Pharmaceutical Combination Patent: Delhi HC Remands Cancer Therapy Patent Case

Summary

Array Biopharma Inc. appealed the refusal of its Indian patent application for a pharmaceutical combination of a B-Raf inhibitor, an EGFR inhibitor, and an optional PI3K-alpha inhibitor used in treating colorectal cancer, before the Delhi High Court. The Deputy Controller of Patents and Designs had refused the application on grounds of lack of inventive step, non-patentability under Section 3(d), and exclusion as a method of treatment under Section 3(i) of the Patents Act, 1970. The Delhi High Court found that the refusal order failed to identify any motivation to combine the prior art or the known compound underlying the Section 3(d) objection, and held that the claim was a product, not a method of treatment. The matter was remanded to the Controller for fresh consideration within six months. The ruling matters because it reinforces that patent refusal orders, particularly on inventive step and Section 3(d), must be reasoned with specificity rather than borrowed across objections.

Background

A patent refusal order that runs several pages yet never identifies the very compound it calls a known substance cannot survive appellate scrutiny, the Delhi High Court has now made clear in a dispute over a cancer combination pharmaceutical combination patent. Array Biopharma Inc. (“Array Biopharma”) is a United States pharmaceutical company whose Indian patent application, No. 450/DELNP/2015, claimed a combination of a B-Raf kinase inhibitor, an EGFR inhibitor, and an optional PI3K-alpha inhibitor for treating proliferative diseases such as colorectal cancer. The application traced its priority to an August 2012 filing in the United States and entered the Indian national phase in January 2015. Following examination and a hearing spread across several adjournments over multiple years, the Deputy Controller of Patents and Designs (“the Controller”) refused the application on 30 June 2023 under Section 15 of the Patents Act, 1970 (“Patents Act”). The refusal rested on three independent grounds: lack of inventive step under Section 2(1)(ja), non-patentability under Section 3(d), and exclusion as a method of treatment under Section 3(i). Array Biopharma appealed the refusal under Section 117A of the Patents Act before the Delhi High Court.

Questions Before the Court

• • Whether the finding of lack of inventive step under Section 2(1)(ja) of the Patents Act was sustainable without the impugned order identifying any motivation for combining the cited prior art references.
  • Whether the claimed combination fell foul of Section 3(d) of the Patents Act without the impugned order identifying the specific known compound from which the claim was said to derive.
  • Whether Claim 1, drafted as a pharmaceutical combination, amounted to a method of treatment excluded under Section 3(i) of the Patents Act.
  • Whether the objection on claim clarity under Sections 10(4) and 10(5) of the Patents Act could stand independently of the other objections.

Array Biopharma’s Arguments

• • Claim 1 was a product claim for a defined pharmaceutical combination, not a method of treatment, relying on Nestle SA v. Controller of Patents & Designs and Medilabo RFP Ink Inc. v. Controller of Patents to submit that words such as “treatment” or “administration” in a claim do not convert a product into a process under Section 3(i).
  • Phase Ib and Phase II clinical trial data showed that the dual combination reduced tumour progression to twelve percent and the triple combination achieved tumour regression, demonstrating synergistic, unexpected technical advancement sufficient to meet the inventive step threshold under Section 2(1)(ja).
  • None of the four cited prior art documents disclosed the specific claimed compounds, Encorafenib, Erlotinib or Cetuximab, and Alpelisib, in the claimed dual or triple combination; the IPAB ruling in Ajantha Pharma Ltd. v. Allergan Inc. was relied on to argue that a combination of independent active pharmaceutical agents cannot be treated as derivatives of each other under Section 3(d).
  • Corresponding grants of the same combination in Australia, Canada, Europe, and the United States over the same prior art were cited as persuasive, though not binding, support.

The Controller’s Arguments

• • The claim, read with the dosing schedules in the complete specification, described a treatment regimen rather than a product, attracting the exclusion under Section 3(i).
  • Each individual compound was independently known, and combining known drugs for the same cancer, already taught by the prior art documents read together, rendered the claim obvious and devoid of inventive step.
  • The Supreme Court’s ruling in Novartis AG v. Union of India and the Delhi High Court’s decision in Zydus Lifesciences Ltd. v. E.R. Squibb & Sons LLC were relied on to argue that public interest in affordable cancer treatment justified refusing a monopoly over a combination of already available drugs.

Court’s Analysis and Observations

Absence of a Disclosed Motivation to Combine

The court observed that each of the four cited prior art documents disclosed at most a generic class of B-Raf, EGFR, or PI3K inhibitors, but none specified the precise combination of Encorafenib, Erlotinib or Cetuximab, and Alpelisib claimed in the pharmaceutical combination patent. The court noted that the impugned order never explained why a person skilled in the art, reading these documents together, would be motivated to select these specific molecules over the many other candidates available within each inhibitor class. The court found that this failure to establish any documented motivation to combine was fatal to the objection of lack of inventive step under Section 2(1)(ja) of the Patents Act.

An Unidentified “Known Compound” Under Section 3(d)

On the Section 3(d) objection, the court held that the impugned order asserted the claimed combination was a derivative of a known substance without ever identifying what that known substance was. The court reasoned that a combination of two or three independent active pharmaceutical agents, each with a distinct chemical identity and mechanism of action, cannot automatically be treated as a derivative of any of its constituents. The court drew on the reasoning in Topotarget UK Limited v. Controller General of Patents and Designs (IPDPTA/50/2023), where the Calcutta High Court had held that a combination of separate active drugs falls outside Section 3(d) unless the specific known substance is identified and tested for efficacy.

Product Claim, Not a Method of Treatment

Addressing Section 3(i), the court observed that Claim 1 described a pharmaceutical combination and that phrases such as “simultaneous, separate or sequential administration” functioned as a functional descriptor of the product rather than a treatment protocol. The court stated that working examples in a specification exist to demonstrate feasibility and do not redefine claim scope, aligning with its earlier decision in Bayer Pharma Aktiengesellschaft v. Controller of Patents and Design (2024:DHC:2395). The court concluded that the pharmaceutical combination patent claim was directed to a product and was not excluded as a method of treatment.

Reasoning Cannot Be Borrowed Across Objections

The court further observed that the objection on claim clarity under Sections 10(4) and 10(5) simply mirrored the unreasoned findings on inventive step, without any independent analysis of its own. The court opined that once the inventive step reasoning collapsed, the clarity objection could not survive either, since it offered no separate basis for refusal.

Findings

In view of the observations and the arguments presented by both the parties, the Delhi High Court held that:

• • The objection of lack of inventive step under Section 2(1)(ja) of the Patents Act was unsustainable for want of any disclosed motivation to combine the cited prior art references.
  • The objection under Section 3(d) of the Patents Act could not stand since the impugned order failed to identify the known compound from which the claimed combination was said to derive.
  • Claim 1 of the subject application was a product claim for a pharmaceutical combination and was not excluded as a method of treatment under Section 3(i) of the Patents Act.
  • The objection on claim clarity under Sections 10(4) and 10(5) of the Patents Act required reconsideration since it rested entirely on the rejected inventive step findings.
  • The subject patent application was remanded to the Deputy Controller of Patents and Designs for de novo consideration of all objections within six months, with an opportunity of hearing to be granted to Array Biopharma, and without the Controller being influenced by the Court’s observations.

Case Citation: Array Biopharma Inc. v. Deputy Controller of Patents and Designs, C.A.(COMM.IPD-PAT) 37/2023, Delhi High Court, decided on 23 July 2026. Available at https://indiankanoon.org/doc/103160954/.

Authored by Gaurav Mishra, Patent Attorney, BananaIP Counsels