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EPO’s Technical Board of Appeal Applies Relaxed Standards for Assessing Priority Entitlement

In a recently-published decision T2360/19, the EPO’s Technical Board of Appeal applied new liberal standards when assessing legal entitlement to priority, following a relaxation of this aspect of the law.

The opposed patent, covering gene editing technology known as CRISPR, was granted from a divisional application stemming from parent EP2771468. The parent patent had previously been revoked by the Technical Board of Appeal in a high-profile case T0844/18, in which certain priority claims were held to be invalid. In this case a co-applicant of earlier-filed US provisional applications (Dr Marraffini), or his successor in title (The Rockefeller University), had been omitted as a co-applicant when filing the international (PCT) application from which EP2771468 was derived. The omission was deliberate, and related to an inventorship/ownership dispute between the parties. Furthermore, there was no evidence of an assignment of the rights of priority from Marraffini/Rockefeller University to the other co-applicants before the PCT filing date. The Board concluded that the relevant priority claims were invalid because the so-called “all applicants” principle had been violated. The claims consequently lacked novelty over documents published after the first priority date. More details of this case can be found in our briefing here.

Following T0844/18, in cases G1/22 and G2/22 the Enlarged Board of Appeal significantly liberalised requirements concerning priority entitlement. This decision established that “…entitlement to priority should in principle be presumed to exist…”, and this conclusion took into account a “...lack of formal requirements for the transfer of priority rights…”[1]. The Enlarged Board stated that the EPO should “accept informal or tacit transfers of priority rights under almost any circumstances.”[2]. The presumption of entitlement may be rebutted, but only in “rare exceptional cases[3]. See our briefing here for more details.

In T2360/19 the Technical Board of Appeal faced the same fact pattern as faced the Board in T0844/18, but it was now required to reassess legal entitlement to priority in light of G1/22 and G2/22.

The Board noted that the PCT co-applicants and Rockefeller University had submitted to binding arbitration to resolve the inventorship/ownership dispute. This was considered to support the presumption of an implied agreement to transfer the relevant rights of priority from Rockefeller University to the other PCT co-applicants. The Board determined that in the absence of contrary evidence, by submitting to arbitration “it is not credible that Marraffini or the Rockefeller University would have acted in a way to invalidate the priority claim of a patent they were seeking to be named as inventor of, and owner of, respectively”[4]. The Board regarded the settlement of the dispute to result in “an ex-post facto transfer agreement.”[5]. Significantly, the Board further noted[6] that even in the absence of any evidence regarding the settlement of the dispute, the conclusion would have been the same. This is because according to G1/22 and G2/22 the presumption of a valid priority claim would have existed, and it had not been rebutted by any other evidence or arguments submitted by the opponents.

The present decision marks a dramatic reversal of the earlier conclusions of the Board on essentially the same fact pattern in a high-profile case at the EPO. More widely, it should be welcomed by proprietors as further evidence of the recent significant liberalisation of the EPO’s case law in relation to priority entitlement.


[1] G1/22 and G2/22, Reasons 105

[2] G1/22 and G2/22, Reasons 99

[3] G1/22 and G2/22, Reasons 108

[4] T2360/19, Reasons 21

[5] T2360/19, Reasons 24

[6] T2360/19, Reasons 25