This decision concerned the interpretation of the phrase “diagnostic methods practised on the human or animal body” in Article 52(4) EPC, such methods being specifically excluded from patentability. Article 52(4) was included in the EPC to protect medical and veterinary practitioners from infringing patents relating to such diagnostic methods in the course of their work.

Unfortunately, the decision makes somewhat tortuous reading and may end up raising more questions than it answers. However, in essence, the decision advocates a narrow interpretation of “diagnostic methods practised on the human or animal body”. Whilst methods leading to a diagnosis in which all the technical steps are practised on the body will still fall foul of the exclusion, it seems that methods for obtaining intermediate information merely of diagnostic relevance could be patentable, as could methods in which one or more technical steps are performed in vitro. Regrettably, no particularly useful definitions of “technical steps” or “intermediate information merely of diagnostic relevance” are offered in the decision. Application of the decision by the examining divisions of the EPO will be monitored with interest.

By way of more detail on this decision, the referral to the Enlarged Board of Appeal (EBA) was provoked by a Technical Board of Appeal decision (T 964/99) in which it was decided that all methods practised on the human or animal body which related to diagnosis or were of value for the purpose of diagnosis should be excluded from patentability. Accordingly, if the claimed method comprised only one step which served diagnostic purposes or related to diagnosis, then it was excluded from patentability under Article 52(4) EPC. This decision was contrary to the previously-held view and went against an earlier decision of the Technical Board of Appeal (T 385/86), which had indicated that the only methods to be excluded were those whose results immediately made it possible to decide on a particular course of treatment.

Due to this conflict of decisions, the EBA convened to clarify the interpretation of Article 52(4) in relation to diagnostic methods. The EBA came to a conclusion which was similar to the view held before the controversial T 964/99 decision. The EBA indicates that there should be a narrow interpretation of Article 52(4): in order for a claim relating to a diagnostic method to fall under the exclusion of Article 52(4), the claim must include all the steps involved in reaching a medical diagnosis. Furthermore, the technical method steps of the diagnosis must also be practised on the human or animal body.

The EBA considered a diagnostic method to be a multi-step process consisting of: data collection; comparison of data with standard values; finding of significant deviation; and attribution of the deviation to a particular clinical picture. Accordingly, all these steps must be present and for such a method to be considered a method of diagnosis and therefore excluded.

The EBA also looked at the interpretation of “practised on the human or animal body”. It considered that a technical method step satisfied the criterion of being “practised on the human or animal body” if the method implied any interaction necessitating the presence of the human or animal body. Therefore, any kind of interaction with the human or animal body, whether it is invasive or non-invasive, is considered to be “practised on the human or animal body”. However, methods which do not require interaction with the human or animal body are not methods of diagnosis. For example, method steps carried out in vitro using ex vivo samples.

In addition, the EBA stated that a “diagnostic method” does not depend on the participation of a medical or veterinary practitioner (e.g. by being present or responsible), nor does it depend on the fact that all method steps can also, or only, be practised by medical or technical support staff, the patient, or an automated system.

It is hoped that the application of this decision will clarify the position on what constitutes a diagnostic method practised on the human or animal body. Even when the revised text of the EPC comes into force (in 2007), the scope of this exclusion, whatever it might be, is expected to remain unchanged.

Nicholas Jones
Life Sciences and Chemistry Group
London Office
22 December 2005