Alnylam to Webcast Conference Call Discussing Second Quarter 2008 Financial Results.

CAMBRIDGE, Mass. -- Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics company, today announced that it will report financial results for the second quarter of 2008 on Wednesday, August 6, 2008, after the U.S. financial markets close.

Management will provide an update on the company, discuss second quarter results, and discuss expectations for the future via conference call on Wednesday, August 6, 2008, at 4:30 p.m. ET. To access the call, please dial 866-800-8651 (domestic) or 617-614-2704 (international) five minutes prior to the start time and provide the passcode 38068202. A replay of the call will be available from 6:30 p.m. ET on August 6, 2008 until August 13, 2008. To access the replay, please dial 888-286-8010 (domestic) or 617-801-6888 (international), and provide the passcode 70977053.

A live audio webcast of the call will also be available on the "Investors" section of the company's website, www.alnylam.com. An archived webcast will be available on the Alnylam website approximately two hours after the event and will be archived for 14 days.

About Alnylam

Alnylam is a biopharmaceutical company developing novel therapeutics based on RNA interference, or RNAi. The company is applying its therapeutic expertise in RNAi to address significant medical needs, many of which cannot effectively be addressed with small molecules or antibodies, the current major classes of drugs. Alnylam is leading the translation of RNAi as a new class of innovative medicines with peer-reviewed research efforts published in the world's top scientific journals including Nature, Nature Medicine, and Cell. The company is leveraging these capabilities to build a broad pipeline of RNAi therapeutics; its most advanced program is in Phase II human clinical trials for the treatment of respiratory syncytial virus (RSV) infection. In addition, the company is developing RNAi therapeutics for the treatment of a wide range of disease areas, including hypercholesterolemia, liver cancers, and Huntington's disease. The company's leadership position in fundamental patents, technology, and know-how relating to RNAi has enabled it to form major alliances with leading companies including Medtronic, Novartis, Biogen Idec, Roche, Takeda, and Kyowa Hakko Kogyo. To reflect its outlook for key scientific, clinical, and business initiatives, Alnylam has established "RNAi 2010" which includes the company's plan to significantly expand the scope of delivery solutions for RNAi therapeutics, have four or more programs in clinical development, and to form four or more new major business collaborations, all by the end of 2010. Alnylam is a joint owner of Regulus Therapeutics LLC, a joint venture focused on the discovery, development, and commercialization of microRNA therapeutics. Founded in 2002, Alnylam maintains headquarters in Cambridge, Massachusetts. For more information, visit www.alnylam.com.