The Delhi High Court’s decision in Array Biopharma Inc. v. Deputy Controller of Patents and Designs [C.A.(COMM.IPD-PAT) 37/2023] provides significant guidance on inventive step, the exclusions under Sections 3(d) and Section 3(i) of the Patent Act, and the standard of reasoning expected from the Patent Office when refusing combination patents involving multiple independently known active agents.
Background
The invention concerned a pharmaceutical combination for treating B-Raf mutant colorectal cancer. The claim comprised a B-Raf inhibitor, Compound A (Encorafenib), with an EGFR inhibitor (Cetuximab or Erlotinib), and optionally a third agent, a PI3K-alpha inhibitor, Compound B (Alpelisib). The specification relied on Phase Ib and Phase II clinical data showing a synergistic effect superior to any individual agent alone.
The Controller rejected the Application No. 450/DELNP/2015 for lack of inventive step under Section 2(1)(ja), and non-patentability under Sections 3(d) and 3(i). On inventive step, the Controller relied on four prior art documents, D1 to D4, holding that read together they made the combination obvious. On Section 3(d), the combination was treated as a derivative of known compounds, without identifying which substance was being varied. On Section 3(i), the Controller held that the phrase “for simultaneous, separate or sequential administration” along with dosing schedules in the working examples, showed the real inventive contribution was a treatment protocol rather than a product.
Array Biopharma appealed the rejection to the Delhi High Court under Section 117A of the Patents Act.
Issues before the Court
- Whether the claim was an excluded method of treatment under Section 3(i), given the administration language and dosing schedules in the working examples?
- Whether the combination was non-patentable under Section 3(d) as a derivative of a known substance, where the rejection order never identified that substance?
- Whether the combinations lacked inventive step under Section 2(1)(ja) in light of D1-D4, and whether a skilled person would have been motivated to arrive at them with a reasonable expectation of success?
- Whether the clinical data established genuine technical advancement?
- Whether the order met the reasoning standard under Sections 10(4) and 10(5), given it found the invention both insufficiently disclosed and obvious in the same breath?
Court’s Analysis
Section 3(i): Method of Treatment
The Court rejected the finding that Claim 1 was a disguised method of treatment. It held that working examples demonstrate feasibility and workability; they do not determine claim scope, which is defined by the claims read with the complete specification. Since Claim 1 was framed as a pharmaceutical combination, not a process or treatment protocol, the phrase “for simultaneous, separate or sequential administration” was treated as a functional description of possible use, not as prescribing a therapeutic procedure. Relying on Bayer Pharma Aktiengesellschaft v. Controller of Patents and Designs [2024:DHC:2395] and Societe Des Produits Nestle SA v. Controller of Patents and Designs [C.A.(COMM.IPD-PAT) 22/2022], the Court reiterated that Section 3(i) excludes processes of treatment, not pharmaceutical compositions or combinations. Accordingly, dosing details in the examples could not transform the product claim into an excluded process.
Section 3(d): Derivative of a Known Substance
The Court also rejected the Section 3(d) objection because the Controller had failed to identify the alleged known substance from which the claimed combination was supposedly derived. Relying on Topotarget UK Limited v. Controller General of Patents and Designs [IPDPTA/50/2023,] the Court noted that Section 3(d) concerns a new form of a known substance and cannot ordinarily be applied to a combination of separate active ingredients. Since the inventive-step objection itself failed to establish any relevant known compound, there was no identified substance against which Section 3(d) could operate.
Inventive Step under Section 2(1)(ja)
The Court undertook a detailed examination of D1–D4 and found that none disclosed, individually or in combination, the claimed combinations.
D1 (WO2011025927): Disclosed B-Raf inhibitors, including Compound 9, and combinations with various therapeutic agents. However, it did not specifically disclose a PI3K-alpha inhibitor or any combination with an EGFR inhibitor.
D2 (1403/DELNP/2012): Concerned diagnostic/prognostic methods involving B-Raf and EGFR inhibition. Although Erlotinib and Cetuximab were disclosed, Encorafenib was not. The RAF inhibitor used in its experiments was structurally different from Encorafenib.
D3 (WO2011/046894 A1): Disclosed a B-Raf/PI3K inhibitor combination, but used Dabrafenib and Omipalisib, not Encorafenib and Alpelisib, and contained no EGFR inhibitor.
D4 (WO2011/029082): Concerned a PI3K inhibitor and referred generally to synergy between EGFR inhibition and the PI3K/Akt pathway, but did not identify the specific inhibitors claimed.
The Court therefore found that the prior art did not disclose the Encorafenib–Erlotinib/Cetuximab dual combination or the further combination with Alpelisib.
Importantly, the Controller had also failed to explain the motivation to combine the teachings of D1, D2 and D4 or identify any specific passage directing the skilled person toward the claimed three-drug combination. The Court consequently found the reasoning on lack of inventive step inadequate.
Technical Advancement and Clinical Data
The Court accepted the relevance of the appellant’s clinical data showing substantially improved results from the claimed combinations. It found that the Controller had incorrectly relied on D2 and D3 to dismiss the results as unremarkable because the compounds tested in those documents were not the same compounds claimed. D3 used different B-Raf and PI3K inhibitors, while D2 used a structurally different RAF inhibitor. Thus, the prior-art synergy data could not properly negate the technical advancement demonstrated by the claimed combinations.
Sections 10(4) and 10(5): Claim Clarity
The Court also rejected the Controller’s treatment of the Sections 10(4) and Section 10(5) objections, observing that the impugned order merely stated that the claims lacked clarity and a significant technological contribution without providing substantive reasons. Since the Court had already found the reasoning on technical advancement deficient, this objection also required reconsideration.
Our Analysis and Conclusion
Array Biopharma reinforces that combination drug patents must be assessed on the actual claimed combination, rather than through a hindsight-based mosaicking of individual disclosures. The Court correctly distinguished a pharmaceutical product claim from a method of treatment under Section 3(i), holding that therapeutic-use language and working examples cannot, by themselves, convert a product claim into an excluded treatment process.
The judgment is particularly important for inventive-step analysis under Section 2(1)(ja). The mere fact that individual components of a combination are known does not establish obviousness. The Patent Office must identify a credible motivation to combine the specific agents, supported by the prior art. This is particularly relevant to pharmaceutical inventions, where arriving at a specific combination may require multiple selections from broad disclosures.
The Court’s treatment of clinical data is equally significant. Enhanced efficacy cannot be dismissed by relying on experiments involving different compounds. The technical effect must be assessed against the actual claimed invention and relevant prior art.
Looking ahead, Examiners shall need to distinguish between broad disclosures of individual agents and a genuine teaching toward their specific combination, while applicants should clearly demonstrate the combination’s technical contribution and support enhanced efficacy with reliable data.
Ultimately, Array Biopharma strengthens the balance between preventing evergreening and protecting genuine pharmaceutical innovation. Its broader significance will depend on consistent application of the principles of specific disclosure, motivation to combine, and demonstrable technical advancement.