[Form 4] ALNYLAM PHARMACEUTICALS, INC. Insider Trading Activity

Rhea-AI Filing Summary

Alnylam Pharmaceuticals executive Kevin Fitzgerald, CSO & EVP, Head of Research, reported an insider transaction in ALNY common stock. On 11/17/2025, he exercised a stock option for 8,161 shares at an exercise price of $119.13 per share and acquired the underlying common stock.

That same day, he reported multiple open-market sales of ALNY common stock in separate small lots, including 8,168 shares at $449 per share and additional sales at weighted average prices spanning from $451.41 to $463.46 per share, each based on multiple individual trades. After these transactions, he reported beneficial ownership of 24,999 shares directly, 537 shares indirectly through a managed account, and 839 derivative securities remaining from the option award. The filing notes that these trades were made under a Rule 10b5-1(c) trading plan adopted on August 14, 2025.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Fitzgerald Kevin Joseph

(Last) (First) (Middle)

675 WEST KENDALL STREET

HENRI A. TERMEER SQUARE

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

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)
	CSO & EVP, Head of Research

3. Date of Earliest Transaction (Month/Day/Year)
11/17/2025

4. If Amendment, Date of 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

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	11/17/2025		M(1)		8,161	A	$119.13	33,392	D
Common Stock	11/17/2025		S(1)		8,168	D	$449	25,224	D
Common Stock	11/17/2025		S(1)		96	D	$450.09	25,128	D
Common Stock	11/17/2025		S(1)		129	D	$451.51(2)	24,999	D
Common Stock	11/17/2025		S(1)		368	D	$455.24(3)	24,631	D
Common Stock	11/17/2025		S(1)		364	D	$456.25(4)	24,267	D
Common Stock	11/17/2025		S(1)		262	D	$457.39(5)	24,005	D
Common Stock	11/17/2025		S(1)		794	D	$458.41(6)	23,211	D
Common Stock	11/17/2025		S(1)		622	D	$459.89(7)	22,589	D
Common Stock	11/17/2025		S(1)		707	D	$460.84(8)	21,882	D
Common Stock	11/17/2025		S(1)		323	D	$461.96(9)	21,559	D
Common Stock	11/17/2025		S(1)		295	D	$463.08(10)	21,264	D
Common Stock								537	I	by Managed Account(11)

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 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: 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)	$119.13	11/17/2025		M(1)			8,161	(12)	03/01/2028	Common Stock	8,161	$0.0	839	D

Explanation of Responses:

1. This transaction was made pursuant to a Rule 10b5-1 (c) trading plan adopted by the Reporting Person on August 14, 2025.

2. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $451.41 to $451.84. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

3. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $454.92 to $455.45. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

4. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $455.97 to $456.94. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

5. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $457.00 to $457.98. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

6. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $458.01 to $458.94. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

7. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $459.40 to $460.36. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

8. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $460.46 to $461.40. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

9. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $461.50 to $462.39. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

10. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $462.82 to $463.46. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

11. 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.

12. This stock option was fully vested and exercisable as of December 1, 2021.

	By: Brett Budzinski, Attorney-in-Fact For: Kevin Fitzgerald	11/19/2025
	** Signature of Reporting Person	Date
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.

FAQ

What insider transaction did ALNY executive Kevin Fitzgerald report?

Kevin Fitzgerald, CSO & EVP, Head of Research at Alnylam Pharmaceuticals (ALNY), reported exercising a stock option for 8,161 shares of common stock and selling portions of those shares in multiple open-market transactions on 11/17/2025.

How many ALNY shares did Kevin Fitzgerald acquire and at what exercise price?

He exercised a stock option covering 8,161 shares of ALNY common stock at an exercise price of $119.13 per share.

At what prices did Kevin Fitzgerald sell ALNY shares on November 17, 2025?

He reported multiple sales, including 8,168 shares at $449 per share, and additional sales at weighted average prices across several ranges, with prices spanning from $451.41 up to $463.46 per share.

How many ALNY shares does Kevin Fitzgerald report owning after the transactions?

Following the reported trades, he beneficially owned 24,999 shares of ALNY common stock directly, plus 537 shares held indirectly through a managed account, and 839 derivative securities related to the stock option.

Was Kevin Fitzgerald27s ALNY trading done under a Rule 10b5-1 plan?

Yes. The filing states that the transactions were made pursuant to a Rule 10b5-1(c) trading plan that he adopted on August 14, 2025, which pre-arranges trades according to predefined instructions.

What does the Form 4 say about the stock option underlying the ALNY shares?

The stock option had an exercise price of $119.13 per share, related to 8,161 shares of common stock, carried an expiration date of 03/01/2028, and was reported as fully vested and exercisable as of December 1, 2021.

What is Kevin Fitzgerald27s role at Alnylam Pharmaceuticals (ALNY)?

He is reported as an officer of Alnylam Pharmaceuticals with the title CSO & EVP, Head of Research, indicating a senior leadership position overseeing the company27s research efforts.