Otsuka Pharmaceutical Co., Ltd. v. Lupin Ltd.

Otsuka Pharmaceutical Co., Ltd. v. Lupin Ltd. The Federal Circuit affirmed non-infringement of both patents because Otsuka failed to prove by a preponderance that Lupin's DMF process reaches practical completion of the reduction reaction before more than one molar equivalent of sodium borohydride is added. The court also affirmed invalidity of the asserted '735 patent claims for obviousness, finding no clear error in the district court's motivation-to-combine and secondary-considerations analyses, and upheld forfeiture of Otsuka's challenge to Lupin's expert's qualifications. In Hatch-Waxman cases involving process and product-by-process claims with quantitative reagent limitations, patentees bear the evidentiary burden of proving that the accused ANDA process actually operates within the claimed range — general expert experience and flawed experimental data will not carry that burden at the clear-error standard. Affirmed Non-infringement (both patents): The asserted claims require a hydrogenating agent in an amount of 0.25–1 (or 0.25–0.5) molar equivalents; Lupin's DMF process adds at least 1.2 molar equivalents of sodium borohydride. The district court construed 'amount' as the quantity present while the reaction is 'taking place' until practical completion — a construction Otsuka itself advocated. Even accepting that construction, Otsuka's only evidence (Experiments 109/115 and Dr. Roush's expert testimony) was undermined by data anomalies, different reaction conditions, and reliance on the same flawed experiments, so the Federal Circuit found no clear error in the non-infringement finding. Forfeiture of expert-qualification challenge: Otsuka failed to file a Daubert motion or timely object at trial to Lupin's expert Dr. Dichtel testifying as a person of ordinary skill in the art. Under Third Circuit law, that failure forfeited the challenge; the Federal Circuit reviewed for abuse of discretion and found none, declining to reach the merits. Obviousness of '735 patent claims: The district court found clear and convincing evidence that a POSA would have started with Kondo (a known tolvaptan synthesis reference), been motivated to reduce the sodium borohydride amount in Kondo's reduction step for cost, safety, and process-simplification reasons, and had a reasonable expectation of success. The Federal Circuit found no clear error in crediting Dr. Dichtel's testimony over Dr. Roush's on motivation. Secondary considerations: The Yukawa declaration compared the claimed process to a process using twice Kondo's reagent amount rather than Kondo itself, undermining the unexpected-purity argument. Although the district court apparently overlooked evidence of unexpected yield improvement (30% vs. 82–93%), the Federal Circuit held any error harmless because weak secondary considerations cannot overcome a strong prima facie obviousness case. This is a nonprecedential disposition; it should not be cited as binding authority, though it illustrates the Federal Circuit's application of the clear-error standard to bench-trial infringement findings in quantitative-limitation cases and the importance of timely Daubert practice. § 103 infringement claim construction Hatch-Waxman / ANDA waiver / forfeiture non-precedential § 103 infringement claim construction Hatch-Waxman / ANDA waiver / forfeiture non-precedential infringement § 103 waiver / forfeiture non-precedential