Regulus, Alnylam and Isis Announce U.S. Allowance of Tuschl III Patent Application Covering miR-21

Regulus Therapeutics Inc., Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY) and Isis Pharmaceuticals, Inc. (Nasdaq: ISIS) announced today that the United States Patent and Trademark Office (USPTO) has allowed claims in a patent application derived from the "Tuschl III" patent series that is assigned to Max Planck. The allowed claims relate to human microRNA miR-21, a microRNA that is a potential target for a number of therapeutic indications. Regulus has access to the Tuschl III patent series for microRNA therapeutics through license agreements amongst Max Planck, Alnylam, and Isis.

"We are pleased with the decision of the USPTO to allow this new patent from the Tuschl III patent series, which originated from the pioneering work performed by Dr. Thomas Tuschl,” said Garry E. Menzel, Ph.D., Executive Vice President, Corporate Development and Finance of Regulus Therapeutics. "We continue to expand and strengthen the scope of our broad and fundamental intellectual property estate that enables development and commercialization of microRNA-based therapeutics, including a miR-21 targeted drug. Regulus scientists and collaborators are working on miR-21 in several therapeutic indications and have recently demonstrated therapeutic benefits in a variety of animal models of disease.”

"The work performed by Dr. Tuschl while at Max Planck led to the elucidation of a new class of non-coding RNAs in mammals that regulate several important biological processes,” said Dr. Joern Erselius, Managing Director, Max Planck Innovation GmbH. "The Tuschl III patent series describes the most important microRNAs in animals and lays the foundation for the discovery and development of a new class of therapeutics that target microRNAs. Regulus is the ideal partner to develop high impact medicines based on microRNA.”

The newly allowed claims cover miR-21, a microRNA that has been linked to a variety of diseases, including cancer, fibrosis, and heart disease. The claims additionally encompass single-stranded and double-stranded antisense compounds complementary to miR-21. The allowance of this second Tuschl III patent in the U.S. extends the scope of this patent estate, which has already yielded patents directed to miR-122 in the U.S. (U.S. Patent No. 7,232,806), Australia (Australia Patent No. 2002 347 035), and Japan (Japan Patent No. 4 371 812).

About microRNAs

The discovery of microRNA in humans is one of the most exciting scientific breakthroughs in the last decade. microRNAs are small RNA molecules, typically 20 to 25 nucleotides in length, that do not encode proteins but instead regulate gene expression. Nearly 700 microRNAs have been identified in the human genome, and more than one-third of all human genes are believed to be regulated by microRNAs. As a single microRNA can regulate entire networks of genes, these new molecules are considered the master regulators of the genome. microRNAs have been shown to play an integral role in numerous biological processes including the immune response, cell-cycle control, metabolism, viral replication, stem cell differentiation and human development. Many microRNAs are conserved across multiple species indicating the evolutionary importance of these molecules as modulators of critical biological pathways. Indeed, microRNA expression or function has been shown to be significantly altered in many disease states, including cancer, heart failure and viral infections. Targeting microRNAs opens the possibility of a novel class of therapeutics and a unique approach to treating disease by modulating entire biological pathways.

About Regulus Therapeutics Inc.

Regulus Therapeutics is a biopharmaceutical company leading the discovery and development of innovative new medicines based on microRNAs. Regulus is targeting microRNAs as a new class of therapeutics by working with a broad network of academic collaborators and leveraging oligonucleotide drug discovery and development expertise from its founding companies Alnylam Pharmaceuticals (Nasdaq:ALNY) and Isis Pharmaceuticals (Nasdaq:ISIS). Regulus is advancing microRNA therapeutics towards the clinic in several areas including hepatitis C infection, cardiovascular disease, fibrosis, oncology, immuno-inflammatory diseases, and metabolic diseases. Regulus’ intellectual property estate contains both the fundamental and core patents in the field as well as over 600 patents and more than 300 pending patent applications pertaining primarily to chemical modifications of oligonucleotides targeting microRNAs for therapeutic applications. In 2008, Regulus entered into a major alliance with GlaxoSmithKline to discover and develop microRNA therapeutics for immuno-inflammatory diseases. 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 and is partnered with Cubist and Kyowa Hakko Kirin. In addition, the company is developing RNAi therapeutics for the treatment of a wide range of disease areas, including liver cancers, TTR amyloidosis, hypercholesterolemia, 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, Kyowa Hakko Kirin, and Cubist. Alnylam and Isis are joint owners of Regulus Therapeutics Inc., a company focused on the discovery, development, and commercialization of microRNA-based therapeutics. Founded in 2002, Alnylam maintains headquarters in Cambridge, Massachusetts. For more information, please visit www.alnylam.com.

About Isis Pharmaceuticals, Inc.

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 22 drugs in development. Isis' drug development programs are focused on treating cardiovascular, metabolic, and severe neurodegenerative diseases and cancer. Isis' partners are developing antisense drugs invented by Isis to treat a wide variety of diseases. Isis and Alnylam Pharmaceuticals are joint owners of Regulus Therapeutics Inc., a company focused on the discovery, development and commercialization of microRNA therapeutics. Isis also has made significant innovations beyond human therapeutics resulting in products that other companies, including Abbott, are commercializing. As an innovator in RNA-based drug discovery and development, Isis is the owner or exclusive licensee of over 1,600 issued patents worldwide. Additional information about Isis is available at www.isispharm.com.

Forward-Looking Statements

This press release includes forward-looking statements regarding the future therapeutic and commercial potential of Regulus’, Alnylam’s, and Isis’ business plans, technologies and intellectual property related to microRNA therapeutics being discovered and developed by Regulus. Any statement describing Regulus’, Alnylam’s, and 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 such parties’ 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. Such parties’ forward-looking statements also involve assumptions that, if they never materialize or prove correct, could cause their results to differ materially from those expressed or implied by such forward-looking statements. Although these forward-looking statements reflect the good faith judgment of the management of each such party, these statements are based only on facts and factors currently known by Regulus’, Alnylam’s, and Isis’ management as the case may be. As a result, you are cautioned not to rely on these forward-looking statements. These and other risks concerning Regulus’, Alnylam’s, and Isis’ programs are described in additional detail in Alnylam’s and Isis’ annual reports on Form 10-K for the year ended December 31, 2008, and their most recent quarterly reports on Form 10-Q which are on file with the SEC. Copies of these and other documents are available from Alnylam or Isis.