Dissecting the Delhi HC’s Assessment of Diagnostic Processes Under Section 3(i) of the Patents Act

The Delhi HC has articulated a detailed interpretative understanding of the exclusion of diagnostic methods from patentability under Section 3(i) of the Patents Act. In three judgments passed in three different appeals (Natera, Sequenom, and Emd Millipore), the Court has laid down the manner in which the provision is to be understood and applied. The Court clarified that the manner in which the diagnosis is to be performed cannot be patented, whereas diagnostic tools, products, and devices can still be patented. The major imperative is to balance the promotion of genuine innovation in medicine and the prevention of hindrance to medical professionals in using critical processes in practice. This discussion on the provision’s interpretation is common across the rulings. 

The subject inventions were the following: 

• The patent application in Natera was titled ‘Methods for Lung Cancer Detection’;
• The patent application in  Sequenom dealt with ‘Process and Compositions for Methylation-Based Enrichment of Fetal Nucleic Acid from a Maternal Sample Useful for Non Invasive Prenatal Diagnoses’; 
• And the invention in Emd Millipore was titled ‘Devices and Methods for Infrared (IR) Based Quantitation of Biomolecules’ and related to an improved method for the quantitative analysis of biomolecules using infra-red (IR) spectroscopy. 

The status till appeal was that Section 3(i) bar was attracted to the inventions in Natera and Sequenom, where Emd Millipore escaped the exclusion. Further, one additional legal issue in Natera was concerned with the amendment of claims and specifications under Section 59 of the Patents Act. 

In this piece, I assess the Delhi High Court’s exposition of the law pertaining to diagnostic methods under Section 3(i) and underline the problems with the same, including a not-so-surgical borrowing of foreign law from the EU. Another peculiar aspect of the judgments is the absence of substantive engagement with the Madras HC’s ruling in Chinese University of Hong Kong v. Assistant Controller of Patents & Designs, which is the other significant decision on diagnostic methods under Section 3(i). 

Looking at the Indian legal trajectory, the Court noted the absence of a provision akin to Section 3(i), in the Patents and Designs Act 1911. This however, was not a hindrance to the exclusion of medicinal, surgical methods since the definition of invention under that legislation necessitated a novel method of manufacture. The Ayyangar Committee report noted the need for a specific provision for exclusion of  medicinal, surgical, curative, prophylactic and other treatment of man or processes for the treatment of plants or animals  under the law (para 332). And this is how Section 3(i) entered the statute books. The original 1970 Patents Act iteration used the following terms: ‘medicinal, surgical, curative, prophylactic or other treatment’. During the TRIPS negotiating process, India had suggested a distinction be drawn between in vitro and in vivo methods in the exclusion pertaining to diagnostic methods (in vitro processes would be patentable). The suggestion was, however, rejected, and the TRIPS agreement, as well as the present section 3(i), evinces no such difference in treatment of diagnostic methods. It is after the TRIPS Agreement that the terms ‘diagnostic’ and ‘therapeutic’ were inserted via the 2002 amendments. 

From a purposive lens, the Court observed the provision’s objective to be the prevention of a monopoly over these methods that are used by medical professionals. As per the Court, the correct interpretation of Section 3(i) would be one which ‘excludes only those methods which directly implicate professional judgment and involve invasive or high-risk procedures, while allowing for the patenting of ancillary tools, devices, and non-invasive methods, especially those practiced in vitro or outside the human/animal body’ (para 59 of Emd Millipore). Assessment has to be done as to whether the concerned process is a core medical activity requiring professional judgment and carrying inherent risk, or it is a low-risk routine procedure commonly done in a commercial, non-medical context (para 60 Emd Millipore). I found it peculiar that the Court articulated these principles for the provision as a whole, despite the framed legal issue being limited to diagnostic methods. Also, the phraseology used is a transplant from EU law and may prove to be unsuited to diagnostic processes here, as I demonstrate later.

As an interpretive guide, the Court also refers to the Manual of Patent Office Practice and Procedure 2019. It defines diagnosis as ‘ identification of the nature of a medical illness, usually by investigating its history and symptoms and by applying tests’. Towards the end, the Court provides the interpretation of the key terms used in 3(i), including that of ‘diagnostic process’. The manner of performing diagnosis will not be patentable, whereas diagnostic products, tools, and devices can be. Section 3(i), the Court notes, doesn’t differentiate between in vitro and in vivo processes. This summary of the law on Section 3(i) is actually quite minimal on substance. Only two points are made here: product versus process distinction in section 3(i), and the irrelevance of in vitro/in vivo classification to the provision. But what about the key question: how to determine whether something is a diagnostic process? The Court provided some guidance in paras 59 and 60, discussed previously. These principles, however, were laid down generally for Section 3(i) and are also not well-defined. 

The principles laid down in paras 59 and 60 of Emd Millipore are definitely not derivable from either the statutory text (which just uses the term ‘diagnostic method’) or the Patent Manual (which just contains a bare bones definition of diagnosis). It is frankly quite puzzling as to why the Court is even using the invasive/ non-invasive and high-risk vocabulary. On what benchmark will courts assess the risk involved in the process? And is the judiciary or IPO even positioned to evaluate this? Let’s say a diagnostic process is of a low-risk nature. Would that justify a grant of exclusionary rights under the patent regime and the resulting denial of its practice to the larger community of medical practitioners? The same question would arise when discussing the professional judgment versus the routine nature of the process distinction. In my opinion, these metrics used by the Court are a complete misfit for the issue and may end up doing more harm than good.  Apart from this, the focus on in vitro methods in the quoted sentence from para 59 is also confusing, considering the legislative history of the provision, which rejected any such differentiation (which it mentions again in para 65 of Emd Millipore). 

The Court in the very next paragraph (para 60) draws a distinction between processes and products (with the latter being patentable, which is valid in line with 3(i)’s language).   But it also states this: ‘This is notwithstanding the fact that both may involve invasive or non-invasive techniques.’ We are left wondering as to whether the application of 3(i) has to concern itself with the invasive nature of the process or not. 

The above mystery of the origin of these standards gets resolved on a reading of the judgments’ portion on UK and EU law. Section 4A of the UK’s Patent Act employs the wording: ‘a method of diagnosis practiced on the human or animal body’. Article 53(c) of EPC similarly uses the phrase ‘diagnostic methods practiced on the human or animal body’.  The Court referred to the Guidelines for examination in EPO to understand the EU’s stance on these subject matter exclusions. It is here that the notions of ‘invasive techniques’, ‘health risks’, ‘routine character’, and ‘non-medical, commercial environment’ find mention in the guidelines. However, this relevant exposition in the guidelines is for ‘treatment by surgery’, which is a different category from diagnostic methods. The Court does cite case law from EU(G 0001/04) on diagnostic methods which hold a diagnostic method under the statutory exclusion to be consisting of four steps:  

(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 (para 48 of Emd Millipore). 

This four pronged legal analysis is not used by the Court while looking at the Indian position on diagnostic methods. However, it ends up using the EPO guidelines portion on Surgery, for its framing of the general approach towards Section 3(i). Sounds like a wrong diagnosis to me. The different categories of exclusions under Section 3(i) would need different approaches and can’t be dealt with using a single interpretive tenor.

Despite my above misgivings with the judgments, the application of the law undertaken in them does appear to be a fair bit of redemption. In Natera, the Court rejected the contention that there has to be an identification of the exact illness/ its particular cause. In Emd Millipore, the core of the invention lay in the increase in efficiency and reliability of quantitative analysis using IR spectroscopy. The Court concluded that the invention was a technical innovation and didn’t entail any diagnostic step or any medical judgment/ clinical decision-making. 

The subject invention in Sequenom was for the detection of aneuploidy (a foetal chromosomal abnormality) or other disorders using an in vitro method. The Court observed that a negative finding from the subject invention test eliminates the test patients from undergoing confirmatory diagnostic tests. Diagnosis under section 3(i) included a negative diagnosis as well; here, the elimination of the need for further examination because of the screening achieves a tangible result. Merely terming a particular process as a screening test doesn’t suffice to protect it from section 3(i) bar. The Madras HC’s decision in Chinese University is cited in Sequenom for this relevant bit on screening and diagnosis. And that’s the start and end of the Court’s engagement with Chinese University. 

Chinese University was more particular in distinguishing the EU position from the Indian law, since the former’s statutory text uses  ‘diagnostic methods practised on the human body’ in contrast to Section 3(i)’s ‘diagnostic….. treatment of human beings’. Indian law thus, is agnostic to the in vivo/ in vitro distinction. The Madras HC also felt that a reliance on the EU approach (especially the four method step definition of diagnostic method) would allow for an easy subversion of Section 3(i). In consideration of this, the Madras HC’s proposed test was to determine whether the claims, read along with the complete specification, ‘specify a process for making a diagnosis for treatment’(para 40). The diagnosis doesn’t have to be definitive. All there is to assess is ‘whether the test is inherently and per se capable of identifying the disease, disorder or condition for treatment of the person’, from the perspective of the person skilled in art (para 45). The Madras HC also reiterated that 3(i) doesn’t employ the term ‘relating to’ diagnosis and thus no overtly broad construction can be imputed. On the oft-drawn distinction between screening and diagnostic tests, the Court held that labelling is not determinative– if that screening test is able to identify the disease, disorder, or condition, it satisfies Section 3(i), even if the result has to be corroborated using definitive tests. This understanding is because of the absence of the qualifier ‘determinative’ in the text.

Chinese University’s dictum on diagnostic processes is targeted more towards explaining the particular exclusion’s scope. It doesn’t use the characteristics (invasiveness, risk level of the process, and requirement for professional judgment, etc.) that the Delhi HC employed in laying its understanding of Section 3(i). Consequently, the Delhi HC judgments’ depth of engagement might be deceptive; their future application as precedent may cause more ambiguities than a first look will reveal. 

Thanks to Swaraj and Praharsh for their comments on the earlier draft.