A synergistic effect that is predictable renders a claim obvious.

Novo Nordisk A/S v. Caraco Pharmaceutical Laboratories, Ltd., No. 2011-1223 (Fed. Cir. June 28, 2013).

After being sued for infringement, a generic drug manufacturer sought to invalidate a patent for treating diabetes with the combination of two drugs that have a synergistic effect. Since it was well-known in the art that using two drugs with different mechanisms for attacking diabetes is more effective than one, the District Court invalidated the patent as obvious, explaining that the key obviousness inquiry was “whether the combination yielded an unexpected synergistic effect.” It found the level of synergy predictable since a reasonable artisan seeking to combine the two drugs “would base his expectations upon prior art” involving similar combinations, some of which “produce beneficial and even synergistic results.”

Additionally, the District Court held the patent unenforceable due to inequitable conduct. The author of a study crucial to the prosecution of the patent had submitted an affidavit to the PTO, but omitted skeptical remarks he made elsewhere about the study, and omitted that the results cited were not measured according to his original test plan. Also, the lawyer who prosecuted the patent described the study as “clear evidence” of synergy, whereas the study’s language indicated the results “strongly suggested” synergy. The court deemed the study omissions and the lawyer’s misrepresentation material and intentional.

The Federal Circuit affirmed the obviousness holding, rejecting the patentee’s argument that the court misallocated the burden of persuasion by forcing the patentee to present evidence of unexpected results once a prima facie case of obviousness was established. It also rejected the patentee’s assertion that the lower court did not properly review the scope and content of the prior art and its argument the trial court should have deferred to the findings of the PTO. The Federal Circuit found no error in the lower court's finding that the synergistic effects of treatment using the two drugs were predictable, thereby rendering the combination obvious.

The inequitable conduct finding was reversed because the Federal Circuit found the author’s statements to be generally consistent and did not view the omissions as material since he “disclosed the results of his original protocol to the examiner” and did not “expressly undermine his stated opinion.” And, while “troubling,” the attorney’s misstatement was not material since he otherwise “employed carefully-chosen language which tracked the qualified nature” of the expert’s opinion.

The dissent claimed that the majority had misapplied the law of obviousness because “the question is not whether it would have been obvious to look for synergistic combinations; the question is whether it was obvious that [the claimed combination] would be 800% more effective than the additive effect of the components separately.”

A copy of the opinion can be found here.