Amgen Wins infringement Suit.

A federal judge ruled in favor of Amgen Inc., the world's largest biotechnology company, in a closely watched patent dispute that's expected to impact the development of new genetically engineered drugs.

The judge found that Thousand Oaks-based Amgen proved that three of its patents covering its anti-anemia drug Epogen were "infringed" by Transkaryotic Therapies Inc. of Cambridge, Mass., and its partner, European pharmaceutical giant Aventis, which want to sell their own version of the drug.

An appeal is expected but the decision was a huge victory for Amgen. Epogen -- the company's brand name for the drug erythropoietin, which treats anemia in patients with kidney failure -- accounts for nearly half of the company's $4 billion in annual sales.

The case raised the fundamental question of how broad a market a company could claim based on its genetic discoveries. Amgen had argued that if Transkaryotic won, it could use the same technology to copy virtually any biotech drug.

Transkaryotic claimed that Amgen's patents were overly broad.

Amgen is awaiting U.S. Food and Drug Administration approval for an improved version of Epogen.