[Form 4] Alnylam Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Pushkal Garg, Executive Vice President & Chief R&D Officer of Alnylam Pharmaceuticals (ALNY), reported transactions on Form 4 showing issued and subsequent sales of common stock tied to performance-based awards and a Rule 10b5-1 plan.

On 08/15/2025, 2,851 shares were issued upon vesting of 30% of a performance-based stock unit awarded 03/01/2024 after the company met a clinical milestone. Between 08/18/2025 and 08/19/2025 the reporting person sold multiple tranches of shares under a previously adopted 10b5-1 trading plan, at weighted-average prices ranging from about $447.98 to $461.74. Following these transactions, Garg directly owned 20,221 shares and indirectly held 431 shares via a managed account and 250 shares in a trust.

Positive

• PSU vesting tied to a clinical milestone resulted in issuance of 2,851 shares, indicating a company-designated performance achievement
• Trades executed under a Rule 10b5-1 plan, showing pre-established, rule-compliant selling, and a mandatory sell-to-cover for tax withholding

Negative

• Net decline in direct ownership: direct shares decreased to 20,221 following multiple sales on 08/18–08/19/2025
• Substantial share sales across multiple price bands may reduce insider’s direct economic exposure to ALNY common stock

Insights

Securities Analyst

TL;DR: Insider received PSU shares after a clinical milestone and then sold portions under a pre-established 10b5-1 plan; ownership declined modestly.

The reporting shows a tranche of PSUs vesting due to a clinical milestone, which is a company-specific operational event that triggered issuance of 2,851 shares. The sales executed 08/18–08/19/2025 were conducted under a Rule 10b5-1(c) plan adopted 09/11/2024 and include multiple blocks with weighted-average prices reported between ~$448 and ~$461. Post-transactions, direct beneficial ownership stands at 20,221 shares with additional indirect holdings. This is a routine executive compensation settlement and automated selling activity rather than an ad hoc disposition.

Corporate Governance Expert

TL;DR: Disclosure aligns with Section 16 reporting; use of 10b5-1 plan and explanation of sell-to-cover are clearly stated.

The Form 4 documents required disclosures: grant history, vesting tied to pre-specified performance metrics, mandatory sell-to-cover to satisfy tax withholding, and that trades were made pursuant to a 10b5-1 plan. The filing also discloses indirect holdings (managed account and trust) and a disclaimer regarding trust shares. From a governance and compliance perspective, the report is thorough and transparent.

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^*

Garg Pushkal

(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)
	EVP Chief R&D

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		A(1)		2,851	A	$0.0	23,072	D
Common Stock	08/18/2025		S(2)		39	D	$447.98(3)	23,033	D
Common Stock	08/18/2025		S(2)		90	D	$449.92(4)	22,943	D
Common Stock	08/18/2025		S(2)		39	D	$450.92(5)	22,904	D
Common Stock	08/18/2025		S(2)		103	D	$451.99(6)	22,801	D
Common Stock	08/18/2025		S(2)		329	D	$452.96(7)	22,472	D
Common Stock	08/18/2025		S(2)		543	D	$454.04(8)	21,929	D
Common Stock	08/18/2025		S(2)		241	D	$454.84(9)	21,688	D
Common Stock	08/18/2025		S(2)		12	D	$455.82(10)	21,676	D
Common Stock	08/19/2025		S(11)		276	D	$455.41(12)	21,400	D
Common Stock	08/19/2025		S(11)		338	D	$457.26(13)	21,062	D
Common Stock	08/19/2025		S(11)		231	D	$458.27(14)	20,831	D
Common Stock	08/19/2025		S(11)		260	D	$459.59(15)	20,571	D
Common Stock	08/19/2025		S(11)		305	D	$461.01(16)	20,266	D
Common Stock	08/19/2025		S(11)		45	D	$461.74	20,221	D
Common Stock								431	I	by Managed Account(17)
Common Stock								250	I	by Trust(18)

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 thirty (30) percent of the shares subject to the PSU based on the achievement of a clinical milestone, as determined by The People, Culture and Compensation Committee of the Issuer Board of Directors on August 15, 2025.

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 required to cover minimum statutory tax withholding obligations that became due upon the vesting and settlement of a tranche of restricted stock units granted to the reporting person on March 1, 2024.

3. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $447.53 to $448.45. 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 $449.21 to $450.16. 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 $450.42 to $451.39. 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.

6. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $451.48 to $452.48. 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 $452.49 to $453.49. 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 $453.50 to $454.45. 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.

9. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $454.58 to $455.55. 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 $455.65 to $456.00. 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.

11. All transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on September 11, 2024.

12. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $454.94 to $455.77. 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 $456.64 to $457.51. 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 $457.76 to $458.65. 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 $459.20 to $460.01. 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.

16. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $460.60 to $461.44. 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. 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.

18. Represents shares held in trust, of which the Reporting Persons spouse is co-trustee. The Reporting Person disclaims beneficial ownership of these shares, and the filing of this report is not an admission that the Reporting Person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.

	By: Brett Budzinski, Attorney-in-Fact For: Pushkal Garg	08/19/2025
	** 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 triggered the issuance of shares to Pushkal Garg reported on Form 4 for ALNY?

The issuance of 2,851 shares on 08/15/2025 resulted from vesting of 30% of a performance-based stock unit awarded 03/01/2024 after a clinical milestone was achieved.

Why did the reporting person sell shares on 08/18–08/19/2025 for ALNY?

The sales represent mandatory sell-to-cover transactions to satisfy tax withholding obligations and other sales executed pursuant to a Rule 10b5-1(c) trading plan adopted 09/11/2024.

How many ALNY shares does Pushkal Garg own after these transactions?

Following the reported transactions, the reporting person directly owned 20,221 shares, indirectly held 431 shares via a managed account and 250 shares in a trust.

What price range were the ALNY shares sold at in these transactions?

Reported weighted-average sales prices across multiple tranches ranged from about $447.98 up to approximately $461.74, with specific ranges disclosed per tranche in the filing.

Were the sales discretionary or part of a pre-established plan?

All reported sales were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on 09/11/2024.