Loss of priority leads to revocation of key CRISPR patent at European Patent Office

In a previous article, we reported on the preliminary opinion of the Opposition Division issued during the opposition to the Broad Institute’s European CRISPR patent EP2771468. Yesterday, the oral hearing before the opposition division at the European Patent Office (EPO) deciding this matter was concluded with complete revocation of the patent. This is a huge blow for the Broad Institute in the long running battle over who owns the rights to the CRISPR gene editing technology.

The problem in this case was that the proper procedure for claiming priority was not followed when the International Patent Application, upon which the European patent was based, was filed. Multiple priority dates were claimed from multiple US patent applications having multiple Applicants. This in itself is not a problem but the international application did not name, as Applicants, all of the applicants (or their successors in title) from the originally filed priority applications. Under the European Patent Office’s interpretation of the Paris Convention (which sets the rules for claiming priority) joint-applicants on a priority application are deemed to be a single “person”. It is possible to assign the right to claim priority separately to the right to a patent but a joint-applicant does not have the right to file a later priority-claiming application as sole applicant unless the earlier joint-applicant has assigned their rights to that applicant. There must be a clear chain of title from the earlier applicant(s) to the applicant(s) on the priority-claiming application.

Further, if there is an assignment of rights before the priority-claiming application is filed, then it must be signed and dated by both Assignor and Assignee before the priority-claiming application is filed for the EPO to recognise the priority claim as valid. There are also substantive, rather than procedural, requirements for a valid claim to priority but I have not commented on these here, although they were invoked in the Broad case.

On the Broad Institute’s patent, an applicant and inventor from some of the original priority applications were not named on the international application and no appropriate assignment was signed before the international application was filed. This led to the loss of the earlier priority dates, which brought key prior art publications into consideration under novelty and inventive step. This rapidly led to revocation of the patent as soon as the important priority dates were lost. The decision can be appealed to the Technical Board of Appeal of the EPO but it is unlikely that the patent can be revived with this fact situation.

If you have any concerns about priority or would like further information, then please get in contact with your usual attorney at GJE.