Regulatory Affairs

Gilead receives Hepsera ANDA Filing notification by Sigmapharm

PBR Staff Writer Published 20 August 2010

Gilead Sciences has received a Paragraph IV Certification Notice Letter advising that Sigmapharm Laboratories submitted an abbreviated new drug application (ANDA) to the US Food and Drug Administration (FDA) requesting permission to manufacture and market a generic version of Hepsera (adefovir dipivoxil).

In the notice letter, Sigmapharm alleges that two patents associated with Hepsera, US Patent numbers 5,663,159 and 6,451,340, owned by Gilead Sciences are invalid, unenforceable and/or will not be infringed by Sigmapharm's manufacture, use or sale of the product described in its ANDA submission.

Gilead Sciences is currently reviewing the notice letter and has 45 days from the date of receipt to commence a patent infringement lawsuit against Sigmapharm.

Such a lawsuit is expected to restrict the FDA from approving Hepsera's ANDA for up to 30 months or until a district court decision that is adverse to Gilead, whichever occurs first.

Hepsera is currently protected by these two patents, which are listed in the FDA's approved drug products list, and both patents would need to be invalidated or not infringed upon before a generic version of Hepsera could be marketed.