Résumé de EPC2000 Art 056 pour la décision T2565/19 du 29.11.2022

See also abstract under Article 84 EPC. In T 2565/19 the board identified the problem to be solved as the provision of a method which can be used to discriminate between a TRH receptor sub-type in human cortex from one in human pituitary. The question to be answered in assessing the obviousness of the claimed method was whether the skilled person starting from the disclosure in document D2 and seeking to solve the technical problem formulated above, would have carried out the differential binding experiments disclosed in document D2 on human tissue. The board noted that in some decisions, especially in the field of biotechnology, the boards had asked whether in the cases in point it was obvious for the skilled person to try a suggested approach, route or method with a reasonable expectation of success. However, in the present case, the board did not consider this to be the right approach. In the case in hand the appellant (applicant) argued that the skilled person had to make at least four choices as to which steps to carry out. In view of the uncertainty inherent in each choice, the skilled person could not have considered that there was a reasonable expectation of success in finding a human homologue of a potential rat receptor. Further uncertainty was present because at the relevant date, the skilled person assumed that in humans, in contrast to the situation in rats, only one receptor sub-type was present. The board considered that the importance of research on humans in a medical context would have led the skilled person to repeat the experiments done in rats in document D2 in humans, even in the face of alternative explanations for the results and even in the face of the knowledge that only one type of TRH receptor had been found in humans. This consideration was similar to the situations described in the case law where "neither the implementation nor the testing of an approach suggested by the prior art involves any particular technical difficulties". In such circumstances it had been held that the skilled person would have at least adopted a "try and see" attitude. The appellant had also argued that the skilled person, considering applying the methods disclosed in document D2 to human tissue, would have faced difficulties obtaining and working with human tissue due to the fact that it had to be obtained post-mortem and because many variables affected the quality of such tissue, as well as because of anatomical differences between rat and human tissue. The board was not convinced by these arguments either. It accepted it was common knowledge in the art that working with post-mortem human tissue and brain tissue in particular was associated with particular practical problems. However, given that the skilled person was seeking to replicate an animal model in humans, they had no choice but to turn to human tissue. In view of the above considerations, the board concluded that the subject-matter of claim 1 lacked an inventive step as too did the auxiliary requests.