Madras High Court explains scope of non-patentable diagnostic methods under Patents Act

Section 3 of the Indian Patents Act, 1970 (the Patents Act) bars patentability for certain inventions. Section 3(i) of the act prohibits the patenting of inventions that are related to “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”. There has been no clarity regarding what methods are barred from patenting under this provision until the Madras High Court’s judgment in the matter of The Chinese University of Hong Kong and Sequenom, Inc. (the Applicants) v The Assistant Controller of Patents & Designs, pronounced on October 12 2023.

Arguments of the Applicants

Under Section 117A of the Patents Act, the Applicants filed an appeal against an order passed by the controller on March 31 2021. The Applicants applied for a patent titled ‘Fetal genomic analysis from a maternal biological sample’. National Phase Application No. 4812/CHENP/2012 was filed on June 1 2012, with 44 claims in the first examination report (FER), and the claims were objected to under sections 2(1)(j), 2(1)(ja), 3(i), and 10(5) of the Patents Act. While filing a response to the FER, claims 1–33 were deleted, and amended claims 1–12 were submitted. The amended claims are related to a method of determining a fractional concentration of fetal DNA in a biological sample taken from a pregnant female.

The Applicants contended that the determination of the fetal fraction does not diagnose a disease, and, thus, the claims do not fall under the purview of Section 3(i). However, the controller, while refusing the claims under Section 3(i), relied on paragraph 0007 of the as-filed specification, which states that the process is for diagnosing that the fetus is suffering from a genetic or another disease.

The counsel for the Applicants argued before the Madras High Court that the object of the amendment to Section 3(i) is to prevent the grant of patents to methods of diagnosis performed by a medical doctor. The counsel’s argument was based on the communication from the Indian Permanent Mission to the Negotiating Group on the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS). Thus, the counsel contended that Section 3(i) should be construed as limited to diagnostic methods practised on the human body.

The principle of interpretation was also relied on and it was argued that “diagnostic” should be interpreted by taking into account the words with which it is associated in the provision (noscitur a sociis). The expressions “other treatment of human beings” and “to render them free of disease” should be considered. Thus, a method would qualify as diagnostic only if it is intended for treating human beings to render them free of disease.

The counsel also argued for the Applicants that the claimed process is an ‘in vitro’ analysis method; thus, it does not fall under the purview of Section 3(i). The counsel relied on paragraph of the Manual of Patent Practice and Procedure, which states that methods of diagnosis practised on human and animal bodies are not patentable. This indicates that diagnosis undertaken in vitro is patent eligible.

To support the argument, the counsel for the Applicants referred to the EPO’s Enlarged Board of Appeal (EBoA) order in case No. G 0001/04. The EBoA had provided that a method is not patentable only if the following four method steps are carried out:

• An examination phase involving the collection of data;
• The comparison of such data with standard/reference values;
• The finding of any significant deviation – i.e., a symptom – during the comparison; and
• The attribution of the deviation to a particular clinical picture; i.e., the deductive medical or veterinary decision phase.

It was argued that the fourth step is not carried out in the claimed process. Therefore, the claims do not fall under the purview of Section 3(i).

Amicus curiae brings valuable insights

The Madras High Court appointed an amicus curiae to assist the court in understanding the issue better. The amicus curiae submitted that Section 3(i) was amended by Act 38 of 2002. According to him, the amendment in the provision contains a drafting error in the nature of casus omissus, or a situation omitted from, or not provided for by, a statute or regulation. Thus, according to him, the first limb of Section 3(i) should be read as “any process for the medical, surgical, curative, prophylactic diagnostic, therapeutic or other methods for treatment of human beings”.

The amicus curiae also referred to the communication from the Indian Permanent Mission to the Negotiating Group on TRIPS. He submitted that a diagnostic method is ineligible for a patent when practised on the human body. This proposal from India is inspired by Article 52(4) of the European Patent Convention of 1973. However, this proposal did not find a place in the final Article 27(3)(a) of the TRIPS agreement.

The amicus curiae also traced the evolution of these exclusions from patentability. He submitted that the Ayyangar Committee Report of 1959 and the Patent Bill did not contain these exclusions from patentability. He pointed out that these exclusions were justified on the ground of non-vendibility or lack of industrial application and not on the ground of public policy. The public policy aspect for patentability exclusion emerged later. He also submitted that public policy exclusion is not all-encompassing or comprehensive. Also, compulsory licensing is available to counterbalance pharmaceutical patents. Such counterbalancing is unavailable with regard to the method of treatment of human beings.

With respect to the manual of the Indian Patent Office, he submitted that it has long been understood that only an in vivo diagnostic process is excluded under Section 3(i). He also commented on the EBoA four-method requirement and stated that the EBoA is conscious that such a requirement could result in clever patent claim drafting to circumvent patent exclusion. Thus, he submitted that the Technical Board of Appeal only grants patents if the claimed invention does not point unambiguously to a clinical diagnosis.

Arguments of the central government

The counsel for the central government, while defending the order of the assistant controller of patents, argued that paragraph 0007 of the filed specification mentions that the claimed invention enables the diagnosis of genetic disorders. Also, it was argued that Section 3(i) does not indicate that the diagnostic process should be limited to in vivo diagnosis. The counsel argued that if the intention of the legislature were to exclude in vitro diagnosis, the provision would have contained such indication.

For the EBoA four-method test, the counsel for the central government contended that the opinion is not binding on the court. The counsel also referred to the Pre-Conception and Pre-Natal Diagnostic Techniques Act, 1994 and argued that sex determination is feasible through the claimed process. Therefore, the grant of this patent would be in spite of the above statute.

The Madras High Court’s findings

The court carefully analysed the submissions made by all the parties. Section 3(i) has two limbs:

• Any process for the medicinal, surgical, curative, prophylactic diagnostic, therapeutic, or other treatment of human beings; and
• 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.

The court held that each limb of Section 3(i) is distinct and self-contained. Based on the analysis of the scope of the two limbs, the court held that it is incorrect to confine the word “diagnostic” to treating human beings to render them free from disease.

The court stated that the expression “any process for the diagnostic treatment of human beings” does not make complete sense, unlike in the case of the forms of treatment mentioned in Section 3(i). Thus, the court proposed to make sense of the expression “any process for the diagnostic… or other treatment of human beings” with reference to both text and immediate context.

The court explained that the word “diagnostic” should be limited to a diagnostic process that discloses pathology for the treatment of human beings. The court stated that nothing in the language of Section 3 or any other provision of the Patents Act led to the inference that the expression “diagnostic” should be confined to in vivo diagnosis. The court carefully examined the amendments to the Patents Act, the discussion regarding the TRIPS agreement, and the provisions of the TRIPS agreement. The court concluded that the travaux préparatoires of Article 27(3)(a) also do not support exempting in vitro diagnostic processes or methods from patent ineligibility.

The court held that the word “diagnostic” should receive a construction that is in agreement with the text and context. Justice Senthilkumar Ramamoorthy proposed to examine the claims in the context of the complete specification to determine whether it specifies a process for making a diagnosis for treatment. It was further held that such determination should be made by assuming that a person skilled in the art, including a medical doctor, examines the claims and complete specifications. As per the test prescribed, if it is concluded that a diagnostic for treatment may be made, even if such diagnosis is not definitive, the subject matter will be patent ineligible. However, if a diagnosis for treatment cannot be made, it would be patent eligible.

While answering the issues related to the exclusion of certain types of tests from the ambit of the expression “diagnostic” in Section 3(i), it was held by the court that the embodiment of a claimed invention is relevant only to ascertain whether the claimed invention per se points to a diagnosis for treatment. If such a process does not cover pathology for any reason, it would not be diagnostic for the purposes of Section 3(i).

The court also discussed the difference between screening and diagnosis, and held that if a screening test is capable of identifying the existence or non-existence of a disease, disorder, or condition and/or the site, extent, severity, or other aspects thereof for the treatment of human beings, irrespective of whether the person concerned is symptomatic or asymptomatic, the screening test would qualify as a diagnostic test. The court also observed that the line between diagnostic and non-diagnostic tests may not always be bright and could be blurred on occasion. In such cases, the court advised controllers to determine on a case-by-case basis into which category the claimed invention falls.

Based on the above analysis, the court held that the claimed invention is, by itself, incapable of identifying the existence or otherwise of a disease, disorder, or condition, and further testing would be required for such a purpose. The court held that the determination of fetal fraction is related to diagnosis but is not diagnostic.

While concluding the order, the court indicated that to incentivise inventors in these cutting-edge areas, albeit without compromising on the public policy exclusion from patent eligibility of methods of diagnosis and treatment adopted by medical doctors, there is a case to consider options such as restricting the scope of the expression “diagnostic” in Section 3(i) to in vivo processes and counterbalancing by providing for compulsory licensing.

Clarity for patent applicants on diagnostic methods

This judgment has provided a much-needed clarification regarding diagnostic methods. Now, it is clear that there is no difference between in vivo and in vitro methods with regard to assessment under Section 3(i). It is also clear that it is incorrect to read the word “diagnostic” in conjunction with treating human beings to render them free from disease.

However, the court has recommended that the legislature consider an amendment to Section 3(i) regarding in vivo processes. Only time will tell whether the legislature will consider this recommendation.

For now, the only relevant question to consider is whether the process is for making a diagnosis for treatment. This has provided clarity to applicants trying to obtain a patent on a diagnostic method. It will be interesting to see how the controllers are going to apply this test to ascertain the patentability of diagnostic methods in India.