The Implausibility of “Plausibility” as an Evidentiary Standard at the EPO

The much-anticipated decision in G2/21 issued from the Enlarged Board of Appeal (“the Board”) at the European Patent Office on 23 March 2023. Three points were referred to the Board regarding the diverging evidentiary standards of using plausibility/implausibility for technical effect determination based on evidence presented after the filing date of the application, “post-filed evidence”. The Board ultimately held that:

1) evidence provided after the effective filing date of the application and relied upon by an applicant/patentee to prove a technical effect may not be disregarded solely because the evidence was not public prior to the filing of the application; and  

2) a technical effect derivable by one of skill in the art from, and embodied by, the technical teachings of the application at time of filing may serve as a basis for an inventive step.

Critical to the Board’s decision in G2/21 was its qualification of free evaluation of evidence in assessing any means of evidence submitted as a “universally applicable principle of both procedural and substantive law” and its determination that “plausibility,” is not a distinct condition of patentability and patent validity as concerns either Articles 56 (inventive step) or 83 (sufficiency of disclosure) of the EPC.  G2/21 ¶¶ 89 and 92. 

Given these principles, the Board concluded that the relevant standard, when assessing inventive step, is what one of skill would understand to be the technical teaching of the application as of the filing date, and whether the technical effect relied upon for inventive step was encompassed in that technical teaching. Evidence demonstrating a technical effect so encompassed, even though only available after the filing date of the application, is to be taken into account when assessing inventive step.  Id. ¶¶ 93-94.

Takeaway: post-filed evidence can be used to support a technical effect, if that technical effect can be derived from the technical teaching of the application at the filing date.

Look for a more detailed analysis of this case coming soon.