Pfizer is set to appeal a decision after the authorities in India revoked the patent on the US major's cancer drug Sutent.

Sutent (sunitinib) a treatment for liver and kidney cancer, was granted a patent in India in 2007 but that decision was challenged by generics specialist Cipla and Natco Pharma. India's Patent Board has backed the latter firm, saying that "the invention that is claimed in the patent does not involve any inventive step".

Jazz Tobaccowalla, Pfizer India's managing director, said that "we believe the decision undermines intellectual property rights in India and we will vigorously defend our basic Sutent patent". As such, the firm will appeal the ruling at the Intellectual Property Appellate Board.

He added that "recognising affordability of cancer treatment can be a challenge for some patients", but noted that Pfizer's Sutent Patient Assistance Programme has been running in India for over four years._

Last month, the High Court in Delhi dismissed a patent infringement case filed by Roche over Cipla's version of its cancer drug Tarceva (erlotinib). Also last month, Bayer failed in the first stage of its bid to stop Natco from selling a cheap version of its liver and kidney cancer drug Nexavar (sorafenib) in India.

The pharmaceutical industry is also keeping a very close eye on the high-profile case of Novartis' legal challenge against India's patent laws following rejection in 2006 of the company's patent application for its leukaemia treatment Glivec (imatinib).