Section 3(d) of the Patents Act prevents the grant of a patent to a new form of a known substance unless it demonstrates significantly enhanced therapeutic efficacy.

The Legal Question Before the Court

Novartis AG sought a patent in India for the beta-crystalline form of Imatinib Mesylate — marketed globally as Glivec, a breakthrough cancer treatment. The Imatinib molecule itself had been known prior to the claimed patent date. Novartis claimed the beta-crystalline form was a distinct, improved substance warranting a new patent. The Indian Patent Office rejected the application under Section 3(d) of the Patents Act, 1970, which was challenged by Novartis as unconstitutional and inconsistent with India's obligations under the TRIPS Agreement.

The Court's Decision

The court upheld the rejection of the patent application and dismissed Novartis's challenge to Section 3(d). The provision is constitutionally valid and consistent with India's TRIPS obligations. The flexibilities built into Article 27 of TRIPS permit member states to define what constitutes a patentable invention, and India's choice to require demonstrated enhanced efficacy for new forms of known substances is within those flexibilities.

On the merits, the beta-crystalline form of Imatinib Mesylate did not satisfy Section 3(d): Novartis had not demonstrated that it possessed "significantly enhanced" therapeutic efficacy compared to the free base form of Imatinib already known in the prior art. The improvement in bioavailability demonstrated was not, in the court's assessment, a demonstration of enhanced therapeutic efficacy.

The Court's Reasoning

The court examined the legislative history and purpose of Section 3(d). Parliament introduced it specifically as a safeguard against "evergreening" — the practice by which pharmaceutical patent holders extend their monopoly by obtaining successive patents on minor modifications of a known compound, thereby delaying the entry of affordable generic versions. This practice had been widely criticised as a barrier to access to essential medicines in developing countries.

The court interpreted "efficacy" in Section 3(d) narrowly as "therapeutic efficacy" — the actual clinical benefit to the patient — not merely physico-chemical properties such as improved flow characteristics or bioavailability. An improvement in a physico-chemical property is relevant only insofar as it translates into demonstrably enhanced therapeutic effect. Novartis did not demonstrate this.

Practical Implications — What This Means Today

Novartis is the cornerstone of Indian pharmaceutical patent law. It has global significance as a declaration that India will use its TRIPS flexibilities to protect access to affordable medicines. The ruling has been cited extensively in international policy discussions on the balance between intellectual property protection and access to healthcare.

For IP practitioners advising pharmaceutical and life sciences companies, this case defines the standard for patentability of "new forms" of known substances in India. Any patent application involving a salt, polymorph, ester, ether, or isomer of a known compound must demonstrate enhanced therapeutic efficacy — not merely improved physico-chemical properties — to qualify for protection under Section 3(d). Patent portfolio strategy for pharmaceutical companies operating in India must be constructed with this constraint at the centre.

Relevant Statutory Provisions

  • Section 3(d), Patents Act, 1970 (as amended in 2005) — What is not an invention — new forms of known substances without enhanced efficacy
  • Section 2(1)(j), Patents Act, 1970 — Definition of "invention" — novelty and inventive step
  • Article 27, TRIPS Agreement — Patentable subject matter — TRIPS flexibilities

Analysis by Vinode V. Luka, Advocate | Published: May 2026 | Last reviewed: May 2026