14 October 2023

Scope of diagnostic methods under Section 3(i) of the Patents Act - Madras High Court elucidates

Introduction

In a first by an Indian Court, the Single Judge of the Madras High Court in the case of The Chinese University of Hong Kong and Sequenom, Inc. v. The Assistant Controller of Patents and Designs, CMA (PT) No.14 of 2023 (Judgement dated 12 October 2023) interpreted the scope of the exclusion for diagnostic methods under Section 3(i) of the Patents Act, 1970 (‘Act’) and held that the invention claimed in the instant case is not excluded under Section 3(i) of the Act.

The Single Judge was adjudicating an appeal against the refusal by the Controller of Patent Application no. 4812/CHENP/2012 for an invention titled “Fetal Genomic Analysis from a Maternal Biological Sample”. The Controller refused grant under Section 3(i) of the Act because the claims qualify as a diagnostic method. The Controller relied upon an extract from the complete specification to conclude that the claimed invention is a process of diagnosing that the foetus is suffering from genetic or other diseases.

Analysis of the Decision

  • Limbs of Section 3(i)

The Single Judge firstly interpreted the two limbs under Section 3(i) of the Act as being distinct and self-contained. The Single Judge held that the phrase, any process for the medicinal, surgical, curative, prophylactic diagnostic, therapeutic or other treatment of human beings – deals only with human beings. Whereas the phrase, 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 - deals only with animals. The Single Judge reasoned that the use of the disjunctive “or” and the pronoun “them” in the provision, coupled with the fact that treatment is not only to free/cure a person of disease but also for prophylactic purposes, to alleviate pain, prevent aggravation of or to better manage a condition or disorder; leads to the conclusion that “diagnostic” in Section 3(i) should not be confined only to treatment of human beings to render them free from disease.

  • Diagnostic methods for the treatment of humans

Secondly, the Single Judge analysed the opening phrase of Section 3(i)- “any process for the”. The Single Judge reasoned that the terms in the provision medicinal, surgical, curative, prophylactic, diagnostic and therapeutic seem complete only when read as “any process for the medicinal/surgical/curative/prophylactic/therapeutic treatment of human beings”. The Single Judge observed that all these terms refer to method of treatment of humans, however, the same cannot be said in respect of the term “diagnostic”. The Single Judge reasoned that the enumeration of multiple forms of treatment followed by the generic “or other treatment” indicates that the word “treatment” is intended to be construed widely.

The Single Judge held that the term “diagnostic” is juxtaposed in Section 3(i) with words such as “medicinal” or “surgical”, which are undoubtedly forms of treatment. Accordingly, the Single Judge accepted that contention that the expression 'diagnostic' should not be construed in isolation but should be understood noscitur a sociis, i.e., in association with the accompanying words of Section 3(i) read as a whole. The Single Judge thus held that the word “diagnostic” should be limited to diagnostic processes that disclose pathology for the treatment of human beings.

  • Section 3(i) is not limited to in vivo diagnosis

Thirdly, the Single Judge held that that the word “diagnostic” should receive a construction which does not limit the scope of “diagnostic” to in vivo diagnosis or definitive diagnosis. The Single Judge analysed Article 27 of the TRIPS Agreement, the travaux préparatoires or preparatory materials leading to the conclusion of TRIPS, the Patent office Manuals and Guidelines, the corresponding provisions under the European Patent Convention, 1973[1], the decision of the Enlarged Board of Appeal (EBoA) case No. G 0001/04 prescribing the 4-method step test for assessing whether a claimed method is diagnostic[2] and other European decisions. As per the EBoA, methods which involve the three constitutive method steps that precede the deductive phase and form the basis of the curative decision, would be patent eligible. The Single Judge reasoned that in vivo diagnosis by devices such as ultrasound, CT scans or MRIs are performed under the supervision by or in consultation with doctors and thus would encompass all 4 method steps. Whereas in vitro methods can be carried out without the supervision by or consultation with doctors, by technicians, and the deductive phase is undertaken by the doctor. The Judge observed that if the EBoA approach is adopted, circumvention of the Section 3(i) exclusion would be possible.

The Single Judge acknowledged that to overcome this possible circumvention, the jurisprudence of the EPC provides that while all four method steps of diagnosis should be involved for a diagnostic method to be patent ineligible, however the fourth method step would become liable to be included as an essential feature if it is clear from the patent application as a whole that the inevitable results of the tests would lead to a particular diagnosis; the reliability thereof being of limited significance.

Having considered the above, the Single Judge noted the difference in the wording of the exclusion under Section 3(i) and corresponding provisions under the EPC and concluded that the word “diagnostic” should receive a construction which is in consonance with text and context. It was held that such construction does not call for curtailment by limiting the scope of “diagnostic” to in vivo diagnosis or definitive diagnosis. Equally, the Single Judge held that expansion is not called for by extension to any process relating to or of some value in diagnosis.

The Single Judge propounded that claims should be examined in the context of the complete specification, to determine whether it specifies a process for making a diagnosis for treatment. Such determination should be made by assuming that a person(s) skilled in the art, including a medical doctor, examines the claims and complete specification. If it is concluded that a diagnosis for treatment may be made, even if such diagnosis is not definitive, it would be patent ineligible, whereas, if diagnosis for treatment cannot be made, it would be patent eligible.

The Single Judge also held that in the context of diagnostic processes, the embodiments of a claimed invention are relevant only for the purpose of ascertaining whether the claimed invention per se points to a diagnosis for treatment. If such process does not uncover pathology for any reason, it would not be diagnostic for purposes of Section 3(i) of the Act.

  • Screening and Diagnosis

The Single Judge acknowledged that medical literature distinguishes screening and diagnostic tests. However, the Single Judge held that if a screening test can identify the existence or non-existence of a disease, disorder or condition and/or the site, extent, severity or other aspects thereof for treatment of human beings, irrespective of whether the person concerned is symptomatic or asymptomatic, such screening test would qualify as a diagnostic test. In other words, the label used for the test - be it screening or anything else - is not determinative.

The Single Judge also held that a screening test that identifies the disease, disorder or condition albeit subject to confirmation by definitive tests, would still qualify as “diagnostic” for purposes of Section 3(i) because the provision does not use the qualifier “definitive”.

  • How to determine whether a test is diagnostic

The Single Judge held that the assessment to be undertaken is whether the test is inherently and per se capable of identifying the disease, disorder or condition for treatment of the person. The test should, in turn, be determined by assuming that person(s) skilled in the art, including a medical doctor, examine the results. If the person(s) skilled in the art would not be in a position to diagnose the disease, disorder or condition, as the case may be, on the basis of the process because the process is not designed to diagnose diseases, disorders or conditions, such process, whether labelled as screening or anything else, would not qualify as diagnostic for purposes of Section 3(i) of the Act.

  • Analysis of the patentability of the claimed invention

The Single Judge observed that the amended claims 1 and 9 of the invention pertain to drawing a biological sample from the pregnant female subject and thereafter testing the nucleic acid molecules in such biological sample with a view to identify the foetal fraction, i.e. the proportion of cell free foetal DNA in the biological sample. The Single Judge noted that medical literature indicates that the foetal fraction should be not less than 4% to enable further testing to identify chromosomal aberrations, such as chromosomal aneuploidies. Until that stage is reached, pathology is not uncovered and, consequently, treatment is not possible.

The Single Judge held that the claimed invention is per se incapable of identifying the existence or otherwise of a disease, disorder or condition and further testing would be required for such purpose. The Single Judge held while the scope of Section 3(i) should not be unduly curtailed by limiting it to in vivo or definitive diagnosis, the scope should also not be unduly expanded by implying the words “relating to” diagnosis. The Court held that determination of foetal fraction is related to diagnosis but is not “diagnostic”.

Conclusion

Since the refusal of the patent application was only based on Section 3(i), which the Single Judge held as inapplicable; it was directed that the patent application shall proceed to grant. The Single Judge suggested that an amendment in the law such as to restrict Section 3(i) to only in vivo methods may be considered by the legislators to incentivize inventors in these areas.

In another matter, The Chinese University of Hong Kong v. The Assistant Controller of Patents and Designs, CMA (PT) No.1 of 2023 (Judgement dated 12 October 2023), applying the same principles as discussed hereinabove, the Single Judge dismissed the appeal against the Controller’s refusal of Patent Application no. 4863/CHENP/2012. The Single Judge reasoned that although the claims delimit the scope and ambit of the monopoly claim, the embodiments set out in the complete specification can and should be examined to assess whether the process is per se diagnostic. The Single Judge held that on examining the claims and paragraphs of the complete specification, it follows that person(s) skilled in the art would be able to arrive at a diagnosis as to whether a specific chromosomal aberration, such as an aneuploidy, exists by adopting the claimed process. The Single Judge held that it cannot be concluded that the process described by the claimed invention is not diagnostic because neither definitive nor comprehensive diagnosis is a prerequisite to qualify as diagnostic.

[1] Article 52(4) and 53(c) of EPC exclude only diagnostic methods practised on the human body

[2] (i) the examination phase involving the collection of data, (ii) the comparison of these data with standard values, (iii) the finding of any significant deviation, i.e. a symptom, during the comparison, and (iv) the attribution of the deviation to a particular clinical picture, i.e. the deductive medical or veterinary decision phase

https://www.epo.org/en/boards-of-appeal/decisions/g040001ep1

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