Ionis Pharmaceuticals Inc number of employees

Ionis Pharmaceuticals Inc reported 1,402 employees at December 31, 2025 in its latest annual report, up 333 (31.2%) on the year before. That compares with 660 at December 31, 2021. Revenue per employee was $673,118.

Headcount by year

Fiscal year end	Employees	Change	Revenue per employee	Source
December 31, 2025	1,402	+333 (31.2%)	$673,118	10-K, filed February 26, 2026
December 31, 2024	1,069	+142 (15.3%)	$659,624	10-K, filed February 19, 2025
December 31, 2023	927	+131 (16.5%)	$849,673	10-K, filed February 21, 2024
December 31, 2022	796	+136 (20.6%)	$737,898	10-K, filed February 22, 2023
December 31, 2021	660	—	$1.2m	10-K, filed February 25, 2022

What the annual reports say

Employees and Human Capital As of February 19, 2026, we employed 1,402 people, the vast majority of whom reside in the U.S. 2025 annual report
Employees and Human Capital As of February 13, 2025, we employed 1,069 people, the vast majority of whom reside in the U.S. 2024 annual report
Employees and Human Capital As of February 15, 2024, we employed 927 people, the vast majority of whom reside in the U.S. 2023 annual report
Employees & Human Capital As of February 16, 2023, we employed 796 people, the vast majority of whom reside in the U.S. 2022 annual report
Employees & Human Capital As of February 16, 2022, we employed 660 people, the vast majority of whom reside in the U.S. 2021 annual report

Headcount as the company states it in Item 1 of its annual report (some count full-time equivalents or exclude part-time and temporary staff), at the date it gives. Years where the report states no clear total are left out rather than estimated. Changes can reflect acquisitions and disposals as well as hiring and job cuts.

Compare with peers

Head to head: BCRX vs IONS BBIO vs IONS IONS vs KNSA

More: Biotechnology stocks compared, Health Care sector, rankings of US companies

Figures from Ionis Pharmaceuticals Inc's SEC filings (10-K and 10-Q), retrieved October 20, 2026. How we read and check them: methodology and data sources. Not investment advice. Back to Ionis Pharmaceuticals Inc.