Judge Tentatively Rejects Some Amgen Claims

A federal judge issued a tentative ruling dismissing several patent-related claims that biotech giant Amgen Inc. brought against rival Transkaryotic Therapies Inc. over Amgen’s best-selling product, an anemia treatment that generates billions of dollars in sales a year. The claims relate to one of five patents that Amgen says Transkaryotic Therapies violated in the production of erythropoietin. U.S. District Judge William Young has already ruled that TKT infringed Amgen’s patent on erythropoietin, but he left issues relating to the four other patents to be decided at the trial. Young said he would think further about the ruling over the weekend and comment Monday, when the trial reconvenes. TKT declined to comment on the ruling. A spokesman for Thousand Oaks-based Amgen said Young’s decision was a disappointment but did not significantly alter its position. Analysts said they regarded the judge’s preliminary ruling as favorable for TKT but added it was too early to say the fight over Amgen’s billion-dollar EPO drug Epogen was decided. Cambridge, Mass.-based TKT’s stock shot up $11.19 in Nasdaq trading, rising above an already strong biotech sector to close at $42.88. Amgen’s shares fell $3.06 to close at $62.63, also on Nasdaq.