Amgen Wins Round in Patent Case; Stock Up 4%

Shares of Thousand Oaks-based Amgen Inc. rose 4%, gaining for a second day, as analysts said the world’s No. 1 biotechnology company won an early round over rival Transkaryotic Therapies Inc. in a patent dispute involving Amgen’s best-selling drug.

U.S. District Judge William Young in Boston supported several Amgen claims during the last two days in a preliminary hearing over patents on Amgen’s best-selling product, the $1.8-billion-a-year anemia treatment Epogen. The drug is a copy of a human protein, erythropoietin, which stimulates production of red blood cells.

But analysts cautioned that it’s too early to predict whether Amgen will prevail in its efforts to keep the Transkaryotic drug off the market.

Young put off until next month a decision on Amgen’s request for a quick ruling on whether Transkaryotic’s plan to sell its own version of erythropoietin in the U.S. violates Amgen’s patents.

Officials at Amgen and Transkaryotic declined to comment on the proceedings.

Amgen rose $2.44 to close at $62.81 on Nasdaq. Cambridge, Mass.-based Transkaryotic fell $8.75 to close at $61.50, also on Nasdaq.