For chemical and pharmaceutical inventions, Section 3(d) of the Patents Act, 1970 poses a significant challenge for the applicants while prosecuting patent applications at the Indian Patent Office (IPO). Section 3(d) prohibits the patenting of 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 or the mere discovery of any new property or new use for a known substance or of the mere use of a known process, machine or apparatus unless such known process results in a new product or employs at least one new reactant. An explanation of this provision further states that “For the purposes of this clause, salts, esters, ethers, polymorphs, metabolites, pure form, particle size, isomers, mixtures of isomers, complexes, combinations and other derivatives of known substance shall be considered to be the same substance, unless they differ significantly in properties with regard to efficacy.”
Therefore, establishing the enhancement of the therapeutic efficacy of the substance to be patented is a critical requirement for the applicants to prove the inapplicability of this provision for such inventions. The Hon’ble High Court of Delhi recently reiterated this requirement of demonstrating the enhancement of the therapeutic efficacy in their judgment in Ischemix LLC vs Controller of Patents. This judgment also highlights the criticality of the Hearing proceedings for the applicants, particularly for the thorough examination of such inventions by the IPO.
This case was an appeal filed against a refusal order passed by the IPO under Section 15 of the Patents Act in an application bearing number 9739/DELNP/2011 titled “Methods for treating Ischemia and Ischemia-Reperfusion Injury.” The invention relates to an isomer of a known compound, and the primary ground taken by the IPO to refuse the application was that the invention falls within the purview of Section 3(d).
The appellant argued that the present application substantially enhances efficacy, and Section 3(d) is therefore not applicable in this case. The appellant further submitted that the therapeutic efficacy of the isomer has been demonstrated by providing data relating to in-vitro and in-vivo studies and clinical trials. In addition, reports of two experts to support the plea for enhanced therapeutic efficacy were also placed on record by the appellant.
On the other hand, the Controller who examined the application appeared virtually before the Court and submitted that while the appellant did provide some data to support the claim of enhanced efficacy, they did not show how the same constituted therapeutic efficacy. The respondent further clarified that when a substance cures a disease better than the existing substances, the substance is said to have a better effect for curing the disease, and it can be termed as showing enhanced therapeutic efficacy.
After hearing both parties, the Court acknowledged that various tables have indeed been included in the specification, providing comparative data relating to isomers that are sought to be patented. However, the Court asked the appellant to submit a short note to explain how the provided data indicates better therapeutic efficacy of the subject compound. The appellant, therefore, filed the short note. After reviewing the note, the Controller admitted that it provides a clear and definite explanation of how the appellant wishes to substantiate its claim of enhanced therapeutic efficacy. The Controller further informed the Court that this was not submitted during the prosecution of the application. However, the Controller agreed to reconsider and re-examine the patent application.
Regarding the applicability of Section 3(d), the Court cited the Hon’ble Supreme Court’s judgment in the Novartis vs Cipla case to highlight the requirement for demonstrating therapeutic efficacy. The Court stated that the applicant must ensure that comparative tables and a clear explanation of the manner that depicts significant enhancement by the new form of the known substance in therapeutic efficacy are placed before the IPO during the prosecution of the application. The same could be in the form of comparative tables, in-vitro and in-vivo data, and clinical trial data.
The Court also cited the judgment in DS Biopharma Limited vs The Controller of Patents and Designs and Anr., wherein the Court had given certain directions for the applicants to overcome the Section 3(d) objection, notably that the appellant may produce efficacy data and support its submission regarding how Section 3(d) is not applicable.
The Court also remarked that in inventions of the present nature, the patent specification ought to contain some data and results of lab experiments to demonstrate the enhancement of efficacy of the subject invention. If any additional data becomes available after the filing of the application, it shall also be submitted before the IPO by the applicant, at least before the date of the final hearing. The Court also observed that the applicants usually present such data only in the Hearing submission, without discussing the data with the Controller during the hearing. It may potentially lead to a situation, as in the present case, where the IPO may have overlooked the data. The data may not be entirely understandable for the Controller if it is directly presented in the Hearing submission and not explained by the applicant during the hearing.
For the present invention, the Court remarked that since this matter is technical in nature, the note on the enhanced therapeutic efficacy ought to have been submitted and explained by the applicant during the hearing. However, since the IPO agreed to re-examine the patent application based on the latest note submitted by the applicant before the Court, the Court did not further discuss the merits of the appeal.
The Court also directed that since the IPO would schedule a fresh Hearing, any data filed after the priority date of the patent application would be permissible, provided the same has a basis in the complete specification. This requirement is in line with the decision in AstraZeneca AB and Ors. v. Intas Pharmaceuticals Limited and Ors. Considering the AstraZeneca case, the Court also reiterated that one of the only exceptions to this requirement could be that there were ongoing clinical trials for the new form of the known substance at the time of filing of the patent application. The Court also cited the judgment of the Calcutta High Court in Oyster Point Pharma Inc. v. The Controller of Patents and Designs, where the Calcutta High Court 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.
The Court, therefore, in the present case, also allowed the submission of the clinical trial data only to support the stand of the applicant in the specification for demonstrating a significant enhancement of therapeutic efficacy. Further, considering that the application was filed more than a decade back, the Court directed the conclusion of the re-examination and the final adjudication within three months from the first date of hearing before the IPO. Further, the Court directed that the date of hearing before the IPO be fixed within a period of four weeks from the date of this judgment.
This judgment has clearly laid out the expectations from the applicants to successfully defend their chemical and pharmaceutical-related inventions against the Section 3(d) objection. The onus is on the applicant to ensure that they submit sufficient data along with supporting explanations to establish the enhancement of therapeutic efficacy by the substance to be patented. The Court also emphasised the importance of the Hearing proceedings and suggested that the applicants submit such data either through the specification at the time of filing or at least before the hearing before the Controller. It would allow the applicant as well as the Controller to discuss the invention and the associated efficacy comprehensively during the hearing only, ensuring thorough examination of the patent application.
This is yet another important judgment from the Hon’ble Court on one of the most recurring objections to the examination of patent applications by the IPO. This decision is encouraging for the applicants operating in the field of chemical and pharmaceutical innovations, as they get clarity in terms of expectations from them to overcome the hurdle of Section 3(d).
Authors: Manisha Singh and Piyush Sharma
First Published By: Lexology Here