Post-published evidence and inventive step: confirmed referral to the EPO’s Enlarged Board of Appeal (case G2/21)

In the race for innovation, being the first to file can be crucial, so much so that it is tempting to file a patent application at a very early stage in the development of an invention, counting on the possibility to submit additional data during the procedure, in particular before the European Patent Office (EPO). But does this possibility really exist?

Paris, October 28, 2021 – In the race for innovation, being the first to file can be crucial, so much so that it is tempting to file a patent application at a very early stage in the development of an invention, counting on the possibility to submit additional data during the procedure, in particular before the European Patent Office (EPO). But does this possibility really exist?

We have previously announced the possibility of a referral to the EPO’s Enlarged Board of Appeal regarding cases in which post-published evidence (i.e. data submitted after the filing date) may be taken into account as part of the analysis of inventive step. This referral is now official, under number G2/21 « plausibility ».

The technical effect of the features which distinguish the claimed invention from the prior art is indeed capital in the problem-solution approach developed by the EPO to assess the inventive step of an invention. If a technical effect demonstrated in the application is always taken into account by the EPO, post-published evidence submitted for the purpose of demonstrating the existence of a technical effect merely alleged in the application may be accepted, but this is not systematic.

Considering that the case law of the Boards of Appeal is not uniform in this respect and that this question is fundamental in case T 116/18 it is in charge of, Technical Board of Appeal 3.3.02 decided to refer the matter to the Enlarged Board of Appeal for general guidelines as to when post-published evidence may be taken into account in the analysis of inventive step.

The referral is made in a reasoned decision, in which the Board of Appeal explains that its conclusion concerning inventive step depends entirely on whether or not it takes into account post-published evidence and highlights the existence of three divergent lines of case law from the Boards of Appeal on this subject:

  • Plausibility ab initio: according to this line of case law, post-published evidence can be taken into account only if, given the application as filed and the common general knowledge at the filing date, the skilled person would have had reason to assume the purported technical effect to be achieved,

  • Implausibility ab initio: according to this line of case law, post-published evidence can only be disregarded if the skilled person would have had legitimate reasons to doubt that the purported technical effect would have been achieved on the filing date of the patent in suit, and

  • No plausibility : third line of case law seems to reject the concept of plausibility altogether, considering that this line of argumentation appears to be incompatible with the assessment of inventive step according to the problem solution approach, which involves a comparison with a closest prior art that was not necessarily known to the applicant at filing.

In order to standardize the practice of the EPO regarding the consideration of post-published evidence during analysis of inventive step, the Board or Appeal refers the following questions to the Enlarged Board of Appeal:

If for acknowledgement of inventive step the patent proprietor relies on a technical effect and has submitted evidence, such as experimental data, to prove such an effect, this evidence not having been public before the filing date of the patent in suit and having been filed after that date (post-published evidence):

  1. Should an exception to the principle of free evaluation of evidence (see e.g. G 3/97, Reasons 5, and G 1/12, Reasons 31) be accepted in that post-published evidence must be disregarded on the ground that the proof of the effect rests exclusively on the post-published evidence?
  2. If the answer is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have considered the effect plausible (ab initio plausibility)?
  3. If the answer to the first question is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have seen no reason to consider the effect implausible (ab initio implausibility)?

These questions are based on the three lines of case law identified by the Board of Appeal, the first question aiming at determining the merits of the third line of case law rejecting any reasoning of plausibility, while the second and third questions intend to clarify which of the plausibility ab initio and implausibility ab initio approaches is to be followed, if a reasoning of plausibility is to be applied in the analysis of inventive step.

Finally, although the referred questions are limited to the consideration of post-published evidence in the context of the analysis of inventive step, we note that in its analysis of the case-law, the referring Board of Appeal considers that the question arises similarly under the heading of sufficiency of disclosure, when the effect demonstrated in the post-published evidence is a feature of the contested claim (see point 13.3 of the reasons). Decisions in which this issue was addressed during the assessment of the sufficiency of description are thus also cited in its review of the various lines of case law. It will be interesting to see if the Enlarged Board of Appeal confirms whether the approach it defines also applies to the assessment of the sufficiency of disclosure.

Without waiting for a decision from the Enlarged Board of Appeal, which must first confirm the admissibility of the referral and whose decision will probably not be issued before at least a year, these considerations are to be taken into account when drafting your patent applications. Regimbeau’s teams are available to advise you on this subject on a case-by-case basis.

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