WASHINGTON, D.C., May 21, 2026 – A team from Knobbe Martens secured a substantial appellate victory on behalf of Lupin Ltd., ensuring patients a cost-effective option for treating life-threatening kidney disease.
In an opinion issued today, the U.S. Court of Appeals for the Federal Circuit affirmed a judgment of non-infringement in favor of Lupin in Hatch-Waxman litigation against Otsuka Pharmaceutical Co., Ltd.
In July 2024, the firm obtained a verdict in U.S. District Court in favor of Lupin’s efforts to market a generic version of Jynarque® (tolvaptan). Following a bench trial, U.S. District Court Judge Richard G. Andrews found for Lupin on non-infringement of the two patents-in-suit and invalidated one of them.
In today’s opinion, the Federal Circuit rejected Otsuka’s arguments, finding no clear error in the district court’s conclusion that Otsuka failed to prove infringement of either patent-in-suit and affirming the invalidation of Otsuka’s method patent.
The Knobbe Martens team representing Lupin was led by William Zimmerman and Carol Pitzel Cruz, Co-Chairs of the firm’s Hatch-Waxman Litigation practice, and litigation partner Jared Bunker.
Commenting on the case, Mr. Zimmerman stated, “We are very pleased with this decision, which continues our longstanding commitment to empowering pharmaceutical companies to provide more patients with access to life-saving medical treatment.”
About Knobbe Martens’ Hatch-Waxman Litigation Practice
For decades, Knobbe Martens has guided leading generic pharmaceutical companies in bringing their versions of best-selling drugs to market. Our experience informs practical legal strategies across all aspects of pharmaceutical IP, with a focus on helping clients maximize R&D value, protect IP rights, and navigate regulatory requirements efficiently. Learn more about the firm’s successful track record in Hatch-Waxman litigation here.
About Knobbe Martens
Knobbe Martens protects the ideas that drive innovation and propel our world forward. As a leading intellectual property and technology law firm, clients worldwide rely on us to safeguard their products, brands, and technologies through strategic counsel and high-impact litigation. With offices across the U.S., our lawyers and technology specialists collaborate to deliver tailored solutions for clients ranging from multinational corporations to start-ups and emerging companies at every stage. Discover more at www.knobbe.com.
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