The European Patent Office’s (EPO’s) Enlarged Board of Appeal (EBoA) has announced that a decision has been made in respect of the G2/21 referral made in 2021. Our article discussing the referral can be found here, and the full decision can be found here.

The referral

The G2/21 referral (linked above) comprised three questions, centring on the use of post-published evidence, and what plausibility standard (if any) is required for the use of such post-published evidence.

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)?

The decision

The EBoA issued the below 2-point order as part of their 75 page decision:

1. Evidence submitted by a patent applicant or proprietor to prove a technical effect relied upon for acknowledgement of inventive step of the claimed subject-matter may not be disregarded solely on the ground that such evidence, on which the effect rests, had not been public before the filing date of the patent in suit and was filed after that date.
2. A patent applicant or proprietor may rely upon a technical effect for inventive step if the skilled person, having the common general knowledge in mind, and based on the application as originally filed, would derive said effect as being encompassed by the technical teaching and embodied by the same originally disclosed invention.

The reasoning

Firstly, the referral was ruled admissible by the EBoA, on the grounds that the referred questions relate to a point of law of fundamental importance, given that the decision would impact many active appeals.

As is often the case, the EBoA didn’t answer the referred questions in the exact form they were asked, rather they construed the questions so as to boil them down to the relevant legal principles and gave a decision on their own terms.

With regards to the first referred question, the EBoA considers in detail the principle of free evaluation of evidence. As noted in the decision itself (para 29), there is no definitive rule on how Boards of Appeal may consider evidence filed in support of appeals, the Boards are instead ‘free’ to determine how to evaluate evidence as appropriate by the circumstances (provided that any such evidence is compliant with any filing requirements).

In line with the principle of free evaluation of evidence, the EBoA goes on to find that the principle must apply to post-filed evidence in support of an inventive step, and such evidence cannot be disregarded simply due to the fact it was not available at the filing date of the patent in question (see para 56).

In effect, the first question has been answered with ‘no’, although the EBoA finds that this does not render questions 2 and 3 to be irrelevant (despite that fact that questions 2 and 3 are dependent upon question 1 being answered ‘yes’).

The EBoA then goes on to consider the issue of plausibility, again doing this on their own terms.

In order to rule on the plausibility issue, the EBoA chose to analyse the relevant case law, as plausibility is a concept which is not required by the EPC or nor its regulations itself and has instead arisen from previous decisions by various Boards of Appeal (hence the differing standards for plausibility in the case law).

In their case law analysis, the EBoA found that the ‘plausibility’ question was not in and of itself the deciding factor, but whether or not the patents in question sufficiently disclosed the technical effect upon which patentability relied.

Therefore, the EBoA felt it unnecessary to define a plausibility threshold for post-published evidence not to use this ‘plausibility language in their decision.

What this means

Point 1 of the decision clearly establishes that post-published evidence can be relied in support of a technical effect for the consideration of inventive step.

Point 2 deliberately does not provide for a plausibility threshold, and thus the answers to questions 2 and 3 can both be considered to be no, i.e. that neither ab initio plausibility nor ab initio implausibility are universally applicable standards when post-published evidence is used in support of a technical effect.

Point 2 instead clarifies that the determination of whether or not an invention is sufficiently disclosed is to be determined on a case by case basis, and that there is no definitive standard which needs to be met.

As always, we shall keep you updated of any decision in this referral, and of any other referrals to the Enlarged Board.

If you have any questions about this case please contact us to speak to one of our patent attorneys.