Ownership Submission
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 OF SECURITIES

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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(Print or Type Responses)
1. Name and Address of Reporting Person *
Greene Barry E
   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)
President
(Last)
(First)
(Middle)
C/O ALNYLAM PHARMACEUTICALS, INC., 300 THIRD STREET		 3. Date of Earliest Transaction (Month/Day/Year)
09/20/2017
(Street)

CAMBRIDGE, MA 02142		 4. If Amendment, Date Original Filed(Month/Day/Year)
 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 09/20/2017   M(1)   76,815 A $ 31.39 165,399 D  
Common Stock 09/20/2017   S(1)   76,815 D $ 100 88,584 D  
Common Stock 09/21/2017   M   6,485 A $ 7.1 95,069 D  
Common Stock 09/21/2017   M   5,359 A $ 18.66 100,428 D  
Common Stock               2,810 I By Managed Account (2)

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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 (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 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
(Month/Day/Year)		 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 2013 (Right to Buy) $ 63 09/20/2017   A(3)   15,000   09/20/2017 12/17/2023 Common Stock 15,000 $ 0 15,000 D  
Stock Option (Right to Buy) $ 7.1 09/21/2017   M     6,485   (4) 11/30/2021 Common Stock 6,485 $ 0 85,915 D  
Stock Option (Right to Buy) $ 18.66 09/21/2017   M     5,359   (4) 12/20/2022 Common Stock 5,359 $ 0 94,641 D  
Stock Option (Right to Buy) $ 31.39 09/20/2017   M(1)     76,815   (4) 12/12/2017(1) Common Stock 76,815 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Greene Barry E
C/O ALNYLAM PHARMACEUTICALS, INC.
300 THIRD STREET
CAMBRIDGE, MA 02142		       President  

Signatures

 /s/ Michael P. Mason, Attorney-in-Fact for Barry E. Greene   09/22/2017
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) The sales reported on this Form 4 were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on January 23, 2017. The 76,815 options exercised and sold by the reporting person were due to expire on December 12, 2017.
(2) The reporting person owns 2,810 shares of ALNY common stock under the ALNY 401(k) plan as a result of the ALNY 401(k) matching contribution program.
(3) On December 18, 2013, the reporting person was granted a performance based stock option to purchase shares of ALNY Common Stock. One-third of the shares subject to the option will vest upon the achievement of each of three specific clinical development and regulatory events, as approved by the compensation committee of the Company. Effective September 20, 2017, the compensation committee of the Company determined the second performance criteria had been met and the option was vested as to one-third of the shares.
(4) The stock option vests as to 25% of the shares on the first 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.

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