Post-filing data and inventive step (case G2/21): the EPO’s Enlarged Board of Appeal gives its preliminary opinion

Is it really reasonable to file a patent application at a very early stage of development of an invention, with little or no experimental data? The preliminary opinion of the EPO's Enlarged Board of Appeal, recently made public, suggests that one should remain cautious, despite a certain tolerance regarding the submission of post-filing data.

Paris, October 19, 2022 – Is it really reasonable to file a patent application at a very early stage of development of an invention, with little or no experimental data? The preliminary opinion of the EPO’s Enlarged Board of Appeal (available here), recently made public, suggests that one should remain cautious, despite a certain tolerance regarding the submission of post-filing data.

We have previously discussed the referral to the Enlarged Board of Appeal of the EPO (case G2/21 “plausibility“) concerning the cases in which post-filing data can be taken into account in the context of the analysis of inventive step.

The Enlarged Board of Appeal has now issued its preliminary opinion, pending the oral proceedings scheduled for November 24, 2022. Such a preliminary opinion is not binding, but already gives some indications regarding the answers that will be given to the questions raised in the referring, which are presented below:

“If for acknowledgement of inventive step the patent proprietor relies on a technical effect and has submitted data or other evidence to proof such effect, such data or other evidence having been generated only after the priority or filing date of the patent (post-published data):

  1. Should an exception to the principle of free evaluation of evidence (see e.g. G 1/21 reasons 31) be accepted in that the post-published data must be disregarded on the ground that the proof of the effect rests exclusively on such post-published data?
  2. If the answer is yes (post published data must be disregarded if the proof of the effect rests exclusively on these data): can post-published data be taken into consideration if based on the information in the patent application the skilled person at the relevant date would have considered the effect plausible (ab initio plausibility)?
  3. If the answer to the first question is yes (post published data must be disregarded if the proof of the effect rests exclusively on these data): can post-published data be taken into consideration if based on the information in the patent application the skilled person at the relevant date would have seen no reasons to consider the effect implausible (ab initio implausibility)?”

In its preliminary opinion, the Enlarged Board of Appeal first confirms the admissibility of the referral and the relevance of the questions asked.

With regard to these questions, it seems at this stage to answer “no” to the first question. Indeed, it considers that the principle of free evaluation of evidence is a key rule of the proceedings before the EPO and its Boards of Appeal, and does not allow disregarding by principle posterior data submitted as exclusive support of the technical effect on which the assessment of the inventive step would be based.

Although questions 2 and 3 should in theory only be answered if the first question is answered in the affirmative, the Enlarged Board of Appeal nevertheless intends to give some guidance as to when post-filing data should or not be taken into account, but only in the context of the analysis of the inventive step.

At this stage, it considers that post-filing data should be taken into account if, on the basis of the teaching of the application as filed and of common general knowledge, the person skilled in the art would have no reason to doubt the technical effect alleged by the applicant to justify the inventive step of the claims. Otherwise, the consideration of post-filing data would be questionable.

The opinion expressed at this stage is still only preliminary and could evolve following the written responses that might be filed and the oral proceedings scheduled for November 24, 2022. However, among the three lines of case law existing to date on this issue (see our previous article here), the approach taken by the Enlarged Board of Appeal regarding the consideration of post-filing data in the context of inventive step seems to be that of implausibility ab initio.

This will certainly be welcomed by applicants, as it is less restrictive than the plausibility ab initio approach favored by some Boards of Appeal, according to which post-filing data could only be taken into account if the technical effect was plausible to the person skilled in the art on the basis of the teaching of the application as filed and common general knowledge.

Nevertheless, in technical fields in which the results can be considered unpredictable (especially chemistry and life sciences), the risk that implausibility ab initio is raised during examination or an opposition procedure should not be neglected. In order to increase the chances of grant and to limit the risks in case of opposition, it is therefore necessary to remain cautious and to find the right balance between the speed and the content of any new filing.

Without waiting for the written decision of the Enlarged Board of Appeal, it is advisable to take these considerations into account when drafting your applications. The Regimbeau teams are at your disposal to advise you on this matter on a case-by-case basis.

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