[Form 4] Ionis Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Brian Birchler, EVP of Corporate and Development Operations at Ionis Pharmaceuticals (IONS), reported an insider purchase of 56,826 shares of Ionis common stock on 08/29/2025 at a price of $27.71 per share. The filing indicates these shares were acquired under the company’s Amended and Restated 2000 Employee Stock Purchase Plan and may not be sold until March 2, 2026. The Form 4 was executed by an attorney-in-fact and reflects that the shares are directly beneficially owned following the transaction.

Insights

Financial Analyst

TL;DR: A routine ESPP purchase by a senior officer totaling 56,826 shares at $27.71; modest informational value for valuation but shows insider participation.

The purchase is executed under a standard employee stock purchase plan and is time-restricted until March 2, 2026, limiting immediate market impact. The transaction size relative to the company’s market capitalization is not provided in the filing, so its materiality cannot be assessed here. As a disclosure, it confirms insider participation in equity ownership but does not include any additional financial metrics or strategic implications.

Corporate Governance Expert

TL;DR: Proper Form 4 disclosure of an ESPP acquisition by an officer/director; restriction period and attorney-in-fact signature are noted.

The filing follows Section 16 reporting requirements, identifying Brian Birchler as an officer and reporting a direct beneficial ownership increase of 56,826 shares. The disclosure states the purchase restriction until March 2, 2026, which is relevant for governance and insider trading compliance. The form was signed by an attorney-in-fact, which is acceptable when properly authorized; no amendments or exemptions are indicated.

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).

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

Birchler Brian

(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, Corp and Development Ops

3. Date of Earliest Transaction (Month/Day/Year)
08/29/2025

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	08/29/2025		J		166(1)	A	$27.71	56,826	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

Explanation of Responses:

1. Reporting shares purchased under the Ionis Pharmaceuticals, Inc. Amended and Restated 2000 Employee Stock Purchase Plan on August 29, 2025. These shares may not be sold until March 2, 2026.

	By: Patrick R. O'Neil, attorney-in-fact For: Brian Birchler	09/03/2025
	** 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 Brian Birchler purchase in the Form 4 for IONS?

He acquired 56,826 shares of Ionis common stock under the company ESPP.

When was the insider transaction executed and at what price?

The transaction occurred on 08/29/2025 at a price of $27.71 per share.

Are the purchased shares immediately tradable?

No. The filing states these shares may not be sold until March 2, 2026.

What is Brian Birchler’s role at Ionis as listed on the Form 4?

He is reported as a Director and an Officer with the title EVP, Corporate and Development Ops.

Who signed the Form 4 and when was it filed?

The form was executed by Patrick R. O'Neil, attorney-in-fact for Brian Birchler and dated 09/03/2025.