An Indian court is to issue a landmark judgment in the coming weeks after German drug company Bayer appealed a decision to over-rule its patent on the cancer drug sorafenib (marketed as Nexavar) so that a local producer could make a much cheaper version.

India’s patent controller issued a compulsory licence in March to local company Natco, which has since made the kidney and liver cancer drug sorafenib tosylate for $175 (£110; €139) per month, 97% less than the cost of sorafenib.

The compulsory licence—the first in India since patent laws were introduced in 2005—was granted to the request of Natco and considered to be in the interests of public health in India where cancer is a growing problem. Natco …