Résumé de EPC2000 R 139 pour la décision T1515/20 du 21.09.2023

In T 1515/20 the board noted that in opinion G 3/89 and decision G 11/91, the Enlarged Board had held that corrections under R. 88, second sentence, EPC 1973 (now R. 139, second sentence, EPC) were special cases of an amendment within the meaning of Art. 123 EPC and fell under the prohibition of extension laid down in this provision. The board referred to the established case law according to which, in the case of a proposed amendment under Art. 123(2) EPC or a correction under R. 139 EPC, the factual disclosure of the patent application as filed had to be established to the standard of certainty "beyond reasonable doubt". The board explained that, based on the above opinion and decision of the Enlarged Board, the boards applied a two-step approach when a correction in the description, the claims or the drawings was requested under R. 139, second sentence, EPC. For a correction to be allowable, both of the following had to be established: (i) it had to be obvious that the application as filed contained such an obvious error that a skilled person was in no doubt that this information was not correct and could not be meant to read as such. Accordingly, it had to be obvious that an error was present and had to be objectively recognisable by the skilled person using common general knowledge; and (ii) the skilled person using common general knowledge would directly and unequivocally have ascertained the precise proposed correction. The correction of the error should be obvious in the sense that it was immediately evident that nothing else would have been intended than what was offered as the correction. In the case in hand, according to the appellant, the skilled person would have immediately recognised that defining the antibody as comprising a light chain variable region consisting of SEQ ID NO: 4 constituted an error. The board was not convinced by the appellant's arguments that criterion i) of the two- step approach was met. First, the board saw no arguments as to why the skilled person, when confronted with the statement "a light chain variable region consisting of SEQ ID NO: 4" as such in the disclosure of the application, would prima facie be alerted and consequently prompted to consider and analyse the corresponding sequence depicted on page 44 with a view to determining the presence of particular functional parts/compounds in the unannotated amino acid sequence, in this case an ER signal sequence. Second, even when inspecting the sequence of SEQ ID NO: 4 and noting a starting methionine residue followed by a stretch of mainly hydrophobic amino acids (which was in fact 25 amino acids long and also included the amino acids at positions 23, 24 and 25) and the slightly above average light chain length for a mature antibody, the skilled person would not, as the appellant alleged, immediately have recognised that the depicted sequence of SEQ ID NO: 4 constituted an error because it included a signal peptide, but instead could, at best, be led to doubt that the depicted sequence was the sequence it purported to represent. This state of doubt however, did not equate with the requirement that the skilled person have no doubt that the depicted sequence was an error and could not be intended to read as such. The request for correction was thus rejected.