Offerings - Offering: 1

Jul. 30, 2025

USD ($)

shares

$ / shares

Offering:

Fee Previously Paid

false

Other Rule

true

Security Type

Equity

Security Class Title

Common Stock, par value $.001 per share

Amount Registered | shares

4,000,000

Proposed Maximum Offering Price per Unit | $ / shares

41.23

Maximum Aggregate Offering Price

$ 164,920,000

Fee Rate

0.01531%

Amount of Registration Fee

$ 25,249.25

Offering Note

(1) In accordance with Rule 416(a) under the Securities Act, this Registration Statement shall be deemed to cover any additional securities that may from time to time be offered or issued by Ionis Pharmaceuticals, Inc. to prevent dilution resulting from stock splits, stock dividends or similar transactions.

(2) Includes 4,000,000 shares issuable pursuant to the Registrant’s Amended and Restated 2011 Equity Incentive Plan.

(3) Estimated solely for the purpose of calculating the amount of the registration fee pursuant to Rule 457(c) and Rule 457(h) of the Securities Act. The price per share and the aggregate offering price are calculated on the basis of $41.23, which is the average of the high and low price per share of Registrant’s Common Stock on July 29, 2025, as reported on the Nasdaq Global Market.