Argatroban is approved by the FDA for the treatment of heparin-induced thrombocytopenia. Encysive is the holder of the new drug application for Argatroban, and has licensed the North American marketing rights for the drug to GlaxoSmithKline.
In November 2007, Encysive received a Paragraph IV certification letter from Barr, notifying the company of the filing of an abbreviated new drug application (ANDA) with the FDA for a generic version of Argatroban injections. Barr’s ANDA seeks approval to market a generic version of Argatroban injections prior to the expiration of the patent covering the drug, which has an expiration date of June 30, 2014.
Barr contends that the patent covering the drug is invalid, unenforceable, and/or will not be infringed by Barr’s manufacture, importation, use or sale of the product for which the ANDA was submitted. Barr has lodged a contention with respect to obviousness, but provided no grounds for alleged unenforceability or noninfringement.