Because No One is Immune to the Law
October 11, 2023 - Intellectual Property

Retaining Your Patent Priority Date in Europe: Formal Priority Given a Rebuttable Presumption in Favor of Applicant/Patentee

paperwork and pen

On October 10, 2023, the Enlarged Board of Appeal of the European Patent Office (EPO) issued a groundbreaking decision that reflects a major change in how formal priority is assessed at the EPO during examination and in post-grant opposition proceedings, to the benefit of applicants/patentees. 

Prior to the decision, a European patent could be found not to be entitled to claim priority to its priority date if all applicants on a priority provisional application were not also named as applicants on the International PCT application.  Without the benefit of the earlier priority date, intervening references published in the priority year between a provisional application and International PCT application could wipe out novelty and patentability of an invention. This formal review of priority entitlement by the EPO has resulted in revocation of numerous patents in Europe; most famously, Broad Institute’s patent relating to CRISPR gene editing technology was revoked in 2020 for not meeting formal priority entitlement.

In the recent decision, the Enlarged Board ruled that “[t]here is a rebuttable presumption … that the applicant claiming priority … is entitled to priority.”  This rebuttable presumption was ruled to also apply “in situations where the European patent application derives from a PCT application and/or where the priority applicant(s) are not identical with the subsequent applicant(s).” 

For instance, if a provisional application was filed by Party A and a PCT application was filed jointly by Parties A and B claiming priority to the provisional application, there will be a presumption that the PCT application filed by Parties A and B is entitled to the formal priority of the provisional application filed by Party A.  However, the Enlarged Board confirmed that the presumption also applies in the reverse scenario—where a provisional application was filed by Parties A and B and the PCT application claiming priority to the provisional application was filed only by Party A.

This ruling represents a groundbreaking shift in how formal priority is assessed at the EPO into being strongly in favor of applicants/patentees by giving them a newfound rebuttal presumption that the applicant is entitled to priority.  This presumption is, however, rebuttable “since in rare exceptional cases the priority applicant may have legitimate reasons not to allow the subsequent applicant to rely on priority,” namely when the claim of priority “appears to be unjustified.”  The Enlarged Board explained that these legitimate reasons can, for example, “be related to bad faith behaviour on the side of the subsequent applicant or to the outcome of other proceedings such as litigation before national courts about the title to the subsequent application.” 

 Further, this presumption is “a strong presumption under normal circumstances” and “[t]he party challenging the entitlement to priority can thus not just raise speculative doubts but must demonstrate that specific facts support serious doubts about the subsequent applicant’s entitlement to priority.”  As such, the Enlarged Board notes that, practically speaking, this rebuttable presumption “substantially limits the possibility of third parties, including opponents, to successfully challenge priority entitlement.”

 For now, Applicants should still take steps to ensure assignment documents are in place from inventors to a Company Applicant before filing an International PCT application. However, this decision may have the effect of aligning with US practices, which has always been more relaxed in its view of priority entitlement.   Practically speaking, this ruling is likely to greatly reduce the number of attacks on formal priority by third party opponents at the EPO seeking to revoke a patent based on mere “speculative doubts.”  This ruling will also make it increasingly difficult for third party opponents to satisfy the evidentiary burden necessary to rebut this presumption.

 Although this presumption will be binding at the EPO during examination and post-grant opposition proceedings, proceedings taking place outside of the EPO, such as patent disputes in national courts of European countries in which the EP patent was validated, are not bound by the Enlarged Board’s ruling on formal priority. While the same presumption may be considered persuasive by such national courts in many instances, it may be some years until this issue is addressed in a national court.