The decision relates an appeal filed by the appellant-opponent [AO] to the decision of the Opposition Division [OD] to reject the opposition against EP2484209 (the patent). The OD decided the requirements of Art. 123(2) EPC and Art. 76(1) EPC were met and the claims were novel over D4 and D8 since at least 2 selections would have to be made. According to the patent in suit, mixtures of thiamethoxam and compounds according to formula “Ia” can produce an insecticidal activity which is greater than that which would have been expected based on their respective individual activities. The patent provided data demonstrating the synergistic effect of example compounds falling under the scope of the claim against two different species of moth (S. litura and P. xylostella).
Since the claims were not directed at conditions under which synergy was achieved, this did not prejudice sufficiency of disclosure (Art. 83 EPC) but was dealt with under inventive step (Art. 56 PC). Documents D21 and D22, containing post-filed data showing a synergistic effect between thiamethoxam and the compounds according to formula “Ia” of claim 1, were admitted in the proceedings by the OD, which decided that the claims were inventive in view of this evidence .
With the Ground of Appeal the AO submitted D23 with their own data, showing that compounds falling under the scope of the claim did not have synergistic effect against two other moth species P. xylostella and S. littoralis at certain weight ratios. In reaction to the Board’s communication under Art 15(1) RPBA 2020 wherein the question whether the technical effect was achieved over the entire breath of the claims the respondent submitted post-published D24.
During oral proceedings before the Board the AO requested to set aside the decision under appeal and revoke the patent, not to admit any of D21 and D22 not D24 and the auxiliary requests filed during the appeal phase. The respondent’s requests were to dismiss the appeal or to maintain the patent in amended form on the basis of auxiliary requests 1-3, to remit the case to the OD, take into account D21 and D22, admit D24 while not to admit figures 1 and 2 of the statement of Grounds of Appeal nor D23. During the oral proceedings both parties additionally requested to refer questions to the Enlarged Board of Appeal [EBoA].
After acknowledgement of sufficiency of disclosure and novelty of the claims the next point to be assessed was inventive step. During the assessment it turned out questions needed to be referred to the EBoA on whether the evidence that was not public before the filing date of the patent and was filed thereafter (‘’post-published evidence’’) such as D21 and D23 in the present case can be taken into consideration in view of the plausibility case law of the Boards. In the present case the Main Request [MR] would not be inventive if only the data in the patent and D23, which convincingly contradicted the data in the patent, could be taken into account. If D21, which is the only proof of a synergistic effect against C. suppressalis, could also be taken into account the MR would be considered inventive though.
On the question of taking post-published evidence into account, the Board observes that three diverging lines of case law have evolved:
On the one hand, according to certain decisions (for example T488 /16, T1329/04, T609/02, T415/11, T1791/11 and T895/13), the technical effect must already be plausible in the application as filed (ab initio plausibility criterion ).
In the ab initio implausibility line of case law, post-published evidence can only be disregarded if there is doubt (e.g. vis-à-vis common general knowledge) that the purported technical effect had in fact been achieved at the filing date. Post-published evidence should then be taken into account if the purported technical effect is not implausible, the test being whether there was substantiated doubt at the filing date (T919/15, T536/07, T1437/07, T266/10, T863/12, T184/16 and T2015/20, it is noted that the majority of these decisions come from the referring board 3.3.2). The Board here also makes reference to UK Supreme Court decision in Warner Lambert.
The third line of case law makes reference to a number of cases which dismiss entirely the requirement for a plausible disclosure of an effect in the application as filed; the so-called “no plausibility” strand of case law. According to T31/18 and T2371/13 the requirement for plausibility of a technical effect at the filing date is not compatible with the problem solution approach.
In view of the diverging lines of case law, the Board concluded that a referral to question the requirements for plausibility was needed to ensure uniform application of the law. Three referral questions were formulated relating to the three lines of case law discussed above.
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):
The referral to the EBoA is now pending under number G2/21.
It is noted that in all the decisions requiring the higher bar of ab initio plausibility, the plausibility was not acknowledged. In all of the cited decisions in the ab initio implausibility line, plausibility was acknowledged though. This discrepancy upfront highlights the implications that an EBoA decision in this referral G2/21 may have on the requirements for patentability.