India’s Supreme Court began to hear final arguments this week in a long legal battle in which the drug company Novartis is challenging what patients’ groups have described as a key public health safeguard in India’s patent law.

Novartis is challenging a decision by India’s patent office in 2006 to reject its patent for the anticancer drug imatinib mesilate under section 3(d) of the patent law, which prohibits patents on new forms or new uses of known molecules.

The legal battle over imatinib in India started eight years ago when the Cancer Patients Aid Association, a patients’ interest group, objected to India’s decision to grant Novartis exclusive marketing rights for the drug, marketed as Glivec.

The association had said that the exclusive marketing rights would block local generic versions of the drug, whose prices were about 10 times lower than the price of Glivec, for which patients paid about 120 000 rupees (£1400; €1700; $2220) …