In the case of Ischemic LLC v. The Controller of Patents (Neutral Citation – 2023:DHC:8496) argued by the firm, the Delhi High Court has set aside a refusal order issued by the Indian Patent Office and remanded the matter to the Patent Office for reconsideration. The invention in question related to a specific isomer of a compound useful for treating ischemia (stoppage of blood flow to any organ in the body) and ischemia- reperfusion injuries, i.e., injuries resulting from restoration of blood flow following an ischemic episode, which had been held as non-patentable by the Patent Office under Section 3(d) of the Patents Act.

The appellant assailed the refusal on the grounds that the order passed by the Patent Office was unreasoned and non-speaking in nature vis-à-vis the rejection under Section 3(d). The court’s attention was invited to the in-vitro and in-vivo data present in the specification as well as the clinical trial data submitted during the prosecution stage to demonstrate enhanced therapeutic efficacy of the claimed isomer. Additionally, it was impressed upon the court that the Patent Office had neither referred to, nor discussed, the findings of two experts that had endorsed the view that the enhanced therapeutic efficacy of the claimed isomer was both surprising and unexpected.

On its part, the Patent Office rebutted the contentions of the appellant and asserted that although some data had been submitted, the correlation between the data and the claim for enhanced therapeutic efficacy was unclear and not readily forthcoming from the submissions filed at a stage subsequent to the oral hearing proceedings.

After perusing the data contained in the specification and hearing the parties at length, the court disagreed with the position espoused by the Patent Office. While placing reliance on the landmark judgment of the Supreme Court in Novartis AG v. Union of India, the court held that, “whenever any patent applicant wishes to place on record and demonstrate therapeutic efficacy, to satisfy the requirements laid down in Novartis AG (supra), the same has to be done precisely. 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. The same could be in the form of comparative tables in-vitro and in-vivo data as also clinical trial data.”

The court also indicated that patent applications, at the time of filing, ought to contain some data which demonstrates enhancement of efficacy. However, if additional data becomes available at a later stage, the same should be placed before the Patent Office prior to the date of final hearing. Referring to the ruling in AstraZeneca AB and Ors v. Intas Pharmaceuticals Limited and Ors. (Neutral Citation – 2020/DHC/3125), the court held that data filed after the priority date of a patent application would be permissible subject to the same having a basis in the complete specification. Acknowledging the complexities and the protracted process of drug development, as elaborated upon in the decision of the Calcutta High Court in Oyster Point Pharma Inc. v. The Controller of Patents and Designs, MANU/WB/1544/2023, the court concluded that “clinical trial data can be submitted – but only to support the stand of the applicant in the specification to demonstrate a significant enhancement of the therapeutic efficacy.”

The decision brings much-needed clarity in respect of Section 3(d) of the Patents Act and ought to serve as a useful guide for the prosecution of future patent applications.