The appeal was filed by the opponent against the opposition division's decision to reject the opposition filed against the European patent.
During the oral proceedings, the opposition division decided not to admit into the opposition proceedings D15 to D17, filed by the opponent (now appellant) the last day for making written submissions or amendments under Rule 116 EPC.
A board should only overrule the way in which a department of first instance exercised its discretion when deciding on the admission of late-filed submissions if it concludes that that department did so according to the wrong principles, without taking into account the right principles or in an unreasonable way, and has thus exceeded the proper limits of its discretion.
The board considers that in the current case, the opposition division exercised its discretion using the wrong criteria and in an unreasonable manner when deciding not to admit the aforementioned documents.
On the decision under appeal, when deciding on the admission of D15 to D17, the opposition division argued, in the first place, that two scenarios could be foreseen, namely:
- "if the opponents arguments in D15-D17 do not go beyond what has already been argued in the notice of opposition they are not more relevant that what already is on file"
- "If the opponents arguments provided in D15-D17 do go beyond what has been submitted in the notice of opposition these arguments and evidence are late filed and the proprietor is not given a fair and expedient chance to respond"
The implementation of this approach would inevitably result in any new submission being inadmissible. This approach pre-empts any possibility to have considered new arguments or facts submitted in preparation for the oral proceedings until the date set under Rule 116(1) EPC. This is unreasonable and not in line with the established case law.
Under established case law, when exercising its discretion to admit late-filed documents, the opposition division should determine their relevance. Prima facie relevance should be the principal factor governing admissibility of late-filed documents.
The opposition division decided that D15 to D17 were not "prima facie relevant" because the allegations and objections had already been brought forward in the notice of opposition, so D15-D17 did not carry more weight and were not more relevant than the submissions already on file.
The board does not agree with the opposition division's assessment of prima facie relevance.
In the notice of opposition, the opponent set out the technical reasons why it considered that the process described in the patent did not afford the claimed geopolymer composite.
In its communication issued in preparation for the oral proceedings, the opposition division did not address the technical arguments set out in the notice of opposition.
The opposition division expressed, however, the preliminary opinion that the opponent's objections were not supported by any evidence and therefore not convincing.
The opponent's letter dated 23 December 2020 and the annexed experimental reports D15 to D17 address the opposition division's preliminary opinion as well as the content of D14, filed by the patent proprietor. These documents aim to show that the claimed invention was not sufficiently disclosed and did not involve an inventive step over the prior art.
It is readily apparent that by filing D15 to D17, the opponent tried to overcome the opposition division's preliminary finding that the objections set out in the notice of opposition were not supported by evidence. The evidence provided clearly goes beyond the submissions in the notice of opposition.
Accordingly, the opposition division's finding that D15 to D17 are not prima facie relevant because the allegations that the claimed composites and foams cannot be obtained and the objections of lack of disclosure, novelty and inventive step "were already brought forward in the notice of opposition" is unreasonable. With this reasoning, the opposition division has de-facto not assessed the prima facie relevance of these documents.
If this approach were to be implemented, a party would lose the right to have any new evidence supporting an attack raised in the notice of opposition considered, irrespective of its prima facie relevance for the outcome of the proceedings.
The opponent requested that the oral proceedings before the opposition division be postponed so it could carry out its own experiments in reply to the experimental report D14 filed by the patent proprietor. This request, as well as a later request from the patent proprietor to postpone the oral proceedings for it to address D15 to D17, was not granted by the opposition division.
The opposition division could have decided to admit these documents without depriving the parties of their right to fair proceedings.
For these reasons, the board concludes that the opposition division, when deciding not to admit D15 to D17, exercised its discretion without taking into account the correct principles and in an unreasonable way.
Finally, in view of these findings and considering that the case is to be remitted for further prosecution the board does not deem it expedient to rule on their admittance.
The decision under appeal is set aside.
The case is remitted to the opposition division for further prosecution.