Chinta & Fratangelo LLP

No. 2009-1553 (Fed. Cir. 6/3/2010) (non precedential). Par filed an ANDA for once daily tramadol, with PIV cert’s against two patents.  Purdue sued, and Par counterclaimed that the patents were invalid under 35 U.S.C. § 112 for lack of enablement and written description, invalid under § 103 for obviousness, and unenforceable due to inequitable conduct. The district ct held that the asserted claims were invalid for obviousness, in view of (1) US 5,580,578, which describes formulations of opioid analgesics, including tramadol, for once-daily dosing and (2) what was known in the art about tramadol and once-daily formulations.

The lower ct was affirmed by the Fed. Cir. panel (Lourie, Linn, and Dyk, opinion by Lourie). The prior art disclosed a controlled-release tramadol formulation, relevant pharmacological parameters, and relevant excipients. With regard to motivation, it appears that the disclosure of tramadol in the ‘578 patent was sufficient (“Oshlack makes that very selection; it lists tramadol as one of fourteen different opioid analgesics to use in a controlled-release formulation that provide effective blood levels for twenty-four hours.”). Evidence of secondary considerations was rejected.