Alnylam Pharmaceuticals (ALNY) CSO reports PSU vesting and stock sales

Rhea-AI Filing Summary

Alnylam Pharmaceuticals CSO & EVP, Head of Research Kevin Fitzgerald reported multiple equity transactions in the company’s common stock. On January 11, 2026, he received 3,800 shares at $0.0 per share upon vesting of a performance-based stock unit grant tied to the company publicly reporting $2.5 billion in annual net product revenue under GAAP, as determined by the board’s People, Culture and Compensation Committee.

On January 12, 2026, shares were automatically sold on his behalf under a mandatory sell-to-cover provision to satisfy minimum tax withholding, including blocks such as 39 shares at $353.95. On January 13, 2026, he executed additional open-market sales under a Rule 10b5-1(c) trading plan adopted on August 14, 2025, including 197 shares at $367.52 and 562 shares at $368.76. After these transactions, he held 21,264 shares directly and 537 shares indirectly through a managed account.

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

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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)
01/11/2026

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	01/11/2026		A(1)		3,800	A	$0.0	25,064	D
Common Stock	01/12/2026		S(2)		39	D	$353.95(3)	25,025	D
Common Stock	01/12/2026		S(2)		42	D	$355.16(4)	24,983	D
Common Stock	01/12/2026		S(2)		41	D	$356.09(5)	24,942	D
Common Stock	01/12/2026		S(2)		96	D	$357.17(6)	24,846	D
Common Stock	01/12/2026		S(2)		123	D	$358.18(7)	24,723	D
Common Stock	01/12/2026		S(2)		85	D	$359.14(8)	24,638	D
Common Stock	01/12/2026		S(2)		155	D	$360.22(9)	24,483	D
Common Stock	01/12/2026		S(2)		98	D	$361.45(10)	24,385	D
Common Stock	01/12/2026		S(2)		73	D	$362.38(11)	24,312	D
Common Stock	01/12/2026		S(2)		47	D	$363.55(12)	24,265	D
Common Stock	01/12/2026		S(2)		199	D	$364.83(13)	24,066	D
Common Stock	01/12/2026		S(2)		220	D	$365.56(14)	23,846	D
Common Stock	01/12/2026		S(2)		50	D	$366.41(15)	23,796	D
Common Stock	01/12/2026		S(2)		41	D	$367.4(16)	23,755	D
Common Stock	01/12/2026		S(2)		92	D	$368.62(17)	23,663	D
Common Stock	01/12/2026		S(2)		40	D	$369.48(18)	23,623	D
Common Stock	01/12/2026		S(2)		19	D	$370.87(19)	23,604	D
Common Stock	01/12/2026		S(2)		2	D	$372.46(20)	23,602	D
Common Stock	01/12/2026		S(2)		14	D	$374.44(21)	23,588	D
Common Stock	01/12/2026		S(2)		19	D	$375.65	23,569	D
Common Stock	01/12/2026		S(2)		15	D	$377.82	23,554	D
Common Stock	01/13/2026		S(22)		197	D	$367.52(23)	23,357	D
Common Stock	01/13/2026		S(22)		562	D	$368.76(24)	22,795	D
Common Stock	01/13/2026		S(22)		644	D	$370(25)	22,151	D
Common Stock	01/13/2026		S(22)		485	D	$371.24(26)	21,666	D
Common Stock	01/13/2026		S(22)		280	D	$372.93(27)	21,386	D
Common Stock	01/13/2026		S(22)		122	D	$374.33(28)	21,264	D
Common Stock								537	I	by Managed Account(29)

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

Explanation of Responses:

1. On March 1, 2024, the reporting person was granted a performance-based stock unit (PSU) under the 2018 Stock Incentive Plan. The shares subject to the PSU vest based on the achievement of three specified performance measures. The shares reported were issued to the reporting person upon vesting of forty (40) percent of the shares subject to the PSU based on the issuer publicly reporting $2.5 billion in annual net product revenue in accordance with GAAP, as determined by the People, Culture and Compensation Committee of the Issuer Board of Directors on January 11, 2026.

2. Represents shares automatically sold by the Company on behalf of the reporting person pursuant to a mandatory sell-to-cover provision in the award agreement to cover minimum statutory tax withholding obligations.

3. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $353.53 to $354.41. 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 $354.54 to $355.53. 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 $356.62 to $356.61. 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 $356.63 to $357.63. 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 $357.68 to $358.68. 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 $358.69 to $359.66. 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 $359.79 to $360.79. 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 $360.90 to $361.89. 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. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $361.93 to $362.92. 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.

12. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $362.99 to $363.99. 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.

13. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $364.00 to $365.00. 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.

14. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $365.01 to $366.01. 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.

15. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $366.03 to $366.96. 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.

16. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $367.04 to $368.00. 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.

17. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $368.09 to $369.08. 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.

18. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $369.13 to $369.93. 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.

19. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $370.43 to $371.23. 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.

20. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $372.35 to $372.50. 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.

21. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $374.08 to $374.89. 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.

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

23. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $367.18 to $367.96. 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.

24. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $368.25 to $369.23. 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.

25. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $369.36 to $370.35. 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.

26. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $370.52 to $371.47. 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.

27. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $372.70 to $373.11. 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.

28. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $374.28 to $374.66. 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.

29. 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.

	By: Brett Budzinski, Attorney-in-Fact For: Kevin Fitzgerald	01/14/2026
	** 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 activity did ALNY CSO Kevin Fitzgerald report on this Form 4?

Kevin Fitzgerald, CSO & EVP, Head of Research at Alnylam Pharmaceuticals (ALNY), reported receipt of performance-based stock units that vested into 3,800 common shares on January 11, 2026, followed by multiple sales of common stock on January 12–13, 2026.

Why did Kevin Fitzgerald receive 3,800 Alnylam (ALNY) shares on January 11, 2026?

The 3,800 shares were issued upon vesting of 40% of a performance-based stock unit (PSU) granted on March 1, 2024, after Alnylam publicly reported $2.5 billion in annual net product revenue under GAAP, as confirmed by the board’s People, Culture and Compensation Committee.

Were some of Kevin Fitzgerald’s ALNY share sales made to cover taxes?

Yes. Footnote (2) explains that certain January 12, 2026 sales represent shares automatically sold by the company under a mandatory sell-to-cover provision to satisfy minimum statutory tax withholding obligations on the vested award.

Did Kevin Fitzgerald use a Rule 10b5-1 trading plan for any ALNY stock sales?

Yes. Footnote (22) states that the January 13, 2026 sales, including trades such as 197 shares at $367.52 and 562 shares at $368.76, were executed under a Rule 10b5-1(c) trading plan adopted on August 14, 2025.

How many Alnylam (ALNY) shares does Kevin Fitzgerald hold after these transactions?

After the reported transactions, Kevin Fitzgerald beneficially owned 21,264 shares of Alnylam common stock directly, and an additional 537 shares indirectly through a managed account.

What were some of the reported sale prices for Kevin Fitzgerald’s ALNY shares?

The Form 4 lists multiple small block sales. Examples include 39 shares at $353.95, 123 shares at $358.18, and later 644 shares at $370.00. Footnotes describe these as weighted average prices across ranges of individual trade prices.