Amgen Patent Invalid, British Court Decrees

Amgen Inc.’s British patent for its Epogen anemia treatment, the company’s bestselling drug, was ruled invalid by Britain’s highest court. The House of Lords in London ruled unanimously in favor of Transkaryotic Therapies Inc., which challenged the patent.

The ruling is expected to have little effect on Amgen; its Epogen patent was already due to expire in Europe on Dec. 11.

The British decision comes after an Oct. 15 ruling by a federal judge in Boston upholding Amgen’s U.S. patents for Epogen. Transkaryotic has said it plans to appeal.

Shares of Thousand Oaks-based Amgen fell $2.13 to $54.28 and Cambridge, Mass.-based Transkaryotic rose 6 cents to $16.79, both on Nasdaq.