IONS

SEC source: 0000874015-26-000061 · edgardoc.xml · nonDerivative · entry 3

Baroldi Joseph · CIK 0001813775 · EVP, Chief Business Officer

10b5-1 filing: No plan indicated

Ownership: Indirect · by Spouse

Disclosed balance after: 5,921

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: Acquired pursuant to vesting and release of shares in accordance with Restricted Stock Unit awards.

F1 · shares: Acquired pursuant to vesting and release of shares in accordance with Restricted Stock Unit awards.

SEC source: 0000874015-26-000061 · edgardoc.xml · nonDerivative · entry 1

Baroldi Joseph · CIK 0001813775 · EVP, Chief Business Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 47,338

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: Acquired pursuant to vesting and release of shares in accordance with Restricted Stock Unit awards.

F1 · shares: Acquired pursuant to vesting and release of shares in accordance with Restricted Stock Unit awards.

SEC source: 0000874015-26-000029 · edgardoc.xml · derivative · entry 15

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 2,971

Underlying: Common Stock · 25,545 shares

Expires 2028-01-03

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · derivative · entry 14

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 9,262

Underlying: Common Stock · 9,264 shares

Expires 2034-01-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · derivative · entry 13

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 9,254

Underlying: Common Stock · 3,829 shares

Expires 2033-01-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · derivative · entry 12

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 7,879

Underlying: Common Stock · 3,460 shares

Expires 2032-01-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · derivative · entry 11

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 11,339

Underlying: Common Stock · 2,101 shares

Expires 2032-01-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 10

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 17,494

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on September 3, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.08 to $85.08 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.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 9

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 26,758

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 8

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 17,494

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on September 3, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.08 to $85.08 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.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 7

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 21,323

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 6

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 17,494

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on September 3, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.08 to $85.08 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.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 5

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 20,954

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 4

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 17,494

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on September 3, 2024.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.10 to $85.64 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.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 3

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 19,595

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 2

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 17,494

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on September 3, 2024.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.10 to $85.64 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.

SEC source: 0000874015-26-000029 · edgardoc.xml · nonDerivative · entry 1

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 43,039

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000026 · edgardoc.xml · derivative · entry 9

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Indirect · by Son

Disclosed balance after: 150

Underlying: Common Stock · 150 shares

Expires 2036-01-01

F5 · derivative.exercise_date: Grant on 01/02/2026 to reporting person's son of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000026 · edgardoc.xml · derivative · entry 8

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F4 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000026 · edgardoc.xml · derivative · entry 7

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 4,065

Underlying: Common Stock · 18,338 shares

Expires 2027-01-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000026 · edgardoc.xml · derivative · entry 6

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 22,403

Underlying: Common Stock · 5,125 shares

Expires 2027-01-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000026 · edgardoc.xml · nonDerivative · entry 4

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 30,453

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on August 14, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $78.88 to $79.70 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.

SEC source: 0000874015-26-000026 · edgardoc.xml · nonDerivative · entry 3

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 48,791

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000026 · edgardoc.xml · nonDerivative · entry 2

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 30,453

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on August 14, 2024.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $78.155 to $78.88 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.

SEC source: 0000874015-26-000026 · edgardoc.xml · nonDerivative · entry 1

Swayze Eric · CIK 0001791058 · EVP Research

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 35,578

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-26-000027 · edgardoc.xml · derivative · entry 1

Jenne Kyle · CIK 0001791857 · EVP, Chf GL Pdt Str Ofcr

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000025 · edgardoc.xml · derivative · entry 1

Schneider Eugene · CIK 0001838539 · EVP, Chf Clinical Develop Ofcr

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000024 · edgardoc.xml · derivative · entry 1

O'NEIL PATRICK R. · CIK 0001564926 · EVP CLO & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000023 · edgardoc.xml · derivative · entry 1

Monia Brett P · CIK 0001537529 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 85,410

Underlying: Common Stock · 85,410 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000022 · edgardoc.xml · derivative · entry 1

Kordasiewicz Holly B. · CIK 0002102721 · EVP, Chief Development Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,100

Underlying: Common Stock · 9,100 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000020 · edgardoc.xml · derivative · entry 1

HOUGEN ELIZABETH L · CIK 0001074773 · EVP, Finance & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,770

Underlying: Common Stock · 25,770 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000019 · edgardoc.xml · derivative · entry 1

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000018 · edgardoc.xml · derivative · entry 1

Birchler Brian · CIK 0001970151 · EVP, Corp and Development Ops

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000017 · edgardoc.xml · derivative · entry 1

BENNETT C FRANK · CIK 0001073387 · EVP, Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000016 · edgardoc.xml · derivative · entry 2

Baroldi Joseph · CIK 0001813775 · EVP, Chief Business Officer

10b5-1 filing: No plan indicated

Ownership: Indirect · by Spouse

Disclosed balance after: 2,600

Underlying: Common Stock · 2,600 shares

Expires 2036-01-01

F2 · derivative.exercise_date: Grant on 01/02/2026 to reporting person's spouse of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000016 · edgardoc.xml · derivative · entry 1

Baroldi Joseph · CIK 0001813775 · EVP, Chief Business Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,350

Underlying: Common Stock · 19,350 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-26-000068 · edgardoc.xml · derivative · entry 1

Kordasiewicz Holly B. · CIK 0002102721 · EVP, Chief Development Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,600

Underlying: Common Stock · 7,500 shares

Expires 2036-01-01

F1 · derivative.exercise_date: Grant on 01/02/2026 to reporting person of stock options under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Following this transaction, the option was exercisable as to 0 shares on 01/02/2026. 25% of the shares subject to the option will vest and become exercisable on 01/02/2027. Thereafter, the remaining shares subject to the option will vest and become exercisable in 36 equal monthly installments over the next 3 years.

SEC source: 0000874015-25-000288 · edgardoc.xml · nonDerivative · entry 2

WENDER JOSEPH H · CIK 0001073384 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 36,035

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on December 26, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $81.12 to $81.435 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.

SEC source: 0000874015-25-000288 · edgardoc.xml · nonDerivative · entry 1

WENDER JOSEPH H · CIK 0001073384 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 43,464

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on December 26, 2024.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.11 to $81.11 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.

SEC source: 0000874015-25-000286 · edgardoc.xml · derivative · entry 11

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 0

Underlying: Common Stock · 4,000 shares

Expires 2030-06-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000286 · edgardoc.xml · derivative · entry 10

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 4,000

Underlying: Common Stock · 4,000 shares

Expires 2030-06-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000286 · edgardoc.xml · derivative · entry 9

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 8,000

Underlying: Common Stock · 4,000 shares

Expires 2030-06-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000286 · edgardoc.xml · nonDerivative · entry 6

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 0

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on January 3, 2024

F2 · ownership.nature: The reporting person disclaims beneficial ownership of all securities held in the children's trusts, 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.

SEC source: 0000874015-25-000286 · edgardoc.xml · nonDerivative · entry 5

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 4,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000286 · edgardoc.xml · nonDerivative · entry 4

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 0

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on January 3, 2024

F2 · ownership.nature: The reporting person disclaims beneficial ownership of all securities held in the children's trusts, 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.

SEC source: 0000874015-25-000286 · edgardoc.xml · nonDerivative · entry 3

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 4,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000286 · edgardoc.xml · nonDerivative · entry 2

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 0

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on January 3, 2024

F2 · ownership.nature: The reporting person disclaims beneficial ownership of all securities held in the children's trusts, 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.

SEC source: 0000874015-25-000286 · edgardoc.xml · nonDerivative · entry 1

KLEIN JOSEPH III · CIK 0001206369 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · by Trust

Disclosed balance after: 4,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000285 · edgardoc.xml · derivative · entry 3

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 16,777 shares

Expires 2026-01-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000874015-25-000285 · edgardoc.xml · nonDerivative · entry 2

Devers Shannon L. · CIK 0002037721 · EVP, Chief Human Resources Ofc

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 17,494

F1 · shares: Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on September 3, 2024.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.66 to $81.14 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.