The Supreme Court's landmark rejection of Novartis's patent for the beta crystalline form of Imatinib Mesylate — marketed globally as Glivec — settled, for the first time at the apex level, what Section 3(d) of the Patents Act actually requires an applicant to show when claiming a new form of a known substance: enhanced therapeutic efficacy, not merely improved physical properties.

Background

Novartis sought an Indian patent for the beta crystalline form of Imatinib Mesylate, the active ingredient in its leukaemia drug Glivec, on the basis that this crystalline form offered improved bioavailability, better flow properties, and thermodynamic stability over the free base compound already known in the prior art (covered by Novartis's own earlier patent, since expired).

Section 3(d): The Core Provision

Section 3(d) — introduced through the 2005 amendments implementing India's TRIPS obligations — excludes from patentability the "mere discovery of a new form of a known substance which does not result in the enhancement of the known efficacy of that substance." It was drafted specifically to prevent "evergreening": the practice of securing new, extended patent protection for minor variations of already-known drugs, which can delay generic entry and keep medicine prices high.

The Supreme Court's Holding

The Court held that Novartis had not demonstrated the beta crystalline form possessed significantly enhanced therapeutic efficacy compared to the known substance — improved physical properties like better flow characteristics or bioavailability, without a showing of superior clinical/therapeutic effect, did not satisfy Section 3(d)'s enhanced-efficacy requirement. The patent application was accordingly rejected.

Significance