Merck has agreed to acquire Sirna Therapeutics for approximately $1.1 billion. Sirna has been at the forefront of efforts to create RNAi-based therapeutics, medicines which selectively catalyze the destruction of the RNA transcribed from an individual gene. This enables an entirely novel approach to discovering drugs with the potential to produce highly specific, potent, and long-lasting effects. The two companies expect to complete the acquisition in the first quarter of 2007.

The acquisition of Sirna is seen as a component of Merck’s RNA expression research that began with the 2001 acquisition of Rosetta Inpharmatics. “We are delighted about our agreement to acquire Sirna Therapeutics, a company that has established a leading presence in the critically important area of RNAi,” said Peter S. Kim, Ph.D., president, Merck Research Laboratories. “We believe that RNAi could significantly change the way in which we go about discovering and developing drugs, and could become a new way to treat patients with unmet medical needs.”

“RNAi is a powerful enabler of drug discovery in cells, in animals, and in humans. We can potentially use this technology to target the activity of genes which control the activity of cancer cells, and so produce their destruction without damaging normal cells,” said Stephen H. Friend, M.D., Ph.D., executive vice president and franchise head, Oncology and Neuroscience, Merck Research Laboratories.

Sirna’s lead clinical development candidate, Sirna-027, is a chemically optimized, short interfering RNA (siRNA) currently moving into Phase II development for the treatment of the wet-form of age related macular degeneration (AMD) as part of a broad collaboration with Allergan, Inc. in the area of ophthalmic diseases. In addition to the collaboration with Allergan, Sirna has established a strategic alliance with GlaxoSmithKline for the development of siRNA compounds for the treatment of respiratory diseases. Besides its external collaborations, Sirna has several programs covering a broad range of therapeutic areas, including infectious diseases, metabolism, CNS and dermatology.

“We are excited about the opportunity to undertake the discovery and development of therapeutic siRNAs with Merck, a company that clearly recognizes the potential of this breakthrough technology,” said Sirna Senior Vice President of Research and Chief Scientific Officer Barry Polisky. “Merck’s commitment to the development of RNAi-based therapeutics will ensure that this novel therapeutic modality will achieve its full potential.”

Richard N. Kender, vice president of Business Development and Corporate Licensing at Merck, noted that Merck’s acquisition of Sirna “is another example of Merck delivering on its strategy of aggressively pursuing biotechnology companies that complement our considerable internal research capabilities.”