X0407 4 2023-05-18 0 0001178670 ALNYLAM PHARMACEUTICALS, INC. ALNY 0001661908 Sigal Charles Elliott 675 WEST KENDALL STREET HENRI A. TERMEER SQUARE CAMBRIDGE MA 02142 1 0 0 0 0 Stock Option (right to buy) 189.87 2023-05-18 4 A 0 3454 0.0 A 2024-05-18 2033-05-18 Common Stock 3454 3454 D This award vests 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. By: /s/ Stephen Hall, Attorney-in-Fact For: Charles Elliott Sigal 2023-05-19