Résumé de EPC2000 Art 084 pour la décision T0042/22 du 17.03.2023

In T 42/22 claim 1 of the main request was a product claim directed to a modified nucleotide, i.e. to a chemical compound as such, which comprised the following components: (i) a purine or pyrimidine base, (ii) a deoxyribose sugar moiety having a 3'-azidomethyl group and (iii) triphosphate. The appeal turned on the interpretation of the term "3'-azidomethyl" in claim 1. In particular, the question was whether claim 1 was directed to nucleotides having an azidomethyl group directly bound to the 3' carbon of the deoxyribose (interpretation 1) or whether it was directed to nucleotides having an azidomethyl group bound via an oxygen to the 3' carbon of the deoxyribose (interpretation 2). After examining what the skilled person understood by the term "3'-azidomethyl" in claim 1, the board concluded that the symbol "3' " without any letter following the number denoted for the skilled person "3'-C", i.e. being directly bound to the carbon atom at position 3' (interpretation 1). A second point addressed in this decision was whether the term "3'-azidomethyl" in claim 1 was to be interpreted in light of the description. In the case at hand, the board held that claim 1 was clear and no technical inconsistencies between the terms in the claim had been identified. Moreover, it considered that interpretation 1 was technically sensible. In the board's judgement, the meaning of a term in a claim which was clear could not vary depending on how well the claim was aligned with the description. Also, in decisions T 1127/16 and T 1896/11, the competent board in each case had considered claim wording which imparted a clear and credible technical teaching when interpreted on its own, although this teaching did not correspond to the invention in the description. The board in each of those cases had held that the description could not be used to give a different meaning to the claim. The board in the current case disagreed with T 1023/02, which had held that a given term in the claim should be interpreted according to the teaching in the description. It followed instead the line of decisions establishing that there was no need to use the description to interpret a claim which was clear and allowed a technically sensible interpretation (see e.g. T 1018/02, T 1172/08, T 197/10, T 1896/11, T 1127/16). Hence, the board concluded that there was no reason to use the description to interpret claim 1. In a case such as this one, where the claim and the description related to different compounds, a technically reasonable interpretation based on the literal wording of the claim should not be discarded and replaced by a different interpretation finding a basis solely in the description. An additional point addressed by the board was whether independent claim 1 was to be interpreted in the context of claim 6 and whether doing so would change the claim interpretation. In the board's view, the interpretation of product claim 1 could not be dependent on whether or not method claim 6 was present in the claim set. Instead, each claim should be interpreted independently. Contrary to the view of the respondent (patent proprietor), the board did not find in Art. 84 EPC support for the contention that all claims needed to be interpreted together. In addition, the board noted that the appellants (opponents) had provided a technically sensible interpretation of claim 6 which was also compatible with interpretation 1 of claim 1. The board pointed out that in line with the case law, a technically sensible interpretation could not be disregarded even if additional interpretations were possible. As such, it was not relevant for the current case which additional interpretations could follow from interpreting claim 6. Hence, the board came to the conclusion that claim 1 should be given interpretation 1. Regarding the basis for the claimed subject-matter in the grandparent and parent applications as filed, the board decided that the claim related to subject-matter extending beyond the content of the earlier applications as filed (Art. 76(1) EPC).