GSK to lose Tykerb exclusivity in India in 2019

A patent invalidation by India's Intellectual Property Appellate Board (IPAB) means GlaxoSmithKline plc (LSE:GSK; NYSE:GSK) will lose exclusivity for breast cancer drug Tykerb lapatinib in India in January 2019, more than two years sooner than expected. IPAB revoked a GSK patent that was set to expire in June 2021 citing obviousness. The patent covered the salt form of lapatinib. IPAB upheld a second GSK patent that expires in 2019 that covers the non-salt form of lapatinib, a HER1 and HER2 receptor kinase inhibitor. GSK said it is considering next steps.

In its rejection of the patent covering the salt formulation, IPAB cited Section 3(d) of the Indian Patent Act, which states that the "mere discovery of a new form of a known substance which does not result in the enhancement of the known efficacy of that substance" is not an invention and not patentable, unless it "results in a new product or employs at least one new reactant." IPAB also cited a decision earlier this year by India's Supreme Court denying a patent for cancer drug Glivec imatinib from Novartis AG (NYSE:NVS; SIX:NOVN) in which the court had said chemical properties such as stability "have nothing to do with therapeutic efficacy." GSK had argued that the salt formulation improved Tykerb's efficacy through enhanced physical stability and "superior moisture [a]sorption properties" (see BioCentury Extra, April 1). ...