Sec Form 4 Filing - Garg Pushkal @ ALNYLAM PHARMACEUTICALS, INC. - 2025-01-27

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

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Garg Pushkal 2. Issuer Name and Ticker or Trading Symbol ALNYLAM PHARMACEUTICALS, INC. [ ALNY] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) CMO & EVP Dev & Med Affairs (Last) (First) (Middle) 675 WEST KENDALL STREET, HENRI A. TERMEER SQUARE 3. Date of Earliest Transaction (MM/DD/YY) 01/27/2025 (Street) CAMBRIDGE, MA02142 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 01/27/2025 M( 1 ) 23,876 A $ 88.95 39,581 D Common Stock 01/27/2025 M( 1 ) 25,000 A $ 88.95 64,581 D Common Stock 01/27/2025 S( 1 ) 52,592 D $ 285 11,989 D Common Stock 431 I by Managed Account ( 2 ) Common Stock 250 I by Trust ( 3 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Performance Stock Option 2015 (right to buy) $ 88.95 01/27/2025 M( 1 ) 25,000 08/06/2019( 4 ) 12/18/2025 Common Stock 25,000 $ 0 0 D Stock Option (right to buy) $ 88.95 01/27/2025 M( 1 ) 23,876 12/18/2019( 5 ) 12/18/2025 Common Stock 23,876 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Garg Pushkal 675 WEST KENDALL STREET HENRI A. TERMEER SQUARE CAMBRIDGE, MA02142 CMO & EVP Dev & Med Affairs Signatures By: Brett Budzinski, Attorney-in-Fact For: Pushkal Garg 01/29/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )All transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on September 11, 2024. The 48,876 options exercised and sold by the reporting person were due to expire on December 18, 2025. ( 2 )Reflects shares of ALNY common stock acquired by the Reporting Person under the issuer 401(k) plan as a result of the issuer 401(k) matching contribution program. ( 3 )Represents shares held in trust, of which the Reporting Persons spouse is co-trustee. The Reporting Person disclaims beneficial ownership of these shares, and the filing of this report is not an admission that the Reporting Person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose. ( 4 )This stock option was fully vested and exercisable as of August 6, 2019. ( 5 )This stock option was fully vested and exercisable as of December 18, 2019.

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.