Oral Proceedings for G2/21 were held on 24 November 2022 before the Enlarged Board of Appeal (EBA) to discuss plausibility and the admissibility of post-published evidence in proceedings before the EPO.

In brief: no decision was announced during the oral proceedings. The EBA acknowledged the significance of this decision for the patent profession in general, suggesting that it will be given priority.

Ahead of the hearing, the EBA gave a preliminary, non-binding, opinion indicating their initial view on the topic. Here, they indicated that they favour the “ab initio implausibility” (medium bar) standard. However, the EBA gave little away about whether any of the arguments were persuasive enough to sway it from the preliminary opinion.

We will have to wait for the written decision for confirmation on whether this preliminary opinion was maintained, and we will bring you more news as soon as we have it.

In more detail: G2/21 (introduced in our previous articles here and here) asks how the EPO should deal with admissibility of post-filed data and the overall patentability concept of “plausibility”. For a detailed digest of G2/21, including practical tips for applicants and attorneys, as well as a comprehensive review of the case law in this field, please see our three-part article series here:

During the oral proceedings, it was debated whether there is a plausibility requirement for admittance of post-published evidence (i.e. a low bar) or, if there is, whether the test should be “ab initio plausibility” (where it is assumed that an invention is implausible unless the patent application as filed shows that it is plausible – a high bar) or “ab initio implausibility” (where it is assumed that an invention is plausible unless there is something to suggest it is not – a medium bar).

During opposition and appeal proceedings, the patentee had relied on post-published evidence demonstrating a synergistic effect of two components of an insecticide composition in support of inventive step. Therefore, unsurprisingly, during the oral proceedings before the EBA, they presented arguments that there was no plausibility requirement and, if there was, the lower bar of “ab initio implausibility” should be applied. The opponent, also unsurprisingly, argued in favour of the higher bar of “ab initio plausibility”.

The representatives of the President of the EPO then presented their opinions and the EBA questioned the parties, clarifying how the Board believed these tests should be defined and what the outcome should be in various situations. It remains to be seen how the EBA will weigh up these arguments.

The question also arose as to whether the conclusions from this case, which deals with post-published evidence in the context of inventive step (Article 56 EPC), should also apply to post-published evidence in the assessment of sufficiency (Article 83 EPC). In their preliminary opinion, the EBA did not consider it appropriate to extend the referral beyond inventive step. During proceedings, the patentee presented arguments agreeing with the preliminary opinion, while the opponent argued that the decision should apply equally to the assessment of sufficiency. Again, it remains to be seen whether the EBA will offer any insights on sufficiency.