In SENJU PHARMACEUTICAL CO. v. LUPIN LTD., Appeal No. 2013-1630, the Federal Circuit affirmed a district court’s obviousness judgment, even though the PTO previously allowed the claims over the same art after reexamination.

Senju sued Apotex for patent infringement, and the claims were found invalid for obviousness. During litigation, Senju petitioned for reexamination of the patent and the PTO allowed one amended claim and five new claims over the references from the Apotex litigation.  Senju then sued Lupin on the reexamined claims and the district court again found the claims invalid for obviousness over the Apotex references. 

The Federal Circuit affirmed the obviousness judgment. The Federal Circuit determined that, while the district court may have applied the same references as the Apotex claims, the district court did not rely on the same analysis.  Rather, the Federal Circuit held the district court properly analyzed the scope and content of the art, applied the art to the claims, and identified a motivation to combine in the art. Regarding Senju’s arguments of unexpected results relied on during reexamination, the Federal Circuit agreed it was not clear error for the district court to conclude the unexpected results evidence did not withstand scrutiny by Lupin’s experts and the district court.

Judge Newman dissented, stating the district court failed to give deference to the PTO’s finding of validity and unexpected results in the narrowed reexamined claims. She argued the majority used impermissible hindsight because the prior art taught away from the claimed concentrations. Judge Newman also argued various scientific references, the experimental record, and the success of the commercial embodiment all supported a conclusion the claimed subject matter would not have been obvious to a person of ordinary skill at the time of the invention.