Amgen Sues Transkaryotic, Hoechst Unit

Amgen Inc. said it sued Transkaryotic Therapies Inc. and Hoechst’s drug unit for infringing U.S. patents that Amgen holds on its Epogen drug. Epogen, which accounted for about half of Amgen’s fourth-quarter revenue of $593.5 million, is used to spur red blood-cell growth in patients with kidney disease. Thousand Oaks-based Amgen said the suit, filed in Boston, seeks to prevent Transkaryotic and Hoechst from making, importing or selling their own version of Epogen in the U.S. Amgen shares rose $1.125 to close at $57 on Nasdaq. Shares of Cambridge, Mass.-based Transkaryotic fell $1.75 to close at $17.25, also on Nasdaq. Amgen also said it was awarded a U.S. patent providing further protection against the unauthorized making or selling of Epogen. The company already holds several patents on how Epogen is made and used.