Method of Treatment in A Petri Dish? Clarifying Section 3(I) Of the Indian Patent Act

Introduction

In recent years, bio-technology has seen an exponential growth in its technical prowess. From genetic cloning in 1996, to gene editing and cell based therapies in 2026. In the wake of the emergence of such technologies, it is imperative to pay attention to their patentability, as governed by the Indian Patent Act, 1970.

Section 3(i) of the Indian Patent Act 1970 bars the patenting of any process for the medicinal, surgical, curative, prophylactic, diagnostic, therapeutic or other treatment of human beings or animals. Historically, this provision was designed on grounds of public policy to prevent monopolisation of healthcare and to ensure unhindered access to healthcare. This has also been provided for in Article 27 of the TRIPS Agreement. Thus, since becoming a member of the World Trade Organisation, this provision was solidified in India to maintain compliance with TRIPS.

However, over time, this section has been extensively litigated upon by pharmaceutical companies and has seen an evolution in its jurisprudence. Each of the terms used, from medicinal to therapeutic is ambiguous in its interpretation and has been gradually clarified. For instance, in October 2025, Justice Prathiba M. Singh of the Delhi High Court, in Natera Inc and Anr v The Assistant Controller of Patents and Designs expounded the meaning of ‘diagnostic’ under this section.

However, each of these terms describe a ‘method of treatment,’ the meaning of which in itself remains ambiguous. The courts continue to interpret methods of treatment for better understanding. In Hirotsu Bio Science Inc V Assistant Controller Of Patents And Designs, the Court emphasised that the exclusion under Section 3(i) is attracted where the claimed invention is intrinsically linked to the act of treating a patient, particularly where it involves clinical application or intervention on the human body. This interpretation has become all the more important with the development of new technologies which can constitute a method of treatment.

Innovations such as gene engineering and lab-engineered immunotherapies pave the way for new legal questions regarding the patentability of methods of treatment as these innovations are developed entirely outside the human body i.e. in vitro, which implies that the inventive step occurs entirely outside of human body and the process is complex and technical in nature. These innovations are then administered to the human or animal body leading to the question whether in-vitro prepared treatments fall outside the scope of Section 3(i) especially when they are for curing diseases and not for cosmetic or fertilization purposes.

As an illustration, if a drug for cancer is prepared in-vitro and then administered into a human body, can a patent be granted for the said administration? Thus, when the root of the section remains unclear especially with these forthcoming innovations, can the interpretative elucidations by Indian judiciary truly be of fruition?

Tracing the Jurisprudence

Internationally, a method of treatment is explicitly excluded from patent protection in all jurisdictions but the United States of America, Australia and New Zealand. Leading patent jurisdictions such as those of the European Union, Japan and the United Kingdom disallow patents of methods of treatment.

Section 3(i) of the Indian Patent Act, 1970 can be traced to early English patent law and was incorporated in Indian law following the recommendation of the Ayyangar Committee Report. It allows for patentability of pharmaceutical products and compositions, but does not allow the same for the methods of applying these products to the human body. This is done to ensure that medical professionals are able to employ the best available course of treatment for their patients and make healthcare accessible. However, this distinction is blurred when biotechnological processes produce treatments engineered specifically for the patient, where the inventive step occurs outside the body and it is capable of industrial application.

EMD Millipore Corporation v Assistant Controller of Patents delved into the nuances of in-vivo and in-vitro distinction and highlighted that while the same was intended by the legislators following the adoption of TRIPS, it was not amalgamated in the existing law. This omission exacerbates the interpretative ambiguity.

A literal interpretation would mean that any process that contributes to treatment, whether directly or indirectly, cannot be patented. In such an instance, say for In-Vitro Fertilisation, no innovative tool or process developed could be patented which would then exclude pharmaceutical manufacturing processes.

On the other hand, if Section 3(i) is interpreted in a manner which broadens its ambit and allows for such patents to be granted easily, it would hinder medical access and lead to untenable consequences that will be detrimental for the public seeking treatment because of the exclusivity of treatments.

However, it is essential to note that patents have been granted to in-vitro methods of treatment in India, especially diagnostic.

Distilling the Ambiguity

In order to simplify the overarching ambiguity, it is essential to trace how the Courts have shaped up the jurisprudence of the different categories given under Section 3(i).

Therapeutic

In AbbVie Biotherapeutics Inc v Assistant Controller of Patents, the Delhi High Court rejected the patent application for dosage administration strategies, holding them to be ‘methods of treatment.’ The Court iterated that the distinguishing factor remains the inventive step, and that if that invention is in the administration technique of the drug rather than the creation of the therapeutic product, then it is excluded from patentability.

Diagnostic

In Chinese University of Hong Kong v Controller of Patents, the Madras High Court dealt with the in-vitro conundrum in a diagnostic method. The Court acknowledged a broader interpretation of Section 3(i) in light of previous exclusion of only in-vivo methods by the Indian Patent Office. It also drew a comparison with the European Patent Office which also follows the narrow interpretation which limits this exclusion only to the methods practiced on the human body.

In a major detour in this regard is the decision of the Delhi High Court in Natera Inc v Assistant Controller of Patents and Designs, where the Court undertook a detailed examination of what constitutes a “diagnostic method” within the meaning of Section 3(i). It clarified that not every process that yields information relevant to diagnosis can be classified as a diagnostic method. Instead, it emphasised that a diagnostic method must be understood in a clinical sense, involving the identification of a pathological condition, and a correlation of observed data with a disease.

This aligned the Court with the European jurisprudence, where diagnostic methods are seen as comprising multiple steps comprising data collection, comparison, and clinical decision-making, rather than one step as a whole.

Prophylactic

Treatments that aim to prevent rather than cure illnesses are also excluded under Section 3(i). However, similar to therapeutic and diagnostic, the distinction is nestled in the nature of the act involved. While it includes vaccines, preventive drug courses etc., these are done through direct interaction with the body and thus fall under section 3(i). However, processes that enable a prophylactic treatment can be patented as stated in EMD Millipore Corporation v Assistant Controller of Patents. These processes are conducted entirely in vitro, often through industrial and technical means, and are capable of large-scale replication. They do not involve clinical intervention, nor do they implicate the policy concerns underlying Section 3(i). To illustrate, while a method of administering a vaccine would be excluded, the process of developing or manufacturing that vaccine remains patentable.

Surgical

While the definition of surgical has been extensively discussed and expounded, making it the least ambiguous of them all, the patentability of in-vitro surgical treatments remains the most ambiguous. Surgical methods have consistently been understood as encompassing direct physical intervention on the human body, particularly those requiring medical skill and involving inherent health risks. It is for this reason that surgical methods have been treated as the textbook example for non-patentable subject matter.

The European Patent Office offers a clear framework for understanding surgical exclusions. In decision G 0001/04, the Enlarged Board of Appeal held that such exclusions must be narrowly construed and apply only to methods “practiced on the human or animal body.” In other words, the exclusion is triggered only where there is direct bodily intervention, not merely because a process contributes to treatment. This distinction is crucial, as it places in vitro processes outside the scope of exclusion, even if they ultimately facilitate surgical outcomes. Moreover, the Enlarged Board of Appeal in G 0001/07 clarified that a method is “surgical” only where it involves substantial physical intervention on the human body requiring medical expertise and carrying health risks, thereby anchoring the exclusion in clinical acts performed on the body. Consequently, processes carried out in vitro, including preparatory or technical steps, fall outside the exclusion. This stance is mirrored in some Indian judgments.

In CIMA Labs Inc v Controller of Patents, the erstwhile IPAB emphasised that processes involving physical manipulation of the body requiring medical skill are excluded under Section 3(i). At the same time, processes removed from clinical intervention, especially laboratory-based or preparatory steps, remain patentable. Thus, it can be inferred that the law excludes acts of surgery, not the science behind it.

Conclusion

The challenge posed by Section 3(i) is one of interpretation in an arena that has not been entirely legislated upon. As biotechnology continues to evolve, the traditional boundaries between treatment and innovation, especially its in vivo and in vitro administration, has become increasingly blurred. The key to striking balance is a well-considered interpretation. A literal or overly expansive reading of the provision risks collapsing this distinction, potentially excluding not only methods of treatment, but also the scientific processes that make such treatment possible.

A careful reading of Indian jurisprudence, alongwith the jurisprudence developed by the European Patent Office is instrumental in providing some clarity. The exclusion under Section 3(i) is not triggered by the purpose of the invention, but by the nature of the act involved. Where the claimed process constitutes direct clinical intervention on the human or animal body, it falls within the exclusion. However, when the process is conducted entirely in vitro and merely enables such intervention, this approach is found lacking.

This distinction is normatively necessary for it preserves the autonomy of medical practitioners while safeguarding incentives for scientific innovation. In the absence of such a boundary, Section 3(i) risks taking the shape of a broad impediment to technological progress. Thus, the way forward lies not in expanding or contracting the scope of the provision arbitrarily, but in cementing a test, such as that the law excludes the act of treatment, not the science that precedes it. In doing so, Indian patent law can strike a sustainable balance between public health safeguards and the demands of a dynamic innovation ecosystem.

Author: Pallakshi Pandiya, in case of any queries please contact/write back to us via email to [email protected] or at IIPRD.