The Enlarged Board of Appeal of the European Patent Office was recently seized by the Technical Board of Appeal 3.3.02 (T 116/18) to determine whether evidence published after the filing date of the patent, such as comparative test reports, can be taken into consideration for the examination of the inventive step when the proof of the effect rests exclusively on the post-published evidence.

In other words, the question was raised as to whether an exception to the principle of free evaluation of evidence (recognized by G3/97 and G1/12) can be accepted in that post-published evidence should not be taken into consideration on the ground that the proof of effect rests exclusively on this post-published evidence.

In the field of chemistry, it is common practice to file, in support of the problem-solution approach developed by the Applicant, subsequent experimental reports based on the closest prior art. However, the subsequent demonstration of the existence of a technical effect raises the question of the plausibility of this technical effect at the time of filing the patent application.

To date, there are 3 main lines of case law on the subject of taking into consideration post-published evidence :
1) The ab initio plausibility : The consideration of post-published evidence requires the person skilled in the art to have reasons to assume the effect to be achieved, on the basis of the application as filed or his general knowledge at the filing date, for example through scientific explanations or experimental data (T1329/04, T609/02, T488/16).
2) The ab initio implausibility : post-published evidence can only be disregarded if the person skilled in the art had legitimate reasons to doubt that the technical effect would have been achieved on the filing date (T919/15, T578/06, T2015/20).
3) The implausibility : this 3^rd line rejects the concept of plausibility on the grounds that not taking into consideration post-published evidence would be incompatible with the problem-solution approach, which sometimes requires reformulating the technical problem in view of prior-art documents that are not cited in the patent (T2371/13).

The Enlarged Board of Appeal is therefore asked to decide whether evidence published after filing can be rejected on the grounds that the alleged technical effect rests exclusively on this evidence, thereby contravening the principle of free evaluation of evidence, and, if so, whether the concept of ab initio plausibility or ab initio implausibility should be applied.

The decision of the Enlarged Board of Appeal could therefore potentially lead to great difficulties in terms of inventive step for European patent applicants, and particularly in the field of chemistry.

Consequently, the President of the EPO has decided, with immediate effect, that all examination and opposition proceedings before the EPO, whose outcome depends entirely on the decision of the Enlarged Board of Appeal, will be suspended ex officio.

CASALONGA will keep you informed of the outcome of this referral G 2/21.