Alnylam (ALNY) CFO receives 1,908 shares as final RSU tranche vests

Rhea-AI Filing Summary

ALNYLAM PHARMACEUTICALS, INC. executive vice president and chief financial officer Jeffrey V. Poulton reported the vesting of restricted stock units that converted into common shares. On February 27, 2026, 1,908 restricted stock units were exercised at $0.00 and settled into 1,908 shares of common stock.

These RSUs were part of a 5,724‑unit grant awarded on February 27, 2023, which vested in three equal annual installments. The filing notes that this transaction represents the third and final tranche from that grant. Following the conversion, Poulton directly owned 61,710 shares of common stock, and an additional 57 shares were held indirectly through a managed account.

Insider Trade Summary

1,908 shares exercised/converted

Mixed 3 txns

Insider Poulton Jeffrey V.

Role EVP, Chief Financial Officer

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units	1,908	$0.00	--
Exercise	Common Stock	1,908	$0.00	--
holding	Common Stock	--	--	--

Holdings After Transaction: Restricted Stock Units — 0 shares (Direct); Common Stock — 61,710 shares (Direct); Common Stock — 57 shares (Indirect, by Managed Account)

Footnotes (1)

1. 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. These shares are represented by restricted stock units (RSUs) granted under the Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock. On February 27, 2023, the reporting person was granted 5,724 restricted stock units that vest ratably on each of the first, second and third anniversaries of the Grant Date. On February 27, 2026, the third and final tranche of restricted stock units from the February 27, 2023 grant vested and was released, as reported on this Form 4. The restricted stock units vest ratably in three installments, with one third vesting on each of the first, second and third anniversaries of the grant date.

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Poulton Jeffrey V.

(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 Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

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	02/27/2026		M		1,908	A	$0.0	61,710	D
Common Stock								57	I	by Managed Account(1)

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
Restricted Stock Units	(2)	02/27/2026		M			1,908	(3)	(4)	Common Stock	1,908	$0.0	0	D

Explanation of Responses:

1. 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.

2. These shares are represented by restricted stock units (RSUs) granted under the Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock.

3. On February 27, 2023, the reporting person was granted 5,724 restricted stock units that vest ratably on each of the first, second and third anniversaries of the Grant Date. On February 27, 2026, the third and final tranche of restricted stock units from the February 27, 2023 grant vested and was released, as reported on this Form 4.

4. The restricted stock units vest ratably in three installments, with one third vesting on each of the first, second and third anniversaries of the grant date.

	By: Brett Budzinski, Attorney-in-Fact For: Jeffrey V. Poulton	03/02/2026
	** 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.