EPO Enlarged Board establishes new practice in transfers of priority rights

The EPO’s Enlarged Board of Appeal has decided that the transfer of a priority right is to be assessed solely according to the European Patent Convention (EPC). The Enlarged Board of Appeal’s consolidated decision G 1/22 and G 2/22 on October 10 2023 means national law will no longer be considered, thus departing from the previous practice (for example, T 1201/14).

Due to the former need in the US to file a patent application in the name of the inventors, the EPO often confronted the scenario that a European patent (EP) application derived from a Patent Cooperation Treaty (PCT) application claimed the priority of a US application, wherein the applicants of the priority application differed from the applicants of the subsequent application. Whether there was an effective transfer of rights from the applicants of the US priority application to the applicants of the subsequent PCT or EP application was then (usually) examined by the EPO under US law. However, this is no longer the case.

According to the decision G 1/22 and G 2/22, an implicit agreement – for example, an implied transfer – is sufficient for a valid transfer, as the EPC does not have any formal requirements for the transfer of a priority right.

The Enlarged Board of Appeal has established a rebuttable presumption that the applicant is entitled to claim priority. This shifts the burden of proof to the effect that the party contesting the right to priority must prove that this right is actually lacking. The intention of the Enlarged Board of Appeal is to ensure that the priority is challenged less frequently in opposition proceedings.

The Enlarged Board of Appeal explicitly leaves open the question of the so-called PCT joint applicants approach. Instead, the Enlarged Board of Appeal establishes the concept of an implied agreement; according to which, the mere fact of the joint filing of a subsequent PCT application is sufficient for the parties to apparently have entered into an implicit agreement to the effect that an additional subsequent applicant may invoke the priority right conferred by the filing of the priority application by another subsequent applicant or other subsequent applicants.

Such an agreement may only be implied if all the applicants of the priority application or their successors in title (‘all applicants’) are also applicants of the subsequent application. However, even if this is not the case, the rebuttable presumption in favour of the priority right of the subsequent applicants still applies.

In this context, it is interesting to look back at the decision T 844/18 (CRISPR) in 2020, in which the board of appeal denied the validity of the priority claim due to violation of the ‘all applicants’ requirement. Against the background of the new decision by the Enlarged Board of Appeal, it is questionable as to what extent the application of the rebuttable presumption would have led to a different result in the above case.

It remains to be seen how the opposition divisions and boards of appeal will implement the new concepts introduced by the Enlarged Board of Appeal in G 1/22 and G 2/22; for example, standards for rebutting the presumption. However, Dr. Martin Huenges and Dr. Kerstin Wolff, respectively a partner and counsel at Maiwald, who are familiar with the consolidated appeal cases T 2360/19, T 2516/19, and T 2689/19 due to their involvement in other CRISPR cases, report that the decision will be based on the new concepts of the Enlarged Board of Appeal, and the presumption of priority entitlement could not be rebutted in these cases.

Meanwhile, the Federal Court of Justice has already adopted this new EPO case law; for example, in Sorafenib-Tosylat and Happy Bit (linked-to pages in German).