Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics company, announced today that the U.S. District Court of the District of Massachusetts has ruled in favor of Alnylam and has denied Tekmira Pharmaceuticals Corporation’s motion to dismiss certain claims and motion to disqualify Alnylam’s counsel in an infringement suit filed in January 2012. The infringement suit against Tekmira is based upon Alnylam’s allegations that Tekmira has improperly provided lipid nanoparticle (LNP)-formulated small interfering RNA (siRNA) molecules to pharmaceutical collaborators. As announced today, the Court has ruled that Alnylam has standing in suing Tekmira for infringement of several patents that Tekmira has exclusively licensed to Alnylam. In addition, Alnylam announced today that it has expanded the infringement action with a suit in Canada.

“Alnylam has contracts with Tekmira granting us exclusive rights to deploy LNP technologies in the RNAi field, and we are resolute in enforcing our intellectual property against infringement,” said Laurence Reid, Ph.D., Senior Vice President, Chief Business Officer of Alnylam. “In this regard, we are pleased with the ruling of the Federal Court that has confirmed Alnylam’s rights to enforce certain in-licensed patents against infringing activities. In addition, Alnylam has multiple other patents that protect our innovative discoveries, including the patent used in our expanded infringement action against Tekmira in Canada.”

As alleged in the complaint filed in January 2012, Tekmira’s activities are not protected under the exemption from patent infringement for drug development. As described in the complaint, Tekmira has allegedly infringed a number of issued patents related to siRNA and LNP technologies, including: U.S. Patent No. 7,695,902; U.S. Patent No. 6,858,225; U.S. Patent No. 6,815,432; U.S. Patent No. 6,534,484; U.S. Patent No. 6,586,410; and, U.S. Patent No. 6,858,224. Under Alnylam’s contractual right to enforce Isis’ patent U.S. Patent No. 7,695,902, Alnylam joined Isis to the suit as a co-plaintiff.

In addition, Alnylam today has expanded its infringement action against Tekmira to include CA Patent No. 2,359,180. In a complaint filed today in the Federal Court of Canada, Alnylam alleges Tekmira is infringing this patent in its collaboration activities and in its own research and development efforts.

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. Small interfering RNA (siRNA), the molecules that mediate RNAi and comprise Alnylam’s RNAi therapeutic platform, target the cause of diseases by potently silencing specific 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 leading the translation of RNAi as a new class of innovative medicines with a core focus on RNAi therapeutics for the treatment of genetically defined diseases, including ALN-TTR for the treatment of transthyretin-mediated amyloidosis (ATTR), ALN-AT3 for the treatment of hemophilia, ALN-PCS for the treatment of severe hypercholesterolemia, ALN-HPN for the treatment of refractory anemia, and ALN-TMP for the treatment of hemoglobinopathies. As part of its “Alnylam 5x15TM” strategy, the company expects to have five RNAi therapeutic products for genetically defined diseases in clinical development, including programs in advanced stages, on its own or with a partner by the end of 2015. Alnylam has additional partnered programs in clinical or development stages, including ALN-RSV01 for the treatment of respiratory syncytial virus (RSV) infection, ALN-VSP for the treatment of liver cancers, and ALN-HTT for the treatment of Huntington’s disease. The company’s leadership position on RNAi therapeutics and intellectual property have enabled it to form major alliances with leading companies including Merck, Medtronic, Novartis, Biogen Idec, Roche, Takeda, Kyowa Hakko Kirin, Cubist, Ascletis, and Monsanto. In addition, Alnylam and Isis co-founded Regulus Therapeutics Inc., a company focused on discovery, development, and commercialization of microRNA therapeutics; Regulus has formed partnerships with GlaxoSmithKline, Sanofi, Biogen and AstraZeneca. Alnylam has also formed Alnylam Biotherapeutics, a division of the company focused on the development of RNAi technologies for applications in biologics manufacturing, including recombinant proteins and monoclonal antibodies. Alnylam’s VaxiRNA™ platform applies RNAi technology to improve the manufacturing processes for vaccines; GlaxoSmithKline is a collaborator in this effort. Alnylam scientists and collaborators have published their research on RNAi therapeutics in over 100 peer-reviewed papers, including many in the world’s top scientific journals such as Nature, Nature Medicine, Nature Biotechnology, and Cell. Founded in 2002, Alnylam maintains headquarters in Cambridge, Massachusetts. For more information, please visit www.alnylam.com.

Alnylam Forward-Looking Statements

Various statements in this release concerning Alnylam’s future expectations, plans and prospects, including, without limitation, statements regarding the allegations included in the complaint filed against Tekmira, Alnylam’s intentions regarding the enforcement of its intellectual property against infringement and statements regarding Alnylam’s expectations with respect to its “Alnylam 5x15” product strategy, 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, without limitation, risks and uncertainties related to the successful pursuit of litigation, Alnylam’s ability to discover and develop novel drug candidates and delivery approaches, successfully demonstrate the efficacy and safety of its drug candidates, the pre-clinical and clinical results for its product candidates, which may not support further development of product candidates, actions of regulatory agencies, which may affect the initiation, timing and progress of clinical trials, obtaining, maintaining and protecting intellectual property, Alnylam’s ability to enforce its patents against infringers and defend its patent portfolio against challenges from third parties, obtaining regulatory approval for products, competition from others using technology similar to Alnylam’s and others developing products for similar uses, Alnylam’s ability to obtain additional funding to support its business activities and establish and maintain strategic business alliances and new business initiatives, Alnylam’s dependence on third parties for development, manufacture, marketing, sales and distribution of products, the outcome of litigation, 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.