Par Pharma., Inc. v TWi Pharma., Inc., No. 14-1391 (Fed. Cir. 2014)Annotate this Case
Megestrol was used to treat wasting in cancer patients. In 1993, Squibb marketed an oral suspension of micronized megestrol, Megace OS, for treatment of anorexia and cachexia in AIDS patients. Other manufacturers submitted Abbreviated New Drug Applications to market generic versions of Megace OS. Par received approval, but continued to experiment and eventually formulated nanosized megestrol. Patients taking Megace OS with a meal showed a significantly higher rate and extent of absorption compared with patients in a fasting state. The nanosized formulation showed a greatly reduced food effect, especially vital for patients with reduced appetites. The Patent Office rejected Par’s claims covering methods for nanosized megestrol formulations as obvious in light of prior art. Par amended to address the lack of a food effect in the nanosized formulation. The FDA approved Par’s New Drug Application for its nanoparticle formulation, Megace ES, which has generated more than $600M in net sales since 2005. Par pled guilty to marketing Megace ES without FDA approval as an effective weight-gain method for geriatric patients and as having superior clinical efficacy over Megace OS despite lack of clinical studies. TWi filed an ANDA for a generic nanosized megestrol, asserting that the Par patent was invalid or would not be infringed. Par sued under 35 U.S.C. 271(e)(2)(A). The Federal Circuit vacated the district court finding of invalidity; that court incorrectly applied the law on inherency in the context of obviousness.