The Chinese University of Hong Kong v Assistant Controller of Patents & Designs (2023)

Summary

“By order dated 26.03.2021, the first respondent rejected the application of the Chinese University of Hong Kong for grant of patent … The said order was originally challenged by filing W.P.No.7666 of 2023. Upon the constitution of this Division, CMA (PT) No.1 of 2023 was filed assailing the same order.” (para 1) “The amended claim 1, as of 07.05.2019, of the appellant” was for “A non-diagnostic in vitro method for measuring a sequence imbalance in a biological sample from a pregnant female subject” (para 4). The Assistant Controller “reached the conclusion that claims 1 to 22, 24 to 33 and 35 to 45 are not patent-eligible under Section 3(i) of the Patents Act because the said claims qualify as a diagnostic method” (para 6) and that “amended claims 1 to 46 lack an inventive step in view of prior art documents, D1 and D2” (para 5).

The Court concluded “that the word ‘diagnostic’ should be limited to diagnostic processes that disclose pathology for the treatment of human beings” (para 25) and that “the expression ‘diagnostic’ in Section 3(i) extends both to in vitro and in vivo diagnosis” (para 31). Of the opinion of the EBoA (“Enlarged Board of Appeal”), it held that “if the approach of the EBoA were to be adopted, the Section 3(i) exclusion would be circumvented with ease” (para 36), and that “the standard I propose is to examine the claims, in the context of the complete specification, to determine whether it specifies a process for making a diagnosis for treatment” (para 41). On the claims, it held 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 this process” (para 50). “For reasons set out above, CMA (PT) No.1 of 2023 and W.P.No.7666 of 2023 are dismissed without any order as to costs.” (para 52)

What the court decided

1. The two limbs of Section 3(i). “Because the text of Section 3(i) does not contain a comma between prophylactic and diagnostic, a tentative argument was made by the appellant that it should be confined to prophylactic or preventive diagnosis. Aside from the fact that punctuation is not determinative, this contention is liable to be rejected because the Patents (Amendment) Act, 2002 (Act 38 of 2002) contains a comma after the word prophylactic but the comma was not placed within the quotation marks … Therefore, the missing comma is no more than printer’s devil. Besides, such contention is wholly incompatible with one of the principal contentions of learned counsel for the appellant that the diagnostic method should be adopted for the treatment of human beings so as to render them free of disease.” (para 21) “In my view, each limb of Section 3(i) is distinct and self-contained.” “Thus, it is clear that the second part of Section 3(i) deals only with the treatment of animals and thereafter sets out three objects and purposes of treatment. When viewed in isolation, the first purpose ’to render them free of disease’ could apply to human beings. However, keeping in mind that the first and the second limbs deal with distinct subjects; they are separated by the disjunctive ‘or’; and the pronoun ’them’ is used after the antecedent ‘animals’, I conclude that said pronoun is referable only to the last antecedent ‘animals’ and not to human beings.” (paras 21–22)
2. The express terms of Section 3(i). “Apart from the above reasons, it bears mention that treatment is provided 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. Hence, I reject the contention that the word ‘diagnostic’ in Section 3(i) should be confined to treatment of human beings to render them free from disease.” (para 22) “When read with any of the above express terms, the opening phrase remains incomplete and does not make complete sense.” “Therefore, each of the above express terms becomes meaningful only if read along with the succeeding words as: ‘any process for the medicinal treatment of human beings’ and so on.” “The common thread running through the following categories - medicinal, surgical, curative, prophylactic and therapeutic - is that they are clearly methods of treatment of human beings.” (para 23) “The use of the disjunctive ‘or’ followed by the expression ‘other treatment’ indicates that it refers to forms of treatments other than the specific forms enumerated above. The enumeration of multiple forms of treatment followed by the generic ‘or other treatment’ also indicates that the word ’treatment’ is intended to be construed widely.” (paras 22–23)
3. The meaning of diagnosis. “The odd one out, as indicated above, is ‘diagnostic’. Diagnosis, in the context of medical science, is a method of identifying the existence or non-existence of a disease or disorder or condition and/or the site, extent, severity or other aspects thereof. Undoubtedly, such identification per se cannot be construed as a form of treatment.” (para 24) “One solution would be to consider it as ‘casus omissus’ and add words such as ‘method for’ after diagnostic. I am not inclined to resort to such option because … the word ‘process’ at the beginning of the provision is incompatible with the proposed word ‘method’, both being analogous. More importantly, it does not resolve the fundamental problem of diagnosis or the diagnostic method not being a form of treatment.” (para 24)
4. Diagnosis and treatment. “Diagnosis - whether by physical examination and/or an analysis of symptoms or by use of diagnostic devices or running laboratory tests - is an essential pre-requisite for rational treatment.” “Whether the interval is short or long, diagnosis and treatment are understood as distinct processes.” (para 25) “Because the word ‘diagnostic’ is juxtaposed in Section 3(i) with words such as ‘medicinal’ or ‘surgical’, which are undoubtedly forms of treatment, learned counsel for the appellant contended 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. In principle, I concur. When viewed in context, i.e. in association with ‘forms of treatment’, I conclude that the word ‘diagnostic’ should be limited to diagnostic processes that disclose pathology for the treatment of human beings.” (para 25)
5. In vitro diagnosis. “As is evident from the language of Section 3(i), there is no indication therein that the word ‘diagnostic’ should be confined to in vivo diagnosis. Even if the net were to be cast wider, I find nothing in the language of Section 3 or in any other provisions of the Patents Act that lead to the inference that the expression ‘diagnostic’ should be confined to in vivo diagnosis.” (para 26) “The fact that Section 3(i), in contrast to Article 52(4) of the EPC, does not contain the expression ‘practised on the human or animal body’, reinforces the conclusion that the expression ‘diagnostic’ in Section 3(i) extends both to in vitro and in vivo diagnosis.” (paras 26, 31)
6. Article 27(3)(a) of the TRIPS Agreement. “Article 27(3)(a), thus, indicates clearly that the diagnostic method should be for the treatment of humans or animals, but no other limitation or restriction on the scope of the expression ‘diagnostic methods’ is discernible from Article 27(3)(a).” (para 28)
7. The European approach declined. “With regard to in vivo diagnosis, such as by use of ultrasound devices, endoscopy, computer tomography (CT) scans, magnetic resonance imaging (MRI) and coronary angiography, the processes of diagnosis are ordinarily performed by or under the supervision of medical doctors.” “Therefore, it is probable, albeit not certain, that in such processes all the four method steps specified by the EBoA would be involved.” (para 35) “By contrast, while carrying out in vitro diagnosis, the first three method steps may be carried out by persons other than medical doctors, even without supervision by medical doctors, whereas the fourth method step may only be carried out by a medical doctor.” “Therefore, in the context of in vitro diagnosis, if the approach of the EBoA were to be adopted, the Section 3(i) exclusion would be circumvented with ease.” (paras 35–36)
8. The standard for diagnostic processes. “By taking note of the above and recognising that Section 3(i) differs materially from Articles 52(4) and 53(c) of the EPC inasmuch as Section 3(i) excludes from patent eligibility any process for the diagnostic treatment of human beings, whereas Article 52(4) and 53(c) exclude only diagnostic methods practised on the human body, I conclude that the word ‘diagnostic’ should receive a construction which is in consonance with text and context.” (para 41) “Such construction does not call for curtailment by limiting the scope of ‘diagnostic’ to in vivo or definitive diagnosis. Equally, expansion is not called for by extension to any process relating to or of some value in diagnosis. Instead, the standard I propose is to examine the claims, 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.” (para 41)
9. Use cases and embodiments. “Nonetheless, it should not be lost sight of that patent eligibility is decided at the threshold by examining claims that could have multiple use cases. Consequently, in the context of diagnostic processes, I am of the view that the embodiments of a claimed invention are relevant only for the purpose of ascertaining whether the process of 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).” (para 42)
10. Screening and diagnosis. “In my view, 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 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.” (para 44) “Medical literature also makes the distinction between screening and diagnosis on the basis that diagnostic tests are required to confirm the results of screening tests.” “Adopting this approach, in my view, is also not in consonance with the meaning of ‘diagnostic’ in Section 3(i), i.e. capable of uncovering the pathology. Put differently, if the screening test identifies the disease, disorder or condition albeit subject to confirmation by definitive tests, it would still qualify as ‘diagnostic’ for purposes of Section 3(i) because the provision does not use the qualifier ‘definitive’.” (paras 44–45)
11. The determinative question. “What is determinative, therefore, of whether a process is diagnostic is to ask the question whether the process is inherently and per se capable of identifying the disease, disorder or condition for treatment of the person. It bears repetition that such capability of the process should, in turn, be determined by assuming that a person(s) skilled in the art, including a medical doctor, examines 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).” (para 46) “I recognise that the line of demarcation between diagnostic and non-diagnostic tests may not always be bright and could blur on occasion; even so, there is sufficient support both in the text and immediate context of the expression ‘diagnostic’ in Section 3(i) to reach the above conclusion. The corollary would be that the Controller would be required to make this determination on a case-by-case basis.” (para 46)
12. Obiter. Isolating cell-free foetal DNA. “It is conceivable that a novel and inventive process to isolate the cell free foetal DNA from the biological sample may be invented. This process cannot per se uncover pathology and, therefore, would not qualify as ‘diagnostic’ as per the principle formulated above.” (para 46)
13. Embodiments in the complete specification. “The contention of learned counsel for the appellant that embodiments of the claimed invention should not be reckoned for determination of the claims cannot be accepted. 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.” (para 50)
14. The claimed size-distribution method. “On examining claim 1 of the amended claim submitted by the appellant before the Assistant Controller or the current claim 1, it is evident that the biological sample is drawn from the pregnant female subject. The nucleic acid molecules in such biological sample are tested by undertaking sequencing to determine the size distribution of the nucleic acid molecules by comparing the same with reference values.” The complete specification, as reproduced, stated: “Certain embodiments of the present invention can provide systems, methods, and apparatus can use a size-based analysis to perform a prenatal diagnosis of a sequence imbalance (e.g. a fetal chromosomal aneuploidy) in a biological sample obtained from a pregnant female subject.” (para 49) The Court held: “In my view, if the amended claim 1 or current claim 1 is examined in the context of the above and other 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 this process.” (paras 49–50) “If a positive result for a chromosomal aneuploidy is returned, medical literature indicates that a medical doctor is likely to opt for definitive diagnosis by undertaking chorionic villi sampling or amniocentesis. It is also possible that the claimed invention may be more effective in identifying certain autosomal aneuploidies and less effective with chromosomal mutations or sex chromosomal monosomies and trisomies. On those counts, however, 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.” (paras 49–50)
15. Disposition. The Court held it “sufficient to record that the impugned order does not warrant interference” (para 50). “For reasons set out above, CMA (PT) No.1 of 2023 and W.P.No.7666 of 2023 are dismissed without any order as to costs. Consequently, connected miscellaneous petitions are closed.” (paras 50, 52)

What the court did not decide

Of the conclusion in the impugned order “that amended claims 1 to 46 lack an inventive step in view of prior art documents, D1 and D2” (para 5), the Court held: “Once it is concluded that the claims are patent ineligible, it is not necessary to deal with the other grounds of decision, such as lack of inventive step” (para 50).

Subsequent treatment

• Followed — On 13 March 2025 the Madras High Court (Senthilkumar Ramamoorthy J) relied on this judgment and on the appeal named in its para 18, “The Chinese University of Hong Kong v. The Assistant Controller of Patents and Designs, CMA (PT) No.14 of 2023”, decided the same day, in remanding two refused applications. In The Chinese University of Hong Kong v Assistant Controller of Patents and Designs, CMA (PT) No.48 of 2024, it held that “As regards Section 3(i), as per judgments referred to earlier, it is necessary for the respondent to examine whether the claimed invention is a method of diagnosing diseases, disorders or conditions” (para 7); in University of Washington v Assistant Controller of Patents and Designs, CMA (PT) No.40 of 2023, citing this judgment as 2023:MHC:4616, it recorded: “I interpreted Section 3(i) and concluded that it applies to claimed inventions which would per se disclose pathology to a person skilled in the art. Put differently, not every claimed invention that is relevant for diagnosis would fall within the ambit of Section 3(i) of the Patents Act.” (para 6)
• Followed — In Hirotsu Bio Science v Assistant Controller of Patents and Designs (2026) the Delhi High Court reproduced paras 45 and 50 of this judgment, held that “Paragraph No. 50 of The Chinese University of Hong Kong (supra) also supports the above view”, and upheld the refusal under s.3(i) (paras 32–34, 40). It cited the decision under the name and report of CMA (PT) No.14 of 2023, Chinese University of Hong Kong and Sequenom, Inc. v. The Assistant Controller of Patents and Designs, 2023 SCC OnLine Mad 6372 (para 7.9).
• Followed — In Geron v Assistant Controller of Patents and Designs (2026) the Delhi High Court, having reproduced the analysis of s.3(i) in CMA (PT) No.14 of 2023 (para 20), recorded that “the same analysis of law is also set out in” this judgment, cited as 2023 SCC OnLine Mad 8616, and held that “The laws settled in these judgments do not persuade this Court to hold that the Appellant’s Subject Patent Application has been incorrectly rejected” (para 35).