Preliminary Opinion Published In G2/21 ("Plausibility")

• Published date: 20 October 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Marks & Clerk
• Author: Mr Gareth Williams

As we reported previously, the EPO's Enlarged Board of Appeal is to consider the question of the admissibility of post-published evidence in the consideration of inventive step, in referral G2/21. In brief, the questions asked of the Enlarged Board may be paraphrased as "must post-filing evidence be disregarded if it provides the sole proof of a technical effect in support of inventive step?"; and if so, is this the case in circumstances in which the patent in question either makes this effect "plausible" or at least "not implausible".

A hearing date has been set for 24 November 2022, and the Board has now issued its non-binding preliminary opinion which identifies what, in the Board's view, are the key issues to be discussed. The opinion also takes into account comments submitted by the President of the EPO, and in the 20 amicus curiae briefs filed.

The Board firstly confirms that it considers the referral is admissible, and secondly that its current view is that no evidence "must" be disregarded as such, but the principle of the "free evaluation of evidence" should apply. While this suggests that the first referred question is to be answered "no", and so normally the subsequent questions need not be considered, the Board goes on to suggest that some guidance is needed regarding plausibility and implausibility.

This guidance is indicated to be confined to the question of plausibility in assessment of inventive step (and not sufficiency, where the same concept has...