Poulton Jeffrey V. 4

4 · ALNYLAM PHARMACEUTICALS, INC. · Filed Mar 4, 2026

Insider Transaction Report

Form 4

Period: 2026-03-02

ALNYLAM PHARMACEUTICALS, INC.ALNY

Poulton Jeffrey V.

EVP, Chief Financial Officer

Transactions

Award
Common Stock
[F1]
2026-03-02+4,769→ 66,479 total
Sale
Common Stock
[F2][F3]
2026-03-02$323.62/sh−65$21,035→ 66,414 total
Sale
Common Stock
[F2][F4]
2026-03-02$324.65/sh−124$40,257→ 66,290 total
Sale
Common Stock
[F2][F5]
2026-03-02$325.63/sh−356$115,924→ 65,934 total
Sale
Common Stock
[F2][F6]
2026-03-02$326.81/sh−541$176,804→ 65,393 total
Sale
Common Stock
[F2][F7]
2026-03-02$327.67/sh−454$148,762→ 64,939 total
Sale
Common Stock
[F2][F8]
2026-03-02$328.71/sh−138$45,362→ 64,801 total
Sale
Common Stock
[F2][F9]
2026-03-02$329.71/sh−234$77,152→ 64,567 total
Sale
Common Stock
[F2][F10]
2026-03-02$330.85/sh−112$37,055→ 64,455 total
Sale
Common Stock
[F2][F11]
2026-03-02$331.93/sh−129$42,819→ 64,326 total
Sale
Common Stock
[F2][F12]
2026-03-02$332.64/sh−53$17,630→ 64,273 total
Award
Stock Option (right to buy)
[F14]
2026-03-02+10,480→ 10,480 total
Exercise: $325.07Exp: 2036-03-02→ Common Stock (10,480 underlying)

Holdings

Common Stock
[F13]
(indirect: by Managed Account)
57

Footnotes (14)

[F1]These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest over a three-year period, with one third vesting on each of the first, second and third anniversaries of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.
[F10]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $330.30 to $331.30. 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.
[F11]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $331.32 to $332.31. 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.
[F12]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $332.34 to $332.24. 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.
[F13]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.
[F14]The stock option vests as to 25% of the shares on the first anniversary of the grant date and the remaining shares vest in equal installments at the end of each successive three-month period thereafter until the fourth anniversary of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.
[F2]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.
[F3]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $323.16 to $324.15. 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.
[F4]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $324.20 to $325.20. 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.
[F5]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $325.21 to $326.21. 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.
[F6]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $326.23 to $327.23. 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.
[F7]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $327.24 to $328.24. 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.
[F8]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $328.28 to $329.26. 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.
[F9]The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $329.29 to $330.29. 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.

Signature

By: Brett Budzinski, Attorney-in-Fact For: Jeffrey V. Poulton|2026-03-04

Documents

1 file

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