Isis and Alnylam Announce Notice of Allowance for New U.S. Patent Application Broadly Covering RNAi Therapeutics

Isis Pharmaceuticals, Inc. (Nasdaq: ISIS) and Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY) announced today that the United States Patent and Trademark Office (USPTO) has issued a Notice of Allowance for U.S. patent application (No. 10/078,949) in the "Crooke” patent family, which broadly covers chemically modified RNA-containing therapeutics. Specifically, the allowed Crooke application includes 75 claims covering methods of using chemically modified double-stranded RNA-containing compounds to activate an RNA nuclease (RNase). The activation of the endogenous cellular RNase "argonaute 2” by double-stranded small interfering RNAs (siRNAs) is a central step in RNAi, resulting in the sequence-specific cleavage of target mRNA.

The Crooke patent family stems from innovative research of Dr. Stanley Crooke and others at Isis to identify and design RNA molecules that harness cellular RNase enzymes as antisense drugs, including RNAi and microRNA therapeutics. The Crooke patents are part of Isis’ overall patent estate, which includes more than 1,600 issued patents worldwide that broadly cover the design and use of RNA-targeting drugs. Under an agreement formed in 2004, the Crooke patent estate and additional Isis-owned patents are licensed exclusively to Alnylam for double-stranded RNAi therapeutics.

"We are very pleased that the U.S. Patent Office has acknowledged these new claims, which will expand the coverage of the Crooke patent series. This series continues to provide broad protection against competitors who are developing RNA-based drugs, including siRNAs,” said Stanley Crooke, M.D., Ph.D., Chairman and Chief Executive Officer of Isis. "With nearly 1,650 patents issued worldwide, we believe that we have an unparalleled intellectual property estate in the field of RNA therapeutics. Because we continue to innovate and advance our technology, we plan to continue to extend our basic patent protections on our drugs and our technologies.”

"Alnylam has maintained an ongoing strategy to consolidate all the intellectual property required to develop and commercialize RNAi therapeutics,” said John Maraganore, Ph.D., Chief Executive Officer of Alnylam. "Our patent licenses from Isis, including the Crooke patent estate, form a key component of Alnylam’s intellectual property position in the field. The allowance of these new claims in the Crooke patent estate clearly validates this strategy and strengthens our efforts and those of our partners to bring RNAi therapeutics to patients.”

Issued patents in the Crooke estate already include U.S. Patent No. 5,898,031 covering chemically modified RNA-containing therapeutic compounds, and U.S. Patent No. 6,107,094 covering methods of using these compounds to interfere with target RNA function, including not only interrupting protein production with single-stranded and double-stranded (siRNA) antisense compounds but also targeting other RNAs, such as microRNAs. U.S. Patent No. 7,432,250 covering methods of treating patients by administering siRNA or single-stranded chemically modified RNA-like compounds; and claims in U.S. Patent No. 7,432,249 cover pharmaceutical compositions containing single-stranded chemically modified RNA-like compounds. U.S. Patent No. 7,629,321 claims methods of cleaving target mRNA using a single-stranded oligonucleotide having a plurality RNA nucleosides and at least one chemical modification.

The newly allowed U.S. patent application (No. 10/078,949) covers methods of activating a double-stranded RNase using a double-stranded chemically modified RNA-containing compound with the following properties:

• two oligonucleotide strands hybridized to each other;
• each oligonucleotide strand comprised of 15 to 25 nucleosides; and
• at least one strand comprising a plurality of ribose sugar moieties and at least one chemical modification.

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 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 21 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.

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, hypercholesterolemia, Huntington’s disease, and TTR amyloidosis. 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. To reflect its outlook for key scientific, clinical, and business initiatives, Alnylam established "RNAi 2010” in January 2008 which includes the company’s plan to significantly expand the scope of delivery solutions for RNAi therapeutics, have four or more programs in clinical development, and to form four or more new major business collaborations, all by the end of 2010. Alnylam is a joint owner of Regulus Therapeutics, a joint venture focused on the discovery, development, and commercialization of microRNA therapeutics. Founded in 2002, Alnylam maintains headquarters in Cambridge, Massachusetts. For more information, please visit http://www.alnylam.com.

Isis Forward-Looking Statement

This press release includes forward-looking statements regarding Isis Pharmaceuticals’ proprietary patent estate, the therapeutic and commercial potential of the Isis’ technologies and products in development and its Regulus joint venture. 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. 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, 2008, and its most recent quarterly report on Form 10-Q, which are on file with the SEC. Copies of these and other documents are available from Isis.

Isis Pharmaceuticals is a registered trademark of Isis Pharmaceuticals, Inc.
Regulus Therapeutics is a trademark of Regulus Therapeutics Inc.

Alnylam Forward-Looking Statement

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 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.