Introduction
The Indian Patents Act, 1970, purposes that only innovations that qualify the patentability criteria are eligible for patent protection. To uphold this standard, Section 3(d) stipulates that new forms of known substances can only be patented if they demonstrate a significant enhancement in efficacy compared to the known substances. This provision aims to prevent the patenting of minor modifications without substantial benefits, thereby fostering meaningful advancement in the field and prevent the evergreening of patents.
The obligation under Section 3(d) raises various issues such as selection of suitable tests for generating comparative data, relevance of additional data generated after the filing of the patent application, the timing of submission of such additional data and co-relating the additional data with enhanced efficacy and linking it to the technical effects described in the specification.
While the decision of the Supreme Court in Novartis AG v. Union of India1 is generally referred for issues related to Section 3(d), the decision in the Novartis case followed more-or-less a facts specific approach which left several issues unaddressed. A few decisions in the recent years by the different High Courts have provided further clarifications. The decision of the Delhi High Court in Ischemix LLC v. The Controller of Patents2 is of particular importance in this regard as it provides useful insights and clarity with respect to overcoming Section 3(d) objections and relevancy of post filing data.
The decision was rendered by the High Court in an appeal filed by Ischemix LLC against the rejection of patent application number 9739/DELNP/2011 under Section 3(d) by the Indian Patent Office. The appellant contended that they had submitted data from in-vitro and in-vivo studies as well as clinical trial data and reports from two experts at the time of filing of the hearing submissions to support their case for enhanced therapeutic efficacy of the claimed isomer of a known compound of medicinal value. The respondent asserted that though comparative data had indeed been included in the submissions filed by the applicant after the oral hearing proceedings, a clear and definitive explanation to co-relate the data with enhanced therapeutic efficacy was not made.
Taking into account the specific facts and circumstances of the case, the Court first directed the appellant to submit a note to explain the co-relation of the data with enhanced efficacy and subsequently remanded the application to the Patent Office for a re-hearing after the Patent Office agreed to re-examine the application in the light of the explanatory note of the appellant.
While adjudicating the appeal, the High Court had the opportunity to dwell upon several issues relating to Section 3(d) and some significant observations were made by the Court on such issues.
Efficacy as Therapeutic Efficacy
The High Court referred to the Supreme Court's decision in Novartis AG v. Union of India3, which interpreted efficacy as therapeutic efficacy for pharmaceutical products and set the benchmark for demonstrating "significant enhancement of therapeutic efficacy" under Section 3(d) for patent applications covering new forms of known substances of medicinal value. The Delhi High Court emphasized that in cases covering medicinal inventions falling under Section 3(d), the applicants must precisely demonstrate enhanced therapeutic efficacy of the claimed form over the known substance.
Comparative Data and Co-relation with Enhanced Efficacy
Referring to its previous judgement inDS Biopharma Limited v. The Controller of Patents and Designs and Anr.4, the High Court pointed out that the applicant is required to submit comparative efficacy data to demonstrate enhanced therapeutic efficacy on the basis of identified known substances. The High Court stressed the importance of submitting such data in the form of comparative tables and pointed out that the same may be in-vitro and in-vivo data and clinical trial results along with a clear explanation as to the manner in which such data establishes enhanced therapeutic efficacy.
Admissibility of Post-Filing Data
The Court emphasized that the patent application, at the time of filing itself, ought to contain some data which demonstrates enhancement of efficacy. However, if additional data becomes available at a later stage it may be submitted by the applicant. The Court also cited the judgment of the Calcutta High Court inOyster Point Pharma Inc. v. The Controller of Patents and Designs5, where the Calcutta High Court had acknowledged the inherent complexities and protracted nature of the process of drug development. The Calcutta High Court had noted that empirical evidence of a drug's efficacy may not be available when filing the patent application, primarily because such data typically emerges only after the execution of clinical trials.
Basis for Additional Data in the Specification
Referring to the ruling inAstraZeneca AB and Ors. v. Intas Pharmaceuticals Limited and Ors6, the Court stipulated that post-filing data would be admissible only if it confirms the existence of technical effects already described in the complete specification and not to establish a new technical effect for the first time.
Timing of Submission of Post-Filing Data
The Court asserted that the additional data should be, at the very least, submitted before the final oral hearing at the Patent Office. The Court referred to the common practice of submitting efficacy data in written submissions after oral hearings and cautioned against this approach, noting that presenting such data in hearing submissions may not be entirely understandable for the Controller if it is not explained by the applicant during the hearing.
Conclusion
The Delhi High Court's stand in Ischemix LLC case, which recognizes the lengthy and complex process of drug development, strikes a balance between allowing post-filing data and maintaining the integrity of the original application. Further, the guidelines laid down by the Court in the will be extremely useful in streamlining the patent application process for applications covering inventions falling under Section 3(d). However, the issues concerning Section 3(d) are varied and it is hoped that more clarifications would be forthcoming when patent cases concerning Section 3(d) with different sets of facts and circumstances reach the Courts for adjudication.
Footnotes
1 Novartis AG v. Union of India [(2013) 6 SCC 1]
2 Ischemix LLC v. The Controller of Patents [C.A.(COMM.IPD-PAT) 33/2022]
3 Novartis AG v. Union of India [(2013) 6 SCC 1]
4 DS Biopharma Limited vs The Controller of Patents and Designs and Anr. [2022:DHC:3563]
5 Oyster Point Pharma Inc. v. The Controller of Patents and Designs [MANU/WB/1544/2023]
6 AstraZeneca AB and Ors. v. Intas Pharmaceuticals Limited and Ors. [2020/DHC/3125]
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