The disputed patent (IN 196774) for Tarceva — an epidermal growth factor receptor type 1 (EGFR1) inhibitor that is used for the treatment of non-small-cell lung cancer — is owned jointly by OSI Pharmaceuticals and Pfizer, but licensed to Roche. Generics company Cipla moved to market their own version of erlotinib, asserting that the '774 patent covered a derivative of a known substance — gefitinib (Iressa; AstraZeneca) — with no evidence of improved efficacy. Under Indian patent law, such derivatives must show improved efficacy to be patentable.
While these patent infringement proceedings were underway, Cipla discovered that Roche had filed two further applications for patents for different crystal forms (polymorphs) of Tarceva. The Court noted that, when applying for the '774 patent, Roche had not let the examiner know that they had pending applications for a single B polymorph, which is thermodynamically more stable than a mixture of polymorphs. Because this would have been relevant for tests of novelty, obviousness and efficacy, this omission was not consistent with the requirement of full disclosure.
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