7.4. Communication under Article 15(1) RPBA

In T 1544/22 the patent proprietor (respondent) submitted a letter, relating inter alia to auxiliary request 2, only two working days before the oral proceedings. They argued that this letter was a direct response to the board's preliminary opinion, which deviated from the impugned decision. According to the patent proprietor, the arguments presented in the letter only elaborated in more detail arguments that had already been presented before. Its aim was to facilitate discussing these arguments during the oral proceedings. Even if the letter had not been filed, its content could have been presented and discussed orally during the oral proceedings. The appellant (opponent 2) took the view that the letter contained a completely new set of arguments, which constituted an amendment to the patent proprietor's appeal case. This amendment would have necessitated contacting a technical expert, which was not possible due to the extremely late submission of the letter.

The board concurred with the patent proprietor that the part of the letter referring to auxiliary request 2 related to arguments considered in the decision under appeal and submitted by the patent proprietor during the written phase of the appeal proceedings (with its reply to the grounds of appeal of opponent 2). In fact, the patent proprietor had already addressed the issues explained in the letter, namely the technical effect of a certain feature and how it was advantageous over the prior art. The late-filed letter merely elaborated these arguments in more detail, as submitted by the patent proprietor. The board held that such a refinement of previously submitted arguments which further illustrated a party's position had to be allowed, especially when, as in the case at hand, the refinement of arguments concerned points where the board's preliminary opinion differed from the impugned decision. Otherwise, the parties could only repeat their arguments put forward in the statement of grounds of appeal and the reply thereto. The board agreed with T 247/20 that oral proceedings, to which the parties had an absolute right under Art. 116 EPC, would serve no purpose if such refinements were not allowed.

The board concluded that the arguments discussed in the late-filed letter relating to auxiliary request 2 were not new arguments and did not represent a fresh case, contrary to opponent 2's submissions. Instead, they concerned further refinements of arguments already addressed in the impugned decision (Art. 12(2) RPBA) and previously presented during the appeal proceedings (Art. 12(3) RPBA). Thus, they did not constitute an amendment to the appeal case as referred to in Art. 12(4), 13(1) and (2) RPBA. Therefore these (very late) submissions had to be considered in the case at hand.

However, the board also stressed that the preliminary opinion of the board had been communicated to the parties more than four months prior to the oral proceedings. Given that the letter in question had been submitted/received in practical terms only two days before the oral proceedings (i.e. on Monday 3 February 2025), the board agreed with opponent 2 that it had been filed extremely late. In addition, the board was of the opinion that the patent proprietor could and should have presented the arguments contained in the late-filed letter earlier in the proceedings. By submitting late-filed arguments with such a high level of detail at such a short notice – two days before the oral proceedings – the patent proprietor had unfairly put opponent 2 in an unnecessarily unfavourable position.

In view of this particular situation, the board had given opponent 2 the opportunity to request an adjournment of the oral proceedings and indicated that it was favourably disposed towards such a request. After opponent 2 had not requested an adjournment of the oral proceedings but preferred to continue them, the board did not consider it necessary to discuss the original accusation of abuse of procedure submitted by this party.