Ionis Pharmaceuticals (NASDAQ: IONS) director sells 21,332 shares

Rhea-AI Filing Summary

Ionis Pharmaceuticals director Joseph Klein III reported mixed stock transactions involving option exercises and share sales. On March 3, 2026, he exercised non-qualified stock options into 16,000 shares of common stock at exercise prices of $40.05 and $42.88 per share, then sold 21,332 shares in open-market transactions at weighted-average prices between $78.615 and $81.025, pursuant to a Rule 10b5-1 trading plan adopted on November 25, 2025. After these trades, he held 11,014 shares directly and 100 shares were reported as held indirectly by his son, for which he disclaimed beneficial ownership.

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

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

X

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^*

KLEIN JOSEPH III

(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)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
03/03/2026

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	03/03/2026		M		12,000	A	$40.05	28,346	D
Common Stock	03/03/2026		M		4,000	A	$42.88	32,346	D
Common Stock	03/03/2026		S		13,526(1)	D	$79.174(2)	18,820	D
Common Stock	03/03/2026		S		6,794(1)	D	$79.995(3)	12,026	D
Common Stock	03/03/2026		S		1,012(1)	D	$80.818(4)	11,014	D
Common Stock								100	I	by Son(5)

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)	$40.05	03/03/2026		M			12,000	07/01/2022	06/30/2031	Common Stock	12,000	$0.0	0	D
Non-Qualified Stock Option (right to buy)	$42.88	03/03/2026		M			4,000	07/01/2021	07/01/2028	Common Stock	4,000	$0.0	0	D

Explanation of Responses:

1. Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on November 25, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $78.615 to $79.60 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.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $79.65 to $80.63 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 (3) on this Form 4.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.67 to $81.025 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 (3) on this Form 4.

5. The reporting person disclaims beneficial ownership of all securities held by his son, and this report should not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

	By: Patrick R. O'Neil, attorney-in-fact For: Joseph Klein, III	03/05/2026
	** 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.
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FAQ

How many Ionis Pharmaceuticals (IONS) shares did director Joseph Klein III sell?

Director Joseph Klein III sold 21,332 shares of Ionis Pharmaceuticals common stock. The sales occurred on March 3, 2026 in open-market transactions at weighted-average prices ranging from $78.615 to $81.025 per share, under a pre-adopted Rule 10b5-1 trading plan.

What stock options did Joseph Klein III exercise in this Ionis (IONS) Form 4 filing?

He exercised non-qualified stock options covering a total of 16,000 shares of Ionis common stock. The options converted into 12,000 shares at an exercise price of $40.05 per share and 4,000 shares at $42.88 per share, all on March 3, 2026.

At what prices were the Ionis (IONS) shares sold by director Joseph Klein III?

His sales were reported at weighted-average prices of $79.174, $79.995, and $80.818 per share. Footnotes explain these represent multiple transactions within ranges of $78.615–$79.60, $79.65–$80.63, and $80.67–$81.025 on March 3, 2026.

How many Ionis Pharmaceuticals (IONS) shares does Joseph Klein III hold after the reported transactions?

After the reported trades, Joseph Klein III directly held 11,014 shares of Ionis Pharmaceuticals common stock. The filing also notes 100 additional shares held indirectly by his son, with the director explicitly disclaiming beneficial ownership of those indirectly held shares.

Was the Ionis (IONS) director’s stock sale part of a Rule 10b5-1 trading plan?

Yes. The filing states the shares were sold under a Rule 10b5-1 trading plan adopted by the reporting person on November 25, 2025. Such plans allow pre-scheduled trades according to predetermined instructions established in advance of the transactions.

What does the Form 4 say about Joseph Klein III’s indirect ownership in Ionis (IONS) shares?

The Form 4 reports 100 shares of Ionis common stock held indirectly by his son. A footnote explains that Joseph Klein III disclaims beneficial ownership of all securities held by his son for purposes of Section 16 and for any other purpose.