Sec Form 3 Filing - Garg Pushkal @ ALNYLAM PHARMACEUTICALS, INC. - 2021-12-31

FORM 3 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

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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) 12/31/2021 (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 11,192 D Common Stock 431 I by Managed Account( 1 ) Common Stock 250 I by Trust( 2 )

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 2014 (right to buy) $ 96.45 08/11/2018 12/17/2024 Common Stock 2,500 D Performance Stock Option 2015 (right to buy) $ 88.95 08/06/2019 12/18/2025 Common Stock 25,000 D Performance Stock Option 2017 (right to buy) $ 119.13 02/11/2021 02/29/2028 Common Stock 13,750 D Stock Option (right to buy) $ 42.22 ( 3 ) 12/20/2026 Common Stock 5,445 D Stock Option (right to buy) $ 85 ( 3 ) 02/27/2029 Common Stock 25,000 D Stock Option (right to buy) $ 88.95 ( 3 ) 12/18/2025 Common Stock 23,876 D Stock Option (right to buy) $ 96.45 ( 3 ) 12/17/2024 Common Stock 2,500 D Stock Option (right to buy) $ 118.05 ( 3 ) 02/25/2030 Common Stock 26,089 D Stock Option (right to buy) $ 119.13 ( 4 ) 02/29/2028 Common Stock 13,750 D Stock Option (right to buy) $ 151.59 ( 3 ) 02/23/2031 Common Stock 23,200 D Stock Option (right to buy) $ 169.58 ( 3 ) 12/30/2031 Common Stock 13,428 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: /s/ Mary Beth DeLena, Attorney-in-Fact For: Pushkal Garg 01/04/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Reflects shares of ALNY common stock acquired by the reporting person under the ALNY 401(k) plan as a result of the ALNY 401(k) matching contribution program. ( 2 )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. ( 3 )The stock option vests as to 25% of the shares on the 1st anniversary of the date of the stock option grant and as to an additional 6.25% of the shares each successive three month period thereafter. ( 4 )The stock option vested as to 25% of the shares on the 1st anniversary of the date of the stock option grant and as to the remaining shares ratably at the end of each three-month period thereafter over the following thirty-three (33) months.

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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