X0306 4 2018-03-13 0 0001178670 ALNYLAM PHARMACEUTICALS, INC. ALNY 0001226295 SHARP PHILIP A 300 THIRD STREET CAMBRIDGE MA 02142 1 0 0 0 Common Stock 2018-03-13 4 M 0 15000 21.35 A 155795 D Common Stock 2018-03-13 4 S 0 15000 149.0 D 140795 D Common Stock 126104 I by Trust Stock Option (right to buy) 21.35 2018-03-13 4 M 0 15000 0.0 D 2009-12-09 2018-12-08 Common Stock 15000 0 D The sales reported on this Form 4 were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on October 10, 2017. The 126,104 shares reported as indirectly owned by trust include: (i) 94,838 shares in the Phillip A. Sharp 2009 Grantor Annuity Trust No. 3, and (ii) 31,266 shares in the Phillip A. Sharp 2008 Grantor Annuity Trust No. 2 (which include shares distributed from the 2010 Trust). By: Michael P. Mason, Attorney-in-Fack For: Phillip A. Sharp 2018-03-14