v3.25.4

Segment Information - Segment Information (Details) - Ionis Operations [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Information [Abstract]
Revenue	$ 943,711	$ 705,138	$ 787,647
Cost of sales	14,008	10,415	8,686
Drug discovery	125,156	114,350	125,649
Drug development	486,199	527,259	530,332
Medical affairs	32,005	27,229	19,454
Manufacturing and development chemistry	87,314	57,729	65,293
R&D support	94,847	82,559	81,019
Selling, general and administrative	351,992	230,478	205,135
Other segment items	133,577	109,016	118,365
Net loss	$ (381,387)	$ (453,897)	$ (366,286)

Expenses related to drug development, including expenses for marketed medicines and those in Phase 3 development.

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IONIS PHARMACEUTICALS INC 10-K