Knoll Pharmaceutical Co. v. Teva Pharmaceuticals USA, Inc. (Fed. Cir. May 19, 2004).
The Federal Circuit reversed and remanded the N.D. Ill. district court judgment of invalidity. (U.S. Patent 4,587,252). The patent covers a method for treating pain with hydrocodone and ibuprofen (an NSAID) and is sold as Vicoprofen®.
In reversing the district court’s obviousness finding, the appellate panel found that:
Although the prior art appears to suggest combining an opioid, such as hydrocodone, with various NSAIDs, . . . [t]here appears to be no record of evidence of prior art teaching or suggesting the enhanced biomedical effect of the combination of hydrocodone and ibuprofen.
Additionally, the district court excluded some evidence of unexpected results because those results were discovered after the patent had issued. In disagreement, the panel would allow such evidence:
Evidence developed after the patent grant is not excluded from consideration, for understanding of the full range of an invention is not always achieved at the time of filing the patent application. It is not improper to obtain additional support consistent with the patented invention, to respond to litigation attacks on validity.
The inherent contradiction of this opinion: Obviousness is judged at the time of the invention, but this case allows evidence that was developed after the invention to be used in determining obviousness.