Patrick R. O'neil - Oct 2, 2025 Form 4 Insider Report for IONIS PHARMACEUTICALS INC (IONS)

Role: EVP CLO & General Counsel
Signature: Patrick R. O'Neil
Stock symbol: IONS
Transactions as of: Oct 2, 2025
Transactions value $: -$563,798
Form type: 4
Date filed: 10/2/2025, 07:35 PM
Previous filing: Oct 1, 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
O'NEIL PATRICK R.	EVP CLO & General Counsel	2855 GAZELLE COURT, CARLSBAD	Patrick R. O'Neil	2025-10-02	0001564926

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	IONS	Common Stock	Options Exercise	$1.71M	+30.2K	+52.87%	$56.78	87.3K	Oct 2, 2025	Direct
transaction	IONS	Common Stock	Sale	-$2.04M	-30.2K	-34.58%	$67.69	57.1K	Oct 2, 2025	Direct	F1, F2
transaction	IONS	Common Stock	Options Exercise	$2.1M	+34.5K	+60.32%	$60.89	91.6K	Oct 2, 2025	Direct
transaction	IONS	Common Stock	Sale	-$2.33M	-34.5K	-37.62%	$67.69	57.1K	Oct 2, 2025	Direct	F1, F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	IONS	Non-Qualified Stock Option (right to buy)	Options Exercise	$0	-30.2K	-100%	$0.00	0	Oct 2, 2025	Common Stock	30.2K	$56.78	Direct
transaction	IONS	Non-Qualified Stock Option (right to buy)	Options Exercise	$0	-34.5K	-100%	$0.00	0	Oct 2, 2025	Common Stock	34.5K	$60.89	Direct

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id	Content
F1	Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on May 2, 2025.
F2	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $67.50 to $68.03 inclusive. The reporting person undertakes to provide to Ionis Pharmaceuticals, Inc. any security holder of Ionis Pharmaceuticals, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) on this Form 4.

Content

Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on May 2, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $67.50 to $68.03 inclusive. The reporting person undertakes to provide to Ionis Pharmaceuticals, Inc. any security holder of Ionis Pharmaceuticals, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) on this Form 4.