Reversing a summary judgment of invalidity on the ground of obviousness, the U.S. Court of Appeals for the Federal Circuit held that a genuine factual dispute existed because there appeared to be no record of evidence that the prior art taught or suggested the enhanced biomedical effect of a claimed analgesic drug combination. Knoll Pharmaceutical Co., Inc. v. Teva Pharmaceuticals, USA, Inc., Case No. 03-1300 (Fed. Cir. May 19, 2004) (per curiam, Newman, Archer & Prost, JJ.).
Knoll Pharmaceutical Co., Inc. (Knoll) appealed the summary judgment of invalidity of U.S. Patent No. 4,587,252 (the `252 patent), claiming compositions and methods for treating pain using a combination of hydrocodone and ibuprofen that provides a greater analgesic effect than that obtainable by use of either drug alone. Vicoprofen, a composition covered by the `252 patent, is marketed by Knoll as a pharmaceutical for pain relief.
Knoll sued the generic drug maker Teva Pharmaceuticals, USA, Inc. (Teva) for infringing the `252 patent on the basis of Teva’s Abbreviated New Drug Application (ANDA) seeking market authorization for an identical combination of hydrocodone and ibuprofen as found in Vicoprofen. The district court held all claims to be obvious on Teva’s motion for summary judgment because the prior art expressly taught the combination of an opioid with a non-steroidal anti-inflammatory drug (NSAID) and that there was a reasonable expectation of success in combining the narcotic analgesic hydrocodone with the NSAID ibuprofen.
Acknowledging that the prior art appeared to suggest an opioid-NSAID combination, the Federal Circuit concluded the summary judgment to be improper because the prior art failed to show the claimed greater analgesic effect of the claimed combination. The district court’s refusal to consider Knoll’s offer of evidence for unexpected results at trial was considered contrary to the patent’s express recognition of the "surprising" efficacy for the hydrocodone-ibuprofen combination. Clarifying that evidence developed after issuance should not be excluded to defend litigation attacks, the Court reasoned that, at the time of filing, understanding the full range of an invention is not always achieved nor is there a requirement for the invention’s properties and advantages be fully known in order for such evidence to be admissible in support of validity. Contradictory evidence of the failure of others in obtaining opioid-NSAID combinations further reinforced the existence of disputed facts in issue.
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