Decision from the Enlarged Board of Appeal in G2/21 Regarding the Doctrine of Plausibility

The EPO’s Enlarged Board of Appeal (EBA) has now published the hotly anticipated decision G 2/21 together with a Press Communiqué. The decision relates to the requirement for a “plausible” disclosure of efficacy in the application as originally filed. The Press Communiqué provides an overview of the background to the decision and the key outcomes. The Press Communiqué can be found here and the full text of the decision can be found here.

The concept of “plausibility” was introduced by the case law of the Boards of Appeal. When arguments for inventive step are supported by evidence/data generated after the priority/filing date of an application (“post-published” data), the case law requires that such post-published data is not the sole basis to establish a technical advantage/effect. In addition to the post-published data, the application as originally filed must provide a disclosure which renders the technical effect “plausible”.

The questions referred to the EBA in G 2/21 related to the conditions under which post-published data can be taken into account to support a technical effect, i.e. what is required for a technical effect to be considered “plausibly” disclosed in the application as originally filed. Three lines of case law had been identified, (i) “ab initio plausibility” (post-published data can be taken into account if there is some data or technical reasoning in the application as filed to support a technical effect), (ii) “ab initio implausibility” (post-published data must always be taken into account if the technical effect is not implausible), and (iii) “no plausibility” (the concept of plausibility is rejected). We previously reported here the specific questions that had been referred to the EBA. The EBA has decided the following:

“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.”

In relation to point 1, the EBA has qualified that post-published data cannot be disregarded solely because it is post-published, which is consistent with the principle of free evaluation of evidence.

In relation to point 2, the EBA has provided criteria for determining whether a technical effect can be relied upon in support of inventive step. It appears that, if the skilled person, in view of the common general knowledge, would consider the technical effect to be “encompassed by the technical teaching and embodied by the same originally disclosed invention”, then the technical effect can be relied upon. If the technical effect can be relied upon, then it appears that the post-published data can be taken into account. The EBA is aware of the abstractness of some of the criteria provided but states that they have provided “guiding principles” to allow a decision to be taken on whether or not post-published data can be relied upon to support a technical effect when assessing inventive step (see page 67, Reason 95).

Interestingly, the criteria do not specifically refer to “plausibility” per se. This seems to be because the EBA does not consider the term “plausibility” to amount to “a distinctive legal concept or a specific patent law requirement under the EPC”, but rather a “generic catchword” (see page 66, Reason 92) used as a criterion for the reliance on a technical effect. The EBA has thus sidestepped the question of whether the technical effect needs to be, for example, “plausibly” established (“ab initio plausibility”) or “not implausibly” established (“ab initio implausibility”) when determining whether post-published data can be relied upon. Instead, for inventive step, it suffices if the technical effect is derivable as being encompassed by the technical teaching and embodied by the same originally disclosed invention.

If you have any questions about this decision or the assessment of the inventive step of inventions unsupported by an express statement of technical effect in the application as filed, please get in touch with your usual J A Kemp contact.