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Focus on Priority Claims in Europe

Feb 19, 2020

Table of contents
    Robert Alderson

    In a highly anticipated decision, the European Patent Office (“EPO”) Board of Appeal, on 17 January 2020, upheld the decision of the EPO´s Opposition Division which revoked a European Patent relating to the gene-editing technique, commonly referred to as CRISPR.

    EP2771468 (“EP ´468”) had been granted in the names of MIT and Harvard, collectively known as the Broad Institute.  EP ´468 was opposed by several parties with the key argument being that the priority claim was invalid since it did not name all applicants listed on the original US provisional patent application on which the priority claim was based.

    Legal Background

    The Opposition Division and the Board of Appeal based their decisions in large part on the interpretation of EPC Article 87(1) which states:

    (1) Any person who has duly filed, in or for 

    • any State party to the Paris Convention for the Protection of Industrial Property or 
    • any Member of the World Trade Organization,  

    an application for a patent, a utility model or a utility certificate, or his successor in title, shall enjoy, for the purpose of filing a European patent application in respect of the same invention, a right of priority during a period of twelve months from the date of filing of the first application. 

    Under the more relaxed standards in the United States, a priority claim can be made to an earlier application even when there is only one inventor is in common. (See MPEP 211.01).

    Brief Factual Background

    EP ´468 was filed with the EPO as a “national” phase application deriving from a PCT application which claimed priority to a US provisional patent application.  The US provisional application named more applicants than the later PCT application.  The missing applicants on the PCT application had not assigned their rights to any of the listed applicants.  Shortly after the filing date of the US provisional application a scientific paper was published which contained the subject matter ultimately claimed in EP ´468.

    Opposition Division

    The Opposition Division agreed with the opponents that Article 87(1) requires all applicants listed in the first application to be accounted for in any second application claiming priority to the first.  EP ´468 did not account for all applicants in the PCT application rendering the priority claim invalid.  The relevant prior art date therefore shifted to the filing date of the PCT application which permitted consideration of the intervening scientific publication as prior art.  In light of the content of this publication, the Opposition Division revoked EP ´468 for lack of novelty.

    Board of Appeals

    Broad Institute´s Appeal was based on 3 grounds:

          1. The EPO should not determine the right to claim priority; this should be determined only by national courts which in this case would be in the United States.
          1. The EPO´s interpretation of “any person” from EPC Article 87(1) requiring “all applicants” is improper (despite the EPO´s longstanding interpretation requiring “all applicants”).
          1. Related to points 1 and 2, even if the EPO is competent to consider the right to claim priority, they should use United States law when doing so.

    At a certain point during the four days of oral hearings it appeared that the Board of Appeal was prepared to refer at least the second ground to the Enlarged Board of Appeal.  Some blogs actually reported that they had done so.  In reality, the Board of Appeal ultimately affirmed the Opposition Division´s decision, rejecting all three grounds of appeal and declining to refer any issue to the Enlarged Board of Appeal, essentially rendering the decision final (barring an exceptional grant of a Petition for Review).  The decision should not come as a big surprise since it is consistent with the long-established EPO interpretation of Article 87.

    On 6 November 2020 the Board of Appeal issued its written decision which can be found here

    Practice Tips in Light of the EPO´s Board of Appeal Decision

          1. Make sure all applicants from the priority application are accounted for in the subsequent application.
          1. This can be accomplished, of course, by naming all applicants listed in the first application in the second application or by assigning rights from applicants listed in the first application to applicants listed in the second.
          1. At the very beginning try to name the smallest number of applicants as possible in the first application so that matching applicants in the second application is easier. Consider whether you are in the position to name only the US university in the first application which makes the priority claim in the second application much easier.
          1. Be particularly careful with assignments that are executed shortly before filing an application which claims priority to an earlier application.

    While the above is only a summary of the priority claim issue, it is important to be aware of the different standards used by the USPTO and EPO and the potential pitfalls this creates for applicants who file first in the United States and later seek patent protection in Europe.  

    For more information on priority claims in Europe or any other aspect of European patent law, please contact Berggren´s International Team at  We would be pleased to assist you.

    Please note that this overview is not meant as legal advice and that each specific matter should be evaluated in detail and on its own merits.

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