1.7.3 Décisions appliquant les critères posés par la Grande Chambre de recours dans les affaires G 1/03 et G 1/16

In T 518/22 the board established that the "A3" mutant disclosed in D2 anticipated the subject-matter of claim 1 of auxiliary request 1 at least under Art. 54(3) EPC.

Claims 1 and 9 of auxiliary request 2 differed from the respective claims in auxiliary request 1 in that an undisclosed disclaimer had been introduced to exclude the A3 mutant disclosed in D2 from the subject-matter claimed.

The board explained that, according to G 1/03, an amendment to a claim by the introduction of a disclaimer may not be refused under Art. 123(2) EPC for the sole reason that neither the disclaimer nor the subject-matter excluded by it from the scope of the claim have a basis in the application as filed. G 1/03 defines the criteria when such an undisclosed disclaimer is allowable, stipulating that it can be introduced into a claim inter alia to restore novelty by delimiting a claim against the state of the art under Art. 54(3) EPC but not under Art. 54(2) EPC (except for a so-called accidental disclosure).

In order to determine whether D2 was prior art under Art. 54(2) or (3) EPC for the claimed subject-matter, the board assessed whether the subject-matter of claim 1 as a whole was entitled to claim priority from P and whether D2 was entitled to claim priority from P1.

The board found that D2's priority based on P1 was valid. Appellant I had objected to D2's formal entitlement to priority because the applicants of P1 and those of the international patent application D2 were not the same. The board explained that G 1/22 and G 2/22 established that a presumption exists that a claim to priority is valid by way of an implicit agreement on the transfer of the right to claim priority in the absence of evidence that such an agreement (implicit or explicit) did not exist. This presumption applies to any case where the subsequent applicant is not identical with the priority applicant. On account of this general teaching, the board understood that the presumption applied also to patent applications cited as prior art, as in the present case (see also T 521/18).

This presumption could be rebutted to take into account "rare exceptional cases" where the subsequent applicant could not justifiably rely on the priority (G 1/22). This, however, involved the reversal of the burden of proof, i.e. the party challenging the subsequent applicant’s priority entitlement (here appellant I) had to prove that this entitlement was missing. Merely raising speculative doubts was not sufficient. Instead, evidence was required that specific facts supported serious doubts about the subsequent applicant's entitlement to priority (G 1/22). In the absence of evidence suitable to establish that the alleged real priority right holder did not allow the subsequent applicant to rely on the priority (see also T 1975/19), appellant I's objection against D2's formal entitlement to priority from P1 was not sufficient to rebut the presumption of validity, which always existed on the date on which priority was claimed (G 1/22). Hence, D2 validly claimed priority from P1.

As regards the validity of the patent's priority claim based on P, the board established that the relevant date for the subject-matter of claim 1 in several embodiments concerning SEQ ID NOs: 5 to 8 was the filing date of the patent application, whereas several embodiments of claim 1 in relation to SEQ ID NO: 4 were entitled to claim partial priority from P (G 1/15).

Therefore, D2 was prior art under Art. 54(2) EPC for the subject-matter of claim 1 not enjoying priority, i.e. in relation to several embodiments concerning SEQ ID NOs: 5 to 8, and prior art under Art. 54(3) EPC for the subject-matter of claim 1 enjoying priority, i.e. in relation to several embodiments concerning SEQ ID NO: 4.

Since the undisclosed disclaimer added to claim 1 in auxiliary request 2 removed embodiments of D2 which belonged to the state of the art pursuant to Art. 54(2) EPC and were not an accidental disclosure, such amendment was not allowable under Art. 123(2) EPC. Auxiliary request 2 comprised added subject-matter (G 1/03 and G 1/16) and did not fulfil the requirements of Art. 123(2) EPC.