You are here: Home > News > When are Diagnostic Methods Patentable at the EPO?

When are Diagnostic Methods Patentable at the EPO?

7 July 2021

Both the European Patent Convention (EPC) and the UK Patents Act prohibit the patenting of diagnostic methods practised on the human or animal body[1]. The intention behind this exclusion is to avoid patent infringement being a concern for medical and veterinary practitioners when carrying out diagnostic examinations. However, in practice the exclusion is interpreted quite narrowly and diagnostic methods based on or including laboratory tests are usually eligible for patent protection.

Which diagnostic methods are excluded from patentability?

EPO case law[2] states that a patent claim relating to a diagnostic method is excluded from patentability if it includes features relating to:

  1. diagnosis for curative purposes in the strict sense , representing the deductive medical or veterinary decision phase as a purely intellectual exercise,
  2. the preceding steps which are constitutive for making that diagnosis (e.g. the examination phase to collect data; comparison of the data with standard values; and finding of any significant deviation), and
  3. the specific interactions with the human or animal body which occur when carrying those out amongst these preceding steps which are of a technical nature.

If any of the above steps are omitted the EPO consider that the claim does not relate to a diagnostic method, but is instead merely an intermediate finding of diagnostic relevance2. However, purposefully omitting a step from the claim in an attempt to avoid the exclusion is unlikely to be successful if the patent application as a whole makes it clear that the omitted step is essential. Such an omission would likely fall foul of the clarity requirement of Article 84 EPC, which necessitates that all essential features be explicitly stated in an independent claim.

When is a method practised “on the body”?

Only diagnostic methods practised on the human or animal body are excluded from patentability. It is important to note that the test outlined above does not specify a type or intensity of interaction with the body, nor does it place any limit on whether that interaction is carried out by medical/veterinary staff or technical staff.

A key question to ask when assessing a claim in relation to this exclusion is therefore whether the patient needs to be ‘in the room’. If their presence is physically required, the claim needs to be considered in more detail. In particular, one should look at the claimed technical steps that are constitutive for making the diagnosis. According to the case law2, if the method includes at least one technical method step that does not require interaction with the body (e.g., processing or displaying data) the diagnostic method should be eligible for patent protection.

Practice points and tips

The most pragmatic approach to this exclusion is to ensure your claims do not require the patient to be in the room when all steps of the claimed method are carried out. Whilst it may be possible to argue that the claim includes technical steps that are not carried out on the body, in practice this argument can be difficult to run. One very simple amendment to avoid this is to change any active steps of “obtaining a sample from a patient” to refer instead to “a sample obtained from a patient”. In this way the claim is clearly limited to the extracorporeal aspects of the method, which may thereby be eligible for patent protection.

[1] Article 53(c) EPC

[2] EPO Enlarged Board of Appeal Decision G1/04


Helen Henderson

Life Sciences & Chemistry

This publication is a general summary of the law. It should not replace legal advice tailored to your specific circumstances.

© Withers & Rogers LLP July 2021