Plausibility Doctrine Found Implausible

The Enlarged Board of Appeal of the European Patent Office issued its decision in G 2/21 on 23 March 2023.

In the case at hand, a synergistic effect was argued to exist between a combination of thiamethoxam with anthranilic diamides (represented by a Markush formula) with respect to insecticidal activity. The evidence for the synergistic effect was provided after the filing date of the patent application.

Board of Appeal 3.3.02 concluded that “… questions need to be referred to the Enlarged Board of Appeal on whether evidence not public before the filing date of the patent in suit and filed after that date (“post-published evidence”) can be taken into consideration in view of the plausibility case law of the boards.” (T 0116/18, point 11.1 of the Reasons for the Decision).

This decision was eagerly awaited by all patent practitioners at the EPO, and also by AIPPI.

Why AIPPI? Because the Amicus Brief Committee of AIPPI filed submissions in response to the Enlarged Board’s call for third party observations on the case and we were eager to see whether they were taken into account.

Technical Board of Appeal 3.3.02 by interlocutory decision T 116/18 referred the following questions to the Enlarged Board of Appeal (referral pending under G 2/21):

If for acknowledgement of inventive step the patent proprietor relies on a technical effect and has submitted evidence, such as experimental data, to prove such an effect, this evidence not having been public before the filing date of the patent in suit and having been filed after that date (post-published evidence):

1. Should an exception to the principle of free evaluation of evidence (see e.g. G 3/97, Reasons 5, and G 1/12, Reasons 31) be accepted in that post-published evidence must be disregarded on the ground that the proof of the effect rests exclusively on the post-published evidence?
2. If the answer is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have considered the effect plausible (ab initio plausibility)?
3. If the answer to the first question is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have seen no reason to consider the effect implausible (ab initio implausibility)?

In our Amicus Brief, AIPPI argued (citing the Resolution regarding Plausibility with reference to Patents, voted during the AIPPI Annual World Congress in London in 2019) that there should be no stand-alone, independent ground of patentability or validity based on plausibility alone.

AIPPI further argued that if a plausibility criterion were indeed to be considered, the threshold for credibility should be narrowly understood.

The Enlarged Board of Appeal’s order in response to the submitted questions was 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.

At paragraph 58 of its reasons, the Enlarged Board stated:

The Enlarged Board considers the conceptional notion inherent in the term “plausibility”, which is often used as a generic catchword, as not being a distinct condition of patentability and patent validity, but a criterion for the reliance on a purported technical effect.

Further, at paragraph 86, the Enlarged Board indicated:

Like the EPC, none of the legal systems of the EPC Contracting States provide for an explicit patentability requirement for what the referring decision discusses and addresses with what is referred to in questions 2 and 3 under the term “plausibility”.

And then at paragraphs 92 and 93:

The term “plausibility” that is found in the case law of the boards of appeal and relied upon by the referring board in questions 2 and 3 of the referral and the reasons for it, does not amount to a distinctive legal concept or a specific patent law requirement under the EPC, in particular under Article 56 and 83 EPC. It rather describes a generic catchword seized in the jurisprudence of the boards of appeal, by some national courts and by users of the European patent system.

The relevant standard for the reliance on a purported technical effect when assessing whether or not the claimed subject-matter involves an inventive step concerns the question of what the skilled person, with the 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 and to embody the same invention, because such an effect does not change the nature of the claimed invention.

We are thus very satisfied that AIPPI’s Amicus Brief was well taken into account by the Enlarged Board of Appeal.

A FINAL WORD from Jeff Lewis, Chair of the Amicus Brief Committee: This case is an example of where an AIPPI member brought an issue to the Amicus Brief Committee, AIPPI had an established position, and there was sufficient time for AIPPI’s substantive committees, Amicus Brief Committee, and the Bureau to act with the approval of the local National and Regional Groups. If you know of a legal issue coming up in your jurisdiction that might benefit from AIPPI amicus participation, please let a member of the Amicus Brief Committee or the RG know.