Prove of a Technical Effect by Post-Filed Data Allowable (G 2/21)

The Enlarged Board of Appeal (EBA) cited in its recently published decision G 2/21 that experimental evidence after filing an application can be used to prove a technical effect for patentability. Due to the possible effects, in particular for parties filing second medical use application, this decision has been awaited quite excitedly.

The EBA dealt with questions on the principle of free evaluation of evidence and the notion of “plausibility” in the context of inventive step.

Until the present decision of the EBA “plausibility” described a principle with regard to the level of disclosure required for medical use. With regard to previous case law, a therapeutic application was accepted as sufficiently disclosed if the application or the patent, respectively, and/or the common general knowledge provided some information rendering it technically plausible for the skilled person that the claimed compounds can be applied for the claimed therapeutic use (T 1599/06 citing T 609/02).

The EBA considered now that the term “plausibility” does not amount to a distinctive legal concept or specific patent law requirement under the EPC – “it rather describes a generic catchword seized in the jurisprudence.”

In its ruling the EBA stresses the principle of free evaluation of evidence:

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.”

Thus, for the reliance on a technical effect when assessing inventive step the question is of what the skilled person, of common general knowledge in mind, would understand at the filing date from the application as originally filed as the technical teaching of the claimed invention. The technical effect relied upon, even at a later stage, needs to be encompassed by that technical teaching. Such guiding principle would allow the competent Board of Appeals or other deciding body to take a decision on whether or not post-published evidence may or may not be relied on in support of an asserted technical effect (press communique of Marc 23, 2023 on Decision G2/21 of the EBA).

Consequently, an application cannot be rejected on the basis of lack of inventive step because data was not available at the time of filing the application. Opposition Divisions as well as Examining Divisions are required to check whether post-filed data fulfil the criteria suggested by the EBA and consider them in their assessment of inventive step.

However, it has to be awaited how the free evaluation of evidence as laid down in the decision will be implemented by the competent bodies in practice.