2. Right of priority of the applicant or its successor in title

In T 98/23 the patent related to a CRISPR-Cas 9 composition for therapeutic use. It was based on a European patent application resulting from an international PCT application claiming priority from 13 earlier US applications including P1, P2, P3, P5 and P13. In its decision revoking the patent, the opposition division had found that formal entitlement to priority from P1, P2, P5 and P13 had not been validly claimed because not all applicants of these priority applications were named in the subsequent application leading to the patent. Thus, novelty and inventive step were examined based only on documents published before P3, in particular D10. The subject-matter of claim 1 of the patent as granted was found to lack novelty over the disclosure of D10.

References to G 1/22 in this abstract should be understood as referring to both G 1/22 and G 2/22.

The board explained that, as in T 844/18, T 2360/19, T 2516/19 and T 2689/19, the issue was whether Mr Marraffini as one of the claimed inventors or The Rockefeller University as his successor in title, had given their consent to the subsequent filing of the patent application in question. A further issue was whether The President and Fellows of Harvard College had given their consent to the subsequent filing of the patent application. The presumption, following G 1/22, is that they did. This presumption may be rebutted.

The board recalled that according to G 1/22, the presumption of priority entitlement, by way of an implicit (implied/informal or tacit) agreement on the transfer of the right to claim priority "under almost any circumstances" applied to any case where the subsequent applicant was not identical with the priority applicant. Also ex-post (retroactive, nunc pro tunc, ex tunc) transfers concluded after the filing of the subsequent application were valid. The presumption of an implied agreement was rebuttable. To question the implied agreement, evidence was thus needed that such agreement had not been reached or was fundamentally flawed.

In the board's opinion, there was no evidence that rebutted the presumption in this case, rather there was evidence on file that supported the presumption. The inventorship dispute between Mr Marraffini/The Rockefeller University and Mr Zhang/The Broad Institute Inc/Massachusetts Institute of Technology had been settled in 2018 by decision of an arbitrator. Applying G 1/22, the settlement by arbitration contained (and confirmed that there was), at least, an implicit agreement nunc pro tunc. Thus, the presumption of entitlement to priority was on the earliest date on which priority was claimed, 12 December 2012. G 1/22 explicitly also stated that "the presumption of entitlement exists on the date on which the priority is claimed and the rebuttal of the presumption must also relate to this date", and that "later developments cannot affect the rebuttable presumption". As being retroactive, the at least implicit transfer agreement by way of the settlement of the inventorship dispute related to this date, and confirmed the presumption of entitlement to exist on this date.

As to whether The President and Fellows of Harvard College had given their consent, no evidence had been filed by the opponents either establishing that the real priority right holder did not allow the subsequent applicants to rely on the priority (see also T 1975/19).

The board concluded that entitlement to priority had been validly claimed in view of G 1/22. The case was remitted to the opposition division for a fresh assessment of the patentability requirements of the main request (the patent as granted), based on a valid priority entitlement to P1.

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.