Actavis challenges Orexigen and Takeda's Contrave patent

US obesity speciality Orexigen Therapeutics (Nasdaq: OREX) and partner, Japan’s Takeda Pharma (TYO: 4502) have received notification of a Paragraph IV certification for certain patents for their weight management product Contrave (naltrexone HCl and bupropion HCl extended release) which are listed in the Food and Drug Administration's Approved Drug Products with Therapeutic Equivalence Evaluations, or the Orange Book.

The certification resulted from the filing by Actavis (NYSE: ACT) of an Abbreviated New Drug Application (ANDA) challenging such patents for Contrave. Orexigen and Takeda plan to vigorously enforce Contrave intellectual property rights.

In accordance with the Hatch-Waxman Act, Takeda and Orexigen have 45 days after effective notice of the Paragraph IV certification to file suit against the ANDA filer in order to obtain an automatic stay of FDA approval of the ANDA until the earlier of (i) 30 months from Takeda's receipt of the notice or (ii) a District Court decision finding that the identified patents are invalid, unenforceable or not infringed.