EPO Board of Appeal confirms Broad Institute’s CRISPR patent lacks priority and upholds revocation decision

In one of the most high profile cases of recent years, a European Patent Office (EPO) Board of Appeal has upheld the revocation of a patent relating to CRISPR/Cas9 technology.  This case was significant because it concerned the rules around the right to claim priority in Europe and one party’s attempts to have the EPO alter its current practice of requiring every applicant named on the priority application, or their successor in title, to also be named on the priority-claiming application.  Had this argument been successful, this would have resulted in a dramatic upheaval of current practice that would have gone against a long line of established case law in Europe.

Although the ultimate decision of the Broad of Appeal to dismiss the appeal and maintain current practice was not unexpected, the decision serves as a timely reminder of the importance of applicants ensuring the right to claim priority is in order before filing the application.  This decision will also come as a disappointment to those who see the EPO’s requirements around priority entitlement as unduly formulistic and an administrative pitfall that is not in keeping with the original principles concerning priority laid down in the Paris Convention. 

We now eagerly await the Board of Appeal’s written decision that will provide its reasons for arriving at this decision.  In the meantime, we provide a brief overview of European practice concerning priority entitlement and the facts that led up to this case below.


Background – priority in Europe

Entitlement to claim priority before the EPO is governed by Article 87 EPC.  This states:

“Any person who has duly filed ... an application for a patent ... 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.” 

In essence, this provision permits “any person” who files a first patent application the right to file a priority-claiming application for the same invention within twelve months and gain the benefit on the earlier date.  A valid priority claim means that any public disclosures made after the priority date will not count as prior art against the patent.

EPO case law has developed to interpret the right to claim priority as belonging simultaneously and jointly to all applicants named on the priority application[1].  In practice, this means that the priority application can only serve as a basis for claiming priority for a subsequent application that designates all applicants (or their successors in title) of the earlier application. 

In other words, if parties A and B are named applicants on a priority application but only A is named on the subsequent application and B has not transferred its right to claim priority to A during the priority year, then the priority claim is invalid in Europe.  Other countries, such as the US, have less stringent priority requirements.


The case before the Board of Appeal

The European patent that this case is concerned with is EP2771468, which was granted in the names of The Broad Institute, Inc., Massachusetts Institute of Technology, and President and Fellows of Harvard College (“the proprietors”) [2].   The patent was subsequently opposed at the EPO by 9 parties.

The key issue at the heart of the opposition proceedings was that one of the applicants listed on some of the earliest priority applications was not also listed on the PCT application from which the European patent was derived.  In accordance with the European case law discussed above, the Opposition Division decided that the proprietors were not entitled to priority to the earliest priority applications.  This loss of priority was fatal to the patent, as it meant a document published after the priority date became novelty-destroying prior art.  The patent was therefore revoked by the Opposition Division.

The proprietors appealed the revocation and presented three main arguments in support of their case to the Board of Appeal.  The first argument was that the EPO should not examine priority entitlement at all and this should instead be left to the national courts.  The second was that “any person” in Article 87(1) EPC should be interpreted to mean “at least one”, rather than “all” as is current EPO practice.  Finally, it was argued that “any person” should be interpreted according to national law of the priority filing, which in this case is US law. 

In its preliminary opinion[3], the Board of Appeal considered in order to reach a decision it would be necessary to weigh up the pros and cons of changing the EPO’s current practice during the scheduled 5 day oral hearing.  Whilst it acknowledged that the practice was long-standing and supported by case law, it also postulated that a relaxing of formalities might be more in line with the original aim of claiming priority as set out in the Paris Convention.

After four days of oral arguments, the Board found that the patent lacked priority and dismissed the appeal, meaning the decision to revoke the patent becomes final.  At one stage during the hearing there was a flurry of excitement as was reported[4] that the Board was unexpectedly poised to refer questions on priority entitlement to the Enlarged Board, the EPO’s highest decision-making body.  Ultimately, however, the Board elected to decide on this point of law without a referral.  



The long established line of case law supporting the EPO’s practice on priority entitlement meant the Board of Appeal’s decision to dismiss the appeal was always the most likely outcome.  Nevertheless, it will be very interesting to read the written decision when it issues in the next few months to discover the reasons the Board provide to order to arrive at this decision.

The outcome of this decision means that there is no change the EPO’s practice in requiring all applicants named on the priority application, or their successor in title, to also be named in the later priority claiming application.  It also serves as an important reminder to applicants of the care that needs to be taken when filing applications that claim priority to earlier filings and the disastrous consequences that can occur if this is done incorrectly.


[1] See, e.g. T 788/05 available here https://www.epo.org/law-practice/case-law-appeals/recent/t050788eu1.html

[2] EP register for this case here: https://register.epo.org/application?number=EP13818570

[3] Available here: https://register.epo.org/application?documentId=E3Z2HAR19821DSU&number=EP13818570&lng=en&npl=false

[4] See, e.g., https://ipkitten.blogspot.com/2020/01/crispr-hearing-days-2-3-board-of-appeal.html