AMGEN INTERLEUKIN-2 PATENT SUIT AGAINST CETUS

AMGEN INTERLEUKIN-2 PATENT SUIT AGAINST CETUS seeks a declaratory judgement that three of Cetus' four interleukin-2 patents are invalid and/or not infringed by the interleukin-2 under development by Amgen, according to the Aug. 29 complaint filed in San Francisco Federal Court. The filing states that Amgen seeks "a declaration that U.S. [Patents 4,518,584, 4,530,787, and 4,569,790 are] invalid, unenforceable and not infringed by Amgen." The suit makes three citations: a patent entitled "Human Recombinant Interleukin-2 Muteins," issued May 21, 1985; a patent entitled "Controlled Oxidation of Microbially Produced Cystein-Containing Proteins," issued July 23, 1985; and a patent entitled "Process for Recovering Microbially Produced Interleukin-2 and Purified Recombinant Interleukin-2 Compositions," issued to Cetus Feb. 11, 1986. Cetus said it has a fourth interleukin-2 patent, related to the formulation of its product, which is not being challenged by the Amgen suit. Amgen alleges that the three patents "are each invalid: (a) for failure to satisfy one or more of the conditions for patentability specified in Chapter 10 of Title 35, United States Code, and/or (b) for failure to satisfy one or more of the requirements of Chapter 11 of Part II of Title 35, United States Code, and/or (c) for being otherwise in violation of one or more Sections of Title 35, United States Code." Cetus said it is currently the only company to hold U.S. patents for DNA-produced interleukin-2. The company noted that it has not filed patent infringement suits against Amgen regarding its interleukin-2 product. However, Amgen said that Cetus notified the company that it was violating certain of Cetus' interleukin-2 patents. The suit states that "on information and belief Cetus . . . has charged that certain recombinant human interleukin-2 products manufactured and sold by Amgen infringe [the three patents] and has threatened suit against Amgen under said patents." The patents "are not and have not been infringed by Amgen and/or are not enforceable against Amgen," the complaint states. Amgen, which is developing its interleukin-2 under a joint venture with J&J, and Cetus are among at least 11 companies, or joint venture/collaborative effort groups, working on the development of an interleukin-2 product. Those firms include: Genentech; Biogen; Roche/Immunex; Collaborative Research/Triton Biosciences; Chiron; Viragen; Liposome Technology; Quidel; and Sandoz/Genetics Institute. Six of the firms are currently in clinicals with their interleukin-2 products -- Cetus, Amgen/J&J, Genentech, Biogen, Collaborative Research/Triton Biosciences, and Roche/Immunex. Amgen's suit against Cetus marks one of the first patent infringement disputes in the biotech drug field to reach the courts. Earlier this year, Genentech filed a suit against Burroughs Wellcome in Britain alleging infringement of its tissue plasminogen activator patent in that country. Roche and Schering, however, took a different approach in addressing their potential patent conflict for related DNA products. Prior to the approval of their DNA-produced alpha interferons, the two firms agreed not to file patent infringement claims against each other ("The Pink Sheet" May 20, 1985, p. 3).