The speculation seemed to have come to an end on June 26 2009 when the Intellectual Property Appellate Board (IPAB) gave its decision on the Novartis patent application directed to the beta crystalline version of imatinib mesylate (Gleevec), refusing the patent application. Novartis then filed a special leave petition (SLP) before the Supreme Court, which has issued notice to the respondents in the matter (Union of India and others) to decide the issue of maintainability.

The facts of the Novartis pre-grant oppositions are well known and this article is only an attempt to summarise the issues and the propositions of law that have been discussed in the judgment.

By way of background, Novartis AG, a Swiss pharmaceutical company, applied for patent number 1602/MAS/1998 claiming Swiss priority of July 18 1997 for an invention directed to a "beta crystalline form of imatinib mesylate". Cancer Patient Aid Association (CPAA), NATCO Pharma, CIPLA Ltd, Ranbaxy and Hetero Drugs filed pre-grant oppositions to the grant of patent on the application under section 25(1) of the Indian Patents Act.

The Assistant Controller of Patents in the pre-grant proceedings issued five distinct orders in January 2006 refusing the grant of a patent. Aggrieved by the orders, novartis filed writ petitions before the High Court of Madras which were later converted into appeals. Some of the main issues that were discussed in the judgment are discussed below.

On the reliability of experts affidavit

The IPAB observed that where experiments have not been conducted by the experts themselves, the reliability of the affidavit of such experts cannot be discredited. It is sufficient if the deponent (expert) supervises the experiments through a technical team of experts who are supposed to carry out the experiments under his supervision and guidance, based on which the group leader comes to a conclusion.

At another level, the IPAB also discussed the reliability of affidavit of employees. The IPAB held that if the affiants are employees, they generally tend to lose their impartiality when making averments and thus reduce their evidentiary value.

Disclosure requirement

With regard to the disclosure of prior art under Section 10(4) of the Indian Patents Act in the patent specification, the IPAB did recognise that under the law (Section 10(4)), disclosure of prior art is not mandatory but held that despite there not being any specific provision under the Indian law, the relevant prior art including the closest one ought to be disclosed in the patent specification and the applicant cannot be considered to have discharged its duty or obligation unless the prior art is disclosed so that the invention can be sufficiently distinguished over the prior art.

Comparative studies with regard to Section 3(d)

As the invention was directed to a novel beta crystalline form of imatinib mesylate, the unique provision of Section 3(d) of the Indian Patents Act was attracted. This section requires the applicant to establish in a case where the invention is directed to a new form of a known substance that there is an enhancement of the known efficacy of that substance over the known substance.