X0306 4 2018-08-10 0 0001178670 ALNYLAM PHARMACEUTICALS, INC. ALNY 0001291963 Greene Barry E 300 THIRD STREET CAMBRIDGE MA 02142 0 1 0 0 President Common Stock 2018-07-31 5 G 0 E 9030 0 D 52938 D Common Stock 2018-01-17 5 J 0 E 17 0 A 2827 I by Managed Account Common Stock 2018-04-16 5 J 0 E 28 0 A 2855 I by Managed Account Common Stock 2018-07-10 5 J 0 E 29 0 A 2884 I by Managed Account Common Stock 2018-07-31 5 G 0 E 9030 0 A 9030 I by Trust Performance Based Stock Option 2013 (right to buy) 63 2018-08-10 4 A 0 15000 0 A 2018-08-10 2023-12-18 Common Stock 15000 45000 D Performance Based Stock Option 2014 (right to buy) 96.45 2018-08-10 4 A 0 15875 0 A 2018-08-10 2024-12-17 Common Stock 15875 47625 D 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. The 9,030 shares were previously reported as directly beneficially owned. On 7/31/2018, the shares were contributed to the "Barry E. Greene Qualified Annuity Interest Trust" (GRAT). Barry E. Greene is the sole trustee. On December 18, 2013, the reporting person was granted a performance based stock option to purchase shares of ALNY Common Stock. One-third of the shares subject to the option will vest upon the achievement of each of three specific clinical development and regulatory events, as approved by our compensation committee. Effective August 10, 2018, the compensation committee of the Company determined the final performance criteria had been met and the option will vest as to the final third of the award. On December 17, 2014, the reporting person was granted a performance based stock option to purchase shares of ALNY Common Stock. One-third of the shares subject to the option will vest upon the achievement of each of three specific clinical development and regulatory events, as approved by our compensation committee. Effective August 10, 2018, the compensation committee of the Company determined the final performance criteria had been met and the option vested as to the final third of the award /s/ Michael P. Mason, Attorney-in-Fact for Barry E. Greene 2018-08-14