2.4. Présomption réfragable du droit de revendiquer la priorité

In T 781/23 the opposition division had held that the patent was entitled to claim priority from the priority document, a US provisional patent application filed in the name of the inventors, with the consequence that documents D12 and D13 did not belong to the state of the art according to Art. 54 EPC. The appellant (opponent) argued that the applicant for the patent in suit was not the successor in title of the applicants for the priority document.

The board recalled that, in accordance with decision G 1/22, under the autonomous law of the EPC there is a rebuttable presumption that the applicant claiming priority is entitled to claim priority. Furthermore, the presumption of priority entitlement applies to any case in which the subsequent applicant is not identical to the priority applicant but receives the support of the priority applicant required under Art. 88(1) EPC. Thus, the presumption applied in the case in hand. The board explained that the existence of a presumption of validity implied that it was the burden of the party challenging the applicant's entitlement to priority to prove that this entitlement was lacking. Thus, the appellant's argument that it was on the proprietor to demonstrate that it had the right to claim priority had to fail..

Also referring to G 1/22, the board stated that the presumption was rebuttable, for example, in cases of bad faith behaviour of the subsequent applicant or as a result of other proceedings such as litigation before national courts concerning title to the subsequent application. It further stated that the presumption of entitlement existed on the date on which the priority was claimed and the rebuttal of the presumption also had to relate to that date.

According to the board, in the case at hand, the appellant had not provided any such evidence to rebut the presumption of priority entitlement. Document D19 was an assignment by the inventors to the applicant of the patent in suit and could not rebut this presumption. The further evidence provided relied on requirements of national law, such as the distinction under French law between the right to the invention and the right to the priority claim. The board was of the view that, following the presumption of priority entitlement existing under the autonomous law of the EPC, considerations based on national law became irrelevant.

In light of the foregoing, the board came to the conclusion that the patent was entitled to the priority claimed.

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.