Regulus Therapeutics Announces Allowance of Key Patent on microRNA Therapeutics for the Treatment of Hepatitis C Virus Infection

Regulus Therapeutics, a joint venture between Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY) and Isis Pharmaceuticals, Inc. (Nasdaq: ISIS) formed to discover, develop, and commercialize microRNA therapeutics, announced today that the United States Patent and Trademark Office (USPTO) recently issued a "Notice of Allowance” for the "Sarnow” patent (U.S. patent application 11/122,328). The allowed claims cover methods for targeting a specific microRNA to inhibit Hepatitis C virus (HCV) replication. The Sarnow patent, a Stanford University patent to which Regulus has exclusive rights, relates to the discovery and development of therapeutic products for HCV infection by inhibiting a liver-specific microRNA known as miR-122. Regulus is developing a microRNA therapeutic targeting miR-122 for the treatment of HCV infection as its most advanced therapeutic program. "The opportunity to selectively antagonize microRNAs involved in the cause or pathway of human disease represents an exciting new frontier for pharmaceutical research. The recent formation of Regulus unites the scientific leadership and intellectual property estates of both Isis and Alnylam to build what we believe is the leading microRNA therapeutics company, and this new U.S. patent allowance represents an early proof point of our value creation strategy,” said John Maraganore, Ph.D., Chairman of Regulus, and President and Chief Executive Officer of Alnylam. "HCV is a serious infectious disease representing a major public health concern affecting 170 million people worldwide. Most current and emerging anti-HCV therapies target viral genes and are therefore prone to the emergence of resistance. By targeting a host factor required for viral replication, a microRNA therapeutic targeting miR-122 is an attractive and differentiated approach for the possible treatment of HCV.” "miR-122, one of over 500 microRNAs expressed in human cells, has been shown to be an important host factor for HCV replication and a promising target for microRNA-based therapeutics,” commented C. Frank Bennett, Ph.D., Senior Vice President of Research of Isis. "We are pleased to announce this patent allowance, as we feel that the Sarnow patent will provide Regulus with broad protection for its most advanced therapeutic program, which targets miR-122.” Data published in 2005 by the Sarnow lab in the journal Science [Jopling et al. Science 309, 1577 (2005)] demonstrated that miR-122, which is specifically and abundantly expressed in the human liver, is required for HCV proliferation. In these studies, miR-122 was found to interact directly with a specific part of the HCV genome leading to increased expression of viral components. Sequestration of miR-122 using antisense oligonucleotides resulted in a dramatic inhibition of HCV reproduction in cultured human liver cells. This links the endogenous expression of a specific microRNA with a major infectious disease, and suggests that antagonism of miR-122 may comprise a novel therapeutic strategy against HCV. Following a Notice of Allowance, the process resulting in final issuance of a patent involves several administrative steps that are typically completed within a year. About microRNAs microRNAs are a recently discovered class of genetically encoded small RNAs, approximately 20 nucleotides in length, and are believed to regulate the expression of a large number of human genes. microRNA therapeutics represent a new approach for the treatment of a broad range of human disease. When inappropriately encoded, microRNAs represent potential disease targets whose selective antagonism can result in the correction of an entire disease pathway in a manner unachievable by today’s medicines. In fact, the inappropriate absence or presence of specific microRNA molecules in various cells has been shown to be associated with specific human diseases including cancer, viral infection, and metabolic disorders. About Regulus Regulus Therapeutics LLC is a biopharmaceutical company formed to discover, develop and commercialize microRNA therapeutics. The company was created as a joint venture between Alnylam Pharmaceuticals, a leader in RNAi therapeutics, and Isis Pharmaceuticals, a leader in antisense technologies and therapeutics. Isis and Alnylam scientists and collaborators were the first to discover microRNA antagonist strategies that work in vivo in animal studies (Krutzfeldt et al. Nature 438, 685-689 (2005); Esau et al. Cell Metab., 3, 87-98 (2006)). Isis and Alnylam have also created and consolidated key intellectual property believed by the companies to be required for development and commercialization of microRNA therapeutics. The company, founded in 2007, maintains facilities in Carlsbad, California. For more information, visit www.regulusrx.com. 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. About Isis Pharmaceuticals Isis is exploiting its expertise in RNA to discover and develop novel drugs for its product pipeline and for its partners. The Company has successfully commercialized the world’s first antisense drug and has 18 drugs in development. Isis’ drug development programs are focused on treating cardiovascular and metabolic diseases. Isis’ partners are developing drugs for a wide variety of diseases. Ibis Biosciences, Inc., Isis’ wholly owned subsidiary, is developing and commercializing the Ibis T5000™ Biosensor System, a revolutionary system to identify infectious organisms. Isis is a joint owner of Regulus Therapeutics LLC, a joint venture focused on the discovery, development and commercialization of microRNA therapeutics. As an innovator in RNA-based drug discovery and development, Isis is the owner or exclusive licensee of over 1,500 issued patents worldwide. Additional information about Isis is available at www.isispharm.com. Alnylam Forward-Looking Statements Various statements in this release concerning Alnylam’s future expectations, plans and prospects, including statements concerning the potential of microRNA therapeutics and the importance of Alnylam’s intellectual property, know-how, and other technology in the discovery, development and commercialization of microRNA therapeutics, 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. Isis Forward Looking Statements This press release includes forward-looking statements regarding the future therapeutic and commercial potential of Isis’ technologies and intellectual property related to microRNA therapeutics being discovered and developed by Regulus. Any statement describing Isis’ goals, expectations, financial or other projections, intentions or beliefs is a forward-looking statement and should be considered an at-risk statement, including those statements that are described as Isis’ goals. Such statements are subject to certain risks and uncertainties, particularly those inherent in the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such products. Isis’ forward-looking statements also involve assumptions that, if they never materialize or prove correct, could cause its results to differ materially from those expressed or implied by such forward-looking statements. Although Isis’ forward-looking statements reflect the good faith judgment of its management, these statements are based only on facts and factors currently known by Isis. As a result, you are cautioned not to rely on these forward-looking statements. These and other risks concerning Isis’ programs are described in additional detail in Isis’ annual report on Form 10-K for the year ended December 31, 2006, and its quarterly report on Form 10-Q for the quarter ended September 30, 2007, which are on file with the SEC. Copies of these and other documents are available from the Company. Isis Pharmaceuticals is a registered trademark of Isis Pharmaceuticals, Inc. Ibis Biosciences and Ibis T5000 are trademarks of Ibis Biosciences, Inc. Regulus Therapeutics is a trademark of Regulus Therapeutics LLC.