The Indian government is challenging the patent legitimacy of two more big-selling biotech drugs. On February 28, the Indian patent office began reviewing a plea from Natco Pharma of Hyderabad, India to produce generic versions of two patent-protected oncology drugs under compulsory license (CL)— Tarceva (erlotinib) owned by Roche, of Basel, and partners OSI, of New York, and Sutent (sunitinib), produced by New York-based Pfizer. This has happened before, as authorities refused in 2006 to uphold the patent on leukemia drug Glivec, held by Novartis, also of Basel, on the grounds that small tweaks should not extend patent life. Roche has now lost its case against Cipla, of Mumbai, India: on March 19, the Delhi High Court ruled Cipla could continue to sell its generic version of Tarceva. “Being a tweaked version [-] Tarceva's patent is invalid and at $120 per tablet it is unaffordable. I can sell it for $20,” says Cipla managing director Yusuf Hamied. The Natco case invokes recently introduced CL rules, granted for use in urgent or emergency situations, and Natco wants to produce the drugs for export to Nepal. If permission is granted, it may trigger a slew of CL applications from other companies, says Mohan Nair, Chennai-based patent consultant to pharmaceutical companies. This will surely make multinational drug companies “think twice” before investing in India in research and development, he says. KSJ