Calcutta High Court Reverses Rejection of Pharmacyclics’ Divisional Patent on Ibrutinib Combination Therapy

The Calcutta High Court recently overturned the rejection of a divisional patent application filed by Pharmacyclics LLC related to a cancer therapy combining ibrutinib with anti-CD20 antibodies such as rituximab or ofatumumab. The divisional application, Indian Patent Application No. 201838043708, was initially refused by the Indian Patent Office’s Deputy Controller of Patents and Designs on grounds that the claims were impermissible amendments beyond the scope of the parent application.

Pharmacyclics’ divisional application arose from parent application no. 3985/KOLNP/2012. While the parent application’s claims were originally directed to methods and later amended to product claims, the divisional application claimed the combination therapy, which was disclosed in the parent specification but not explicitly claimed there. Pharmacyclics argued that the combination demonstrated unexpected synergistic effects, notably reducing infusion-related reactions associated with anti-CD20 antibody therapy and improving treatment efficacy for hematological malignancies.

The Controller rejected the divisional application, reasoning that the claims to the combination were not maintainable as they were not present in the parent claims and amounted to impermissible amendments under Sections 57 to 59 of the Patents Act, 1970. Pharmacyclics appealed this decision under Section 117A before the Calcutta High Court.

The Court examined three key issues: whether a divisional application is maintainable when the claims are not in the parent claims but are disclosed in the parent specification; whether the Controller was correct in holding that the divisional claims exceeded permissible amendments; and whether the divisional application should be examined independently of the parent application’s outcome.

Relying on precedents including Syngenta Limited v. Controller of Patents & Designs (2023), Gensquare LLC v. The Assistant Controller of Patents and Design (2023), and Victaulic Company v. The Controller of Patents and Designs (2024), the Court held that a divisional application is maintainable if the parent specification discloses multiple inventions, even if the divisional claims are not derived from the parent claims themselves.

The Court noted that the Controller had initially acknowledged in the First Examination Report that the divisional claims were supported by the parent specification and had not raised maintainability objections at that stage. Regarding amendments, the Court found no changes had been made to the divisional claims since filing, and thus no impermissible amendment had occurred. The Court cited Allergan Inc. v. The Controller of Patents (2023) to affirm that amendments supported by the description are permissible.

Furthermore, the Court considered the technical evidence submitted by Pharmacyclics demonstrating that the combination therapy reduced infusion-related reactions and enhanced efficacy. It emphasized that under Section 16(3) of the Patents Act, a divisional application must be treated as a substantive application and examined independently from the parent application. The Controller erred by linking the divisional application’s fate to the amended claims of the parent.

Concluding that the refusal order was legally unsustainable, the Court set aside the rejection and remanded the matter to the Controller for fresh examination by a different Controller. The Court directed that the examination process be completed within six months.