ALNYLAM PHARMACEUTICALS, INC. (ALNY) Insider Transactions

Reported filing row; may be amended. Do not sum filings blindly.

F1 Shares held by Sigal Family Investments, LLC, of which the reporting person is Managing Member.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 The options exercised and held by the reporting person were due to expire on June 1, 2027.

F2 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 The options exercised and held by the reporting person were due to expire on June 1, 2027.

F2 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

References:

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 On February 23, 2016, the People, Culture, and Compensation Committee of the issuer approved the issuance of shares of Company common stock having an aggregate value of USD $50,000 to each employee who completes 10 consecutive years of employment. The shares issued and reported here on Form 4, net of the minimum statutory tax liability, were issued to the reporting person in recognition of 10 years of continuous employment on September 19, 2026.

F2 Reflects shares of ALNY common stock acquired by the reporting person under the ALNY 401(k) plan as a result of the ALNY 401(k) matching contribution program.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1, F7

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1, F5

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1, F4

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1, F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 The transactions reported on this Form 4 were made pursuant to a Rule 10b5-1(c) trading plan adopted by the reporting person on November 12, 2025. The options exercised by the reporting person were due to expire on June 3, 2026.

F2 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $297.31 to $297.99. 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.

F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $298.33 to $299.33. 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 $299.36 to $300.19. 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 $300.45 to $301.15. 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.

F6 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F7 This stock option was fully vested and exercisable as of June 3, 2017.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 The stock option will vest as to one third of the shares on each of the first, second and third anniversaries of the date of grant.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 Shares held by Sigal Family Investments, LLC, of which the reporting person is Managing Member.

F3 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 Shares held by Sigal Family Investments, LLC, of which the reporting person is Managing Member.

F3 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F2

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F2

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F3 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The shares of ALNY common stock were purchased by the David E I Pyott Trust, of which the reporting person is trustee.

F3 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F2

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

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 in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

F2 The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

References: F2