ALNYLAM PHARMACEUTICALS INC

Adoption of 10b5-1 Trading Plans by Our Officers and Directors

During our fiscal quarter ended September 30, 2024, certain of our officers (as defined in Rule 16a-1(f) under the Exchange Act) and directors entered into contracts, instructions or written plans for the purchase or sale of our securities that are intended to satisfy the conditions specified in Rule 10b5-1(c) under the Exchange Act for an affirmative defense against liability for trading in securities on the basis of material nonpublic information. We refer to these contracts, instructions, and written plans as “Rule 10b5-1 trading plans” and each one as a “Rule 10b5-1 trading plan.” We describe the material terms of these Rule 10b5-1 trading plans below.

David E.I. Pyott, Director

On September 5, 2024, David E.I. Pyott, a member of our board of directors, entered into a Rule 10b5-1 trading plan that provides that Mr. Pyott, acting through a broker, may sell up to an aggregate of 7,440 shares of our common stock received upon the exercise of options granted to Mr. Pyott as director compensation, subject to adjustments for stock splits, stock combinations, stock dividends and other similar changes to our common stock. Sales of shares under the plan may only occur if the market price of our common stock is above specified prices from January 1, 2025 to December 17, 2025. The plan is scheduled to terminate on December 17, 2025, subject to earlier termination upon the sale of all shares subject to the plan, upon termination by Mr. Pyott or the broker, or as otherwise provided in the plan.

Pushkal P. Garg, Chief Medical Officer

On September 11, 2024, Pushkal P. Garg, our Chief Medical Officer, entered into a Rule 10b5-1 trading plan that provides that Dr. Garg, acting through a broker, may sell up to an aggregate of 94,925 shares of our common stock received upon the settlement of awards granted to Dr. Garg as equity incentive compensation, subject to adjustments for stock splits, stock combinations, stock dividends and other similar changes to our common stock. Sales of shares under the plan may only occur from December 12, 2024 to December 18, 2025. The plan is scheduled to terminate on December 18, 2025, subject to earlier termination upon the sale of all shares subject to the plan, upon termination by Dr. Garg or the broker, or as otherwise provided in the plan.

Yvonne L. Greenstreet, MBChB, MBA, Chief Executive Officer and Director

On September 12, 2024, Yvonne L. Greenstreet, MBChB, MBA, our Chief Executive Officer, entered into a Rule 10b5-1 trading plan that provides that Dr. Greenstreet, acting through a broker, may sell up to an aggregate of 50,937 shares of our common stock received upon the settlement of awards granted to Dr. Greenstreet as equity incentive compensation, subject to adjustments for stock splits, stock combinations, stock dividends and other similar changes to our common stock. Sales of shares under the plan may only occur if the market price of our common stock is above specified prices from December 16, 2024 to June 6, 2025. The plan is scheduled to terminate on June 6, 2025, subject to earlier termination upon the sale of all shares subject to the plan, upon termination by Dr. Greenstreet or the broker, or as otherwise provided in the plan.

Tolga Tanguler, Chief Commercial Officer

On September 12, 2024, Tolga Tanguler, our Chief Commercial Officer, entered into a Rule 10b5-1 trading plan that provides that Mr. Tanguler, acting through a broker, may sell up to an aggregate of 4,070 shares of our common stock received upon the settlement of awards granted to Mr. Tanguler as equity incentive compensation, subject to adjustments for stock splits, stock combinations, stock dividends and other similar changes to our common stock. Sales of shares under the plan may only occur if the market price of our common stock is above specified prices from December 13, 2024 to May 10, 2025. The plan is scheduled to terminate on May 10, 2025, subject to earlier termination upon the sale of all shares subject to the plan, upon termination by Mr. Tanguler or the broker, or as otherwise provided in the plan.