Patent complaint filed against Glaxo, Genmab drug

COPENHAGEN/LONDON, March 25 (Reuters) - GlaxoSmithKline (GSK.L) and Genmab (GEN.CO) said on Thursday that two rival drugmakers had filed a patent infringement related complaint with a Californian district court over leukaemia drug Arzerra.

U.S.-based Biogen Idec Inc (BIIB.O) and Swiss Roche (ROG.VX) filed the complaint "based on GSK's manufacture, marketing and sale of Arzerra in the U.S. for the treatment of fludarabine and alemtuzumab refractory chronic lymphocytic leukemia (CLL)", Genmab said in a statement.

Arzerra became Genmab's first drug to the market when it was launched in the Unites States in November. It is produced and marketed by Glaxo, which was the subject of the complaint.

A Glaxo spokeswoman confirmed the move, which follows granting of a patent to Biogen and Roche on March 23 -- but she said the British company did not believe the claims were valid or enforceable.

The action by Biogen and Roche is not aimed at seeking an injunction to stop sales of Arzerra, she added.

"U.S. patent No 7,682,612 was issued to Genentech, Inc. and Biogen Idec, Inc. on March 23, 2010 and contains a claim to a method of treating CLL with anti-CD20 antibodies, wherein the method does not comprise treatment with radiolabeled anti-CD20 antibodies," Genmab said in a statement.

Genmab and Glaxo said they would assess the claim and determine how to respond.

Shares in Genmab were down 1 percent at 1325 GMT. Glaxo shares were up 0.3 percent. (Reporting by Anna Ringstrom and Ben Hirschler; Editing by Hans Peters)