Press Communiqué of 23 March 2023 on decision G 2/21 of the Enlarged Board of Appeal
The Enlarged Board of Appeal is the highest judicial authority under the European Patent Convention (EPC). Its main task is to ensure the uniform application of the EPC.
Technical Board of Appeal 3.3.02 referred questions on the principle of free evaluation of evidence and the notion of "plausibility" in the context of inventive step to the Enlarged Board of Appeal. With regard to the latter, the referring board identified three different lines of case law (see interlocutory decision T 116/18, Reasons 13.4-13.6).
European patent EP 2 484 209 concerns an insecticide composition for controlling an insect pest. According to the patent, two compounds which were already known for their respective insecticidal activity have more than a purely additive effect when used as a mixture, i.e. a synergistic effect.
Determining the technical effect of an invention plays an important role when applying the so-called "problem and solution approach". This approach is regularly applied by the boards of appeal and the administrative departments of the EPO in the course of deciding whether or not the claimed subject matter involves an inventive step.
According to established case law, it rests with the patent applicant or proprietor to properly demonstrate that the purported technical effects or results of the claimed invention have successfully been achieved. In the case underlying the referral, the patent proprietor relied on test data filed and published after the filing date of the patent (post-published evidence) in support of the alleged synergistic effect. According to the referring board, it is decisive for the assessment of inventive step whether or not this post-published evidence is to be taken into account as proof for the alleged synergistic effect.
In its decision, the Enlarged Board of Appeal qualified the principle of free evaluation of evidence as a universally applicable principle in assessing any means of evidence under the EPC. Hence, evidence submitted by a patent applicant or proprietor to prove the technical effect relied upon for acknowledgement of inventive step may not be disregarded solely on the ground that such evidence had not been public before the filing date of the patent in suit and was filed after that date.
The Enlarged Board further considered that the term "plausibility" did not amount to a distinctive legal concept or a specific patent law requirement under the EPC.
According to the Enlarged Board, the relevant standard for the reliance on the purported technical effect when assessing whether or not the claimed subject matter involved an inventive step under Article 56 EPC concerns the question of what the skilled person, with 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.
The Enlarged Board of Appeal held that these guiding principles would allow the competent board of appeal or other deciding body to take a decision on whether or not post-published evidence may or may not be relied upon in support of an asserted technical effect when assessing whether or not the claimed subject-matter involves an inventive step.
The order issued by the Enlarged Board of Appeal reads as follows:
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.
Spokespersons of the Boards of Appeal of the European Patent Office
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