A patent is a right secured through law on an invention that fulfils features of novelty, non-obviousness or inventive step and utility or industrial application. The process of obtaining a patent is called patent prosecution. The process entails preparing and filing a patent application through opposition to the issuance of a patent or the rejection or abandonment of the application. After examination of the application and acceptance of the specification of the invention, a patent application is published for opposition before the grant of a patent. This is also known as pre-grant opposition. The Patents Act 1970, as amended by the Patents (Amendment) Act 2005, specifies the grounds on which the application may be opposed. An application may be opposed on the following grounds:
wrongful obtention of the invention;
publication before the priority date of the claim;
the priority date of a claim in a specification being earlier than the application;
public knowledge or public use of the invention in India;
not being an invention or entitled to be patented under the act;
failure to disclose information required by the controller;
in the case of a convention application, failure to apply within 12 months of the date of the first application;
insufficient description of the invention in the complete specification;
wrongful mention of the source or geographical origin of biological material used for the invention; and
knowledge of the invention within the local or indigenous community in India.
The opposition ground that the subject of any claim is not an invention or is not patentable under the act is often raised as an argument to combat a patent application, and it has become fertile ground for generic drug manufacturers to raise oppositions against the patent applications of pioneer drug manufacturers in the new product patent regime. For example, the pharmaceutical company Novartis was recently denied a patent in respect of its drug Glivec. Glivec is used to treat chronic myeloid leukaemia, a rare cancer. It fights the cancer by cutting off an enzyme that causes cells to become cancerous. A multiple pre-grant opposition against Novartis's product patent application (1602/MAS/1998) for a beta-crystal form of methanesulphonic acid salt, commercially called imatinib mesylate, was filed before the Chennai patents controller in regard to an invention entitled "crystal modification of AN phynyl-2-pyrimidineamine derivative, processes for its manufacture and use". The applicant claimed that the invention involved two improvements on the current invention: (i) the imatinib-free base had been chemically changed into a salt form; and (ii) a particular crystal form of the salt had been created through human intervention. Cipla Ltd, Ranbaxy Laboratories, Natco Pharma, Hetero Drugs and the Cancer Patients Aid Association India opposed this patent application under Section 3(d) of the Patents Act.
Relying on the technical expert's opinion with regard to the efficacy of the drug, as required under Section 3(d), the controller held that the patent application claimed only a new form of a known substance without making any significant improvements in efficacy, and hence constituted non-patentable subject matter.
Further pre-grant oppositions are in the pipeline. Oseltamivir, a drug which became popular as a result of the possible bird flu epidemic, was developed by Gilead Sciences and sold globally by Roche under the brand name Tamiflu. A pre-grant opposition application is now pending against it at the New Delhi Patent Office. The pre-grant opposition application was filed on the grounds that:
it is a known prior invention;
the claim is invalid; and
there is a lack of novelty or inventive steps.
Similarly, the Manipur Network of Positive People and the Indian Network of People have filed pre-grant oppositions at the Kolkata Patent Office against the anti-HIV drug Combivir, which is manufactured by GlaxoSmithKline, alleging that it is not a new formulation.
The denial of a patent to the drug Glivec through a pre-grant opposition, as well as the various imminent pre-grant oppositions, leads to the consideration of the most important aspect of the present product regime - patent eligibility.