How will the Boards interpret the plausibility test in G 2/21?

News | 28.07.2023

The million euro question in European patent law these days is: how will the Boards interpret the plausibility test in G 2/21? HOFFMANN EITLE's Munich partner Jan Zillies took part in one of the very first cases to give an answer - as reviewed in this article by HOFFMANN EITLE's London partner Adam Lacy.

Uncertainty remains at the EPO about the role of plausibility in admitting post-published data for inventive step after the much-criticised G 2/21. Many are looking to the referring Board 3.3.02 for guidance on what the key test “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” actually means. Help is already at hand from Board 3.3.07, who applied this test in T 873/21 handled by HOFFMANN EITLE and give some clues about what they think it means.

In the case at hand, the post-published evidence related to a synergistically improved insulin sensitivity with the claimed combination of compounds. Both compounds were generally known to have metabolic effects, and the application generally stated that the invention delivers improved insulin sensitivity compared to monotherapy. The specific combination of compounds was also identified as preferred.

Applying the test in G 2/21, the general statements and known activity of the compounds in T 873/21 were enough for the synergistic effect to be "derivable" at reason 3.3.2 such that the data was considered as providing the quantification of the obtained improvement. It also seems to have been considered "encompassed by the technical teaching" of the application for the same reason. The fact that both were preferred also meant that the effect was "embodied by" the claimed combination – see reason 3.3.3. So the data could be relied upon and inventive step was acknowledged.

Congratulations to Jan Zillies who dealt with this case. We think it is a very reasonable and pragmatic decision, and makes life easier for patentees wishing to rely on post-published evidence to support inventive step at the EPO.