The Indian context: Section 3(i) of the Patents Act
Section 3(i) of the Indian Patents Act, 1970, states that "any process for the medicinal, surgical, curative, prophylactic, diagnostic, therapeutic, or other treatment of human beings or any process for a similar treatment of animals to render them free of disease or to increase their economic value or that of their products" is not an invention and therefore not patentable. This provision is intended to prevent monopolies over essential medical practices, thereby safeguarding public access to healthcare.
Recent judicial interpretations: Madras High Court decisions
Two recent decisions from the Madras High Court have significantly contributed to the understanding of what constitutes a "diagnostic method" under Section 3(i). These decisions involved two separate appeals by The Chinese University of Hong Kong, where the court had to determine whether the claimed inventions were diagnostic methods and therefore patent-ineligible. The said decisions are elucidated hereafter:
1. CMA (PT) No. 14 of 2023: patent granted
In this case, the invention involved a method for identifying the "fetal fraction" — the proportion of cell-free fetal DNA in a maternal biological sample. The method was used to ensure that the fetal fraction was adequate for further testing, but it did not, by itself, identify any disease or condition. The court ruled that since the method did not uncover any pathology, it did not fall under the diagnostic exclusion of Section 3(i) and was therefore patentable.
2. CMA (PT) No. 1 of 2023: patent refused
The second case involved a method for prenatal diagnosis of a sequence imbalance in fetal DNA, which could indicate chromosomal aneuploidy. Here, the court found that the method directly uncovered a potential pathology — chromosomal imbalance — which could lead to further medical treatment. As such, the court held that this method was a diagnostic method and therefore not patentable under Section 3(i).
These decisions are pivotal as they delineate the scope of what constitutes a "diagnostic method" under Indian patent law. The court highlighted that a method could be considered diagnostic, and hence patent-ineligible, if it is capable of identifying a disease, disorder, or condition for treatment.
The broader interpretation: “nositur a sociis” and diagnostic methods
The Madras High Court emphasised that the term "diagnostic" in Section 3(i) should be interpreted in conjunction with other medical treatment terms like medicinal, surgical, and therapeutic treatments. This legal principle, known as *noscitur a sociis*, implies that the meaning of a word is influenced by the words surrounding it. Consequently, the court concluded that diagnostic methods that identify pathology for treatment purposes are patent-ineligible.
Furthermore, the court discussed the two distinct limbs of Section 3(i): the first pertaining to human beings and the second to animals. The latter limb includes additional considerations like increasing economic value, which do not apply to humans. This distinction reinforced the view that the term "diagnostic" in the context of human treatment should be understood as encompassing methods that reveal pathology directly linked to treatment.
Diagnostic methods: In Vivo vs. In Vitro
Historically, the Indian Patent Office distinguished between in vivo and in vitro diagnostic methods, with the former generally considered non-patentable. However, recent guidelines, such as the 2019 Patent Manual, and the Madras High Court's interpretation suggest that this distinction no longer holds good. The court found no basis in the language of Section 3(i) to confine the term "diagnostic" to in vivo methods alone, thereby expanding the exclusion to cover certain in vitro methods under its ambit as well.
Europe: the EPO's approach to diagnostic methods
In Europe, the European Patent Convention (EPC) excludes methods of treatment and diagnostic methods from patentability under Article 53(c). However, the European Patent Office (EPO) has provided detailed guidelines and case law on what constitutes a "diagnostic method."
The EPO's Technical Board of Appeal, in Decision G 1/04, clarified that for a method to be considered diagnostic and thus excluded from patentability, it must include the following steps:
- Examination phase involving data collection
- Comparison of the collected data with standard values
- Identification of any significant deviation
- Deductive medical decision phase, attributing the deviation to a specific condition.
If a method does not involve all the steps above, it may not be considered a diagnostic method and could be patentable. This detailed approach provides a clearer framework than the one currently available in India.
United States: the Mayo and Myriad decisions
In the United States, the Supreme Court has significantly shaped the patentability of diagnostic methods through landmark decisions.
1. Mayo Collaborative Services v. Prometheus Laboratories, Inc. (2012
The Supreme Court ruled that a method of optimising drug dosage based on the measurement of metabolite levels in the blood was not patentable because it was essentially a law of nature. The Court emphasised that adding routine steps to a natural law does not make it patentable.
2. Association for Molecular Pathology v. Myriad Genetics, Inc. (2013)
In this case, the Supreme Court held that naturally occurring DNA sequences cannot be patented, but synthetic cDNA (complementary DNA) can be. While the case primarily addressed genetic patents, it also impacted the patentability of diagnostic methods, as many such methods involve the analysis of genetic material.
These decisions reflect the US approach, where the focus is on distinguishing between natural laws, which are not patentable, and human-made inventions, which can be. Diagnostic methods that rely solely on natural laws without significant inventive steps are generally not patentable in the US.
The recent Madras High Court decisions have highlighted inconsistencies in the practices of Indian patent examiners regarding the patentability of diagnostic methods. Despite these judicial clarifications, there remains uncertainty in the application of Section 3(i), leading to inconsistent decisions at the Patent Office level. The court acknowledged these inconsistencies and suggested that further judicial interpretation might be necessary to bring consistency and clarity to this area of law. Notably, the Delhi High Court is expected to hear similar cases soon, which could further refine the interpretation of Section 3(i).
Implications and conclusion
The patentability of diagnostic methods remains a contentious issue worldwide, with significant implications for innovation and public health. In India, the recent decisions by the Madras High Court provide some clarity but also highlight the need for more detailed guidelines. While India’s exclusion under Section 3(i) aims to protect public health, it must also balance the need to encourage innovation in medical diagnostics.
Globally, the trend is towards restricting the patentability of methods that do not involve significant human intervention beyond the application of natural laws. However, the approach varies significantly between jurisdictions, reflecting different priorities and legal traditions. As medical technology continues to evolve, ongoing judicial interpretation and potential legislative amendments will be necessary to address these challenges in a way that balances innovation with public access to essential healthcare.
FICPI's view and involvement
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Next steps
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