Alnylam Receives Biotechnology Industry's Most Prestigious Award For Corporate Excellence; Awarded the James D. Watson Helix Award at BIO CEO & Investor Conference.

CAMBRIDGE, Mass. -- Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics company, announced that it has been awarded the James D. Watson Helix award for corporate excellence in the 'emerging/mid-cap' category. The award was announced today at the 8th Annual BIO CEO & Investor Conference in New York. The Helix award, the biotechnology industry's sole award for outstanding corporate achievement, honors biotechnology companies that display leadership in three distinct areas: product development, economic growth, and corporate citizenship.

"We are deeply honored to be chosen as a recipient of the Helix award," said John Maraganore, Ph.D., President and Chief Executive Officer of Alnylam. "We have made great progress at Alnylam over the last year in our effort to advance the field of RNAi for the development of innovative medicines to make a significant difference in patients' lives. In 2005, we transitioned to a clinical-stage company and signed a major collaboration with Novartis to discover and develop RNAi therapeutics. We are sincerely grateful to our industry peers for their recognition of our progress and accomplishments."

"When we founded Alnylam in 2002, we recognized the potential of harnessing the impact and discovery of RNAi to create a whole new class of human therapeutics," said Phillip A. Sharp, Ph.D., Institute Professor of MIT, Nobel Laureate, and co-founder of Alnylam and Biogen Idec. "It is truly gratifying to see Alnylam's efforts recognized by the biotechnology industry, as we aim to create a leading biopharmaceutical company such as those that emerged from other important biological discoveries like recombinant DNA and monoclonal antibody technologies."

As this year's recipient, Alnylam becomes the fifth 'emerging/mid-cap' biotechnology company to receive the Helix award. Alnylam joins Genentech and Novo Nordisk who are this year's large cap and international Helix award recipients, respectively.

About RNA Interference (RNAi)

RNA interference, or RNAi, is a naturally occurring mechanism within cells for selectively silencing and regulating specific genes. Since many diseases are caused by the inappropriate activity of specific genes, the ability to silence genes selectively through RNAi could provide a new way to treat a wide range of human diseases. RNAi is induced by small, double-stranded RNA molecules. One method to activate RNAi is with chemically synthesized small interfering RNAs, or siRNAs, which are double-stranded RNAs that are targeted to a specific disease-associated gene. The siRNA molecules are used by the natural RNAi machinery in cells to cause highly targeted gene silencing.

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 building a pipeline of RNAi therapeutics; its lead program is in Phase I human clinical trials for the treatment of respiratory syncytial virus (RSV) infection, which is the leading cause of hospitalization in infants in the U.S. 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 Merck, Medtronic, and Novartis. The company, founded in 2002, maintains global headquarters in Cambridge, Massachusetts, and has an additional operating unit in Kulmbach, Germany. For more information, please visit www.alnylam.com.

Alnylam Forward-Looking Statements

Various statements in this release concerning our future expectations, plans and prospects, constitute forward-looking statements for the purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including risks related to: our approach to discover and develop novel drugs, which is unproven and may never lead to marketable products; obtaining, maintaining and protecting intellectual property utilized by our products; our ability to enforce our patents against infringers and to defend our patent portfolio against challenges from third parties; our ability to obtain additional funding to support our business activities; our dependence on third parties for development, manufacture, marketing, sales and distribution of our products; the successful development of products, all of which are in early stages of development; obtaining regulatory approval for products; competition from others using technology similar to ours and others developing products for similar uses; our dependence on collaborators; and our short operating history; as well as those risks more fully discussed in the "Certain Factors That May Affect Future Results" section of our most recent quarterly report on Form 10-Q on file with the Securities and Exchange Commission. In addition, any forward-looking statements represent our views only as of today and should not be relied upon as representing our views as of any subsequent date. We do not assume any obligation to update any forward-looking statements.