[Form 4] IONIS PHARMACEUTICALS INC Insider Trading Activity

Rhea-AI Filing Summary

Patrick R. O'Neil, Executive Vice President, Chief Legal Officer and General Counsel of Ionis Pharmaceuticals (IONS), reported option exercise and an offsetting sale on 09/12/2025. He exercised a non-qualified stock option to purchase 1,700 shares at a $56.78 exercise price and concurrently sold 1,700 shares under a Rule 10b5-1 trading plan for a weighted average price of $64.5807, leaving him with 55,503 shares directly owned and 57,130 shares following the transactions as reported. The filing includes an explanation that the shares sold were transacted at prices ranging from $64.53 to $64.605 and that the sale was pursuant to a 10b5-1 plan adopted May 2, 2025.

Positive

• Transaction disclosed promptly on Form 4 with signature and explanation
• Sale executed under a Rule 10b5-1 plan, indicating pre-arranged trading and reduced risk of opportunistic timing
• Commitment to provide trade-level pricing details on request enhances transparency

Negative

• Reduction in direct beneficial ownership by 1,700 shares following the sale
• Insider monetized shares, which may be viewed unfavorably by some investors despite being planned

Insights

Corporate Governance Expert

TL;DR: Routine insider option exercise and programmed sale under a 10b5-1 plan, disclosed and signed.

The report shows a standard exercise of a non-qualified stock option and an immediate sale executed under a pre-established Rule 10b5-1 plan. The disclosure includes the weighted average sale price range and a commitment to provide detailed trade-level pricing on request, which aligns with good governance and SEC reporting practices. The transactions did not change control and appear administrative rather than strategic.

Securities Analyst

TL;DR: Insider monetized gain from option exercise via planned sales; impact on ownership is modest.

The exercise price of $56.78 and weighted average sale price of $64.5807 imply a realized gross gain per share before taxes and fees. The net effect reduced reported direct holdings modestly from 58,830 to 57,130 shares following the transactions. Because the sale was pre-planned under a 10b5-1 agreement and the sizes are small relative to total outstanding shares, this is unlikely to be material to company valuation.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

O'NEIL PATRICK R.

(Last) (First) (Middle)

2855 GAZELLE COURT

(Street)

CARLSBAD CA 92010

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
IONIS PHARMACEUTICALS INC [ IONS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP CLO & General Counsel

3. Date of Earliest Transaction (Month/Day/Year)
09/12/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/12/2025		M		1,700	A	$56.78	58,830	D
Common Stock	09/12/2025		S		1,700(1)	D	$64.5807(2)	57,130	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Non-Qualified Stock Option (right to buy)	$56.78	09/12/2025		M			1,700	01/04/2022	01/03/2028	Common Stock	1,700	$0.0	55,503	D

Explanation of Responses:

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

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.53 to $64.605 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.

	Patrick R. O'Neil	09/15/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did the Ionis (IONS) Form 4 filed by Patrick R. O'Neil report?

It reports exercise of a non-qualified option for 1,700 shares at $56.78 and an immediate sale of 1,700 shares on 09/12/2025 under a Rule 10b5-1 plan.

Was the sale by the IONS executive pre-planned or discretionary?

The filing states the shares were sold pursuant to a Rule 10b5-1 Trading Plan adopted May 2, 2025, indicating pre-planned sales.

What price did Patrick O'Neil receive for the IONS shares sold?

The reported weighted average sale price was $64.5807 per share, with individual trade prices ranging from $64.53 to $64.605.

How many IONS shares does O'Neil own after the transactions?

The Form 4 reports 55,503 shares held via exercised options underlying and 57,130 shares beneficially owned following the reported transactions, as applicable.

Does this Form 4 indicate any material change in control at Ionis Pharmaceuticals (IONS)?

No. The filing shows routine option exercise and sale by an officer and does not indicate any change in control or large ownership shift.