Natco challenges Novartis' patent application

Hyderabad-based Natco Pharma Limited has opposed an application made by Novartis India Limited for grant of patent for an anti-cancer drug "� Imatinib Mesylate, a press release said.

Novartis had obtained exclusive marketing rights (EMRs) for Imatinib Mesylate, that is useful in the treatment of certain forms of chronic myeloid leukemia, in November 2003.

Natco Pharma had challenged the grant of EMRs for this drug to Novartis and the case is at present before the Supreme Court of India.

Natco Pharma has now filed a pre-grant opposition application with the Controller of Patents, Government of India, challenging the validity of the patent application concerning crystalline modification of Imatinib Mesylate.

To curb a widely prevailing practice called the 'evergreening' strategies, which essentially involves a manufacturer obtaining patent beyond the basic molecule, the Indian Patents Act was amended in April 2005.

This involved excluding grant of patents to salts, esters, ethers, polymorphs and similar forms, complexes and combinations of known substances unless they differ significantly in properties with regard to efficacy.

The basic ground of opposition is that the application for patent would squarely fall within the concept of 'evergreening' as the polymorph claimed is the same as that of the 1993 molecule.

Natco Pharma has also claimed 'lack of novelty and inventive step' in the said application for grant of patent.