Incremental Patents: IPAB Creates Confusion - Part I

The Intellectual Property Appellate Board (IPAB), so called specialized and apex body for patent and trademark disputes, has finally put the last nail in the three year old, high-profile dispute concerning the patentability of Novartis’s anticancer drug Glivec, specifically beta-crystalline variant of Imatinib Mesylate which earlier got rejected by the Indian Patent Office. Well we personally believe this was one of the important cases that possibly will be deciding factor for incremental patents in India. Though the Appellate Board took a lengthy period of three years to decide the matter but the decision made by the Appellate Board is nothing more than confusion and despair for the Indian Patent Law.

The application for beta-crystalline Imatinib Mesylate (1062/MAS/1998) was filed by Novartis on July 17, 1998 claiming priority from corresponding Swiss application. Importantly, when Novartis filed the application in India, Switzerland was not recognized as a conventional country to India. Technically, a priority can only be claimed to a foreign patent application filing date if the country in which the patent application is first filed is conventional country to the later filed country (concept originated from Paris Convention). In fact, claiming priority from Switzerland was one of the grounds made during the pre-grant opposition. The beta-crystalline Imatinib Meyslate application was filed in 1998 but it was not taken for examination till 2005 (mail-box application). Post 2005, the application was separately opposed by Cancer Patients Aid Association, Natco Pharma Ltd., Cipla Ltd., Ranbaxy Ltd. and Hetero Drugs Ltd. and subsequently got rejected by the Chennai Patent Office on January 25, 2006. Following refusal from the Chennai Patent Office, Novartis filed writ petitions before the Madras High Court against the Assistant Controller decision to reject patent application for beta-crystalline imatinib mesylate. However, during the pendency of the writ petitions, the Central Government by notification made the IPAB operational and following that the Madras High Court transferred the writ petitions to the Appellate Board to decide the patentability of the beta-crystalline variant of Imatinib Mesylate.

On June 26, 2009, the Appellate Board finally denied to allow beta-crystalline imatinib mesylate application for grant of a patent. In its 192-pages decision (a copy of judgment can be found on the website of SpicyIP and we sincerely appreciate Shamnad for the same), the Appellate Board detailed the lengthy arguments and counter arguments made by the parties during the hearing focusing on issues of priority date, anticipation, inventive step, selection invention and section 3(d). Odd 133 pages discussed the arguments made by the parties, however, one of the arguments that we would like to make special mention is argument made by Novartis Counsel in support of patentability of beta-crystalline imatinib mesylate. Novartis counsel interestingly brought concept of selection invention in context of polymorph which was quite unlikely. This argument was strongly opposed by the defendants. The concept of selection invention is often discussed when a particularly compound/group of compounds is claimed from earlier known markush structure, even selection of specific salt of drug compound is considered to be selection invention. During the hearing, Novartis Counsel puzzled the Appellate Board by combining two different phenomenons to make case of selection patent, first selection of mesylate salt from large number of known salts of imatinib and second selection of beta-crystal. Interestingly, Novartis Counsel was successful in making the Appellate Board accept the argument for selection invention in context of polymorph application and also to consider that such selection constitute inventive step.