Home > Insights > Inventive Step at the EPO – Plausibility and Post-Published Evidence (G2/21)
11 January, 2022

The Enlarged Board of Appeal of the European Patent Office has been challenged with a new referral (G2/21) concerning the admissibility of post-published evidence for the assessment of inventive step. The outcome of this referral could have significant consequences for the assessment of patentability at the European Patent Office, particularly for inventions in the fields of biotechnology, life sciences and chemistry.

Background
European patent No. 2 484 209 owned by Sumitomo Chemical Company, Limited was opposed by Syngenta Limited on multiple grounds including lack of inventive step. The Opposition Division rejected the opposition and upheld the patent. The decision was appealed (T0116/18).

In considering inventive step, the Board of Appeal decided that this turned on the admissibility of post-published data to support the technical effect relied upon by the proprietor.

The patent is directed to an insecticide composition comprising a combination of compounds for which synergy is demonstrated in the examples.

The opponent/appellant sought to attack inventive step by filing evidence to challenge the existence of synergy across the whole scope of claim 1. The proprietor defended inventive step by filing their own supplementary data providing further evidence of synergy for the claimed combination.

The Board of Appeal decided that if the proprietor’s post-published data were taken into account, then inventive step could be acknowledged. However, if the supplementary data were not admissible, then the claimed subject matter would be non-inventive on account of being merely an obvious alternative insecticide composition. The outcome of the appeal thus turns on whether the post-published evidence can be admitted.

Post-Published Evidence and Plausibility
With regard to the admissibility of post-published evidence to support inventive step, the Board of Appeal considered there to be three, divergent lines of EPO case law in which differing standards were applied in previous decisions.

Ab initio plausibility” – this line of case law follows the approach whereby the application as filed must render plausible the technical effect relied on for inventive step. Only thereafter can post-published data be used to further demonstrate the technical effect. This standard follows Board of Appeal decision T1329/04 and has been widely adopted at the EPO. This standard reflects the need to prevent “armchair inventors” from obtaining rights based on speculative assertions that are not commensurate with the actual contribution to the art.

“No plausibility” – the case law following this standard rejects the concept of plausibility arguing that there is no legal basis in the European Patent Convention for requiring plausibility. The decisions in which this standard have been applied are typically very generous when it comes to the admissibility of post-published evidence to support inventive step. This standard reflects the concern that truly ground-breaking, first-of-its-kind inventions deserve broad claim scope commensurate with their contribution to the art, yet rendering such scope plausible or not implausible ab initio can be an undue burden for an applicant.

Ab initio implausibility” – this third line of case law permits post-published data to be used in support of inventive step provided that the purported technical effect is not implausible. In other words, the skilled person at the filing date would see no reason to doubt the achievement of the technical effect (in view of their common general knowledge and the disclosure of the application as filed). This standard lies somewhere between the two extremes noted above.

Referral
In view of the different standards applied in the case law, the Board of Appeal considered it necessary to refer the following questions to the EBA:

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)? [emphasis added]
  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)? [emphasis added]

We look forward to reading the EBA’s decision and welcome the greater certainty it will provide to applicants going forward.

If you wish to know more about these issues or seek advice, please contact Joanna Peak or your usual Boult Wade Tennant LLP advisor.