X0306 4 2018-08-10 0 0001178670 ALNYLAM PHARMACEUTICALS, INC. ALNY 0001458494 Vaishnaw Akshay 300 THIRD STREET CAMBRIDGE MA 02139 0 1 0 0 President, R&D Common Stock 2018-08-13 4 A 0 1724 0 A 12939 D Common Stock 2018-08-13 4 F 0 766 90.95 D 12173 D Common Stock 2018-04-16 5 J 0 E 28 0 A 366 I by Managed Account Common Stock 2018-07-10 5 J 0 E 29 0 A 395 I by Managed Account Performance Based Stock Option 2013 (right to buy) 63 2018-08-10 4 A 0 10832 0 A 2018-08-10 2023-12-18 Common Stock 10832 32500 D Performance Based Stock Option 2014 (right to buy) 96.45 2018-08-10 4 A 0 11707 0 A 2018-08-10 2024-12-17 Common Stock 11707 35125 D On January 4, 2016, the reporting person was granted a restricted stock unit (RSU) to purchase shares of ALNY common stock. The shares subject to release vest upon the commercial launch of Alnylams first internally developed product, as approved by our compensation committee. Effective August 13, 2018, the compensation committee of the Company determined the performance criterion has been met and the RSU shares have vested. 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. 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 Akshay K. Vaishnaw 2018-08-14