Introduction
The case addresses a recurring tension in patent jurisprudence: the boundary between patentable technical innovations and non-patentable methods of medical treatment. In an era where personalized medicine and biomarker-driven therapies are gaining prominence, the Court’s ruling assumes critical importance in clarifying whether screening and selection methods for treatment fall within the statutory exclusion of “diagnostic” processes. The judgment provides a deeply reasoned analysis of statutory interpretation, international obligations under TRIPS, and evolving judicial precedents in India.
Factual Background
The appellant, Geron Corporation, a biopharmaceutical entity engaged in developing telomerase inhibitors, filed an Indian national phase patent application titled “Diagnostic Markers for Treating Cell Proliferative Disorders with Telomerase Inhibitors.” The invention related to an in vitro method for identifying cancer patients who would benefit from treatment with telomerase inhibitors based on the relative length of telomeres in cancer cells.
The patent application claimed a method involving the analysis of telomeric nucleic acids from biological samples of individuals diagnosed with or suspected of having cancer. Based on whether the telomere length fell within a specified percentile threshold, the method enabled selection of patients likely to benefit from specific therapeutic intervention. The invention thus operated at the intersection of biomarker detection and therapeutic decision-making.
- Analysis of telomeric nucleic acids
- Use of biological samples from suspected or diagnosed cancer patients
- Application of percentile threshold for telomere length
- Selection of patients for targeted therapy
The Patent Office, however, objected to the application on multiple grounds, including lack of novelty, inventive step, and most significantly, non-patentability under Section 3(i) of the Patents Act. The core objection was that the claimed invention constituted a diagnostic method and was therefore excluded from patentability.
Procedural Background
Following the filing of the application and issuance of the First Examination Report, the appellant submitted responses and amended claims to address objections raised by the Controller. A hearing was conducted, and further written submissions along with amended claims were filed by the appellant.
Despite these efforts, the Controller refused the application by order dated 31.12.2021, holding that the claims fell squarely within the ambit of Section 3(i) as a diagnostic method related to treatment of cancer. Aggrieved, the appellant preferred an appeal under Section 117-A of the Patents Act before the High Court of Delhi.
Procedural Timeline
| Stage | Event |
|---|---|
| Patent Filing | Indian national phase application filed by Geron Corporation |
| Examination | First Examination Report issued with objections |
| Response | Amended claims and submissions filed by appellant |
| Decision | Controller rejected application (31.12.2021) |
| Appeal | Appeal filed before High Court of Delhi under Section 117-A |
Reasoning
The Court undertook an exhaustive examination of the statutory framework, particularly Section 3(i), which excludes from patentability any process for medicinal, surgical, curative, prophylactic, diagnostic, therapeutic, or other treatment of human beings. The central question before the Court was whether the claimed “in vitro screening method” constituted a diagnostic method for treatment.
The Court rejected the appellant’s attempt to distinguish “screening” from “diagnosis” by holding that nomenclature is not determinative. What is crucial is the functional role of the claimed process. If a method contributes to or forms the basis of a treatment decision, it may fall within the scope of “diagnostic” under Section 3(i).
In interpreting the scope of “diagnostic,” the Court relied heavily on prior judicial precedents and Patent Office Guidelines. It emphasized that diagnosis need not be definitive; even a process that aids or influences treatment decisions qualifies as diagnostic. The Court also clarified that the statutory exclusion does not distinguish between in vivo and in vitro methods, thereby rejecting the appellant’s contention that laboratory-based techniques should be patentable.
Treatment Nexus Test
A key aspect of the reasoning was the application of the “treatment nexus” test. The Court examined whether the claimed method inherently enabled a medical practitioner to make a treatment decision. It found that the method, by determining telomere length and applying a threshold, directly guided the selection of patients for telomerase inhibitor therapy. This, in substance, constituted a diagnostic process integral to treatment.
- Determination of telomere length
- Application of predefined threshold values
- Direct linkage to therapeutic decision-making
- Selection of patients for specific treatment
The Court further observed that granting patent protection to such methods would result in monopolisation of clinical decision-making processes, which is precisely what Section 3(i) seeks to prevent. The legislative intent behind the provision, reinforced by TRIPS, is to ensure that medical practitioners are not constrained by patent rights in performing diagnostic and therapeutic functions.
Judgments with Complete Citations Discussed
The Court engaged in a detailed analysis of prior judicial decisions to articulate the scope of Section 3(i). It relied extensively on Chinese University of Hong Kong v. Assistant Controller of Patents & Designs, 2023 SCC OnLine Mad 6372, wherein the Madras High Court held that diagnostic processes must be understood in the context of treatment and include processes capable of identifying pathology for therapeutic purposes.
Further reliance was placed on Chinese University of Hong Kong v. Controller of Patents & Designs, 2023 SCC OnLine Mad 8616, which clarified that diagnostic methods are not confined to in vivo procedures and must be interpreted in light of their role in treatment.
The Court also referred to Natera Inc. & Anr. v. Assistant Controller of Patents and Designs, 2025:DHC:8937, where it was held that processes employed by medical practitioners for diagnosis are excluded from patentability, irrespective of whether they are performed in vivo or in vitro.
Additionally, Sequenom Inc. & Anr. v. The Controller of Patents, 2025:DHC:8926, was cited to reinforce the principle that even non-definitive diagnostic processes, which influence treatment decisions, fall within the exclusion under Section 3(i).
Key Principles Derived from Precedents
- Diagnostic processes are interpreted in the context of treatment.
- Both in vivo and in vitro diagnostic methods fall within the exclusion.
- Processes aiding medical practitioners in diagnosis are not patentable.
- Even non-definitive diagnostic processes influencing treatment decisions are excluded.
Collectively, these precedents were harmonised to establish that any process contributing to diagnosis for treatment—whether labelled as screening, monitoring, or otherwise—is not patentable.
Decision of the Court
The Court upheld the order of the Controller and dismissed the appeal. It held that the claimed invention, though framed as an in vitro screening method, was in substance a diagnostic method forming the basis of treatment decisions for cancer patients. Consequently, it fell squarely within the exclusion under Section 3(i) of the Patents Act.
The Court further rejected the argument that grant of patents in foreign jurisdictions such as the United States or Europe should influence the Indian position, reiterating that patentability must be assessed strictly in accordance with Indian law.
Point of Law Settled
The judgment conclusively establishes that any method—whether termed as screening, monitoring, or selection—that contributes to or enables a medical practitioner to make a treatment decision qualifies as a “diagnostic method” under Section 3(i) and is therefore not patentable. It further settles that the exclusion applies equally to in vitro processes and that the determinative test is the functional role of the claimed invention in the treatment pathway, not its form or drafting.
Case Details
| Particulars | Details |
|---|---|
| Case Title | Geron Corporation Vs. The Assistant Controller of Patents and Designs |
| Date of Order | 17 March 2026 |
| Case Number | C.A.(Comm.IPD-Pat) 244/2022 |
| Neutral Citation | 2026:DHC:2206 |
| Court | High Court of Delhi |
| Judge | Hon’ble Justice Manmeet Pritam Singh Arora |
Disclaimer: Readers are advised not to treat this as substitute for legal advise as it may contain errors in perception, interpretation, and presentation]
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
