41	XCSE
GENMAB A/S	18/04/2024	1:34:38 PM	1,998.50	39	XCSE
GENMAB A/S	18/04/2024	1:35:37 PM	1,998.50	38	XCSE
GENMAB A/S	18/04/2024	1:36:17 PM	1,998.50	7	CEUX
GENMAB A/S	18/04/2024	1:36:17 PM	1,998.50	13	CEUX
GENMAB A/S	18/04/2024	1:36:17 PM	1,998.50	4	TQEX
GENMAB A/S	18/04/2024	1:36:50 PM	1,998.50	21	CEUX
GENMAB A/S	18/04/2024	1:36:50 PM	1,998.50	15	CEUX
GENMAB A/S	18/04/2024	1:37:07 PM	1,998.00	11	XCSE
GENMAB A/S	18/04/2024	1:37:07 PM	1,998.00	12	CEUX
GENMAB A/S	18/04/2024	1:37:07 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:38:09 PM	1,998.00	18	CEUX
GENMAB A/S	18/04/2024	1:38:09 PM	1,998.00	18	CEUX
GENMAB A/S	18/04/2024	1:38:16 PM	1,998.00	4	CEUX
GENMAB A/S	18/04/2024	1:38:16 PM	1,998.00	8	XCSE

105

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	1:38:23 PM	1,998.00	4	CEUX
GENMAB A/S	18/04/2024	1:38:23 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:38:23 PM	1,998.00	8	XCSE
GENMAB A/S	18/04/2024	1:38:31 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	1:38:31 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:38:31 PM	1,998.00	7	XCSE
GENMAB A/S	18/04/2024	1:38:59 PM	1,998.00	9	CEUX
GENMAB A/S	18/04/2024	1:38:59 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:39:08 PM	1,998.00	9	CEUX
GENMAB A/S	18/04/2024	1:39:08 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:39:08 PM	1,998.00	8	XCSE
GENMAB A/S	18/04/2024	1:39:22 PM	1,998.00	9	CEUX
GENMAB A/S	18/04/2024	1:39:22 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:39:22 PM	1,998.00	6	XCSE
GENMAB A/S	18/04/2024	1:40:13 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	1:40:13 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:40:13 PM	1,998.00	7	XCSE
GENMAB A/S	18/04/2024	1:40:45 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	1:40:45 PM	1,998.00	5	TQEX
GENMAB A/S	18/04/2024	1:40:45 PM	1,998.00	8	CEUX
GENMAB A/S	18/04/2024	1:40:45 PM	1,998.00	7	XCSE
GENMAB A/S	18/04/2024	1:41:45 PM	1,998.00	41	CEUX
GENMAB A/S	18/04/2024	1:43:34 PM	1,998.50	19	CEUX
GENMAB A/S	18/04/2024	1:43:34 PM	1,998.50	61	CEUX
GENMAB A/S	18/04/2024	1:44:22 PM	1,998.50	17	CEUX
GENMAB A/S	18/04/2024	1:44:29 PM	1,998.50	17	CEUX
GENMAB A/S	18/04/2024	1:44:36 PM	1,998.50	2	CEUX
GENMAB A/S	18/04/2024	1:44:39 PM	1,998.50	7	CEUX
GENMAB A/S	18/04/2024	1:44:49 PM	1,998.50	14	CEUX
GENMAB A/S	18/04/2024	1:44:59 PM	1,998.50	21	CEUX
GENMAB A/S	18/04/2024	1:45:12 PM	1,998.50	20	CEUX
GENMAB A/S	18/04/2024	1:45:29 PM	1,998.50	14	CEUX
GENMAB A/S	18/04/2024	1:45:32 PM	1,998.50	6	CEUX
GENMAB A/S	18/04/2024	1:45:46 PM	1,998.50	20	CEUX
GENMAB A/S	18/04/2024	1:46:00 PM	1,998.50	20	CEUX
GENMAB A/S	18/04/2024	1:46:41 PM	1,998.50	9	AQEU
GENMAB A/S	18/04/2024	1:46:41 PM	1,998.50	49	CEUX
GENMAB A/S	18/04/2024	1:46:41 PM	1,998.50	8	TQEX
GENMAB A/S	18/04/2024	1:48:12 PM	1,998.50	23	XCSE

106

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	1:48:12 PM	1,998.50	86	XCSE
GENMAB A/S	18/04/2024	1:48:12 PM	1,998.50	15	XCSE
GENMAB A/S	18/04/2024	1:48:12 PM	1,998.50	8	XCSE
GENMAB A/S	18/04/2024	1:48:12 PM	1,998.50	14	XCSE
GENMAB A/S	18/04/2024	1:48:16 PM	1,998.00	63	XCSE
GENMAB A/S	18/04/2024	1:48:16 PM	1,998.00	43	XCSE
GENMAB A/S	18/04/2024	1:48:16 PM	1,998.00	43	XCSE
GENMAB A/S	18/04/2024	1:54:43 PM	1,998.50	30	CEUX
GENMAB A/S	18/04/2024	1:54:43 PM	1,998.50	6	CEUX
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	11	AQEU
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	5	CEUX
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	73	CEUX
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	11	TQEX
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	44	XCSE
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	11	XCSE
GENMAB A/S	18/04/2024	1:54:49 PM	1,997.50	32	XCSE
GENMAB A/S	18/04/2024	1:54:58 PM	1,997.50	1	TQEX
GENMAB A/S	18/04/2024	2:00:30 PM	1,997.50	7	AQEU
GENMAB A/S	18/04/2024	2:00:30 PM	1,997.50	11	CEUX
GENMAB A/S	18/04/2024	2:00:30 PM	1,997.50	24	XCSE
GENMAB A/S	18/04/2024	2:00:43 PM	1,997.50	8	CEUX
GENMAB A/S	18/04/2024	2:00:52 PM	1,997.50	98	XCSE
GENMAB A/S	18/04/2024	2:00:52 PM	1,997.50	19	CEUX
GENMAB A/S	18/04/2024	2:00:57 PM	1,997.50	17	XCSE
GENMAB A/S	18/04/2024	2:00:57 PM	1,997.50	36	XCSE
GENMAB A/S	18/04/2024	2:01:01 PM	1,997.50	14	XCSE
GENMAB A/S	18/04/2024	2:01:01 PM	1,997.50	48	XCSE
GENMAB A/S	18/04/2024	2:05:14 PM	1,998.00	8	XCSE
GENMAB A/S	18/04/2024	2:05:14 PM	1,998.00	14	XCSE
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	2	AQEU
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	6	AQEU
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	31	CEUX
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	51	CEUX
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	6	TQEX
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	37	XCSE
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	16	XCSE
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	156	XCSE
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	71	CEUX
GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	17	TQEX

107

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	2:06:37 PM	1,997.50	15	CEUX
GENMAB A/S	18/04/2024	2:10:09 PM	1,995.50	47	XCSE
GENMAB A/S	18/04/2024	2:10:09 PM	1,995.50	47	XCSE
GENMAB A/S	18/04/2024	2:10:13 PM	1,995.50	15	XCSE
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	9	XCSE
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	9	CEUX
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	1	TQEX
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	9	XCSE
GENMAB A/S	18/04/2024	2:14:15 PM	1,994.00	9	XCSE
GENMAB A/S	18/04/2024	2:15:19 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:16:20 PM	1,994.50	1	AQEU
GENMAB A/S	18/04/2024	2:16:20 PM	1,994.50	17	AQEU
GENMAB A/S	18/04/2024	2:16:39 PM	1,994.50	17	AQEU
GENMAB A/S	18/04/2024	2:18:48 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:19:33 PM	1,994.50	44	XCSE
GENMAB A/S	18/04/2024	2:19:46 PM	1,994.50	6	XCSE
GENMAB A/S	18/04/2024	2:19:46 PM	1,994.50	104	XCSE
GENMAB A/S	18/04/2024	2:19:46 PM	1,994.50	50	XCSE
GENMAB A/S	18/04/2024	2:19:46 PM	1,994.50	41	XCSE
GENMAB A/S	18/04/2024	2:22:04 PM	1,997.50	23	XCSE
GENMAB A/S	18/04/2024	2:22:04 PM	1,997.50	13	XCSE
GENMAB A/S	18/04/2024	2:22:48 PM	1,997.50	34	XCSE
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	10	CEUX
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	10	CEUX
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	1	TQEX
GENMAB A/S	18/04/2024	2:23:02 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:23:03 PM	1,996.50	10	CEUX
GENMAB A/S	18/04/2024	2:23:03 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:23:03 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:24:39 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:25:05 PM	1,997.00	19	XCSE
GENMAB A/S	18/04/2024	2:25:05 PM	1,997.50	17	XCSE
GENMAB A/S	18/04/2024	2:25:46 PM	1,997.50	23	XCSE

108

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	10	CEUX
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	5	XCSE
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	5	XCSE
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	4	XCSE
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	4	XCSE
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:25:59 PM	1,996.50	4	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	22	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	28	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	26	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	28	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	16	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	28	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	10	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	13	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	28	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	24	CEUX
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	28	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	4	XCSE
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	3	CEUX
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	27	CEUX
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	2:27:05 PM	1,996.50	4	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	6	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	6	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	6	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	4	AQEU

109

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	40	CEUX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	40	CEUX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	5	CEUX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	6	CEUX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	6	TQEX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	1	TQEX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	44	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	19	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	25	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	10	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	19	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	3	AQEU
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	19	CEUX
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	19	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,995.00	25	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	46	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	19	XCSE
GENMAB A/S	18/04/2024	2:30:08 PM	1,994.50	2	XCSE
GENMAB A/S	18/04/2024	2:37:50 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:37:50 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:37:50 PM	1,994.00	17	XCSE
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	1	AQEU
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	CEUX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	CEUX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	CEUX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	CEUX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	1	CEUX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	CEUX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	1	TQEX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	1	XCSE
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	16	XCSE
GENMAB A/S	18/04/2024	2:38:58 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	2:39:00 PM	1,994.00	18	XCSE

110

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	2:39:00 PM	1,994.00	4	XCSE
GENMAB A/S	18/04/2024	2:39:00 PM	1,994.00	14	XCSE
GENMAB A/S	18/04/2024	2:39:00 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	2:39:00 PM	1,994.00	22	XCSE
GENMAB A/S	18/04/2024	2:39:00 PM	1,994.00	18	XCSE
GENMAB A/S	18/04/2024	2:41:22 PM	1,992.00	11	CEUX
GENMAB A/S	18/04/2024	2:41:22 PM	1,992.00	45	CEUX
GENMAB A/S	18/04/2024	2:41:22 PM	1,992.00	22	XCSE
GENMAB A/S	18/04/2024	2:41:27 PM	1,992.00	4	CEUX
GENMAB A/S	18/04/2024	2:44:24 PM	1,991.00	27	XCSE
GENMAB A/S	18/04/2024	2:44:24 PM	1,991.00	1	CEUX
GENMAB A/S	18/04/2024	2:44:55 PM	1,991.50	38	AQEU
GENMAB A/S	18/04/2024	2:45:10 PM	1,991.00	27	XCSE
GENMAB A/S	18/04/2024	2:45:56 PM	1,992.00	8	TQEX
GENMAB A/S	18/04/2024	2:46:00 PM	1,991.00	27	XCSE
GENMAB A/S	18/04/2024	2:46:00 PM	1,991.00	19	CEUX
GENMAB A/S	18/04/2024	2:46:02 PM	1,991.00	44	CEUX
GENMAB A/S	18/04/2024	2:46:02 PM	1,991.00	27	XCSE
GENMAB A/S	18/04/2024	2:46:02 PM	1,991.00	27	CEUX
GENMAB A/S	18/04/2024	2:46:19 PM	1,990.50	42	XCSE
GENMAB A/S	18/04/2024	2:46:20 PM	1,990.50	42	XCSE
GENMAB A/S	18/04/2024	2:46:20 PM	1,990.50	30	XCSE
GENMAB A/S	18/04/2024	2:46:20 PM	1,989.50	2	AQEU
GENMAB A/S	18/04/2024	2:46:20 PM	1,989.50	6	CEUX
GENMAB A/S	18/04/2024	2:46:20 PM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	2:46:20 PM	1,989.50	15	XCSE
GENMAB A/S	18/04/2024	2:46:20 PM	1,989.50	3	XCSE
GENMAB A/S	18/04/2024	2:46:21 PM	1,989.50	11	CEUX
GENMAB A/S	18/04/2024	2:46:21 PM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	2:46:21 PM	1,989.50	18	XCSE
GENMAB A/S	18/04/2024	2:50:57 PM	1,990.00	11	XCSE
GENMAB A/S	18/04/2024	2:50:57 PM	1,990.00	29	XCSE
GENMAB A/S	18/04/2024	2:51:34 PM	1,990.00	11	XCSE
GENMAB A/S	18/04/2024	2:51:34 PM	1,990.00	23	XCSE
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	47	XCSE
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	39	XCSE
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	47	XCSE
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	2	XCSE
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.00	95	XCSE

111

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	43	CEUX
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	6	AQEU
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	6	AQEU
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	2	AQEU
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	28	CEUX
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	15	CEUX
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	37	CEUX
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	6	AQEU
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.50	20	XCSE
GENMAB A/S	18/04/2024	2:52:05 PM	1,992.00	21	XCSE
GENMAB A/S	18/04/2024	2:56:46 PM	1,991.00	19	CEUX
GENMAB A/S	18/04/2024	2:56:46 PM	1,991.00	33	CEUX
GENMAB A/S	18/04/2024	2:56:46 PM	1,991.00	25	XCSE
GENMAB A/S	18/04/2024	2:56:46 PM	1,991.00	36	CEUX
GENMAB A/S	18/04/2024	2:58:00 PM	1,989.00	48	XCSE
GENMAB A/S	18/04/2024	2:58:01 PM	1,989.00	48	XCSE
GENMAB A/S	18/04/2024	2:58:01 PM	1,989.00	35	XCSE
GENMAB A/S	18/04/2024	3:02:27 PM	1,990.00	10	CEUX
GENMAB A/S	18/04/2024	3:02:27 PM	1,990.00	4	CEUX
GENMAB A/S	18/04/2024	3:02:27 PM	1,990.00	1	CEUX
GENMAB A/S	18/04/2024	3:02:27 PM	1,990.00	2	CEUX
GENMAB A/S	18/04/2024	3:02:27 PM	1,990.00	5	CEUX
GENMAB A/S	18/04/2024	3:02:27 PM	1,990.00	4	TQEX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	8	XCSE
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	8	XCSE
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	8	XCSE
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	9	CEUX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	5	CEUX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	4	CEUX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	3	CEUX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	3	TQEX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	2	TQEX
GENMAB A/S	18/04/2024	3:02:31 PM	1,989.50	3	XCSE
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	9	XCSE
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	10	CEUX
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	5	TQEX
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	1	AQEU
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	2	AQEU
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	10	CEUX

112

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	3	CEUX
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	5	TQEX
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	2	TQEX
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	9	XCSE
GENMAB A/S	18/04/2024	3:02:58 PM	1,990.00	13	XCSE
GENMAB A/S	18/04/2024	3:03:04 PM	1,990.00	1	AQEU
GENMAB A/S	18/04/2024	3:03:04 PM	1,990.00	10	CEUX
GENMAB A/S	18/04/2024	3:03:04 PM	1,990.00	5	TQEX
GENMAB A/S	18/04/2024	3:03:04 PM	1,990.00	9	XCSE
GENMAB A/S	18/04/2024	3:03:05 PM	1,990.00	1	AQEU
GENMAB A/S	18/04/2024	3:03:05 PM	1,990.00	10	CEUX
GENMAB A/S	18/04/2024	3:03:05 PM	1,990.00	10	CEUX
GENMAB A/S	18/04/2024	3:03:05 PM	1,990.00	5	TQEX
GENMAB A/S	18/04/2024	3:03:05 PM	1,990.00	9	XCSE
GENMAB A/S	18/04/2024	3:04:52 PM	1,991.00	11	XCSE
GENMAB A/S	18/04/2024	3:04:52 PM	1,991.00	31	XCSE
GENMAB A/S	18/04/2024	3:04:52 PM	1,991.00	42	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,993.00	37	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,993.00	37	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,993.00	5	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,993.00	37	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,993.00	37	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,993.00	3	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,992.50	10	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,992.50	36	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,992.50	23	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,992.50	46	XCSE
GENMAB A/S	18/04/2024	3:06:44 PM	1,992.50	35	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	27	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	21	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	27	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	21	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	21	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	6	XCSE
GENMAB A/S	18/04/2024	3:12:40 PM	1,995.00	21	XCSE
GENMAB A/S	18/04/2024	3:12:41 PM	1,995.00	27	XCSE
GENMAB A/S	18/04/2024	3:12:41 PM	1,995.00	21	XCSE
GENMAB A/S	18/04/2024	3:12:41 PM	1,995.00	27	XCSE
GENMAB A/S	18/04/2024	3:12:41 PM	1,995.00	21	XCSE

113

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:12:41 PM	1,995.00	25	CEUX
GENMAB A/S	18/04/2024	3:12:41 PM	1,995.00	2	XCSE
GENMAB A/S	18/04/2024	3:15:43 PM	1,994.00	95	XCSE
GENMAB A/S	18/04/2024	3:16:11 PM	1,994.00	7	CEUX
GENMAB A/S	18/04/2024	3:16:11 PM	1,994.00	7	TQEX
GENMAB A/S	18/04/2024	3:16:11 PM	1,994.00	50	XCSE
GENMAB A/S	18/04/2024	3:16:11 PM	1,994.00	6	AQEU
GENMAB A/S	18/04/2024	3:16:22 PM	1,993.00	39	AQEU
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	21	XCSE
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	21	XCSE
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	21	XCSE
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	36	CEUX
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	23	XCSE
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	21	XCSE
GENMAB A/S	18/04/2024	3:19:27 PM	1,996.00	10	XCSE
GENMAB A/S	18/04/2024	3:22:15 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:22:15 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:22:15 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:22:15 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:22:15 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:22:15 PM	1,995.00	42	XCSE
GENMAB A/S	18/04/2024	3:25:23 PM	1,994.50	35	CEUX
GENMAB A/S	18/04/2024	3:25:23 PM	1,994.50	37	CEUX
GENMAB A/S	18/04/2024	3:25:23 PM	1,994.50	92	XCSE
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	11	CEUX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	11	CEUX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	11	CEUX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	11	CEUX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	8	CEUX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	22	TQEX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	3:28:00 PM	1,994.00	17	CEUX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	7	TQEX
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	10	XCSE
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	8	XCSE
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	10	XCSE
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	30	XCSE
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	8	AQEU

114

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	17	AQEU
GENMAB A/S	18/04/2024	3:28:00 PM	1,995.00	18	AQEU
GENMAB A/S	18/04/2024	3:29:34 PM	1,993.50	68	XCSE
GENMAB A/S	18/04/2024	3:29:34 PM	1,993.50	68	XCSE
GENMAB A/S	18/04/2024	3:29:34 PM	1,993.50	20	XCSE
GENMAB A/S	18/04/2024	3:29:34 PM	1,993.50	2	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	20	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	21	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	20	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	21	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	3	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	16	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	21	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	3	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	19	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	19	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	20	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	10	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	18	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	19	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	1	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	2	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	19	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	20	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	21	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	8	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	47	XCSE
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	5	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	4	AQEU
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	5	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	32	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	40	AQEU
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	7	AQEU

115

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	15	AQEU
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	15	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	22	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	10	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	10	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.50	6	TQEX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	4	CEUX
GENMAB A/S	18/04/2024	3:30:03 PM	1,991.00	10	CEUX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	59	XCSE
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	9	XCSE
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	39	XCSE
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	33	CEUX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	8	TQEX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	8	TQEX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	24	CEUX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	8	AQEU
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	29	CEUX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	8	TQEX
GENMAB A/S	18/04/2024	3:36:40 PM	1,980.50	36	CEUX
GENMAB A/S	18/04/2024	3:39:55 PM	1,983.50	49	XCSE
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	44	CEUX
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	15	XCSE
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	14	XCSE
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	7	AQEU
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	27	CEUX
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	6	TQEX
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	6	TQEX
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	8	AQEU
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	17	AQEU
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	36	CEUX
GENMAB A/S	18/04/2024	3:40:00 PM	1,983.50	2	TQEX
GENMAB A/S	18/04/2024	3:40:01 PM	1,982.00	22	CEUX
GENMAB A/S	18/04/2024	3:40:01 PM	1,982.00	22	CEUX
GENMAB A/S	18/04/2024	3:40:01 PM	1,982.00	5	TQEX
GENMAB A/S	18/04/2024	3:40:01 PM	1,982.00	23	XCSE
GENMAB A/S	18/04/2024	3:40:02 PM	1,982.00	22	CEUX
GENMAB A/S	18/04/2024	3:40:02 PM	1,982.00	23	XCSE
GENMAB A/S	18/04/2024	3:42:22 PM	1,985.00	56	XCSE
GENMAB A/S	18/04/2024	3:42:22 PM	1,985.00	9	AQEU

116

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:42:22 PM	1,985.00	45	CEUX
GENMAB A/S	18/04/2024	3:42:22 PM	1,985.00	19	CEUX
GENMAB A/S	18/04/2024	3:42:22 PM	1,985.00	10	TQEX
GENMAB A/S	18/04/2024	3:42:22 PM	1,985.00	15	XCSE
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	9	XCSE
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	1	AQEU
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	12	AQEU
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	10	CEUX
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	10	CEUX
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	4	CEUX
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	5	TQEX
GENMAB A/S	18/04/2024	3:43:25 PM	1,987.00	9	XCSE
GENMAB A/S	18/04/2024	3:43:29 PM	1,987.00	1	AQEU
GENMAB A/S	18/04/2024	3:43:29 PM	1,987.00	10	CEUX
GENMAB A/S	18/04/2024	3:43:29 PM	1,987.00	3	TQEX
GENMAB A/S	18/04/2024	3:43:29 PM	1,987.00	10	CEUX
GENMAB A/S	18/04/2024	3:43:29 PM	1,987.00	2	TQEX
GENMAB A/S	18/04/2024	3:43:29 PM	1,987.00	9	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	6	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	12	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	20	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	31	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	9	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	60	XCSE
GENMAB A/S	18/04/2024	3:43:33 PM	1,987.00	7	XCSE
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	1	AQEU
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	2	AQEU
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	1	AQEU
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	CEUX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	2	CEUX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	CEUX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	CEUX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	2	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	1	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	CEUX

117

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	5	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	11	TQEX
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	XCSE
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	10	XCSE
GENMAB A/S	18/04/2024	3:45:52 PM	1,989.50	8	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	55	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	20	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	10	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	91	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	26	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	25	XCSE
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	11	AQEU
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	11	AQEU
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	11	AQEU
GENMAB A/S	18/04/2024	3:47:04 PM	1,993.00	7	XCSE
GENMAB A/S	18/04/2024	3:47:55 PM	1,995.50	18	XCSE
GENMAB A/S	18/04/2024	3:47:55 PM	1,995.50	74	XCSE
GENMAB A/S	18/04/2024	3:47:55 PM	1,995.50	117	XCSE
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	1	AQEU
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	8	CEUX
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	8	CEUX
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	5	TQEX
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	5	TQEX
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	8	XCSE
GENMAB A/S	18/04/2024	3:49:19 PM	1,995.50	8	XCSE
GENMAB A/S	18/04/2024	3:50:21 PM	1,996.00	19	CEUX
GENMAB A/S	18/04/2024	3:50:21 PM	1,996.00	80	XCSE
GENMAB A/S	18/04/2024	3:50:21 PM	1,996.00	2	XCSE
GENMAB A/S	18/04/2024	3:50:21 PM	1,996.00	56	CEUX
GENMAB A/S	18/04/2024	3:50:21 PM	1,996.00	11	CEUX
GENMAB A/S	18/04/2024	3:50:21 PM	1,996.00	11	TQEX
GENMAB A/S	18/04/2024	3:51:19 PM	1,995.00	10	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	9	AQEU
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	65	CEUX
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	10	TQEX
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	12	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	20	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	52	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	2	XCSE

118

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	20	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	2	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	22	XCSE
GENMAB A/S	18/04/2024	3:52:06 PM	1,995.00	31	XCSE
GENMAB A/S	18/04/2024	3:54:03 PM	1,995.00	7	XCSE
GENMAB A/S	18/04/2024	3:54:03 PM	1,995.00	10	XCSE
GENMAB A/S	18/04/2024	3:54:03 PM	1,995.00	8	CEUX
GENMAB A/S	18/04/2024	3:54:03 PM	1,995.00	1	AQEU
GENMAB A/S	18/04/2024	3:54:03 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	1	AQEU
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	1	AQEU
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	17	AQEU
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	8	CEUX
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	1	AQEU
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	8	CEUX
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	4	XCSE
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	2	XCSE
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	1	XCSE
GENMAB A/S	18/04/2024	3:54:21 PM	1,995.00	6	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	22	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	24	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	22	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	24	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	22	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	2	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	10	XCSE
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	15	AQEU
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	7	AQEU
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	36	CEUX
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	17	AQEU
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	8	AQEU
GENMAB A/S	18/04/2024	3:54:48 PM	1,994.50	7	TQEX
GENMAB A/S	18/04/2024	3:56:03 PM	1,992.00	23	XCSE
GENMAB A/S	18/04/2024	3:56:03 PM	1,992.00	23	XCSE
GENMAB A/S	18/04/2024	3:56:03 PM	1,992.00	15	AQEU
GENMAB A/S	18/04/2024	3:56:03 PM	1,992.00	36	CEUX

119

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	3:56:03 PM	1,992.00	20	XCSE
GENMAB A/S	18/04/2024	3:56:03 PM	1,992.00	23	AQEU
GENMAB A/S	18/04/2024	3:56:04 PM	1,992.00	7	AQEU
GENMAB A/S	18/04/2024	3:57:27 PM	1,990.50	5	XCSE
GENMAB A/S	18/04/2024	3:57:27 PM	1,990.50	20	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	25	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	22	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	25	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	22	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	1	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	25	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	22	XCSE
GENMAB A/S	18/04/2024	3:59:12 PM	1,990.50	22	XCSE
GENMAB A/S	18/04/2024	3:59:13 PM	1,990.50	3	XCSE
GENMAB A/S	18/04/2024	3:59:13 PM	1,990.50	22	XCSE
GENMAB A/S	18/04/2024	3:59:36 PM	1,990.00	22	XCSE
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	5	AQEU
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	71	CEUX
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	12	TQEX
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	22	XCSE
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	9	XCSE
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	27	XCSE
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	44	XCSE
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	22	XCSE
GENMAB A/S	18/04/2024	3:59:45 PM	1,990.00	5	CEUX
GENMAB A/S	18/04/2024	4:00:00 PM	1,987.50	12	XCSE
GENMAB A/S	18/04/2024	4:00:00 PM	1,987.50	2	AQEU
GENMAB A/S	18/04/2024	4:00:00 PM	1,987.50	20	CEUX
GENMAB A/S	18/04/2024	4:00:00 PM	1,987.50	5	TQEX
GENMAB A/S	18/04/2024	4:02:04 PM	1,993.50	20	XCSE
GENMAB A/S	18/04/2024	4:02:44 PM	1,994.00	9	AQEU
GENMAB A/S	18/04/2024	4:02:44 PM	1,994.00	52	CEUX
GENMAB A/S	18/04/2024	4:02:44 PM	1,994.00	8	CEUX
GENMAB A/S	18/04/2024	4:02:44 PM	1,994.00	9	TQEX
GENMAB A/S	18/04/2024	4:02:44 PM	1,994.00	67	XCSE
GENMAB A/S	18/04/2024	4:03:29 PM	1,993.00	9	AQEU
GENMAB A/S	18/04/2024	4:03:29 PM	1,993.00	60	CEUX
GENMAB A/S	18/04/2024	4:03:29 PM	1,993.00	9	TQEX
GENMAB A/S	18/04/2024	4:03:29 PM	1,993.00	47	XCSE

120

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:03:29 PM	1,993.00	19	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	26	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	23	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	8	TQEX
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	10	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	16	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	23	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	3	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	23	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	3	XCSE
GENMAB A/S	18/04/2024	4:04:22 PM	1,993.00	14	XCSE
GENMAB A/S	18/04/2024	4:06:16 PM	1,993.00	41	CEUX
GENMAB A/S	18/04/2024	4:06:49 PM	1,993.00	55	XCSE
GENMAB A/S	18/04/2024	4:06:49 PM	1,993.00	10	XCSE
GENMAB A/S	18/04/2024	4:06:49 PM	1,993.00	9	AQEU
GENMAB A/S	18/04/2024	4:06:49 PM	1,993.00	86	CEUX
GENMAB A/S	18/04/2024	4:06:49 PM	1,993.00	59	CEUX
GENMAB A/S	18/04/2024	4:08:32 PM	1,991.00	8	AQEU
GENMAB A/S	18/04/2024	4:08:32 PM	1,991.00	53	CEUX
GENMAB A/S	18/04/2024	4:08:32 PM	1,991.00	8	TQEX
GENMAB A/S	18/04/2024	4:08:32 PM	1,991.00	58	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	20	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	66	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	66	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	11	AQEU
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	7	AQEU
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	4	AQEU
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	7	AQEU
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	11	AQEU
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	20	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	62	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	11	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	25	XCSE
GENMAB A/S	18/04/2024	4:10:41 PM	1,992.00	15	XCSE
GENMAB A/S	18/04/2024	4:13:17 PM	1,992.50	75	XCSE
GENMAB A/S	18/04/2024	4:13:17 PM	1,992.50	53	XCSE
GENMAB A/S	18/04/2024	4:13:17 PM	1,992.50	22	XCSE
GENMAB A/S	18/04/2024	4:15:43 PM	1,998.00	36	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE

121

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	1	AQEU
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	14	AQEU
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	1	AQEU
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	6	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	2	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	1	TQEX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	1	AQEU
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	1	AQEU
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	10	CEUX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:15:46 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:47 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:15:47 PM	1,997.00	9	XCSE
GENMAB A/S	18/04/2024	4:16:05 PM	1,996.50	84	CEUX
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	19	CEUX
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	3	CEUX
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	5	TQEX
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	18	CEUX
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	23	XCSE
GENMAB A/S	18/04/2024	4:16:09 PM	1,995.00	19	XCSE

122

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	11	AQEU
GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	37	CEUX
GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	5	CEUX
GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	9	TQEX
GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	2	TQEX
GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	32	CEUX
GENMAB A/S	18/04/2024	4:19:09 PM	1,994.00	17	XCSE
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	1	AQEU
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	14	AQEU
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	9	CEUX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	3	CEUX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	6	CEUX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	4	XCSE
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	61	XCSE
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	8	XCSE
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	28	XCSE
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	6	CEUX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	1	AQEU
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	3	CEUX
GENMAB A/S	18/04/2024	4:20:26 PM	1,994.00	5	TQEX
GENMAB A/S	18/04/2024	4:22:49 PM	1,995.00	40	CEUX
GENMAB A/S	18/04/2024	4:23:13 PM	1,995.00	37	XCSE
GENMAB A/S	18/04/2024	4:23:13 PM	1,994.50	6	TQEX
GENMAB A/S	18/04/2024	4:23:13 PM	1,994.50	6	AQEU
GENMAB A/S	18/04/2024	4:23:13 PM	1,994.50	2	AQEU
GENMAB A/S	18/04/2024	4:23:13 PM	1,995.00	33	XCSE
GENMAB A/S	18/04/2024	4:23:55 PM	1,995.00	35	XCSE
GENMAB A/S	18/04/2024	4:24:10 PM	1,994.50	4	AQEU
GENMAB A/S	18/04/2024	4:24:10 PM	1,994.50	3	AQEU
GENMAB A/S	18/04/2024	4:24:10 PM	1,994.50	1	TQEX
GENMAB A/S	18/04/2024	4:24:10 PM	1,994.50	44	XCSE
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	3	AQEU
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	3	AQEU
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	24	CEUX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	19	CEUX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	5	TQEX

123

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	5	TQEX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	32	TQEX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	32	TQEX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	3	AQEU
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	4	AQEU
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	5	TQEX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	5	TQEX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	13	XCSE
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	24	XCSE
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	135	XCSE
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	24	XCSE
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	33	CEUX
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	21	AQEU
GENMAB A/S	18/04/2024	4:24:36 PM	1,994.50	3	AQEU
GENMAB A/S	18/04/2024	4:24:37 PM	1,994.50	7	AQEU
GENMAB A/S	18/04/2024	4:27:24 PM	1,993.50	19	AQEU
GENMAB A/S	18/04/2024	4:27:24 PM	1,993.50	5	TQEX
GENMAB A/S	18/04/2024	4:27:24 PM	1,993.50	19	TQEX
GENMAB A/S	18/04/2024	4:27:24 PM	1,993.50	171	XCSE
GENMAB A/S	18/04/2024	4:27:24 PM	1,993.50	3	AQEU
GENMAB A/S	18/04/2024	4:28:14 PM	1,994.00	8	AQEU
GENMAB A/S	18/04/2024	4:28:14 PM	1,994.00	75	XCSE
GENMAB A/S	18/04/2024	4:28:14 PM	1,994.00	23	XCSE
GENMAB A/S	18/04/2024	4:28:14 PM	1,994.00	65	XCSE
GENMAB A/S	18/04/2024	4:28:14 PM	1,994.00	13	AQEU
GENMAB A/S	18/04/2024	4:28:14 PM	1,994.00	22	TQEX
GENMAB A/S	18/04/2024	4:32:09 PM	1,994.50	2	AQEU
GENMAB A/S	18/04/2024	4:32:14 PM	1,995.50	3	CEUX
GENMAB A/S	18/04/2024	4:32:45 PM	1,995.00	3	AQEU
GENMAB A/S	18/04/2024	4:32:45 PM	1,995.00	7	XCSE
GENMAB A/S	18/04/2024	4:32:45 PM	1,995.00	16	XCSE
GENMAB A/S	18/04/2024	4:32:45 PM	1,995.00	8	XCSE
GENMAB A/S	18/04/2024	4:32:45 PM	1,995.00	19	XCSE
GENMAB A/S	18/04/2024	4:32:50 PM	1,995.50	26	TQEX
GENMAB A/S	18/04/2024	4:32:54 PM	1,995.50	9	TQEX
GENMAB A/S	18/04/2024	4:33:04 PM	1,995.50	19	TQEX
GENMAB A/S	18/04/2024	4:33:56 PM	1,997.00	24	XCSE
GENMAB A/S	18/04/2024	4:34:07 PM	1,997.00	19	AQEU
GENMAB A/S	18/04/2024	4:34:07 PM	1,997.00	7	AQEU

124

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:34:07 PM	1,997.00	80	XCSE
GENMAB A/S	18/04/2024	4:34:07 PM	1,997.00	201	XCSE
GENMAB A/S	18/04/2024	4:34:07 PM	1,997.00	23	XCSE
GENMAB A/S	18/04/2024	4:34:07 PM	1,997.00	23	XCSE
GENMAB A/S	18/04/2024	4:35:07 PM	1,997.50	91	XCSE
GENMAB A/S	18/04/2024	4:35:07 PM	1,997.50	8	XCSE
GENMAB A/S	18/04/2024	4:35:16 PM	1,997.50	13	AQEU
GENMAB A/S	18/04/2024	4:35:16 PM	1,997.50	99	XCSE
GENMAB A/S	18/04/2024	4:35:16 PM	1,997.50	3	XCSE
GENMAB A/S	18/04/2024	4:35:16 PM	1,997.50	13	AQEU
GENMAB A/S	18/04/2024	4:35:16 PM	1,997.50	13	AQEU
GENMAB A/S	18/04/2024	4:35:16 PM	1,997.50	1	AQEU
GENMAB A/S	18/04/2024	4:37:02 PM	1,999.00	19	AQEU
GENMAB A/S	18/04/2024	4:37:04 PM	1,999.00	299	XCSE
GENMAB A/S	18/04/2024	4:37:04 PM	1,999.00	16	XCSE
GENMAB A/S	18/04/2024	4:37:04 PM	1,999.00	21	AQEU
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	5	TQEX
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	32	TQEX
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	75	XCSE
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	75	XCSE
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	81	XCSE
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	56	XCSE
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	19	XCSE
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	18	XCSE
GENMAB A/S	18/04/2024	4:40:48 PM	1,997.00	137	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	36	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	110	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	68	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	14	AQEU
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	15	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	27	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	37	XCSE
GENMAB A/S	18/04/2024	4:42:24 PM	1,996.50	26	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	15	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	7	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	8	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	14	AQEU

125

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	14	AQEU
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	15	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	2	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	15	XCSE
GENMAB A/S	18/04/2024	4:44:08 PM	1,997.50	3	XCSE
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	15	XCSE
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	15	XCSE
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	19	AQEU
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	5	TQEX
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	7	TQEX
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	23	TQEX
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	23	TQEX
GENMAB A/S	18/04/2024	4:44:09 PM	1,997.50	20	TQEX
GENMAB A/S	18/04/2024	4:45:02 PM	1,996.50	6	AQEU
GENMAB A/S	18/04/2024	4:45:02 PM	1,996.50	1	AQEU
GENMAB A/S	18/04/2024	4:45:02 PM	1,996.50	48	XCSE
GENMAB A/S	18/04/2024	4:45:02 PM	1,996.50	17	XCSE
GENMAB A/S	18/04/2024	4:45:02 PM	1,996.50	2	AQEU
GENMAB A/S	18/04/2024	4:45:02 PM	1,996.50	43	XCSE
GENMAB A/S	18/04/2024	4:45:03 PM	1,996.50	1	AQEU
GENMAB A/S	18/04/2024	4:45:08 PM	1,996.50	3	AQEU
GENMAB A/S	18/04/2024	4:45:08 PM	1,996.50	5	XCSE
GENMAB A/S	18/04/2024	4:45:08 PM	1,996.50	5	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	14	AQEU
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	3	AQEU
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	14	AQEU
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	26	XCSE

126

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	75	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	9	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	18	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	75	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	4	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	14	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	18	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	77	XCSE
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	10	TQEX
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	3	AQEU
GENMAB A/S	18/04/2024	4:46:15 PM	1,996.50	20	XCSE
GENMAB A/S	18/04/2024	4:47:21 PM	1,996.00	200	XCSE
GENMAB A/S	18/04/2024	4:47:21 PM	1,996.00	25	XCSE
GENMAB A/S	18/04/2024	4:48:16 PM	1,995.00	19	AQEU
GENMAB A/S	18/04/2024	4:49:05 PM	1,996.50	75	XCSE
GENMAB A/S	18/04/2024	4:49:05 PM	1,996.50	5	XCSE
GENMAB A/S	18/04/2024	4:49:05 PM	1,996.50	62	XCSE
GENMAB A/S	18/04/2024	4:49:05 PM	1,996.50	26	XCSE
GENMAB A/S	18/04/2024	4:49:08 PM	1,996.50	5	XCSE
GENMAB A/S	18/04/2024	4:49:11 PM	1,996.00	3	AQEU
GENMAB A/S	18/04/2024	4:49:11 PM	1,996.00	18	XCSE
GENMAB A/S	18/04/2024	4:49:12 PM	1,996.00	3	AQEU
GENMAB A/S	18/04/2024	4:49:12 PM	1,996.00	18	XCSE
GENMAB A/S	18/04/2024	4:49:12 PM	1,996.00	3	AQEU
GENMAB A/S	18/04/2024	4:49:12 PM	1,996.00	18	XCSE
GENMAB A/S	18/04/2024	4:49:13 PM	1,996.00	3	AQEU
GENMAB A/S	18/04/2024	4:49:13 PM	1,996.00	18	XCSE
GENMAB A/S	18/04/2024	4:49:13 PM	1,996.00	3	AQEU
GENMAB A/S	18/04/2024	4:49:13 PM	1,996.00	15	XCSE
GENMAB A/S	18/04/2024	4:49:30 PM	1,996.50	154	XCSE
GENMAB A/S	18/04/2024	4:50:02 PM	1,997.50	51	XCSE
GENMAB A/S	18/04/2024	4:50:17 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	19	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	38	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	19	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	6	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	19	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	6	XCSE

127

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	19	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	6	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	19	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	9	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	3	AQEU
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	3	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	22	XCSE
GENMAB A/S	18/04/2024	4:50:27 PM	1,997.50	9	AQEU
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	5	AQEU
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	34	XCSE
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	34	XCSE
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	5	AQEU
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	5	TQEX
GENMAB A/S	18/04/2024	4:51:02 PM	1,996.50	20	XCSE
GENMAB A/S	18/04/2024	4:51:04 PM	1,996.50	44	XCSE
GENMAB A/S	18/04/2024	4:51:04 PM	1,996.50	18	XCSE
GENMAB A/S	18/04/2024	4:51:36 PM	1,996.00	92	XCSE
GENMAB A/S	18/04/2024	4:51:36 PM	1,996.00	12	AQEU
GENMAB A/S	18/04/2024	4:51:36 PM	1,996.00	13	TQEX
GENMAB A/S	18/04/2024	4:51:55 PM	1,995.00	24	AQEU
GENMAB A/S	18/04/2024	4:51:55 PM	1,995.00	190	XCSE
GENMAB A/S	19/04/2024	9:02:50 AM	1,988.50	14	XCSE
GENMAB A/S	19/04/2024	9:02:50 AM	1,988.50	13	CEUX
GENMAB A/S	19/04/2024	9:03:33 AM	1,987.00	39	CEUX
GENMAB A/S	19/04/2024	9:03:33 AM	1,987.00	6	TQEX
GENMAB A/S	19/04/2024	9:03:33 AM	1,987.00	43	XCSE
GENMAB A/S	19/04/2024	9:04:04 AM	1,988.50	6	TQEX
GENMAB A/S	19/04/2024	9:04:04 AM	1,988.50	13	XCSE
GENMAB A/S	19/04/2024	9:04:10 AM	1,988.50	20	XCSE
GENMAB A/S	19/04/2024	9:04:10 AM	1,988.50	20	XCSE
GENMAB A/S	19/04/2024	9:04:10 AM	1,988.50	6	TQEX
GENMAB A/S	19/04/2024	9:05:18 AM	1,988.50	5	XCSE
GENMAB A/S	19/04/2024	9:05:18 AM	1,988.50	4	XCSE
GENMAB A/S	19/04/2024	9:05:18 AM	1,988.50	9	XCSE
GENMAB A/S	19/04/2024	9:05:18 AM	1,988.50	10	CEUX
GENMAB A/S	19/04/2024	9:05:18 AM	1,988.50	6	CEUX
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	14	CEUX

128

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	2	CEUX
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	12	CEUX
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	1	CEUX
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	6	TQEX
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	13	CEUX
GENMAB A/S	19/04/2024	9:05:24 AM	1,987.50	1	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	13	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	3	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	11	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	6	TQEX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	14	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	1	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	13	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	1	CEUX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	6	TQEX
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	15	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	9	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	6	XCSE
GENMAB A/S	19/04/2024	9:05:25 AM	1,987.50	9	XCSE
GENMAB A/S	19/04/2024	9:05:46 AM	1,986.50	2	CEUX
GENMAB A/S	19/04/2024	9:06:10 AM	1,990.00	35	CEUX
GENMAB A/S	19/04/2024	9:06:10 AM	1,990.00	46	XCSE
GENMAB A/S	19/04/2024	9:06:10 AM	1,990.00	8	CEUX
GENMAB A/S	19/04/2024	9:06:10 AM	1,990.00	35	CEUX
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	46	XCSE
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	20	XCSE
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	26	XCSE
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	6	XCSE

129

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	18	XCSE
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	21	XCSE
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	43	CEUX
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	43	CEUX
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	7	XCSE
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	7	CEUX
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	17	CEUX
GENMAB A/S	19/04/2024	9:06:12 AM	1,990.00	18	XCSE
GENMAB A/S	19/04/2024	9:09:43 AM	1,975.50	5	XCSE
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	3	XCSE
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	8	XCSE
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	9	CEUX
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	9	CEUX
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	5	TQEX
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	5	TQEX
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	9	CEUX
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	5	TQEX
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	3	XCSE
GENMAB A/S	19/04/2024	9:10:04 AM	1,975.50	5	XCSE
GENMAB A/S	19/04/2024	9:11:09 AM	1,978.00	12	XCSE
GENMAB A/S	19/04/2024	9:11:09 AM	1,978.00	47	XCSE
GENMAB A/S	19/04/2024	9:11:09 AM	1,978.00	12	CEUX
GENMAB A/S	19/04/2024	9:11:11 AM	1,978.00	26	XCSE
GENMAB A/S	19/04/2024	9:11:11 AM	1,978.00	35	XCSE
GENMAB A/S	19/04/2024	9:11:11 AM	1,978.00	55	XCSE
GENMAB A/S	19/04/2024	9:11:11 AM	1,978.00	82	XCSE
GENMAB A/S	19/04/2024	9:11:11 AM	1,978.00	5	AQEU
GENMAB A/S	19/04/2024	9:11:11 AM	1,978.00	31	CEUX
GENMAB A/S	19/04/2024	9:12:31 AM	1,979.50	41	XCSE
GENMAB A/S	19/04/2024	9:12:31 AM	1,979.50	41	XCSE
GENMAB A/S	19/04/2024	9:12:31 AM	1,979.50	26	XCSE
GENMAB A/S	19/04/2024	9:14:30 AM	1,979.00	11	XCSE
GENMAB A/S	19/04/2024	9:14:30 AM	1,979.00	10	CEUX
GENMAB A/S	19/04/2024	9:14:30 AM	1,979.00	10	CEUX
GENMAB A/S	19/04/2024	9:14:30 AM	1,979.00	11	XCSE
GENMAB A/S	19/04/2024	9:14:30 AM	1,979.00	11	XCSE
GENMAB A/S	19/04/2024	9:14:30 AM	1,979.00	4	XCSE
GENMAB A/S	19/04/2024	9:15:24 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:24 AM	1,983.50	9	XCSE

130

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:15:24 AM	1,983.50	9	CEUX
GENMAB A/S	19/04/2024	9:15:24 AM	1,983.50	5	TQEX
GENMAB A/S	19/04/2024	9:15:24 AM	1,983.50	9	CEUX
GENMAB A/S	19/04/2024	9:15:24 AM	1,983.50	5	TQEX
GENMAB A/S	19/04/2024	9:15:51 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:51 AM	1,983.50	9	CEUX
GENMAB A/S	19/04/2024	9:15:51 AM	1,983.50	1	CEUX
GENMAB A/S	19/04/2024	9:15:51 AM	1,983.50	8	CEUX
GENMAB A/S	19/04/2024	9:15:51 AM	1,983.50	1	CEUX
GENMAB A/S	19/04/2024	9:15:51 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	8	CEUX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	1	CEUX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	8	CEUX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	9	CEUX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	9	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	2	CEUX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	1	AQEU
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	7	CEUX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	5	TQEX
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	1	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,982.00	39	XCSE
GENMAB A/S	19/04/2024	9:15:53 AM	1,982.50	8	AQEU
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.00	8	AQEU
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.00	4	AQEU
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.00	4	AQEU
GENMAB A/S	19/04/2024	9:15:53 AM	1,983.50	6	AQEU
GENMAB A/S	19/04/2024	9:16:18 AM	1,982.00	32	XCSE
GENMAB A/S	19/04/2024	9:16:18 AM	1,982.00	28	XCSE
GENMAB A/S	19/04/2024	9:16:18 AM	1,982.00	31	CEUX
GENMAB A/S	19/04/2024	9:16:18 AM	1,982.00	5	TQEX
GENMAB A/S	19/04/2024	9:16:18 AM	1,982.00	27	CEUX
GENMAB A/S	19/04/2024	9:16:18 AM	1,982.00	5	TQEX
GENMAB A/S	19/04/2024	9:17:09 AM	1,980.50	33	XCSE
GENMAB A/S	19/04/2024	9:17:09 AM	1,980.50	27	CEUX
GENMAB A/S	19/04/2024	9:17:09 AM	1,980.50	4	CEUX

131

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:17:09 AM	1,980.50	5	TQEX
GENMAB A/S	19/04/2024	9:17:09 AM	1,980.50	27	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,980.50	74	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,980.50	27	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	22	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	3	AQEU
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	21	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	8	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	5	TQEX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	11	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	3	AQEU
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	10	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	5	TQEX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	22	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.00	21	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.00	12	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.00	5	TQEX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	3	AQEU
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	15	AQEU
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	1	CEUX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	5	TQEX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	27	TQEX
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.00	22	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.00	14	XCSE
GENMAB A/S	19/04/2024	9:17:33 AM	1,979.50	10	XCSE
GENMAB A/S	19/04/2024	9:17:34 AM	1,979.00	3	AQEU
GENMAB A/S	19/04/2024	9:17:34 AM	1,979.00	1	CEUX
GENMAB A/S	19/04/2024	9:17:34 AM	1,979.00	5	TQEX
GENMAB A/S	19/04/2024	9:17:34 AM	1,979.50	16	AQEU
GENMAB A/S	19/04/2024	9:21:46 AM	1,976.00	7	AQEU
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	1	AQEU
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	51	CEUX
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	15	XCSE
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	41	XCSE
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	23	XCSE
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	11	XCSE
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	56	XCSE
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	23	XCSE
GENMAB A/S	19/04/2024	9:22:25 AM	1,976.00	1	XCSE

132

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:23:44 AM	1,973.00	9	XCSE
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	20	CEUX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	7	CEUX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	7	CEUX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	7	CEUX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	10	CEUX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	3	CEUX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	2	TQEX
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	28	XCSE
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	23	XCSE
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	23	XCSE
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	5	XCSE
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	23	XCSE
GENMAB A/S	19/04/2024	9:24:34 AM	1,974.50	5	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	47	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	39	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	9	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	9	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	9	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	9	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	2	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	2	CEUX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	5	TQEX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	5	TQEX
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	8	AQEU
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	10	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	10	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	10	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	10	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	1	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,974.50	26	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,972.50	44	XCSE
GENMAB A/S	19/04/2024	9:25:35 AM	1,972.50	6	AQEU
GENMAB A/S	19/04/2024	9:25:35 AM	1,972.50	8	AQEU
GENMAB A/S	19/04/2024	9:25:35 AM	1,972.50	6	TQEX
GENMAB A/S	19/04/2024	9:25:35 AM	1,972.50	8	AQEU
GENMAB A/S	19/04/2024	9:25:35 AM	1,972.50	23	XCSE
GENMAB A/S	19/04/2024	9:25:36 AM	1,972.00	46	CEUX
GENMAB A/S	19/04/2024	9:25:36 AM	1,972.00	4	CEUX

133

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:25:36 AM	1,972.00	41	CEUX
GENMAB A/S	19/04/2024	9:28:49 AM	1,971.00	29	XCSE
GENMAB A/S	19/04/2024	9:28:49 AM	1,971.00	78	XCSE
GENMAB A/S	19/04/2024	9:30:34 AM	1,968.50	6	AQEU
GENMAB A/S	19/04/2024	9:30:34 AM	1,968.50	40	CEUX
GENMAB A/S	19/04/2024	9:30:34 AM	1,968.50	6	TQEX
GENMAB A/S	19/04/2024	9:30:34 AM	1,968.50	9	XCSE
GENMAB A/S	19/04/2024	9:30:34 AM	1,968.50	32	XCSE
GENMAB A/S	19/04/2024	9:30:34 AM	1,968.50	3	XCSE
GENMAB A/S	19/04/2024	9:32:02 AM	1,966.00	75	CEUX
GENMAB A/S	19/04/2024	9:32:02 AM	1,966.00	19	CEUX
GENMAB A/S	19/04/2024	9:34:25 AM	1,969.50	94	XCSE
GENMAB A/S	19/04/2024	9:34:25 AM	1,969.50	12	AQEU
GENMAB A/S	19/04/2024	9:34:25 AM	1,969.50	40	CEUX
GENMAB A/S	19/04/2024	9:34:25 AM	1,969.50	44	CEUX
GENMAB A/S	19/04/2024	9:34:25 AM	1,969.50	13	TQEX
GENMAB A/S	19/04/2024	9:36:13 AM	1,966.00	75	CEUX
GENMAB A/S	19/04/2024	9:36:13 AM	1,966.00	8	CEUX
GENMAB A/S	19/04/2024	9:36:13 AM	1,966.00	4	CEUX
GENMAB A/S	19/04/2024	9:36:13 AM	1,966.00	6	CEUX
GENMAB A/S	19/04/2024	9:36:15 AM	1,964.50	16	XCSE
GENMAB A/S	19/04/2024	9:36:15 AM	1,964.50	28	XCSE
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	8	XCSE
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	8	XCSE
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	8	XCSE
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	9	CEUX
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	9	CEUX
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	5	TQEX
GENMAB A/S	19/04/2024	9:39:02 AM	1,969.00	5	TQEX
GENMAB A/S	19/04/2024	9:39:44 AM	1,969.00	8	XCSE
GENMAB A/S	19/04/2024	9:39:44 AM	1,969.00	8	XCSE
GENMAB A/S	19/04/2024	9:39:44 AM	1,969.00	9	CEUX
GENMAB A/S	19/04/2024	9:39:44 AM	1,969.00	5	TQEX
GENMAB A/S	19/04/2024	9:40:29 AM	1,969.50	21	CEUX
GENMAB A/S	19/04/2024	9:40:29 AM	1,969.50	21	XCSE
GENMAB A/S	19/04/2024	9:40:29 AM	1,969.50	24	XCSE
GENMAB A/S	19/04/2024	9:40:29 AM	1,969.50	55	XCSE
GENMAB A/S	19/04/2024	9:40:29 AM	1,969.50	69	CEUX
GENMAB A/S	19/04/2024	9:40:29 AM	1,969.50	14	TQEX

134

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:40:30 AM	1,969.50	13	XCSE
GENMAB A/S	19/04/2024	9:42:35 AM	1,969.50	48	CEUX
GENMAB A/S	19/04/2024	9:42:35 AM	1,969.50	63	XCSE
GENMAB A/S	19/04/2024	9:42:36 AM	1,969.50	3	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,971.00	25	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,971.00	121	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,970.00	8	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,970.00	40	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,970.00	40	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,970.00	8	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,970.00	52	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,969.50	23	XCSE
GENMAB A/S	19/04/2024	9:43:38 AM	1,969.50	20	XCSE
GENMAB A/S	19/04/2024	9:48:50 AM	1,966.00	4	XCSE
GENMAB A/S	19/04/2024	9:50:00 AM	1,971.50	35	XCSE
GENMAB A/S	19/04/2024	9:50:01 AM	1,970.50	19	XCSE
GENMAB A/S	19/04/2024	9:50:02 AM	1,970.50	15	CEUX
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	4	XCSE
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	84	XCSE
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	3	XCSE
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	71	CEUX
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	12	TQEX
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	24	XCSE
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	7	XCSE
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	9	XCSE
GENMAB A/S	19/04/2024	9:50:49 AM	1,970.00	8	XCSE
GENMAB A/S	19/04/2024	9:53:20 AM	1,973.00	24	AQEU
GENMAB A/S	19/04/2024	9:53:20 AM	1,973.00	74	CEUX
GENMAB A/S	19/04/2024	9:53:20 AM	1,973.00	75	CEUX
GENMAB A/S	19/04/2024	9:53:20 AM	1,973.00	17	CEUX
GENMAB A/S	19/04/2024	9:54:24 AM	1,971.00	8	AQEU
GENMAB A/S	19/04/2024	9:54:24 AM	1,971.00	8	TQEX
GENMAB A/S	19/04/2024	9:54:24 AM	1,971.00	16	XCSE
GENMAB A/S	19/04/2024	9:54:24 AM	1,971.00	25	CEUX
GENMAB A/S	19/04/2024	9:54:26 AM	1,971.00	26	CEUX
GENMAB A/S	19/04/2024	9:54:26 AM	1,971.00	41	XCSE
GENMAB A/S	19/04/2024	9:55:25 AM	1,967.50	17	XCSE
GENMAB A/S	19/04/2024	9:55:25 AM	1,967.50	39	XCSE
GENMAB A/S	19/04/2024	9:55:25 AM	1,967.50	8	AQEU

135

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	9:55:25 AM	1,967.50	7	TQEX
GENMAB A/S	19/04/2024	9:55:25 AM	1,967.50	51	CEUX
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	95	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	6	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	6	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	6	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	6	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	75	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	8	XCSE
GENMAB A/S	19/04/2024	9:59:43 AM	1,969.50	21	XCSE
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	19	XCSE
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	19	CEUX
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	5	TQEX
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	19	CEUX
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	5	TQEX
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	16	CEUX
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	19	XCSE
GENMAB A/S	19/04/2024	10:02:42 AM	1,967.50	1	XCSE
GENMAB A/S	19/04/2024	10:02:43 AM	1,967.50	5	TQEX
GENMAB A/S	19/04/2024	10:03:26 AM	1,970.50	61	XCSE
GENMAB A/S	19/04/2024	10:03:26 AM	1,970.50	2	CEUX
GENMAB A/S	19/04/2024	10:03:26 AM	1,970.50	10	CEUX
GENMAB A/S	19/04/2024	10:03:26 AM	1,970.50	4	TQEX
GENMAB A/S	19/04/2024	10:03:26 AM	1,970.50	42	CEUX
GENMAB A/S	19/04/2024	10:03:26 AM	1,970.50	13	CEUX
GENMAB A/S	19/04/2024	10:05:11 AM	1,968.50	22	XCSE
GENMAB A/S	19/04/2024	10:05:13 AM	1,968.50	22	XCSE
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	1	AQEU
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	10	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	10	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	7	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	10	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	7	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	6	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	5	TQEX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	5	TQEX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	2	TQEX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	10	XCSE
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	5	XCSE

136

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	5	XCSE
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	5	XCSE
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	1	AQEU
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	4	AQEU
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	4	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	10	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	7	CEUX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	3	TQEX
GENMAB A/S	19/04/2024	10:06:15 AM	1,970.00	2	TQEX
GENMAB A/S	19/04/2024	10:07:25 AM	1,970.00	12	XCSE
GENMAB A/S	19/04/2024	10:07:25 AM	1,970.00	9	XCSE
GENMAB A/S	19/04/2024	10:07:25 AM	1,970.00	12	XCSE
GENMAB A/S	19/04/2024	10:09:06 AM	1,970.50	17	XCSE
GENMAB A/S	19/04/2024	10:09:06 AM	1,970.50	5	XCSE
GENMAB A/S	19/04/2024	10:09:06 AM	1,970.50	17	XCSE
GENMAB A/S	19/04/2024	10:09:06 AM	1,970.50	2	XCSE
GENMAB A/S	19/04/2024	10:09:45 AM	1,972.00	36	XCSE
GENMAB A/S	19/04/2024	10:10:14 AM	1,972.00	39	XCSE
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	24	XCSE
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	24	XCSE
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	23	CEUX
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	22	CEUX
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	1	CEUX
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	18	CEUX
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	23	CEUX
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	5	CEUX
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	24	XCSE
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	7	XCSE
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	10	XCSE
GENMAB A/S	19/04/2024	10:10:28 AM	1,971.50	7	XCSE
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	11	AQEU
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	46	CEUX
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	30	CEUX
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	12	TQEX
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	52	XCSE
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	23	XCSE
GENMAB A/S	19/04/2024	10:12:40 AM	1,970.50	84	XCSE
GENMAB A/S	19/04/2024	10:17:19 AM	1,970.00	2	AQEU
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	44	XCSE

137

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	6	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	6	AQEU
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	6	AQEU
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	8	AQEU
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	34	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	34	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	6	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	21	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	31	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	1	TQEX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	5	TQEX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	1	TQEX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	9	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	36	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	6	TQEX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	5	CEUX
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	29	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	7	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	8	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	7	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	8	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	24	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	5	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	10	XCSE
GENMAB A/S	19/04/2024	10:20:19 AM	1,973.00	9	CEUX
GENMAB A/S	19/04/2024	10:20:31 AM	1,972.50	39	XCSE
GENMAB A/S	19/04/2024	10:20:31 AM	1,972.50	10	XCSE
GENMAB A/S	19/04/2024	10:20:31 AM	1,972.50	29	XCSE
GENMAB A/S	19/04/2024	10:20:31 AM	1,972.50	18	XCSE
GENMAB A/S	19/04/2024	10:20:31 AM	1,972.50	35	XCSE
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	2	AQEU
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	8	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	8	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	1	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	7	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	1	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	7	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	5	TQEX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	1	XCSE

138

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	7	XCSE
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	1	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	7	CEUX
GENMAB A/S	19/04/2024	10:23:05 AM	1,970.50	5	TQEX
GENMAB A/S	19/04/2024	10:23:11 AM	1,970.50	23	XCSE
GENMAB A/S	19/04/2024	10:23:11 AM	1,970.50	23	XCSE
GENMAB A/S	19/04/2024	10:23:11 AM	1,970.50	20	XCSE
GENMAB A/S	19/04/2024	10:25:14 AM	1,970.50	25	XCSE
GENMAB A/S	19/04/2024	10:25:14 AM	1,970.50	25	XCSE
GENMAB A/S	19/04/2024	10:25:14 AM	1,970.50	61	XCSE
GENMAB A/S	19/04/2024	10:25:15 AM	1,970.50	25	XCSE
GENMAB A/S	19/04/2024	10:27:17 AM	1,970.50	41	CEUX
GENMAB A/S	19/04/2024	10:27:17 AM	1,970.50	11	XCSE
GENMAB A/S	19/04/2024	10:29:40 AM	1,970.50	8	AQEU
GENMAB A/S	19/04/2024	10:29:40 AM	1,970.50	22	CEUX
GENMAB A/S	19/04/2024	10:29:40 AM	1,970.50	3	CEUX
GENMAB A/S	19/04/2024	10:29:40 AM	1,970.50	8	TQEX
GENMAB A/S	19/04/2024	10:30:14 AM	1,970.50	32	AQEU
GENMAB A/S	19/04/2024	10:30:14 AM	1,970.50	2	TQEX
GENMAB A/S	19/04/2024	10:30:19 AM	1,969.50	6	AQEU
GENMAB A/S	19/04/2024	10:30:19 AM	1,969.50	40	CEUX
GENMAB A/S	19/04/2024	10:30:19 AM	1,969.50	6	CEUX
GENMAB A/S	19/04/2024	10:30:19 AM	1,969.50	4	CEUX
GENMAB A/S	19/04/2024	10:30:19 AM	1,969.50	13	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	22	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	13	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	67	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	25	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	21	CEUX
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	19	CEUX
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	52	CEUX
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	21	CEUX
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	2	CEUX
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	5	TQEX
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	3	AQEU
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	10	AQEU
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	1	CEUX
GENMAB A/S	19/04/2024	10:31:03 AM	1,968.50	3	AQEU
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	12	TQEX

139

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	49	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	2	XCSE
GENMAB A/S	19/04/2024	10:31:03 AM	1,969.00	23	XCSE
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	22	XCSE
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	20	CEUX
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	22	XCSE
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	3	AQEU
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	20	CEUX
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	4	CEUX
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	8	TQEX
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.00	9	XCSE
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	2	XCSE
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	8	AQEU
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	8	AQEU
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	42	AQEU
GENMAB A/S	19/04/2024	10:31:04 AM	1,968.50	5	AQEU
GENMAB A/S	19/04/2024	10:37:11 AM	1,962.00	51	XCSE
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	26	CEUX
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	30	CEUX
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	71	CEUX
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	26	CEUX
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	26	CEUX
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	1	CEUX
GENMAB A/S	19/04/2024	10:39:37 AM	1,965.00	16	TQEX
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	64	XCSE
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	21	CEUX
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	3	TQEX
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	1	CEUX
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	7	CEUX
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	29	CEUX
GENMAB A/S	19/04/2024	10:42:37 AM	1,961.00	14	CEUX
GENMAB A/S	19/04/2024	10:44:50 AM	1,960.50	9	XCSE
GENMAB A/S	19/04/2024	10:46:09 AM	1,962.00	8	AQEU
GENMAB A/S	19/04/2024	10:46:09 AM	1,962.00	32	AQEU
GENMAB A/S	19/04/2024	10:46:09 AM	1,962.00	1	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	44	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	14	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	13	CEUX

140

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	14	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	4	AQEU
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	7	AQEU
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	27	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	2	TQEX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	3	TQEX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	6	TQEX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	10	TQEX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	31	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	11	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	37	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	31	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	6	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	13	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	18	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	13	XCSE
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	27	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	27	CEUX
GENMAB A/S	19/04/2024	10:48:26 AM	1,964.50	15	CEUX
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	31	XCSE
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	8	CEUX
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	7	CEUX
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	17	XCSE
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	8	AQEU
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	36	CEUX
GENMAB A/S	19/04/2024	10:48:27 AM	1,964.50	12	XCSE
GENMAB A/S	19/04/2024	10:53:05 AM	1,964.50	6	XCSE
GENMAB A/S	19/04/2024	10:53:05 AM	1,964.50	16	XCSE
GENMAB A/S	19/04/2024	10:55:08 AM	1,967.50	30	XCSE
GENMAB A/S	19/04/2024	10:55:08 AM	1,967.50	11	XCSE
GENMAB A/S	19/04/2024	10:55:51 AM	1,967.50	3	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	22	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	22	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	22	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	22	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	66	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	22	XCSE
GENMAB A/S	19/04/2024	10:56:10 AM	1,968.00	21	XCSE
GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	1	XCSE

141

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	21	XCSE
GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	22	XCSE
GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	12	XCSE
GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	10	XCSE
GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	4	XCSE
GENMAB A/S	19/04/2024	10:56:11 AM	1,968.00	4	XCSE
GENMAB A/S	19/04/2024	11:00:44 AM	1,966.50	8	AQEU
GENMAB A/S	19/04/2024	11:00:44 AM	1,966.50	26	AQEU
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	8	CEUX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	8	XCSE
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	22	XCSE
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	8	CEUX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	8	CEUX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	1	TQEX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	11:02:32 AM	1,968.50	1	TQEX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	35	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	12	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	15	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	11	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	24	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	27	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	5	AQEU
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	5	AQEU
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	5	AQEU
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	22	CEUX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	32	CEUX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	32	CEUX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	22	CEUX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	32	CEUX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	5	TQEX
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	35	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	27	XCSE
GENMAB A/S	19/04/2024	11:03:43 AM	1,968.50	28	XCSE
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	18	CEUX

142

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	14	CEUX
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	16	CEUX
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	22	CEUX
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	35	XCSE
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	27	XCSE
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	8	AQEU
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	64	CEUX
GENMAB A/S	19/04/2024	11:03:44 AM	1,968.50	15	XCSE
GENMAB A/S	19/04/2024	11:10:41 AM	1,965.00	50	XCSE
GENMAB A/S	19/04/2024	11:10:41 AM	1,965.00	7	XCSE
GENMAB A/S	19/04/2024	11:10:41 AM	1,965.00	8	AQEU
GENMAB A/S	19/04/2024	11:10:41 AM	1,965.00	52	CEUX
GENMAB A/S	19/04/2024	11:10:41 AM	1,965.00	8	TQEX
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	26	XCSE
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	26	XCSE
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	1	XCSE
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	26	XCSE
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	26	XCSE
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	1	XCSE
GENMAB A/S	19/04/2024	11:12:53 AM	1,965.00	10	TQEX
GENMAB A/S	19/04/2024	11:14:18 AM	1,964.50	39	XCSE
GENMAB A/S	19/04/2024	11:14:18 AM	1,964.50	15	XCSE
GENMAB A/S	19/04/2024	11:14:18 AM	1,964.50	7	AQEU
GENMAB A/S	19/04/2024	11:14:18 AM	1,964.50	48	CEUX
GENMAB A/S	19/04/2024	11:14:18 AM	1,964.50	8	TQEX
GENMAB A/S	19/04/2024	11:18:54 AM	1,963.50	8	AQEU
GENMAB A/S	19/04/2024	11:18:54 AM	1,963.50	30	AQEU
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	39	CEUX
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	2	CEUX
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	35	CEUX
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	14	CEUX
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	42	XCSE
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	23	CEUX
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	34	CEUX
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	85	XCSE
GENMAB A/S	19/04/2024	11:19:41 AM	1,963.50	31	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	34	XCSE

143

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	38	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	1	AQEU
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	7	AQEU
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	1	AQEU
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	31	AQEU
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	9	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	3	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	5	TQEX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	5	TQEX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	TQEX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	6	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	6	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	3	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	3	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	3	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	3	CEUX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	5	TQEX
GENMAB A/S	19/04/2024	11:25:57 AM	1,967.50	8	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	12	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	11	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	11	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	11	XCSE

144

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	1	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	24	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	23	XCSE
GENMAB A/S	19/04/2024	11:25:59 AM	1,967.50	7	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	75	XCSE
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	46	XCSE
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	16	AQEU
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	88	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	21	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	12	TQEX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.50	4	TQEX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	5	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	5	TQEX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	13	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	5	XCSE
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	11	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	5	TQEX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	7	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	4	CEUX
GENMAB A/S	19/04/2024	11:33:11 AM	1,968.00	5	TQEX
GENMAB A/S	19/04/2024	11:33:26 AM	1,966.50	66	CEUX
GENMAB A/S	19/04/2024	11:33:26 AM	1,966.50	52	XCSE
GENMAB A/S	19/04/2024	11:33:26 AM	1,966.50	66	XCSE
GENMAB A/S	19/04/2024	11:42:57 AM	1,971.50	24	XCSE
GENMAB A/S	19/04/2024	11:42:57 AM	1,971.50	1	XCSE
GENMAB A/S	19/04/2024	11:42:57 AM	1,971.50	16	XCSE
GENMAB A/S	19/04/2024	11:42:58 AM	1,971.00	59	XCSE
GENMAB A/S	19/04/2024	11:42:58 AM	1,971.00	8	AQEU
GENMAB A/S	19/04/2024	11:42:58 AM	1,971.00	54	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	4	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	7	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	7	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	1	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	47	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	4	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	3	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	38	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	7	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	75	CEUX

145

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	3	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	8	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	28	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	2	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	14	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	5	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	5	TQEX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	7	XCSE
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	1	AQEU
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	3	CEUX
GENMAB A/S	19/04/2024	11:47:22 AM	1,972.50	4	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,969.50	20	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	6	AQEU
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	34	AQEU
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	17	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	18	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	4	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	39	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	39	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	26	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	6	TQEX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	8	TQEX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	6	TQEX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	6	TQEX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	43	XCSE
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	115	XCSE
GENMAB A/S	19/04/2024	11:49:00 AM	1,969.00	27	XCSE
GENMAB A/S	19/04/2024	11:49:00 AM	1,969.50	46	CEUX
GENMAB A/S	19/04/2024	11:49:00 AM	1,970.00	16	TQEX
GENMAB A/S	19/04/2024	11:49:00 AM	1,969.00	14	XCSE
GENMAB A/S	19/04/2024	11:55:30 AM	1,974.00	26	XCSE
GENMAB A/S	19/04/2024	11:55:30 AM	1,974.00	26	XCSE
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	10	XCSE
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	50	XCSE
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	11	CEUX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	11	CEUX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	6	CEUX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	5	CEUX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	1	CEUX

146

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	5	CEUX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	5	TQEX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	5	TQEX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	6	TQEX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	5	TQEX
GENMAB A/S	19/04/2024	11:56:01 AM	1,975.00	34	XCSE
GENMAB A/S	19/04/2024	11:56:02 AM	1,975.00	4	CEUX
GENMAB A/S	19/04/2024	11:57:15 AM	1,975.00	23	XCSE
GENMAB A/S	19/04/2024	11:57:15 AM	1,975.00	23	XCSE
GENMAB A/S	19/04/2024	11:57:52 AM	1,976.00	52	XCSE
GENMAB A/S	19/04/2024	11:57:52 AM	1,976.00	4	XCSE
GENMAB A/S	19/04/2024	11:57:52 AM	1,976.00	47	CEUX
GENMAB A/S	19/04/2024	11:57:52 AM	1,976.00	5	XCSE
GENMAB A/S	19/04/2024	11:58:47 AM	1,975.00	10	CEUX
GENMAB A/S	19/04/2024	11:58:47 AM	1,975.00	5	TQEX
GENMAB A/S	19/04/2024	11:58:47 AM	1,975.00	9	XCSE
GENMAB A/S	19/04/2024	11:59:15 AM	1,974.50	1	AQEU
GENMAB A/S	19/04/2024	11:59:15 AM	1,974.50	8	CEUX
GENMAB A/S	19/04/2024	11:59:15 AM	1,974.50	5	TQEX
GENMAB A/S	19/04/2024	11:59:15 AM	1,974.50	5	TQEX
GENMAB A/S	19/04/2024	11:59:15 AM	1,974.50	5	XCSE
GENMAB A/S	19/04/2024	11:59:15 AM	1,974.50	2	XCSE
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	10	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	10	XCSE
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	10	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	10	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	10	XCSE
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	10	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	9	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	36	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	25	XCSE
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	8	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	4	CEUX
GENMAB A/S	19/04/2024	11:59:49 AM	1,974.50	42	XCSE
GENMAB A/S	19/04/2024	12:01:30 PM	1,972.50	1	XCSE
GENMAB A/S	19/04/2024	12:01:51 PM	1,973.00	15	CEUX
GENMAB A/S	19/04/2024	12:03:02 PM	1,974.00	41	CEUX
GENMAB A/S	19/04/2024	12:03:02 PM	1,974.00	41	CEUX
GENMAB A/S	19/04/2024	12:03:02 PM	1,974.00	6	CEUX

147

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	12:03:02 PM	1,974.00	7	TQEX
GENMAB A/S	19/04/2024	12:03:02 PM	1,974.00	46	XCSE
GENMAB A/S	19/04/2024	12:03:02 PM	1,973.50	15	XCSE
GENMAB A/S	19/04/2024	12:03:02 PM	1,973.50	14	XCSE
GENMAB A/S	19/04/2024	12:04:05 PM	1,974.50	7	XCSE
GENMAB A/S	19/04/2024	12:04:14 PM	1,974.00	15	XCSE
GENMAB A/S	19/04/2024	12:04:52 PM	1,974.00	1	AQEU
GENMAB A/S	19/04/2024	12:04:52 PM	1,974.00	9	CEUX
GENMAB A/S	19/04/2024	12:04:52 PM	1,974.00	5	TQEX
GENMAB A/S	19/04/2024	12:04:52 PM	1,974.00	9	XCSE
GENMAB A/S	19/04/2024	12:06:03 PM	1,976.00	3	XCSE
GENMAB A/S	19/04/2024	12:06:03 PM	1,976.00	23	XCSE
GENMAB A/S	19/04/2024	12:06:03 PM	1,976.00	15	XCSE
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	45	CEUX
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	45	CEUX
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	17	CEUX
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	49	XCSE
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	9	XCSE
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	40	XCSE
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	9	XCSE
GENMAB A/S	19/04/2024	12:06:41 PM	1,976.00	12	XCSE
GENMAB A/S	19/04/2024	12:08:36 PM	1,976.00	8	CEUX
GENMAB A/S	19/04/2024	12:10:34 PM	1,976.50	34	TQEX
GENMAB A/S	19/04/2024	12:11:16 PM	1,976.50	8	AQEU
GENMAB A/S	19/04/2024	12:11:16 PM	1,976.50	8	TQEX
GENMAB A/S	19/04/2024	12:11:16 PM	1,976.50	8	AQEU
GENMAB A/S	19/04/2024	12:11:43 PM	1,976.50	31	CEUX
GENMAB A/S	19/04/2024	12:11:43 PM	1,976.50	1	CEUX
GENMAB A/S	19/04/2024	12:11:43 PM	1,976.50	8	TQEX
GENMAB A/S	19/04/2024	12:12:03 PM	1,976.00	17	XCSE
GENMAB A/S	19/04/2024	12:12:03 PM	1,976.00	2	XCSE
GENMAB A/S	19/04/2024	12:12:03 PM	1,976.00	25	XCSE
GENMAB A/S	19/04/2024	12:13:03 PM	1,975.50	23	XCSE
GENMAB A/S	19/04/2024	12:13:03 PM	1,975.50	1	XCSE
GENMAB A/S	19/04/2024	12:13:46 PM	1,976.50	5	TQEX
GENMAB A/S	19/04/2024	12:13:46 PM	1,976.50	17	XCSE
GENMAB A/S	19/04/2024	12:15:05 PM	1,976.50	23	XCSE
GENMAB A/S	19/04/2024	12:15:05 PM	1,976.50	16	XCSE
GENMAB A/S	19/04/2024	12:15:08 PM	1,976.00	38	TQEX

148

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	12:17:05 PM	1,977.00	28	CEUX
GENMAB A/S	19/04/2024	12:18:32 PM	1,977.00	7	CEUX
GENMAB A/S	19/04/2024	12:18:32 PM	1,977.00	12	CEUX
GENMAB A/S	19/04/2024	12:18:32 PM	1,977.00	6	CEUX
GENMAB A/S	19/04/2024	12:18:32 PM	1,977.00	25	CEUX
GENMAB A/S	19/04/2024	12:18:32 PM	1,977.00	10	XCSE
GENMAB A/S	19/04/2024	12:18:41 PM	1,977.00	36	XCSE
GENMAB A/S	19/04/2024	12:19:19 PM	1,977.00	39	CEUX
GENMAB A/S	19/04/2024	12:19:50 PM	1,976.00	19	CEUX
GENMAB A/S	19/04/2024	12:19:50 PM	1,976.00	52	CEUX
GENMAB A/S	19/04/2024	12:19:50 PM	1,976.00	4	CEUX
GENMAB A/S	19/04/2024	12:19:50 PM	1,976.00	12	TQEX
GENMAB A/S	19/04/2024	12:19:53 PM	1,976.00	20	XCSE
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.50	22	XCSE
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.50	58	XCSE
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.50	35	XCSE
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.50	10	AQEU
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.50	71	CEUX
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.50	12	TQEX
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.00	3	CEUX
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.00	12	CEUX
GENMAB A/S	19/04/2024	12:23:03 PM	1,976.00	20	CEUX
GENMAB A/S	19/04/2024	12:27:27 PM	1,976.50	8	AQEU
GENMAB A/S	19/04/2024	12:27:37 PM	1,976.50	8	AQEU
GENMAB A/S	19/04/2024	12:27:37 PM	1,976.50	8	AQEU
GENMAB A/S	19/04/2024	12:27:38 PM	1,975.50	10	CEUX
GENMAB A/S	19/04/2024	12:27:38 PM	1,975.50	10	XCSE
GENMAB A/S	19/04/2024	12:27:43 PM	1,975.50	1	AQEU
GENMAB A/S	19/04/2024	12:27:43 PM	1,975.50	10	CEUX
GENMAB A/S	19/04/2024	12:27:43 PM	1,975.50	5	TQEX
GENMAB A/S	19/04/2024	12:27:43 PM	1,975.50	5	TQEX
GENMAB A/S	19/04/2024	12:27:43 PM	1,975.50	10	XCSE
GENMAB A/S	19/04/2024	12:27:43 PM	1,975.50	10	XCSE
GENMAB A/S	19/04/2024	12:29:29 PM	1,977.00	7	XCSE
GENMAB A/S	19/04/2024	12:30:02 PM	1,977.00	4	XCSE
GENMAB A/S	19/04/2024	12:31:46 PM	1,978.50	23	XCSE
GENMAB A/S	19/04/2024	12:31:46 PM	1,978.50	21	CEUX
GENMAB A/S	19/04/2024	12:31:46 PM	1,978.50	21	CEUX
GENMAB A/S	19/04/2024	12:31:46 PM	1,978.50	6	CEUX

149

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	12:31:46 PM	1,978.50	2	CEUX
GENMAB A/S	19/04/2024	12:31:46 PM	1,978.50	32	XCSE
GENMAB A/S	19/04/2024	12:32:11 PM	1,978.50	41	XCSE
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	6	AQEU
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	6	AQEU
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	24	CEUX
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	19	CEUX
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	42	CEUX
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	7	TQEX
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	7	TQEX
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	48	XCSE
GENMAB A/S	19/04/2024	12:32:25 PM	1,977.50	47	XCSE
GENMAB A/S	19/04/2024	12:39:25 PM	1,978.00	1	AQEU
GENMAB A/S	19/04/2024	12:40:45 PM	1,979.50	36	CEUX
GENMAB A/S	19/04/2024	12:40:45 PM	1,979.50	7	XCSE
GENMAB A/S	19/04/2024	12:40:45 PM	1,979.50	25	XCSE
GENMAB A/S	19/04/2024	12:40:45 PM	1,979.50	34	XCSE
GENMAB A/S	19/04/2024	12:40:46 PM	1,979.50	23	XCSE
GENMAB A/S	19/04/2024	12:41:29 PM	1,979.50	51	XCSE
GENMAB A/S	19/04/2024	12:41:29 PM	1,979.50	49	XCSE
GENMAB A/S	19/04/2024	12:42:13 PM	1,979.50	37	XCSE
GENMAB A/S	19/04/2024	12:42:54 PM	1,980.00	40	XCSE
GENMAB A/S	19/04/2024	12:44:00 PM	1,980.00	25	XCSE
GENMAB A/S	19/04/2024	12:44:00 PM	1,980.00	4	XCSE
GENMAB A/S	19/04/2024	12:44:00 PM	1,980.00	7	XCSE
GENMAB A/S	19/04/2024	12:44:26 PM	1,980.00	36	XCSE
GENMAB A/S	19/04/2024	12:45:23 PM	1,980.00	2	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	1	AQEU
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	22	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	22	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	12	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	12	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	2	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	TQEX

150

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	5	TQEX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	5	TQEX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	TQEX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	5	TQEX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	5	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	3	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	3	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	3	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	5	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	5	TQEX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	6	TQEX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	4	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	34	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	22	XCSE
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	AQEU
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	10	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	22	CEUX
GENMAB A/S	19/04/2024	12:46:36 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	12:50:04 PM	1,980.00	65	CEUX
GENMAB A/S	19/04/2024	12:50:04 PM	1,980.00	10	CEUX
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.50	71	CEUX
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.50	7	CEUX
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.50	24	TQEX
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.50	56	TQEX
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.00	35	XCSE
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.00	1	XCSE
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.00	7	AQEU
GENMAB A/S	19/04/2024	12:50:04 PM	1,979.00	36	CEUX

151

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	12:50:04 PM	1,979.00	1	CEUX
GENMAB A/S	19/04/2024	1:00:14 PM	1,980.50	18	TQEX
GENMAB A/S	19/04/2024	1:00:14 PM	1,980.50	37	XCSE
GENMAB A/S	19/04/2024	1:00:14 PM	1,980.50	72	XCSE
GENMAB A/S	19/04/2024	1:00:14 PM	1,980.50	10	XCSE
GENMAB A/S	19/04/2024	1:00:16 PM	1,980.50	19	XCSE
GENMAB A/S	19/04/2024	1:00:16 PM	1,980.50	22	XCSE
GENMAB A/S	19/04/2024	1:00:16 PM	1,980.50	7	XCSE
GENMAB A/S	19/04/2024	1:01:42 PM	1,982.00	11	XCSE
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	5	XCSE
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	7	XCSE
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	15	XCSE
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	82	XCSE
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	2	AQEU
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	9	AQEU
GENMAB A/S	19/04/2024	1:02:48 PM	1,982.00	74	CEUX
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	20	CEUX
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	6	CEUX
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	5	TQEX
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	22	XCSE
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	14	CEUX
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	5	TQEX
GENMAB A/S	19/04/2024	1:02:48 PM	1,981.00	19	CEUX
GENMAB A/S	19/04/2024	1:02:57 PM	1,981.00	26	XCSE
GENMAB A/S	19/04/2024	1:09:05 PM	1,979.00	10	CEUX
GENMAB A/S	19/04/2024	1:09:05 PM	1,979.00	5	TQEX
GENMAB A/S	19/04/2024	1:09:05 PM	1,979.00	9	XCSE
GENMAB A/S	19/04/2024	1:09:05 PM	1,979.00	10	CEUX
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	1	AQEU
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	3	AQEU
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	10	CEUX
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	3	CEUX
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	5	TQEX
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	3	TQEX
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	9	XCSE
GENMAB A/S	19/04/2024	1:09:06 PM	1,979.00	6	XCSE
GENMAB A/S	19/04/2024	1:09:48 PM	1,979.00	5	XCSE
GENMAB A/S	19/04/2024	1:12:14 PM	1,980.50	19	CEUX
GENMAB A/S	19/04/2024	1:12:14 PM	1,980.50	15	CEUX

152

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	1:12:55 PM	1,980.50	8	CEUX
GENMAB A/S	19/04/2024	1:13:00 PM	1,980.00	18	CEUX
GENMAB A/S	19/04/2024	1:13:00 PM	1,980.00	1	CEUX
GENMAB A/S	19/04/2024	1:13:00 PM	1,980.00	19	CEUX
GENMAB A/S	19/04/2024	1:13:00 PM	1,980.00	6	TQEX
GENMAB A/S	19/04/2024	1:13:00 PM	1,980.00	6	TQEX
GENMAB A/S	19/04/2024	1:13:00 PM	1,980.00	10	XCSE
GENMAB A/S	19/04/2024	1:13:02 PM	1,980.00	6	AQEU
GENMAB A/S	19/04/2024	1:13:02 PM	1,980.00	18	CEUX
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	43	XCSE
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	24	XCSE
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	19	XCSE
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	18	XCSE
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	6	AQEU
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	38	CEUX
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	38	CEUX
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	6	TQEX
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	20	CEUX
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	6	TQEX
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.00	25	XCSE
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	34	XCSE
GENMAB A/S	19/04/2024	1:13:34 PM	1,979.50	5	XCSE
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	13	CEUX
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	13	CEUX
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	13	CEUX
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	8	CEUX
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	1	CEUX
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	13	XCSE
GENMAB A/S	19/04/2024	1:18:40 PM	1,982.00	40	XCSE
GENMAB A/S	19/04/2024	1:23:03 PM	1,981.00	19	XCSE
GENMAB A/S	19/04/2024	1:26:03 PM	1,982.50	19	XCSE
GENMAB A/S	19/04/2024	1:27:34 PM	1,983.50	21	CEUX
GENMAB A/S	19/04/2024	1:27:34 PM	1,983.50	21	CEUX
GENMAB A/S	19/04/2024	1:28:45 PM	1,984.00	25	CEUX
GENMAB A/S	19/04/2024	1:28:45 PM	1,984.00	4	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	22	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	9	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	3	AQEU
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	1	AQEU

153

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	3	AQEU
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	1	AQEU
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	3	AQEU
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	10	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	13	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	8	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	10	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	21	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	8	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	10	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	1	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	22	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	2	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	25	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	2	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	41	CEUX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	25	XCSE
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	4	TQEX
GENMAB A/S	19/04/2024	1:29:02 PM	1,984.00	5	TQEX

154

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	1:33:06 PM	1,984.50	19	CEUX
GENMAB A/S	19/04/2024	1:33:17 PM	1,984.50	7	CEUX
GENMAB A/S	19/04/2024	1:33:17 PM	1,984.50	13	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	1	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	16	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	5	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	1	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	5	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	23	CEUX
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	39	XCSE
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	25	XCSE
GENMAB A/S	19/04/2024	1:36:05 PM	1,984.50	13	XCSE
GENMAB A/S	19/04/2024	1:36:06 PM	1,984.50	7	CEUX
GENMAB A/S	19/04/2024	1:36:06 PM	1,984.50	8	CEUX
GENMAB A/S	19/04/2024	1:36:06 PM	1,984.50	25	XCSE
GENMAB A/S	19/04/2024	1:36:06 PM	1,984.50	12	XCSE
GENMAB A/S	19/04/2024	1:37:42 PM	1,984.50	34	XCSE
GENMAB A/S	19/04/2024	1:40:37 PM	1,985.00	43	XCSE
GENMAB A/S	19/04/2024	1:40:37 PM	1,985.00	97	XCSE
GENMAB A/S	19/04/2024	1:44:51 PM	1,987.00	9	XCSE
GENMAB A/S	19/04/2024	1:44:51 PM	1,987.00	1	XCSE
GENMAB A/S	19/04/2024	1:44:51 PM	1,987.00	25	XCSE
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.00	18	XCSE
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	10	CEUX
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	5	CEUX
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	45	CEUX
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	5	CEUX
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	50	CEUX
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	1	CEUX
GENMAB A/S	19/04/2024	1:45:03 PM	1,986.50	4	CEUX
GENMAB A/S	19/04/2024	1:46:06 PM	1,986.50	65	CEUX
GENMAB A/S	19/04/2024	1:46:06 PM	1,986.50	3	CEUX
GENMAB A/S	19/04/2024	1:46:15 PM	1,985.50	31	XCSE
GENMAB A/S	19/04/2024	1:46:15 PM	1,985.50	28	CEUX
GENMAB A/S	19/04/2024	1:46:15 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	1:46:15 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	1:46:15 PM	1,985.50	8	TQEX
GENMAB A/S	19/04/2024	1:46:15 PM	1,985.50	31	XCSE
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	18	CEUX

155

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	18	CEUX
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	4	CEUX
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	5	TQEX
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	19	XCSE
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	36	CEUX
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	5	TQEX
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	15	TQEX
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	19	XCSE
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	4	XCSE
GENMAB A/S	19/04/2024	1:47:20 PM	1,985.00	21	CEUX
GENMAB A/S	19/04/2024	1:53:01 PM	1,982.00	8	AQEU
GENMAB A/S	19/04/2024	1:53:01 PM	1,982.00	31	XCSE
GENMAB A/S	19/04/2024	1:54:02 PM	1,981.00	19	CEUX
GENMAB A/S	19/04/2024	1:54:02 PM	1,981.00	3	CEUX
GENMAB A/S	19/04/2024	1:54:02 PM	1,981.00	4	CEUX
GENMAB A/S	19/04/2024	1:54:02 PM	1,981.00	5	TQEX
GENMAB A/S	19/04/2024	1:54:02 PM	1,981.00	24	XCSE
GENMAB A/S	19/04/2024	1:54:02 PM	1,981.00	30	XCSE
GENMAB A/S	19/04/2024	1:55:48 PM	1,982.00	35	CEUX
GENMAB A/S	19/04/2024	1:55:48 PM	1,982.00	28	XCSE
GENMAB A/S	19/04/2024	1:55:48 PM	1,982.00	14	CEUX
GENMAB A/S	19/04/2024	1:55:48 PM	1,982.00	6	TQEX
GENMAB A/S	19/04/2024	1:55:48 PM	1,982.00	11	XCSE
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.50	75	XCSE
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.50	1	XCSE
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	10	CEUX
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	5	TQEX
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	1	TQEX
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	1	AQEU
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	10	CEUX
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	2	CEUX
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	10	XCSE
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	25	XCSE
GENMAB A/S	19/04/2024	1:59:45 PM	1,983.00	10	XCSE
GENMAB A/S	19/04/2024	2:01:29 PM	1,984.00	15	XCSE
GENMAB A/S	19/04/2024	2:01:29 PM	1,984.00	17	XCSE
GENMAB A/S	19/04/2024	2:02:12 PM	1,984.50	3	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	41	CEUX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	2	TQEX

156

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	37	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	14	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	11	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	19	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	27	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	25	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	2	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	7	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	6	AQEU
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	17	CEUX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	24	CEUX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	11	CEUX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	5	TQEX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	3	TQEX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	6	AQEU
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	7	TQEX
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	25	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	2	XCSE
GENMAB A/S	19/04/2024	2:03:53 PM	1,984.50	17	CEUX
GENMAB A/S	19/04/2024	2:03:56 PM	1,984.50	1	XCSE
GENMAB A/S	19/04/2024	2:03:56 PM	1,984.50	46	XCSE
GENMAB A/S	19/04/2024	2:03:56 PM	1,984.50	6	CEUX
GENMAB A/S	19/04/2024	2:03:56 PM	1,984.50	18	CEUX
GENMAB A/S	19/04/2024	2:03:56 PM	1,984.50	13	CEUX
GENMAB A/S	19/04/2024	2:11:07 PM	1,986.00	39	XCSE
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	10	CEUX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	6	CEUX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	1	AQEU
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	4	CEUX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	4	CEUX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	10	XCSE
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	10	XCSE
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	7	XCSE
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	10	XCSE
GENMAB A/S	19/04/2024	2:11:07 PM	1,985.50	7	XCSE
GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	6	CEUX

157

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	10	CEUX
GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	2	CEUX
GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	7	XCSE
GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	5	TQEX
GENMAB A/S	19/04/2024	2:12:10 PM	1,985.50	7	TQEX
GENMAB A/S	19/04/2024	2:12:20 PM	1,985.50	26	XCSE
GENMAB A/S	19/04/2024	2:12:20 PM	1,985.50	29	XCSE
GENMAB A/S	19/04/2024	2:15:16 PM	1,985.00	23	XCSE
GENMAB A/S	19/04/2024	2:15:16 PM	1,985.00	1	XCSE
GENMAB A/S	19/04/2024	2:15:16 PM	1,985.00	1	XCSE
GENMAB A/S	19/04/2024	2:15:45 PM	1,984.50	6	AQEU
GENMAB A/S	19/04/2024	2:15:45 PM	1,984.50	41	CEUX
GENMAB A/S	19/04/2024	2:15:45 PM	1,984.50	7	TQEX
GENMAB A/S	19/04/2024	2:15:45 PM	1,984.50	45	XCSE
GENMAB A/S	19/04/2024	2:19:01 PM	1,985.50	14	CEUX
GENMAB A/S	19/04/2024	2:19:01 PM	1,985.50	26	CEUX
GENMAB A/S	19/04/2024	2:19:44 PM	1,986.50	33	XCSE
GENMAB A/S	19/04/2024	2:19:44 PM	1,986.50	19	XCSE
GENMAB A/S	19/04/2024	2:19:44 PM	1,987.00	7	CEUX
GENMAB A/S	19/04/2024	2:19:44 PM	1,987.00	33	CEUX
GENMAB A/S	19/04/2024	2:21:52 PM	1,987.50	36	CEUX
GENMAB A/S	19/04/2024	2:22:05 PM	1,987.50	37	CEUX
GENMAB A/S	19/04/2024	2:23:03 PM	1,987.50	17	XCSE
GENMAB A/S	19/04/2024	2:23:03 PM	1,987.50	24	XCSE
GENMAB A/S	19/04/2024	2:23:45 PM	1,987.50	14	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	21	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	3	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	35	CEUX
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	13	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	8	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	21	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	21	XCSE
GENMAB A/S	19/04/2024	2:23:55 PM	1,987.00	21	XCSE
GENMAB A/S	19/04/2024	2:27:02 PM	1,987.50	18	XCSE
GENMAB A/S	19/04/2024	2:27:02 PM	1,987.50	19	XCSE
GENMAB A/S	19/04/2024	2:28:30 PM	1,988.50	14	CEUX
GENMAB A/S	19/04/2024	2:29:49 PM	1,988.50	12	CEUX
GENMAB A/S	19/04/2024	2:30:43 PM	1,988.00	7	AQEU

158

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	2:30:43 PM	1,988.00	19	CEUX
GENMAB A/S	19/04/2024	2:30:43 PM	1,988.00	25	CEUX
GENMAB A/S	19/04/2024	2:30:43 PM	1,988.00	2	TQEX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	48	XCSE
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	47	XCSE
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	48	XCSE
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	30	XCSE
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	6	AQEU
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	33	CEUX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	11	CEUX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	5	CEUX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	4	TQEX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	7	TQEX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	3	TQEX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	37	CEUX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	27	CEUX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	6	CEUX
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	8	AQEU
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	16	XCSE
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	30	XCSE
GENMAB A/S	19/04/2024	2:30:48 PM	1,988.00	6	XCSE
GENMAB A/S	19/04/2024	2:36:35 PM	1,988.50	40	XCSE
GENMAB A/S	19/04/2024	2:37:30 PM	1,988.50	15	XCSE
GENMAB A/S	19/04/2024	2:37:30 PM	1,988.50	14	XCSE
GENMAB A/S	19/04/2024	2:37:30 PM	1,988.50	12	XCSE
GENMAB A/S	19/04/2024	2:38:10 PM	1,988.50	35	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	9	AQEU
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	1	AQEU
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	26	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	44	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	8	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	25	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	28	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	62	CEUX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	8	CEUX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	10	TQEX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	3	TQEX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	2	TQEX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	8	CEUX

159

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	1	AQEU
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	8	CEUX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	5	TQEX
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	22	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	22	XCSE
GENMAB A/S	19/04/2024	2:38:42 PM	1,987.50	27	XCSE
GENMAB A/S	19/04/2024	2:38:43 PM	1,987.50	22	XCSE
GENMAB A/S	19/04/2024	2:38:43 PM	1,987.50	10	XCSE
GENMAB A/S	19/04/2024	2:42:33 PM	1,987.00	10	XCSE
GENMAB A/S	19/04/2024	2:42:33 PM	1,987.00	51	XCSE
GENMAB A/S	19/04/2024	2:42:33 PM	1,987.00	12	CEUX
GENMAB A/S	19/04/2024	2:42:33 PM	1,987.00	9	CEUX
GENMAB A/S	19/04/2024	2:43:17 PM	1,986.00	10	XCSE
GENMAB A/S	19/04/2024	2:43:20 PM	1,986.00	32	XCSE
GENMAB A/S	19/04/2024	2:46:35 PM	1,987.00	12	CEUX
GENMAB A/S	19/04/2024	2:46:35 PM	1,987.00	2	CEUX
GENMAB A/S	19/04/2024	2:46:35 PM	1,987.00	16	XCSE
GENMAB A/S	19/04/2024	2:46:36 PM	1,987.00	14	CEUX
GENMAB A/S	19/04/2024	2:46:36 PM	1,987.00	16	XCSE
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	14	CEUX
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	16	XCSE
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	16	XCSE
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	9	XCSE
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	2	XCSE
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	14	CEUX
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	33	XCSE
GENMAB A/S	19/04/2024	2:46:37 PM	1,987.00	18	XCSE
GENMAB A/S	19/04/2024	2:50:34 PM	1,989.00	9	XCSE
GENMAB A/S	19/04/2024	2:50:34 PM	1,989.00	18	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	43	CEUX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	40	CEUX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	TQEX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	41	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	47	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	25	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	17	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	3	CEUX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	37	CEUX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	TQEX

160

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	6	AQEU
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	TQEX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	TQEX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	TQEX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	23	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	25	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	25	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	25	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	1	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	16	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	7	TQEX
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	8	AQEU
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	3	AQEU
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	3	AQEU
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	38	XCSE
GENMAB A/S	19/04/2024	2:53:03 PM	1,992.00	24	XCSE
GENMAB A/S	19/04/2024	2:54:42 PM	1,990.00	72	CEUX
GENMAB A/S	19/04/2024	2:54:42 PM	1,990.00	41	XCSE
GENMAB A/S	19/04/2024	2:54:42 PM	1,990.00	7	XCSE
GENMAB A/S	19/04/2024	2:54:42 PM	1,990.00	32	CEUX
GENMAB A/S	19/04/2024	2:54:42 PM	1,990.00	8	AQEU
GENMAB A/S	19/04/2024	2:54:42 PM	1,990.00	32	CEUX
GENMAB A/S	19/04/2024	3:03:17 PM	1,990.50	10	CEUX
GENMAB A/S	19/04/2024	3:03:39 PM	1,991.50	23	CEUX
GENMAB A/S	19/04/2024	3:03:39 PM	1,991.50	11	CEUX
GENMAB A/S	19/04/2024	3:04:00 PM	1,992.00	3	XCSE
GENMAB A/S	19/04/2024	3:04:00 PM	1,992.00	25	XCSE
GENMAB A/S	19/04/2024	3:04:27 PM	1,992.00	34	XCSE
GENMAB A/S	19/04/2024	3:05:01 PM	1,992.00	34	XCSE
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	46	XCSE
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	46	XCSE
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	22	XCSE
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	23	XCSE
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	34	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	8	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	20	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	20	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	2	CEUX

161

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	20	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	2	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	15	CEUX
GENMAB A/S	19/04/2024	3:05:01 PM	1,991.50	2	CEUX
GENMAB A/S	19/04/2024	3:05:02 PM	1,990.00	19	XCSE
GENMAB A/S	19/04/2024	3:05:02 PM	1,990.00	19	XCSE
GENMAB A/S	19/04/2024	3:05:06 PM	1,990.00	3	XCSE
GENMAB A/S	19/04/2024	3:05:06 PM	1,990.00	20	CEUX
GENMAB A/S	19/04/2024	3:05:06 PM	1,990.00	5	TQEX
GENMAB A/S	19/04/2024	3:05:06 PM	1,990.00	3	XCSE
GENMAB A/S	19/04/2024	3:05:06 PM	1,990.00	22	XCSE
GENMAB A/S	19/04/2024	3:11:25 PM	1,990.00	38	XCSE
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	9	CEUX
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	9	CEUX
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	1	CEUX
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	5	TQEX
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	9	XCSE
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	9	XCSE
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	23	XCSE
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	11	XCSE
GENMAB A/S	19/04/2024	3:11:25 PM	1,989.50	14	XCSE
GENMAB A/S	19/04/2024	3:11:30 PM	1,989.50	25	XCSE
GENMAB A/S	19/04/2024	3:11:30 PM	1,989.50	10	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	53	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	25	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	10	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	43	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	25	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	10	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	12	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	1	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	21	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	3	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	24	XCSE
GENMAB A/S	19/04/2024	3:13:49 PM	1,988.50	14	CEUX
GENMAB A/S	19/04/2024	3:19:29 PM	1,990.00	56	TQEX
GENMAB A/S	19/04/2024	3:19:29 PM	1,990.00	22	TQEX
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	43	XCSE
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	35	XCSE

162

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	23	XCSE
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	2	XCSE
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	58	XCSE
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	25	XCSE
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	23	CEUX
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	19	CEUX
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	4	CEUX
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	23	CEUX
GENMAB A/S	19/04/2024	3:19:29 PM	1,989.50	4	CEUX
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	3	AQEU
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	23	AQEU
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	26	AQEU
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	17	AQEU
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	9	AQEU
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	8	AQEU
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	23	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	3	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	26	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	29	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	4	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	1	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	5	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	12	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	4	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	12	XCSE
GENMAB A/S	19/04/2024	3:23:35 PM	1,988.00	10	XCSE
GENMAB A/S	19/04/2024	3:28:14 PM	1,991.50	8	AQEU
GENMAB A/S	19/04/2024	3:28:36 PM	1,992.00	26	XCSE
GENMAB A/S	19/04/2024	3:28:36 PM	1,992.00	25	CEUX
GENMAB A/S	19/04/2024	3:28:36 PM	1,992.00	12	CEUX
GENMAB A/S	19/04/2024	3:28:36 PM	1,992.00	13	CEUX
GENMAB A/S	19/04/2024	3:28:36 PM	1,992.00	7	CEUX
GENMAB A/S	19/04/2024	3:28:36 PM	1,992.00	37	CEUX
GENMAB A/S	19/04/2024	3:29:07 PM	1,992.00	40	XCSE
GENMAB A/S	19/04/2024	3:29:09 PM	1,991.50	9	XCSE
GENMAB A/S	19/04/2024	3:29:09 PM	1,991.50	44	XCSE
GENMAB A/S	19/04/2024	3:29:09 PM	1,991.50	9	XCSE
GENMAB A/S	19/04/2024	3:29:09 PM	1,991.50	16	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX

163

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	8	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	4	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	5	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	11	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	8	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	5	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	10	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	5	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	6	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	9	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	40	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	9	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	9	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	15	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	2	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	7	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	9	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	7	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	2	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	7	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	2	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	7	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	1	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	7	AQEU
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	14	AQEU
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	7	AQEU
GENMAB A/S	19/04/2024	3:30:01 PM	1,991.50	12	AQEU
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	23	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	18	CEUX

164

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	21	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	21	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	4	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	3	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	18	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	16	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	5	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	48	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	22	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	1	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	48	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	43	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	14	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	16	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	13	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	2	TQEX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	23	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	1	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	7	AQEU
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	36	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	3	CEUX
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	25	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	3	XCSE
GENMAB A/S	19/04/2024	3:30:01 PM	1,990.50	3	XCSE
GENMAB A/S	19/04/2024	3:39:57 PM	1,994.50	8	XCSE
GENMAB A/S	19/04/2024	3:40:25 PM	1,995.50	38	AQEU
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.50	53	XCSE
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.50	67	XCSE
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.50	15	AQEU
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.50	91	CEUX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.50	16	CEUX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.50	17	TQEX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	20	CEUX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	1	CEUX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	20	CEUX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	5	TQEX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	22	XCSE
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	9	CEUX
GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	6	CEUX

165

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:40:36 PM	1,994.00	22	XCSE
GENMAB A/S	19/04/2024	3:43:21 PM	1,994.50	105	XCSE
GENMAB A/S	19/04/2024	3:45:43 PM	1,998.00	2	XCSE
GENMAB A/S	19/04/2024	3:45:45 PM	1,998.00	10	CEUX
GENMAB A/S	19/04/2024	3:45:45 PM	1,998.00	10	CEUX
GENMAB A/S	19/04/2024	3:45:45 PM	1,998.00	11	XCSE
GENMAB A/S	19/04/2024	3:45:45 PM	1,998.00	11	XCSE
GENMAB A/S	19/04/2024	3:45:45 PM	1,998.00	82	XCSE
GENMAB A/S	19/04/2024	3:47:13 PM	1,999.50	38	CEUX
GENMAB A/S	19/04/2024	3:47:13 PM	1,999.00	37	XCSE
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	67	XCSE
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	41	XCSE
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	43	CEUX
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	7	CEUX
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	6	CEUX
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	13	CEUX
GENMAB A/S	19/04/2024	3:47:14 PM	1,999.00	42	XCSE
GENMAB A/S	19/04/2024	3:50:30 PM	2,001.00	40	CEUX
GENMAB A/S	19/04/2024	3:50:37 PM	2,000.00	11	TQEX
GENMAB A/S	19/04/2024	3:50:51 PM	2,000.00	17	CEUX
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	16	AQEU
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	58	CEUX
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	16	CEUX
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	6	AQEU
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	172	XCSE
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	63	CEUX
GENMAB A/S	19/04/2024	3:51:02 PM	2,000.00	13	TQEX
GENMAB A/S	19/04/2024	3:53:17 PM	2,001.00	35	XCSE
GENMAB A/S	19/04/2024	3:53:17 PM	2,001.00	5	XCSE
GENMAB A/S	19/04/2024	3:53:17 PM	2,001.00	8	CEUX
GENMAB A/S	19/04/2024	3:53:17 PM	2,001.00	5	TQEX
GENMAB A/S	19/04/2024	3:55:06 PM	2,001.00	3	XCSE
GENMAB A/S	19/04/2024	3:55:27 PM	2,002.00	38	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	1	AQEU
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE

166

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	5	TQEX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	5	TQEX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	13	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	3	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	2	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	1	AQEU
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	2	AQEU
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	3	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	4	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	5	TQEX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	13	TQEX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	24	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	1	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	7	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	3	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	4	CEUX
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	5	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	21	XCSE
GENMAB A/S	19/04/2024	3:55:46 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	8	XCSE
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	2	XCSE
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	7	AQEU
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	14	AQEU
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	36	CEUX
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	15	XCSE
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	30	XCSE
GENMAB A/S	19/04/2024	3:55:49 PM	2,002.00	26	XCSE
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	11	TQEX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	5	TQEX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	36	TQEX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	81	XCSE
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	9	XCSE

167

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	216	XCSE
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	11	AQEU
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	1	AQEU
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	1	AQEU
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	3	AQEU
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	73	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	10	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	4	CEUX
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	1	AQEU
GENMAB A/S	19/04/2024	3:57:55 PM	2,002.00	34	AQEU
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	9	CEUX
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	9	CEUX
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	2	CEUX
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	5	TQEX
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	5	TQEX
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	8	XCSE
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	8	XCSE
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	1	XCSE
GENMAB A/S	19/04/2024	4:04:45 PM	1,994.50	9	CEUX
GENMAB A/S	19/04/2024	4:04:46 PM	1,994.50	9	CEUX

168

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	4:04:46 PM	1,994.50	8	XCSE
GENMAB A/S	19/04/2024	4:07:01 PM	1,998.00	36	CEUX
GENMAB A/S	19/04/2024	4:07:16 PM	1,998.00	41	CEUX
GENMAB A/S	19/04/2024	4:07:54 PM	2,001.00	7	CEUX
GENMAB A/S	19/04/2024	4:08:06 PM	2,002.00	5	CEUX
GENMAB A/S	19/04/2024	4:08:11 PM	2,002.00	36	CEUX
GENMAB A/S	19/04/2024	4:08:11 PM	2,002.00	36	CEUX
GENMAB A/S	19/04/2024	4:08:33 PM	2,002.00	35	CEUX
GENMAB A/S	19/04/2024	4:08:55 PM	2,002.00	36	CEUX
GENMAB A/S	19/04/2024	4:08:57 PM	2,001.00	38	CEUX
GENMAB A/S	19/04/2024	4:08:57 PM	2,001.00	24	TQEX
GENMAB A/S	19/04/2024	4:08:57 PM	2,001.00	173	XCSE
GENMAB A/S	19/04/2024	4:08:57 PM	2,001.00	24	TQEX
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	17	XCSE
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	38	XCSE
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	56	XCSE
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	10	CEUX
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	8	CEUX
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	46	CEUX
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	7	TQEX
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	30	XCSE
GENMAB A/S	19/04/2024	4:09:56 PM	2,001.00	28	XCSE
GENMAB A/S	19/04/2024	4:11:45 PM	1,999.00	6	XCSE
GENMAB A/S	19/04/2024	4:14:37 PM	2,003.00	3	XCSE
GENMAB A/S	19/04/2024	4:14:40 PM	2,004.00	29	CEUX
GENMAB A/S	19/04/2024	4:14:40 PM	2,004.00	12	CEUX
GENMAB A/S	19/04/2024	4:14:57 PM	2,004.00	36	CEUX
GENMAB A/S	19/04/2024	4:14:57 PM	2,004.00	3	CEUX
GENMAB A/S	19/04/2024	4:15:51 PM	2,005.00	50	XCSE
GENMAB A/S	19/04/2024	4:15:51 PM	2,005.00	22	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	12	AQEU
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	16	AQEU
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	14	AQEU
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	37	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	217	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	59	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	158	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	62	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	9	AQEU

169

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	5	AQEU
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	113	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	65	XCSE
GENMAB A/S	19/04/2024	4:15:57 PM	2,004.00	28	XCSE
GENMAB A/S	19/04/2024	4:24:13 PM	2,004.00	10	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	24	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	33	AQEU
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	15	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	53	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	9	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	445	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	20	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	14	XCSE
GENMAB A/S	19/04/2024	4:24:29 PM	2,004.00	41	AQEU
GENMAB A/S	19/04/2024	4:31:31 PM	2,010.00	34	CEUX
GENMAB A/S	19/04/2024	4:32:02 PM	2,009.00	20	AQEU
GENMAB A/S	19/04/2024	4:32:02 PM	2,009.00	159	XCSE
GENMAB A/S	19/04/2024	4:32:02 PM	2,009.00	10	AQEU
GENMAB A/S	19/04/2024	4:32:03 PM	2,009.00	56	XCSE
GENMAB A/S	19/04/2024	4:32:03 PM	2,009.00	103	XCSE
GENMAB A/S	19/04/2024	4:32:03 PM	2,009.00	30	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	45	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	42	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	42	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	6	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	26	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	11	AQEU
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	11	AQEU
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	23	AQEU
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	13	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	13	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	14	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	6	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	4	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	7	AQEU
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	14	AQEU
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	7	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	10	TQEX
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	15	XCSE

170

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	38	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	37	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	37	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	7	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	7	XCSE
GENMAB A/S	19/04/2024	4:33:09 PM	2,008.00	19	XCSE
GENMAB A/S	19/04/2024	4:34:35 PM	2,006.00	26	XCSE
GENMAB A/S	19/04/2024	4:34:35 PM	2,006.00	9	XCSE
GENMAB A/S	19/04/2024	4:34:35 PM	2,006.00	5	AQEU
GENMAB A/S	19/04/2024	4:34:35 PM	2,006.00	5	TQEX
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	36	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	36	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	37	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	45	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	87	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	20	AQEU
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	5	AQEU
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	3	AQEU
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	17	TQEX
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	2	TQEX
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	2	TQEX
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	54	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	29	TQEX
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	72	XCSE
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	8	AQEU
GENMAB A/S	19/04/2024	4:35:09 PM	2,006.00	11	AQEU
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	3	AQEU
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	5	TQEX
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	5	TQEX
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	19	XCSE
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	2	XCSE
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	19	XCSE
GENMAB A/S	19/04/2024	4:41:35 PM	2,001.00	18	XCSE
GENMAB A/S	19/04/2024	4:42:47 PM	2,004.00	21	AQEU
GENMAB A/S	19/04/2024	4:42:47 PM	2,004.00	23	TQEX
GENMAB A/S	19/04/2024	4:42:47 PM	2,004.00	52	XCSE
GENMAB A/S	19/04/2024	4:42:52 PM	2,004.00	19	CEUX
GENMAB A/S	19/04/2024	4:42:52 PM	2,004.00	29	CEUX
GENMAB A/S	19/04/2024	4:42:52 PM	2,004.00	14	XCSE

171

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	4:43:46 PM	2,004.00	5	AQEU
GENMAB A/S	19/04/2024	4:43:46 PM	2,004.00	22	TQEX
GENMAB A/S	19/04/2024	4:43:46 PM	2,004.00	75	XCSE
GENMAB A/S	19/04/2024	4:43:46 PM	2,004.00	88	XCSE
GENMAB A/S	19/04/2024	4:43:46 PM	2,004.00	16	AQEU
GENMAB A/S	19/04/2024	4:45:53 PM	2,003.00	24	XCSE
GENMAB A/S	19/04/2024	4:45:54 PM	2,003.00	24	XCSE
GENMAB A/S	19/04/2024	4:45:54 PM	2,003.00	2	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	23	AQEU
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	10	AQEU
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	14	AQEU
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	10	AQEU
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	34	CEUX
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	49	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	75	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	142	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	75	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	75	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	30	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	23	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	243	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	54	XCSE
GENMAB A/S	19/04/2024	4:47:01 PM	2,004.00	1	XCSE
GENMAB A/S	19/04/2024	4:49:32 PM	2,005.00	3	AQEU
GENMAB A/S	19/04/2024	4:49:32 PM	2,005.00	22	XCSE
GENMAB A/S	19/04/2024	4:49:34 PM	2,005.00	22	XCSE
GENMAB A/S	19/04/2024	4:49:45 PM	2,005.00	3	AQEU
GENMAB A/S	19/04/2024	4:49:45 PM	2,005.00	2	XCSE
GENMAB A/S	19/04/2024	4:50:02 PM	2,005.00	20	XCSE
GENMAB A/S	19/04/2024	4:50:08 PM	2,005.00	10	XCSE
GENMAB A/S	19/04/2024	4:51:16 PM	2,005.00	12	XCSE
GENMAB A/S	19/04/2024	4:51:16 PM	2,005.00	3	AQEU
GENMAB A/S	19/04/2024	4:51:16 PM	2,005.00	22	XCSE
GENMAB A/S	19/04/2024	4:52:14 PM	2,005.00	8	AQEU
GENMAB A/S	19/04/2024	4:52:17 PM	2,005.00	2	AQEU
GENMAB A/S	19/04/2024	4:52:32 PM	2,007.00	2	CEUX
GENMAB A/S	19/04/2024	4:52:32 PM	2,007.00	11	CEUX
GENMAB A/S	19/04/2024	4:52:32 PM	2,007.00	10	CEUX
GENMAB A/S	19/04/2024	4:52:32 PM	2,007.00	14	CEUX

172

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April15, – April 19, 2024

GENMAB A/S	19/04/2024	4:52:32 PM	2,006.00	18	XCSE
GENMAB A/S	19/04/2024	4:52:32 PM	2,006.00	19	XCSE
GENMAB A/S	19/04/2024	4:52:32 PM	2,006.00	18	XCSE
GENMAB A/S	19/04/2024	4:52:32 PM	2,006.00	20	XCSE
GENMAB A/S	19/04/2024	4:52:58 PM	2,007.00	7	AQEU
GENMAB A/S	19/04/2024	4:53:03 PM	2,007.00	5	AQEU
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	11	AQEU
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	14	AQEU
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	14	AQEU
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	14	AQEU
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	11	TQEX
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	15	XCSE
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	68	XCSE
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	112	XCSE
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	63	XCSE
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	2	AQEU
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	24	XCSE
GENMAB A/S	19/04/2024	4:53:19 PM	2,007.00	11	XCSE
GENMAB A/S	19/04/2024	4:53:45 PM	2,007.00	11	XCSE
GENMAB A/S	19/04/2024	4:53:45 PM	2,007.00	59	XCSE
GENMAB A/S	19/04/2024	4:53:45 PM	2,007.00	56	XCSE
GENMAB A/S	19/04/2024	4:53:45 PM	2,007.00	16	XCSE

173