Patenting Diagnostic Methods in Europe and Beyond

Both the European Patent Convention and the UK Patents Act exclude from patentability “diagnostic methods practised on the human or animal body”. The intention behind this exclusion is to allow medical and veterinary practitioners to act in the best interests of their patients without fear of patent infringement.  


While at first sight this exclusion appears to rule out obtaining any patent protection within the diagnostics sphere, with careful patent drafting many diagnostic inventions can still be protected. 


What cannot be patented?


Although, in Europe diagnostic methods practised on the human or animal body are excluded from patentability, methods are only excluded if they include the following four steps:


  1. the collection of data;
  2. the comparison of these data with standard values;
  3. the finding of a significant deviation during the comparison; and
  4. the attribution of the deviation to a particular clinical picture.


Furthermore, methods only fall within the exclusion if the collection of data is practised on the human or animal body. Direct physical contact with the body is not necessary as long as the presence of the body is required. For example, a step involving imaging a body without physical contact would still fall within the exclusion.

However, it is worth noting that this requirement relates to living bodies and so diagnostic methods which are performed post-mortem are patentable.


What can be patented?


Products for use in diagnostic methods


The exclusion of diagnostic methods does not apply to products intended for use in such methods. There is, however, a distinction between the protection that can be obtained for substances and compositions as opposed to other types of products such as devices, instruments and computer programs.


Substances and compositions intended for use in diagnostic methods, e.g. an antibody for detecting a disease biomarker or a composition comprising such an antibody, can be patented in two ways. Firstly, if a substance or composition is novel, it can be patented without reference to a proposed diagnostic use.

Otherwise, if a substance or composition is already known, it can still be patented by specifying a novel diagnostic use, for example for identifying cancer, or another disease, in a patient.


In contrast, other types of products which may be used in diagnostic methods such as devices, instruments and computer programs, must be novel and the diagnostic use cannot be used to provide novelty.


Methods of collecting and/or analysing data


As discussed above, methods only fall within the exclusion if they involve each of the steps from the collection of data up to the diagnosis of a particular clinical picture. It follows that methods which omit at least one of these steps are not excluded from patentability.  


Methods of collecting and/or analysing data from a human or animal subject which do not directly enable a diagnosis are therefore patentable and can be considered as an intermediate finding of diagnostic relevance. However, care must be taken when drafting applications: if one of the four steps is omitted to avoid the exclusion but the patent application makes it clear that such a step is essential, such an approach will likely not be successful in overcoming the diagnostic method exclusion.   


In vitro testing


As discussed above, diagnostic methods are only excluded if the method is practised on the human or animal body. Therefore, diagnostic methods based on testing of samples in vitro are eligible for patent protection. For example, a diagnostic method based on detecting a biomarker in a blood sample or cell sample is patentable.


What about outside Europe?


In the last few years, US courts have invalidated several patents directed to diagnostic methods as lacking patent eligibility and the US Patent and Trademark Office take an extremely strict stance when assessing diagnostic claims. In the US, claims directed towards a law of nature or natural phenomenon are not patentable and this can be problematic for diagnostic methods which are often based on the identification of a correlation between a biomarker and a disease. Such a correlation is deemed to be a natural phenomenon. However, with careful drafting it is possible to obtain protection in the US. One approach can be to associate the diagnosis with a specific treatment, thereby practically applying the “natural phenomenon”. For example, the diagnostic finding could be used to direct the treatment of a specific patient using a specific dose. An alternative approach is to cast claims as methods of preparation of a diagnostic sample using defined steps. Such claims have recently been considered allowable in the US.


Outside the US it is possible to obtain protection for diagnostic methods in certain jurisdictions including Australia and Canada for example. However, it is important to bear in mind the specific requirements of every jurisdiction of interest when drafting applications directed towards methods of diagnosis to maximise the chance of obtaining protection for these inventions.


If you have any questions or for further information please contact patent attorney Rachel Mercer at Appleyard Lees IP LLP.



Rachel Mercer, Patent Attorney, Appelyard Lees IP

Andrew Mullins, Trainee Patent Attorney, Appleyard Lees IP