Law Settled in the Case
1. Section 3(d) and Section 2(1)(ja) of the Patents Act are not mutually exclusive:
A patent application may be novel and still fail the test under Section 3(d) if the claimed compound is a derivative of a known substance without demonstrating enhanced therapeutic efficacy. Even if an invention meets the requirements under Section 2(1)(j) or 2(1)(ja), it can still be rejected under Section 3(d).
2. Enhanced efficacy under Section 3(d) must be “therapeutic efficacy”:
Relying on Novartis AG v. Union of India, (2013) 6 SCC 1, the Court reiterated that the test of efficacy in pharmaceutical inventions relates strictly to therapeutic efficacy. Physico-chemical improvements like solubility, stability, or reaction yield are not sufficient unless directly linked to enhanced therapeutic effect.
3. Routine experimentation by a person skilled in the art (PSITA) negates inventive step:
If a claimed invention involves modifications (e.g., substituting ethoxy with methoxy) that are within the realm of routine choices or predictable variations, such invention lacks an inventive step under Section 2(1)(ja).
4. Burden of proof on the applicant to demonstrate inventive step and therapeutic efficacy:
It is the responsibility of the applicant to provide adequate and specific data supporting therapeutic superiority or inventive technical advancement over the prior art. Unsupported claims or reliance on non-therapeutic advantages are insufficient.
5. “Teaches away” argument requires strong proof:
The Court clarified that merely because a prior art does not directly teach the invention does not imply it "teaches away" from it. The absence of contrary suggestion is not proof that the prior art discourages the claimed invention.
6. Disclosure in prior art includes generic suggestions:
Where prior art generically suggests both methoxy and ethoxy substitutions, and the invention merely selects one, it may not suffice to demonstrate inventiveness if no unexpected results or efficacy improvements are shown.
Zeria Pharmaceutical Co. Ltd. Vs. The Controller of Patents:May 27, 2025:C.A. (COMM.IPD-PAT) 452/2022:2025:DHC:4431: High Court of Delhi :Hon’ble Mr. Justice Saurabh Banerjee
