MONTVALE, N.J. (AP) — Generic drug maker Barr Pharmaceuticals Inc. Tuesday said it launched a patent challenge against GlaxoSmithKline PLC over its prostate drug Avodart.
Barr is ultimately seeking approval to market a generic version of Avodart, or dutasteride.
On Monday, British drug maker Glaxo filed suit in the U.S. District Court for the District of Delaware to prevent Barr from marketing its drug. Barr said that action formally kicked off the patent challenge process.
As a result, Barr said it believes it is the first generic drug maker to file an Abbreviated New Drug Application (ANDA) containing what is known as a ''paragraph IV certification,'' which indicates its generic drug would infringe an existing patent, but that it claims the patent is invalid.
Glaxo said Avodart generated $98 million in 2007 total sales.
Shares of Montvale, N.J.-based Barr fell 72 cents to $48.49 in morning trade.