Katten secured a decisive victory for Lupin Ltd. and Lupin Pharmaceuticals, Inc. in patent litigation brought by Vertex Pharmaceuticals Inc. involving generic versions of Vertex's cystic fibrosis drug Kalydeco® (ivacaftor) granules.
Following a bench trial in the US District Court for the District of Delaware, the court issued a decision in favor of Lupin on all claims, finding that Vertex failed to prove infringement of any asserted patent claims relating to formulations of ivacaftor. In a post-trial memorandum opinion and accompanying order issued August 24, 2026, the court rejected both Vertex's literal infringement and doctrine-of-equivalents theories and directed the parties to submit a proposed final judgment in favor of Lupin.
The case, Vertex Pharmaceuticals Inc. v. Lupin Limited et al., centered on four patents covering formulations of ivacaftor. The court held that Vertex failed to establish that Lupin's proposed generic product infringed any of the asserted claims, finding that Vertex's infringement theories improperly sought to expand the scope of patent claims that were narrowly prosecuted before the US Patent and Trademark Office. The court concluded that Vertex "is entitled to the patent claims that it prosecuted successfully, not the ones that it failed to prove," and rejected all of Vertex's patent infringement claims.
"This ruling reflects the court's careful analysis of both the patent claims and the prosecution history underlying the asserted patents," said Deepro Mukerjee, Chair of Katten's global Intellectual Property Department. "We're pleased to have secured this victory for Lupin on all infringement claims."
The Katten team representing Lupin was led by Intellectual Property Partners Deepro Mukerjee, Lance Soderstrom and Joseph Janusz, with considerable support from Litigation and Appeals and Critical Motions Partners Eric Werlinger and Timothy Gray.