Enhanced Therapeutic Efficacy Be Shown 'Precisely' By Patent Applicant, Clinical Data Acceptable Only To Support Specification Claims: Delhi HC

“The Applicant must ensure that comparative tables, and a clear explanation as to the manner in which the new form of the known substance has significant enhancement in therapeutic efficacy is placed before the Patent Office during prosecution of the application. The same could be in the form of comparative tables, in-vitro and in-vivo data as also clinical trial data,” the court said.

Considering that after filing of a detailed note, the Patent Office itself agreed to reconsider/re-examine the appellant's patent application, Justice Prathiba M Singh did not go into the merits of the issue and disposed of the matter.

Pertinently, while referring to AstraZeneca AB and Ors. v. Intas Pharmaceuticals Limited and Ors., it was observed that any benefit of reliance on data filed after priority date of the subject patent application was permissible subject to the same having basis in the complete specification.

The only exception to this requirement, the court said, could be that there were on-going clinical trials for the new form of the known substance at the time of filing of the subject patent application.

“…clinical trial data can be submitted – however, to only support the stand of the applicant in the Specification to demonstrate a significant enhancement of therapeutic efficacy”.

Highlighting the need for filing requisite data during pendency of the patent application before the Patent Office, Justing Singh added,

“It is often observed that patent applicants file such data in written submissions, after conclusion of oral hearings before the Patent Office, without referring to the said data during oral hearings. This may potentially lead to a situation, as in the present case, where the Patent Office may have overlooked the data and failed to consider the same. There is also the possibility of the data not being completely understandable, in mere written submissions without oral explanation.”

Notably, the issue had arisen in the context of Section 3(d) of the Patents Act. The appellant, which had filed a patent application relating to an isomer of a known compound, maintained that therapeutic efficacy of the isomer had been demonstrated.

Conversely, on behalf of the Patents Controller, it was contended that the appellant had initially given some data but failed to show how it constituted therapeutic efficacy.

In response to the court's query as to what would be the method to show therapeutic efficacy, the following reply was forthcoming from the Patents Controller,

“…when a substance cures the disease in a better way than the existing substances, the substance has a better effect for curing of diseases, it can be termed as showing enhanced therapeutic efficacy”.

Pursuant to court directions, the appellant had filed a note on enhanced therapeutic efficacy of the isomer. On perusing the same, the respondent conceded that a clear and definitive explanation of how the appellant wished to substantiate claim of enhanced therapeutic efficacy had become apparent.

Considering that the matter was technical in nature, the court remarked,

“…the note on enhanced therapeutic efficacy ought to have been handed over by the concerned Patent Agents/Attorney of the patent Applicant during the final oral hearing. Further, the therapeutic efficacy of the substance ought to have been clearly explained by the Agent/ Attorney of the patent Applicant to the concerned official reviewing and examining the patent application.”

Advocates Ankush Verma, Vineet Rohilla, Debashish Banerjee, Pankaj Soni & Vaishali Joshi, Advocates appeared for appellant

Senior Central Government Counsel TP Singh appeared for respondent (Patents Controller)

Case Title: Ischemix LLC v. The Controller of Patents, C.A.(COMM.IPD-PAT) 33/2022

Citation: 2023 LiveLaw (Del) 1196