Multinational drug major Astra Zeneca's attempts to have a patent protection for its branded lung cancer drug Iressa (geftinib) in the country have been challenged by two Indian companies.

The Delhi patent office will hear pleas of Hyderabad-based Natco Pharma and Mumbai-based GM Pharma as part of the patent pre-grant opposition process.

While Astra Zeneca's geftinib is costing over Rs 85,000 (30 tablets) for a month's treatment, Natco, the only generic competitor in Indian market, is selling it at Rs 10,200 (30 tablets). While a decision in favour of Astra Zeneca will compel Natco to withdraw its product, the rejection will see more generic competition in the market.

According to the Mumbai-based Cancer Patients' Aid Association (CPAA), many Indians fall victims to lung cancer. Among the eight lakh patients diagnosed with cancer every year in the country, almost four lakh are hit with tobacco-related cancer.

However, geftinib is not a common treatment for lung cancer patients in India.

"Indian doctors do not prescribe costly treatments such as geftinib. Even Indian generic version is beyond the reach of 60 per cent of lung cancer patients," CPAA said.

According to sources, Astra Zeneca had stopped the supply of its geftinib brand after the Indian generic maker introduced a low cost version of the drug.

"It has resumed the supply and is likely to have Rs 2 crore sales today. Natco must be selling Rs 24 crore worth geftinib in a year," the sources said.

The Indian companies feel that geftinib cannot get a patent right in India as the molecule is a pre-1995 one, thereby failing the criteria of "patentable drugs". Prior use and lack of inventive steps are the claims made to oppose the patent application.

Indian firms also feel that the convention application, as required under the Indian Patent Act, was not made within 12 months from the date of first application for protection made in the convention country, thereby making patent application redundant.