Statement of Changes in Beneficial Ownership (4)

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

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3235-0287

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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * MARAGANORE JOHN	2. Issuer Name and Ticker or Trading Symbol ALNYLAM PHARMACEUTICALS, INC. [ ALNY ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) Chief Executive Officer
(Last)          (First)          (Middle) 675 WEST KENDALL STREET, HENRI A. TERMEER SQUARE	3. Date of Earliest Transaction (MM/DD/YYYY) 2/24/2021
(Street) CAMBRIDGE, MA 02142 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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	2/25/2021		M(1)		33979	A	$7.1	240015	D
Common Stock	2/25/2021		S(1)		1001	D	$143.88 (2)	239014	D
Common Stock	2/25/2021		S(1)		6129	D	$145.15 (3)	232885	D
Common Stock	2/25/2021		S(1)		9376	D	$146.13 (4)	223509	D
Common Stock	2/25/2021		S(1)		6097	D	$146.98 (5)	217412	D
Common Stock	2/25/2021		S(1)		4375	D	$148.0 (6)	213037	D
Common Stock	2/25/2021		S(1)		1364	D	$148.96 (7)	211673	D
Common Stock	2/25/2021		S(1)		2054	D	$150.22 (8)	209619	D
Common Stock	2/25/2021		S(1)		1415	D	$151.31 (9)	208204	D
Common Stock	2/25/2021		S(1)		1138	D	$152.46 (10)	207066	D
Common Stock	2/25/2021		S(1)		431	D	$153.33 (11)	206635	D
Common Stock	2/25/2021		S(1)		599	D	$154.59 (12)	206036	D
Common Stock								3133	I	by Managed Account (13)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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
Stock Option (right to buy)	$151.59	2/24/2021		A		79998 (14)		(15)	2/23/2031	Common Stock	79998	$0.0	79998	D
Stock Option (right to buy)	$7.1	2/25/2021		M (1)			33979	(16)	11/30/2021	Common Stock	33979	$0.0	101936	D

Explanation of Responses:
(1)	All sales reported on this Form 4 were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 9, 2020. The 33,979 options exercised and sold by the reporting person were due to expire on November 30, 2021.
(2)	Sale prices ranged from $143.50 to $144.43.
(3)	Sale prices ranged from $144.54 to $145.54.
(4)	Sale prices ranged from $145.55 to $146.55.
(5)	Sale prices ranged from $146.59 to $147.59.
(6)	Sale prices ranged from $147.60 to $148.59.
(7)	Sale prices ranged from $148.66 to $149.65.
(8)	Sale prices ranged from $149.73 to $150.62.
(9)	Sale prices ranged from $150.88 to $151.68.
(10)	Sale prices ranged from $151.92 to $152.76.
(11)	Sale prices ranged from $153.05 to $153.90.
(12)	Sale prices ranged from $154.37 to $154.68.
(13)	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.
(14)	Represents the time-vested stock option portion of the reporting person's Annual Equity Award for 2020. The reporting person also received 42,879 performance stock units that will vest upon the achievement of four specific performance conditions, which will be reported on a Form 4 if and when each performance condition is met and the performance stock units vest.
(15)	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.
(16)	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 an additional 6.25% of the shares each successive three month period thereafter.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MARAGANORE JOHN 675 WEST KENDALL STREET HENRI A. TERMEER SQUARE CAMBRIDGE, MA 02142	X		Chief Executive Officer

Signatures
By: /s/ Mary Beth DeLena, Attorney-in-Fact For: John M. Maraganore		2/26/2021
**Signature of Reporting Person		Date