Alnylam Pharmaceuticals, Inc.

Item 5.02. Departure of Directors or Principal Officers; Election of Directors; Appointment of Principal Officers; Compensatory Arrangements of Certain Officers. Effective as of June 1, 2026, the Board of Directors (the “Board”) of Alnylam Pharmaceuticals, Inc. (the “Company”), following the recommendation of its Nominating and Corporate Governance Committee, expanded the size of the Company’s Board from ten to eleven and elected Benjamin F. Cravatt, Ph. D. to fill the newly created vacancy. Dr. Cravatt will serve as a Class III director with a term expiring at the annual meeting of stockholders to be held in 2028. Dr. Cravatt will also serve as a member of the Board’s Science and Technology Committee. As a non-employee director, Dr. Cravatt will receive an annual cash retainer of $75,000. In addition, in connection with his election to the Board, Dr. Cravatt will be granted, on his first date of service on the Board, a stock option to purchase shares of the Company’s common stock, $0.01 par value per share (“Common Stock”), having an aggregate grant date fair value equal to $600,000 using the Company’s then-current Black-Scholes valuation model, and vesting as to one-third of the shares underling the stock option on each of the first, second and third anniversaries of the grant date, with an exercise price equal to the closing price of the Common Stock on the NASDAQ Global Select Market on the grant date. Following his election, Dr. Cravatt will be eligible to receive an annual equity award, in an aggregate amount to be determined by the Board upon recommendation of the People, Culture and Compensation Committee. Currently, each of the Company’s non-employee directors receives an annual equity award consisting of (i) restricted stock units having an aggregate grant date fair value of $200,000 (determined based on the closing price of the Common Stock on the NASDAQ Global Select Market on the grant date) and (ii) a stock option to purchase shares of Common stock having an aggregate grant date fair value equal to $200,000 using the Company’s then-current Black-Scholes valuation model, and with an exercise price equal to the closing price of the Common Stock on the NASDAQ Global Select Market on the grant date, each vesting in full on the one-year anniversary of the grant date. The Company will also reimburse Dr. Cravatt for reasonable travel and other related expenses incurred in connection with his service on the Board. In addition, Dr. Cravatt will enter into an indemnification agreement with the Company consistent with the form of the existing indemnification agreement entered into between the Company and its non-employee directors.

Item 5.07. Submission of Matters to a Vote of Security Holders. As of March 25, 2026, the record date for the Annual Meeting, 133,427,910 shares of the Company’s common stock were issued and outstanding. A summary of the matters voted upon by stockholders at the Annual Meeting is set forth below. 1. The Company’s stockholders re-elected the three persons listed below as Class I directors, each to serve until the Company’s 2029 annual meeting of stockholders or until his or her successor is duly elected and qualified. The voting results were as follows: Votes For Votes Against Abstentions Broker Non-Votes ────────────────────────────────────────────────────────────────────────────────────────────────────────── Stuart A. Arbuckle 115,269,659 5,068,463 28,296 5,450,286 Yvonne L. Greenstreet, M.D. 119,787,307 513,049 66,062 5,450,286 Elliott Sigal, M.D., Ph. D. 107,495,421 12,844,836 26,161 5,450,286 The terms of office of the following directors continued after the Annual Meeting: Dennis A. Ausiello, M.D. Olivier Brandicourt, M.D. Margaret A. Hamburg, M.D. Peter N. Kellogg David E.I. Pyott Colleen F. Reitan Amy W. Schulman 2. The Company’s stockholders approved, in a non-binding advisory vote, the compensation of the Company’s named executive officers. The voting results were as follows: Votes For Votes Against Abstentions Broker Non-Votes ───────────────────────────────────────────────────────────────────────── 111,772,389 8,552,534 41,495 5,450,286 3. The Company’s stockholders ratified the appointment by the Company’s Board of Directors of PricewaterhouseCoopers LLP as the Company’s independent auditors for the fiscal year ending December 31, 2026. The voting results were as follows: Votes For Votes Against Abstentions Broker Non-Votes ───────────────────────────────────────────────────────────────────────── 119,847,735 5,937,274 31,695 0