Patentability of Diagnostic Methods

A recent decision AUSTRALIAN NATIONAL UNIVERSITY’S APPLICATION (T1197/02) demonstrates the practical application of the diagnostics method test set out in Enlarged Board of Appeal decision G1/04. A method will be excluded as diagnostic if it comprises all four phases of diagnosis set out in the Enlarged Board decision. But only the data gathering step is considered technical. To be patentable, this step must therefore be novel and inventive in isolation.

Medical methods of therapy, surgery and diagnosis are excluded from patentability in Europe under Article 52(4) and in the UK under Section 4 PA 1977 as incapable of industrial application. There are a number of reasons for this exclusion (which is not present in US law), relating to the central idea that medical practice, although commercial in nature, is not to be viewed as a branch of industry. The exclusion supports the unrestricted freedom of a medical practitioner to practice as he believes appropriate in order to preserve the health of his patient. A somewhat academic amendment in the EPC 2000 due to come into force no later than 13th December 2007 will exclude medical methods under Article 53 EPC rather than Article 57 EPC, and this will be reflected in UK law although the practical difference for applicants is likely to be minimal.

The question of what constitutes a method of diagnosis in particular has been a difficult one. According to Article 52(4) the method must be practised on the human body in order to be excluded. For example, methods of analysis of blood or cell samples in vitro are patentable as they are conducted away from the body. Diagnosis is however a multi-step procedure combining technical and non-technical features which are practised on and away from the human body and it has therefore been difficult to identify what features will render a claim excluded as a diagnostic method claim.

In BRUKER (T 385/86), four steps were identified as necessary and sufficient for exclusion as a diagnostic method:

i) a first examination phase during which data is gathered

ii) a further comparative phase, in which the data gathered is processed and compared with a normal value

iii) the recording of a significant deviation from this normal value when a comparison is made

iv) the attribution of the deviation to a particular clinical picture

This narrow interpretation of what constitutes an excluded diagnostic method established that even if only one of these steps were missing, the method was not to be regarded as diagnostic, but rather a method for gathering data which could be used for a diagnostic method. Methods which produced interim results such as X-rays or MRI imaging would therefore be patentable.

In a later Technical Board of Appeal decision (CYGNUS T 964/99 referred to in our Spring 2004 edition of Patent issues), a different approach was taken which suggested that step (i) alone could constitute an excluded diagnostic method. This very wide interpretation of ‘diagnostic method’ was contradictory to BRUKER but has been overruled in the Enlarged Board of Appeal decision G1/04. The Enlarged Board confirmed that BRUKER, with it’s narrow exclusion, was the correct approach.

In G1/04, steps (i)-(iii) were described as ‘intermediate findings of diagnostic relevance’.

• Step (i) is usually technical and practised on the body, usually using some kind of device to collect data.

• Steps (ii)-(iii) are preliminary processing of data.

• Step (iv) is a diagnosis for curative purposes and as such is an intellectual exercise.

Only step (i) can be taken into account for the purposes of novelty and inventive step, although steps (ii) and (iii) will be allowable in a claim if essential to achieve the technical effect.

This approach was applied in July 2006 in AUSTRALIAN NATIONAL UNIVERSITY’S APPLICATION (T 1197/02). A test for early detection of glaucoma by presenting ‘zones’ to a patient and measuring contrast thresholds was held to be excluded as a diagnostic method.

In claim 1, various initial steps involved the examination of the patient and the collection of data. The court stated:

"in most cases only . . . the collection of data can actually be of a technical nature and therefore (is) concerned with the criterion ‘practised on the…body.’"

These steps were therefore held to constitute the “collection of data” phase - step (i) under G1/04).

Various further steps of claim 1 involved a calculation of a mean of the threshold values to determine which ‘zone’ produced the highest threshold level. This was regarded as preliminary processing in the sense of steps (ii)-(iii) of G1/04. The board held that these steps

are not part of making the comparison per se and thus are of no relevance for making the diagnosis. As a consequence, they are not to be considered, for the question whether or not the claim refers to a diagnostic method in the sense of Article 52(4) EPC.

A final step in the claim involved a comparison of the collected thresholds with standard values exhibited by subjects with normal vision. This constituted the final diagnosis, or step (iv) under G1/04. All the elements required under the approach of G1/04 were therefore present and the method was excluded as being diagnostic.

 

Comment

Unless the method to be claimed has novelty and inventiveness in an initial examination phase during which data is gathered from the body, an applicant trying to claim a diagnostic method is stuck between a rock and a hard place. Steps (ii)-(iii) are considered non-technical, so these cannot be relied upon for novelty and inventiveness. And if you throw in step (iv), you have completed the set and fall within the exclusion.

AUSTRALIAN NATIONAL UNIVERSITY’S APPLICATION illustrates how, under Enlarged Board of Appeal Decision G1/04, a claim relating to a diagnostic method will only constitute patentable subject matter if it constitutes a novel and inventive way of collecting interim data from a patient which does not lead directly to a diagnosis.