India has partly revoked patents granted to a Roche Holding AG breast cancer medicine, the Swiss firm said on Sunday, in the latest regulatory setback for western drugmakers trying to crack the fast-growing market. A Roche spokesman said the company was considering what further course of action to take. The Kolkata Patent Office said the company had failed to file its patent applications for Herceptin correctly and the patents had not been revoked. Roche declined to comment on that statement. Herceptin is Roche's third biggest seller and registered global revenues of 3.08 billion Swiss francs in the first half of this year. It treats breast cancer patients who have tumours that generate a protein called HER-2, which tends to make their disease more aggressive. Rulings on intellectual property and pricing have frustrated attempts by a number of foreign drugmakers to sell their medicines in India. On Friday, India revoked a patent granted to GlaxoSmithKline's for breast cancer drug Tykerb, following on from a landmark court ruling in April disallowing patents for incremental innovations. Roche has adapted its business model in India to increase affordable access to drugs and try to stave off trouble from patent authorities. In August 2012, it introduced cut-price versions of Herceptin and another cancer drug MabThera, under an alliance with Indian generics firm Emcure Pharmaceutics. Last year, India revoked patents granted to Roche's hepatitis C drug Pegasys, Pfizer Inc's cancer drug Sutent, and Merck & Co's asthma treatment aerosol suspension formulation. All were revoked on grounds that included lack of innovation. The revocation of Pfizer's Sutent has been set aside by the Intellectual Property Appellate Board on a "procedural issue" and the matter has been "remanded back", the Kolkata patent office said. (Reuters)