Diagnostic Method Patent Eligibility Puzzle

Section 3 (i) of the Patents Act, 1970 was amended in 2002 to specifically exclude any process of diagnostic, therapeutic or other treatment practiced on the human and animal body to render them free of disease from patent eligibility. But the question of what is excluded under this exception is not an easy one to answer even after when this provision was implemented as long back as in May 2003. In absence of any guideline relating to this exception the general trend earlier was to allow patents on diagnostic methods performed outside the human or animal body. The only diagnostic methods that are excluded from the patent protection in almost all the jurisdictions invariably includes those methods whose result immediately make it possible to decide on a particular course of medical treatment. Those diagnostic methods that provide only interim results normally escape the axe of non-eligibility under the patent law of every country even where it is conceded that they can be utilised in making diagnosis.

Same subject patent different approaches: UK, US And Australia

It is not uncommon to find that related or at times, same subject matter relating to diagnostic method is treated differently by courts in UK and Australia and US for the purpose of determining patent eligibility under a legally sound test. For example, In Illumina, Inc v Premaitha Health Plc (Illumina) [2017] EWHC 2930 (Pat) the UK court identified the relevant test as determining whether the invention claimed was a practical product or process, as opposed to information about the natural world. The claim in this dispute was directed to a practical process being the detection of foetal DNA in a sample of plasma or serum. Court observed that both the samples of plasma/serum and the method of detection were artificial in nature and did not exist in the natural world. Therefore, subject claim is patentable.

In US on the contrary, in Ariosa Diagnostics Inc vs Sequenom, Inc 788 F.3d 1371 (Fed. Cir. 2015), decided before UK case, same subject matter was not considered as patent ineligible because court found tha t the alleged patent was not directed to patentable subject matter. Circuit Judge applied the legal test established in Mayo Collaborative Services v Prometheus Laboratories. This test required twin determination, first whether the claims were directed to patent-ineligible content and, if so, second whether the elements of each claim both individually and as an ordered combination had transformed the claim into a patent-eligible application. Applying the Mayo test, court held that the claims were directed to a naturally occurring phenomenon and were therefore patent-ineligible concepts. The court observed that there was no inventive concept that could then transform the cffDNA from natural phenomenon into patentable invention.

When same subject matter patent came before Full Federal Court of Australia in an infringement action in Ariosa Diagnostics Inc v Sequenom Inc [2021] FCAFC 101, where the patentability of the genetic based diagnostic method claims was questioned, the court took a view that genetic based diagnostic method claims are patent eligible. Court observed that as with other cases involving genetics, the question of patentability turned on drawing a distinction between naturally occurring phenomena and the practical application of such phenomena. The fundamental question before court of appeal was whether what was claimed was a mere discovery of a naturally occurring phenomenon, or a method involving a practical application that goes beyond the discovery itself. Claim 1 in question was

A detection method performed on a maternal serum or plasma sample taken from a pregnant female, which method comprises detecting the presence of a nucleic acid of foetal origin in the sample.”

Speaking on the contested argument of ‘mere discovery’ the Appeal Court observed that-.

“the distinction between mere discovery and an invention lies in its practical application to a useful end. an invention may reside in an abstract idea, such as the condensation of steam, that is then put to a useful end, even though the way of putting it to that end can be carried out in many useful ways, all of which are otherwise known.”

It is interesting to note that subject patent allowed in this case is same as the cases decided by UK court (patent allowed) and US courts (denied in view of Mayo) discussed above. To this extent, the UK court reached the same conclusion as the Full Court but UK court did so by applying different legal tests.

Biological inventions occurring outside human body

Most biological inventions that seek patents exist in the world outside the human body. Nonetheless, as the usual legal rules of the patentability and interpreting the thin line between in vivo and in vitro as stated in the catena of case law apply. Inventions ranging from mechanical medical devices, Medical electrical gadgets, synthetic medicinal chemicals, electronic medical devices fall within statutory boundaries of patentable inventions in all the jurisdictions. But when the question of patenting metabolic products or genetic products or biotech products crops up before patent office it is hit by wall of unrecognized exceptions. Human intervention in certain cases is treated as inventive cue to cross the statutory line of patentability. Normally, patent claims that require the participation of a human being fit uneasily into patent law. Does it mean inventions that include a human being as part of their structure or operation normally sit outside of the patentability spectrum? This question has undergone many rounds of debates within the patent office and in the courts of many jurisdictions. It is also reflected in the statues and guidelines of many patent jurisdictions. In Diamond v. Chakrabarty, for example, US supreme court has extended the potentially patentable subject almost to the limits of the human imagination. However, biological /genetic related diagnostic method patent eligibility is always shrouded with a mystery in all most all jurisdictions including India.

Diagnostic methods

So far as patentability of diagnostic methods is concerned, they fall under a general exclusion from patentability in all jurisdictions if such diagnostic methods are practiced on the human or animal body. Although, patent law after TRIPS agreement prides itself on being ‘technology neutral’, the uncertainties facing patent eligibilities of certain biological inventions leaves many questions on the so called “technology neutrality’ unanswered when these inventions are kept outside the patent cover in many member states. For example, the discovery of a naturally occurring correlation between a biomarker and a disease if put into a practical use can be useful as a method for diagnosing the disease but patent eligibility of such use suffers from the legal stigma of natural phenomena that take it outside the spectrum of patent eligibility in many jurisdictions.

Position of diagnostic method in Europe and US

EPO being quite progressive to match with new vistas of diagnostic inventions issued guidelines for Examination G-II, 3.1 to allow patentability of such practical use in a method of diagnosis. In US on the other hand such diagnostic inventions were denied patents protection on the ground of they are being ‘natural phenomena’ under section 102 of US 35 code. US Patent Office USPTO) considers that the discovery of a natural phenomenon is not patent eligible.

In Europe the patent eligibility of biological inventions is guided by EPO directives and rule which states that

“an element isolated from the human body or otherwise produced by means of a technical process, which is susceptible of industrial application, including the sequence or partial sequence of a gene, may constitute a patentable invention, even if the structure of that element is identical to that of a natural element. Such an element is not a priori excluded from patentability since it is, for example, the result of technical processes used to identify, purify and classify it and to produce it outside the human body, techniques which human beings alone are capable of putting into practice and which nature is incapable of accomplishing itself.”

The main issue with diagnostic methods before the EPO examiner is a general exclusion under Article 53(c) EPC which exclude patentability of diagnostic methods that are practiced on the human or animal body.

53 (c ) methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body; this provision shall not apply to products, in particular substances or compositions, for use in any of these methods.

In practice, a claim to a method of diagnosis is not patentable in Europe if:

“the method is carried out on the human or animal body, and

it includes (explicitly or implicitly) all the steps of collecting data, comparing the data with standard values, finding a deviation from normal (a symptom), and attributing that deviation/symptom to a clinical picture (i.e. making a diagnosis) (decision G1/04).

A method that avoids any of these requirements is not considered to be a diagnostic method that is practiced on the human or animal body, and so that method is patent eligible at the EPO.

If the technical steps of the claimed diagnostic method can be carried out separately from the body, then the method can be patent eligible at the EPO.  For example, a diagnostic method that is carried out on an in vitro tissue sample is not carried out on the human or animal body so can be patented (decision T666/05). “

Similarly, a method that merely provides information or intermediate results, without actually leading to a diagnosis of what is wrong with the patient, is not a method that attributes the information to a clinical picture and so can be claimed at the EPO.  Examples of such methods that do not reach a final diagnosis include a method of determining ear temperature (decision T1555/06) and a method of imaging an artery in a patient by MRI (decision T663/02).

Both USPTO and the European Patent Office (EPO) considers that the discovery of a natural phenomenon is not patent eligible. However, unlike the USPTO, the EPO takes the view that a patentable invention can derive from a practical use of that discovery (EPO Guidelines for Examination G-II, 3.1), such as its use in a method of diagnosis.  For example, the discovery of a naturally-occurring correlation between a biomarker and a disease can be put to a practical use in the form of a method for diagnosing the disease.  A claim directed to a method of diagnosing the disease involving detecting the presence or amount of that biomarker may therefore be patentable at the EPO, even if the underlying naturally-occurring correlation is not patentable.

Position in India

There exists a verbatim similarity between the exclusion under section 3(i) of the Indian Patent Act, 1970 and Article 53(c) in EPO so far as methods for treatment or diagnostic method practised on human or animal body is concerned for the purpose of patentability exception.

“3. What are not inventions.—The following are not inventions within the meaning of this Act,—

(i) 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.”

Interestingly, a claim for a method of diagnosing the disease involving detecting the presence or amount of certain biomarker is patentable at the EPO with ridder that the underlying naturally occurring correlation may not be patentable. Though the statutory position in Indian law is incline towards EPO position under article 53(c) but Indian practice appears to be more tilted towards US practice of blanket ban on patents on diagnostic methods. The main stress with diagnostic method exclusions at the EPO is a general exclusion from patentability of diagnostic methods that are practiced on the human or animal body (Article 53(c) EPC) like Indian stand. It is interesting to note that explanation of diagnostic method provided by the Guidelines for Examination of Biotechnology Applications for Patent issued by the Indian Patent Office in 2016 stated:

“(e) Diagnostic methods: Diagnosis is the identification of the nature of a medical illness, usually by investigating its history and symptoms and by applying tests. Determination of the general physical state of an individual (e.g. a fitness test) is considered to be diagnostic.”

Therefore, method for identification/detection/screening of biomolecule is not considered as method of diagnosis.

Looking forward

If Australian decision affirms the established position in Australia that diagnostic methods that relate to the practical application of naturally occurring genetic information, rather than naturally occurring phenomena per se, are patentable, it provides food for thought to examiners in other jurisdictions to relook into their position and reconsider on what amounts to a “product resulting from the use” of a method claim. In view of the exiting trends, it is normal to construe section 3(i) exclusions narrowly. Any diagnostic, therapeutic or other treatment practiced on the human and animal body in the meaning of this exclusion is one where both examination and establishment of symptoms on the basis examination results are performed on a living human or animal. It is true that courts in different jurisdictions differ about patentability issues relating to diagnostic methods which are difficult. In certain cases, it also expected where it is reasonable to hold differing opinions. The decision of the Australian Appeal Court and the related cases abroad highlights the varying approaches taken by different countries in relation to the patentability of diagnostic methods relating to use of genetic material. However, one thing is common in all the cases decided by courts that patent office around the world favour granting patents on such diagnostic methods rather than giving a blanket rejection. We may perhaps agree with Circuit Judge Linn when he observed in Ariosa case (US) that “no reason, in policy or statute, why this breakthrough invention should be deemed patent ineligible“. We can expect Indian patent office to follow ‘practical use approach’ rather than ‘subject matter approach’ as well in this nascent but most progressive and growing field of heath industry. A word of caution for those who are dealing with such cases before patent offices around the world that there is need to reconsider and weigh the reasons that you put forward on the diagnostic method cases in view of the recent decisions of the courts in UK and Australia in related patents. It is worthwhile to seek an expert advice to solve the diagnostic method patentability puzzle.


DPS Parmar gives a comprehensive overview of the patentability of diagnostic methods in India and other major countries.

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