Summary
In a critical patent law judgment, the Calcutta High Court ruled that disregarding post-filing data violates natural justice. The case involved Takeda’s cancer drug Brigatinib, where the Patent Office had rejected the application without considering crucial evidence. The Court overturned the decision, highlighting procedural fairness and remanded the matter for fresh review.
Indian courts have emphasized the importance of transparency, reasoned decision-making, and procedural fairness in the patent examination process. In a strong reaffirmation of these principles, the Calcutta High Court, in Takeda Pharmaceutical Co. Ltd. v. Controller of Patents and Designs & Ors., set aside an unreasoned refusal order issued by the Patent Office. The Court found that failure to consider crucial post-filing data demonstrating technical advancement constituted a violation of the principles of natural justice and remanded the matter for fresh consideration.
Facts of the Case
Takeda Pharmaceutical Co. Ltd. (“Takeda”) filed a patent application in 2010 for a novel class of protein kinase inhibitors intended for the treatment of cancers associated with abnormal kinase activity. The application specifically claimed Brigatinib, a compound which selectively inhibits Anaplastic Lymphoma Kinase (ALK) over closely related kinases, including the insulin receptor (Ins-R). This selective inhibition is critical to Brigatinib’s superior therapeutic efficacy, as it significantly reduces side effects arising from off-target binding to Ins-R.
To establish Brigatinib’s enhanced therapeutic efficacy, Takeda submitted experimental data demonstrating the compound’s improved selectivity for ALK, as evidenced by reduced IC50 values. In addition, the company furnished expert affidavits, comparative data with other marketed drugs, and evidence of industrial acclaims during the course of prosecution.
Refusal Order by the Controller
The Controller rejected the application on three grounds: lack of inventive step under Section 2(1)(ja), non-patentability under Section 3(d), and insufficiency of disclosure under Section 10(4).
According to the Controller, Brigatinib was structurally obvious in light of prior art, particularly the ALK inhibitor TAE684. He observed that the only distinguishing feature, the substitution of a sulfonyl group with a phosphoryl group, was an obvious bioisosteric modification well-documented in existing scientific literature. Furthermore, the Controller noted that the disclosure failed to furnish any evidence of technical advancement or enhanced efficacy at the time of filing the specification.
Arguments by Takeda
Takeda challenged the refusal order, asserting that it was issued without proper application of mind and violated the principles of natural justice. They argued that the Controller disregarded supplementary data and expert affidavits submitted during prosecution, which clearly established Brigatinib’s superior selectivity, technical advancement, and therapeutic efficacy. They also argued that the inventive step analysis was influenced by hindsight, as similar compounds were picked selectively and changes to functional groups were made without clear scientific reasoning. The order, according to Takeda, ignored the well-established principle that even a single functional group substitution can profoundly alter the pharmacological and physicochemical properties of a compound.
Court’s Findings
The Court found that the Controller failed to apply the settled principles for assessing inventive step and erred in appreciating the true scope of the invention. Referring to judicial precedents, it reiterated that the invention must be considered as a whole, and the mere presence of known or structurally similar elements does not render the invention obvious. The Court further clarified that assertions of common general knowledge must be supported with specific evidence and cannot be presumed.
The Court sided with Takeda, observing that the prior art lacked any teaching or motivation that would have led a person skilled in the art to modify the structure of TAE684 in the specific manner required to arrive at Brigatinib. It noted that the cited prior arts did not disclose the concept of bioisosterism in the context of herbicidal compounds, let alone suggest its potential relevance for achieving selective inhibition among different kinases.
On the issue of technical advancement, the Court observed that Takeda had submitted data demonstrating Brigatinib’s increased selectivity for ALK over Ins-R, as reflected by higher IC50 values for Ins-R and a consequent reduction in off-target effects. The Court found this data directly relevant to establishing therapeutic efficacy and observed that the Controller had erroneously disregarded it.
Regarding sufficiency of disclosure, the Court observed that the Controller had misapplied the standards for assessing sufficiency of disclosure under Section 10(4) of the Patents Act. It clarified that Section 10(4) only requires that the invention be fully and particularly described and does not require data proving efficacy or technical advantage unless such claims are part of the invention.
The Court also found that the Controller had overlooked critical evidence demonstrating Brigatinib’s technical advancement and industrial acclaim, including FDA approval, peer-reviewed studies, and expert affidavits. Furthermore, it noted that no weight was given to the fact that Brigatinib had been granted in over 50 countries, in compliance with international patentability standards.
Importantly, the Court reaffirmed that the Patents Act does not prohibit submission of post-filing data. Any data demonstrating technical advancement or efficacy must be duly considered. The Controller’s failure to evaluate such evidence, including written submissions and post-filing experimental data, was found to violate both the provisions of the Act and the principles of natural justice.
Conclusion
The High Court set aside the refusal order and remanded the matter to the Patent Office for fresh consideration, directing that an adequate opportunity of hearing be provided to all parties and that all material, including experimental data, be taken into account. The Court directed the entire exercise to be completed within three months from the date of communication of the order.
Citation: Takeda Pharmaceutical Co Ltd vs Controller Of Patents And Designs And Ors, IPDPTA/119/2023 (H.C. Calcutta April 11, 2025). Available at https://indiankanoon.org/doc/54286831/
Article and Accessibility review by: Gaurav Mishra
