Barr challenges GSK's Avodart patent

US generics major Barr Pharmaceuticals has confirmed that its subsidiary, Barr Laboratories, has initiated a challenge of the patents listed by UK-based drugs giant GlaxoSmithKline in connection with its Avodart (dutasteride) soft gelatin capsules, 0.5mg. The company believes that it is the first to file an Abbreviated New Drug Application containing a Paragraph IV certification for Avodart, seeking approval to market a generic version of the drug.

Barr filed its ANDA with the Food & Drug Administration in October 2007, and received notification of the application's acceptance for filing in January 2008. Following receipt of the notice from the FDA that Barr's Abbreviated NDA had been accepted for filing, the firm notified GSK.

As a result, on February 25, GSK filed suit in the US District Court for the District of Delaware to prevent Barr from proceeding with the commercialization of its generic product. This action formally initiates the patent challenge process under the Hatch-Waxman Act.