Court’s Decision
The Delhi High Court dismissed the appeal against the Patent Office’s refusal to grant a patent for Indian Patent Application No. 3630/DELNP/2011. The Court upheld the Controller’s findings that the claimed compound lacked an inventive step under Section 2(1)(ja) of the Patents Act, 1970 and also failed to demonstrate enhanced efficacy under Section 3(d) of the Act. The Court concluded:
“The subject application is neither falling within Section 3(d) nor Section 2(1)(ja) of the Act.”
Facts
The case pertained to a divisional application filed on 13.05.2011 for a compound described as 2-[(2-hydroxy-4,5-dimethoxybenzoyl) amino]-1,3-thiazole-4-carboxylic acid methyl ester. The application was rejected by the Controller of Patents on 20.10.2016 on the grounds that:
- The invention lacked novelty and inventive step in view of prior art documents D1 (EP 0994108 A1) and D2 (US 5981557 A).
- It was also barred under Section 3(d) of the Act for being a mere derivative of known substances without enhanced efficacy.
Issues
- Whether the claimed compound qualified as an invention under Section 2(1)(ja) of the Act.
- Whether the claimed compound was barred under Section 3(d) for being a derivative of a known substance lacking enhanced efficacy.
Petitioner’s Arguments
- The Controller misapplied the prior art documents and failed to recognize the technical advancement of the invention.
- Prior art D1 “teaches away” from the claimed compound.
- The compound in D2 has an ethoxycarbonyl group, whereas the claimed invention has a methoxycarbonyl group, which was not obvious.
- Experimental data showed higher yield, reduced reaction time, and lower impurities.
- The rejection suffered from “impermissible hindsight” and did not consider an expert affidavit asserting the inventive step.
Respondent’s Arguments
- The difference between the prior art and the claimed compound was minor (ethoxy vs. methoxy), and thus obvious.
- Both D1 and D2 belong to the same field and were authored by the same inventor as the claimed application.
- The compound fell squarely under Section 3(d) as a derivative without any proven enhanced “therapeutic efficacy”.
- Experimental data referred only to process efficiency, not therapeutic efficacy as required under the law.
Analysis of the Law
- The Court reiterated that Section 3(d) and Section 2(1)(ja) must be independently satisfied.
- Novelty alone is not sufficient if the invention fails to overcome the bar under Section 3(d).
- Enhanced efficacy under Section 3(d) must mean “therapeutic efficacy” as interpreted by the Supreme Court in Novartis v. Union of India.
- Section 2(1)(ja) requires a “technical advance” that is not obvious to a Person Skilled In The Art (PSITA).
Precedent Analysis
- Novartis v. Union of India (2013): Reinforced the requirement of “therapeutic efficacy” and narrow interpretation of Section 3(d).
- Novozymes v. Assistant Controller of Patents: Section 3 and Section 2(1)(j)/(ja) operate independently.
- Agriboard International LLC v. Deputy Controller: For inventive step, the Controller must compare the prior art and explain how the invention would be obvious.
- Astrazeneca AB v. Torrent Pharmaceuticals Ltd.: Mere absence of “teaching away” is not enough to establish an inventive step.
Court’s Reasoning
- The Controller correctly identified the closest prior art (Example 6 of D2) and found that substituting ethoxy with methoxy was routine experimentation.
- “Methoxy” was already listed in the prior art as a lower alkoxy group.
- The applicant failed to show therapeutic efficacy; the experimental data only addressed process efficiency.
- The Court rejected the claim that D1 teaches away from the invention, holding that absence of teaching is not the same as active discouragement.
Conclusion
The Court upheld the rejection of the patent application, holding that:
- The claimed compound was a mere derivative of prior art compounds without enhanced therapeutic efficacy.
- Substituting methoxy for ethoxy did not involve an inventive step.
- The patent application was rightly rejected under both Sections 3(d) and 2(1)(ja) of the Patents Act.
Implications
This judgment reinforces that:
- Patent applicants must clearly demonstrate enhanced therapeutic efficacy for claims to survive Section 3(d).
- Subtle structural changes that fall within routine experimentation without technical advancement do not meet the “inventive step” threshold.
- The standard for patentability in pharmaceutical inventions remains stringent to prevent evergreening.
