The Madras High Court, on November 21, 2024, delivered its judgement in the appeal filed by Intervet, in Intervet International B.V. & Anr. vs Deputy Controller of Patents and Design [(T)CMA(PT) No. 119 of 2023], challenging the order passed by the Controller that refused their patent application number 449/CHENP/2010 on grounds of non-patentability under Sections 3(d) and 3(e) of the Patents Act, 1970. The subject application relates to solvated and non-solvated crystalline forms of 20,23-dipiperidinyl-5-O-mycaminosyl-tylonolide, a compound known for its use in the treatment or prevention of infectious diseases viz pasteurellosis, swine respiratory diseases or bovine respiratory disease in animals.

Section 3(d) prohibits the patentability of new forms of a known substance unless such new forms show enhancement of known efficacy. Intervet’s challenge to the refusal under section 3(d) was primarily on the ground that the Controller had failed to consider the expert evidence filed by them which substantiated their stand that the claimed crystalline form of the compound was more stable and a more stable drug is less likely to decompose into its by-products, which, in turn, results in enhanced therapeutic efficacy. The claimed crystalline form was asserted to exhibit improved physical and chemical stability, thermodynamic, kinetic and filtration properties, which provided technical advancements and economic benefits not obvious to a person skilled in the art. Intervet emphasised that while the Controller did not question the veracity of the submitted data he proceeded to reject the application without proper reasoning, stating simply that the superior stability data did not constitute an enhancement of known efficacy. It was argued that such a non-speaking order violated the principles of natural justice.

With regard to Section 3(e), which prohibits the patentability of mere admixtures, Intervet argued that the Controller erred in applying said section. It was contended that the Controller failed to follow the Guidelines for Examination of Patent Applications in the Field of Pharmaceuticals 2014, which should have guided the evaluation of their application. The Controller, in the impugned order, explicitly acknowledged that the claimed polymorphic form of the compound of Formula 1 was a novel crystalline form of 20,23-dipiperidinyl-5-O-mycaminosyl-tylonolide. Given this admission, Intervet argued that, since the invention was recognized as a novel substance, the application of Section 3(e) was improper.

Pointing out to Section 64(1)(h) Intervet submitted that for a sufficient and fair description of the invention the only requirement was that of a fair description of the method or instructions that would enable a person skilled in the art to work the invention and synergistic data on individual components of the composition was not mandated.

The Madras High Court concurred with Intervet’s submissions regarding the refusal on the ground of Section 3(d). The Court noted that the Controller did not give due consideration to the expert affidavit filed by Intervet and did not provide any explanation regarding why the expert’s deposition on improved stability amounting to improved efficacy did not hold good. This lack of reasoning and failure to properly consider the evidence led the Court to conclude that Intervet had been denied a fair opportunity to prove the patentability of their invention. The impugned order was thus found to be a non-speaking one and in violation of the principles of natural justice.

The Court clarified that in the case of Novartis AG vs. Union of India & Ors. [MANU/SC/0281/2013], which was cited by the Controller to justify the refusal of the subject application, it was held that that applicants are only required to prove that their claimed invention has enhanced therapeutic efficacy. There is no requirement to take a specific plea in the application that the invention has therapeutic efficacy.

Regarding the refusal on the ground of Section 3(e), the Court noted that the Controller did not adhere to the Guidelines for Examination of Patent Applications in the Field of Pharmaceuticals 2014. Noting that the guidelines are simply a codification of the intent to prevent the grant of patents for mere combinations of old integers or components, the Court criticised the Controller’s unreasoned decision to refuse the subject application, particularly after the Controller had explicitly acknowledged that the claimed polymorphic form was a novel crystalline form of an already known compound. Furthermore, with regards to Intervet’s submission that Section 10(4)(a) does not mandate the provision of synergistic data in the specification, the Court noted that the impugned order lacked an explanation for applying Section 3(e) to refuse the application. This lack of explanation contributed to the Court’s conclusion that the decision was unsubstantiated.

In view of the aforesaid, the Court set aside the impugned order and remanded the application back to the Patent Office for reconsideration by a different Controller.