Priority at the EPO


The Board of Appeal has issued its written decision revoking one of the patents owned by The Broad Institute (and others), related to CRISPR technology (T 884/18 hyperlink to The revocation is based on a lack of novelty due to an invalid claim to priority.

The Board concluded that:

  • The EPO is both empowered and obliged by Article 87(1) EPC to assess the validity of a claim to priority;
  • A valid priority claim requires that all persons listed as applicants for the priority application are also listed as applicants for the subsequent application, allowance being made for successors in title. This confirms the so-called “all applicants” approach;
  • The identity of “any person” who has “duly filed” an earlier application, as referred to in Article 87(1) EPC, is determined by the Paris Convention, and not national law.

The two earliest, US-filed priority documents (12 December 2012 and 2 January 2013), amongst others, named Luciano Marraffini of Rockefeller University as an inventor-applicant. However, Marraffini was not listed as an applicant on the international application and had not assigned his priority rights to any of the Patentees. They had argued that, under the relevant US law, inventorship (and valid claim to priority) would be defined by a person’s contribution to the subject matter of the invention, with the result that the omission of Marraffini could be justified on the basis that he did not contribute to the later filed invention.  The EPO rejected this argument, affirming the EPO’s existing case law and practice. 

For more information, please see our article outlining best practice in relation to successfully claiming priority in at the EPO. Should you have any questions, please contact our patents team.

This is for guidance only and should not be taken as legal advice.