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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1. Name and Address of Reporting Person * Greenstreet Yvonne   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) EVP, Chief Operating Officer (Last) (First) (Middle) 300 THIRD STREET 3. Date of Earliest Transaction (Month/Day/Year) 08/13/2018 (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 08/13/2018   A(1)   7,500 A $ 0 7,500 D   Common Stock 08/13/2018   F   3,084 D $ 90.95 4,416 D   Common Stock 04/16/2018   J(2) V 37 A $ 0 (2) 270 I by Managed Account (2) Common Stock 07/10/2018   J(2) V 38 A $ 0 (2) 308 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 2016 (right to buy)

$ 77.1

08/13/2018

A(3)

25,000

08/13/2018

09/19/2026

Common Stock

25,000

$ 0

25,000

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Greenstreet Yvonne 300 THIRD STREET CAMBRIDGE, MA 02142			EVP, Chief Operating Officer

Signatures

By: /s/ Michael P. Mason, Attorney-in-Fact For: Yvonne Greenstreet		08/14/2018
**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)	On June 29, 2017, the reporting person was granted a restricted stock unit (RSU) to purchase shares of ALNY common stock. One half of the shares subject to release will vest upon the achievement of each of two specific commercial events as approved by our compensation committee. Effective August 13, 2018, the compensation committee of the Company determined the first performance criterion has been met and one half of the shares have vested.
(2)	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.
(3)	On September 19, 2016, the reporting person was granted a performance based stock option to purchase shares of ALNY common stock. The shares subject to the option will vest upon the commercial launch of Alnylams first internally developed product, as approved by our compensation committee. Effective August 13, 2018, the compensation committee of the Company determined the performance criterion has been met and the option shares have vested.

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