Alnylam Appoints Barry Greene President and Chief Operating Officer.

CAMBRIDGE, Mass. -- Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics company, today announced that it has promoted Barry Greene to the new position of President and Chief Operating Officer. Mr. Greene previously held the title of Chief Operating Officer. In his new role, he will assume responsibility for business, corporate, and commercial development activities and will continue to report to Dr. John Maraganore, who remains the company's Chief Executive Officer.

"We are delighted to promote Barry to the new role of President and Chief Operating Officer. He has excelled in the business leadership of Alnylam and has aptly earned this advancement and new recognition," said John Maraganore, Ph.D., Chief Executive Officer of Alnylam. "Barry and I have worked together successfully as a team for several years and I look forward to working closely with him over the long term in building Alnylam as a leading biopharmaceutical company founded on RNAi."

"Alnylam has been leading the advancement of RNAi therapeutics as a broad platform for innovative medicines, with business execution continuing to support this objective," said Barry Greene, President and Chief Operating Officer of Alnylam. "With Alnylam's scientific excellence, unparalleled intellectual property estate, and leading business alliances, I am more excited and confident than ever about the potential for RNAi therapeutics to have broad commercial impact as a new approach for the treatment of human disease."

Barry Greene joined Alnylam in September 2003, and brings more than 20 years of experience in healthcare and product development. Prior to Alnylam, he was General Manager of Oncology at Millennium Pharmaceuticals, Inc., where he led the company's global strategy and execution for its oncology business including strategic business direction and execution, culminating in the successful approval and launch of VELCADE[TM] (bortezomib) in 2003. Mr. Greene's past positions include Vice President of Marketing and Customer Services for AstraZeneca formerly AstraMerck; Vice President Strategic Integration with responsibility for the AstraZeneca North American post merger integration; and Partner, Andersen Consulting responsible for the pharmaceutical/biotechnology marketing and sales practice. He received his B.S. in Industrial Engineering from the University of Pittsburgh and is a Senior Scholar at Duke University, Fuqua School of Business. Mr. Greene also serves as a Director for Acorda Therapeutics, Inc.

About RNA Interference (RNAi)

RNAi (RNA interference) is a revolution in biology, representing a breakthrough in understanding how genes are turned on and off in cells, and a completely new approach to drug discovery and development. Its discovery has been heralded as "a major scientific breakthrough that happens once every decade or so," and represents one of the most promising and rapidly advancing frontiers in biology and drug discovery today which was awarded the 2006 Nobel Prize for Physiology or Medicine. RNAi is a natural process of gene silencing that occurs in organisms ranging from plants to mammals. By harnessing the natural biological process of RNAi occurring in our cells, the creation of a major new class of medicines, known as RNAi therapeutics, is on the horizon. RNAi therapeutics target the cause of diseases by potently silencing specific messenger RNAs (mRNAs), thereby preventing disease-causing proteins from being made. RNAi therapeutics have the potential to treat disease and help patients in a fundamentally new way.

About Alnylam Pharmaceuticals

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 influenza, hypercholesterolemia, and liver cancers, among other diseases. 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, and Roche. The company, founded in 2002, maintains headquarters in Cambridge, Massachusetts. For more information, visit www.alnylam.com.

Alnylam Forward-Looking Statements

Various statements in this release concerning Alnylam's 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: Alnylam's approach to discover and develop novel drugs, which is unproven and may never lead to marketable products; obtaining, maintaining and protecting intellectual property; Alnylam's ability to enforce its patents against infringers and to defend its patent portfolio against challenges from third parties; Alnylam's ability to obtain additional funding to support its business activities; Alnylam's dependence on third parties for development, manufacture, marketing, sales and distribution of products; obtaining regulatory approval for products; competition from others using technology similar to Alnylam's and others developing products for similar uses; Alnylam's dependence on collaborators; and Alnylam's short operating history; as well as those risks more fully discussed in the "Risk Factors" section of its most recent quarterly report on Form 10-Q on file with the Securities and Exchange Commission. In addition, any forward-looking statements represent Alnylam's views only as of today and should not be relied upon as representing its views as of any subsequent date. Alnylam does not assume any obligation to update any forward-looking statements.