Members of our Life Sciences team have been at the European Patent Office (EPO) in Munich this week, attending the public hearing of the Appeal for patent EP2771468, owned by the Broad Institute, MIT and Harvard College. This was one of the earliest patents granted in Europe in the field of CRISPR gene-editing technology.

The patent was revoked in 2018 by the Opposition Division due to lack of novelty, after various opponents successfully argued that the patent was not entitled to its earliest claimed priority date. The patentee appealed that decision, resulting in this week’s hearing.

It is the long-standing practice of the EPO, based the relevant provisions of the Paris Convention and the European Patent Convention (EPC), to require that the applicants of a first application filed by a group of parties jointly hold a single right to claim priority from that application. Therefore, the applicant(s) of a subsequent application claiming priority must include all the applicants listed for the first application (or their successor(s) in title), not just some of them. Applicants can be added, but not removed without an assignment of their share in the priority right being completed in favour of one of the parties which does continue as an applicant. It must be remembered that any such assignment must be completed before the subsequent application is filed.

In this case, the first application was filed as a US provisional application in the names of the various inventors who had contributed to the work disclosed. When the PCT application which resulted in EP2771468 was filed, claiming the priority of that first application, the applicants were not the same as for the priority application (or their successors in title) – one inventor was not named and had also not assigned his share of the priority right to one of the applicants. Since that inventor (or his successor in title) was not named as an applicant on the PCT application, the priority was not validly claimed. This changed the effective filing date of the patent and, therefore, the relevant prior art, which resulted in the patent being revoked for lack of novelty.

The patentee appealed, arguing (as they had before the Opposition Division) that:

• The EPO does not have jurisdiction to consider the question of whether a priority claim was made by the correct party. It should only consider whether a priority claim has been made for the same invention as that disclosed in the first application. A claim to priority should not fail “just because” it has been not been made jointly by all of the parties which were the applicants on the first application, or their successors in title.
• If the EPO does assess priority, the meaning of the term “any person who has duly filed” a first application has been interpreted wrongly by the EPO, thus far. The term “any person” should mean “any one of the parties who has filed the first application” instead of (as has been practice since the creation of the EPO) “the group of parties who filed the first application”. 
• The EPO should use the national law of the country in which the priority application was filed (USA, in this case) to decide who is entitled to claim priority, not its own law.

The Appeal hearing started in the afternoon of Monday 13^thJanuary. On Wednesday morning, having heard all of the arguments for the second issue only, the Board of Appeal surprisingly gave a preliminary indication that they were minded to refer questions relating to the above three issues to the Enlarged Board of Appeal. This would have been necessary if they felt that there was an issue of fundamental legal importance which they were not in a position to decide on without guidance from the Enlarged Board. Importantly, this is usually only possible if there is case law from the Boards of Appeal of the EPO which has reached different conclusions, which was not the case here.

The Opponents fought back hard against this suggestion, encouraging the Board of Appeal that it not only had the ability, but also the duty, to make a decision without a referral. Indeed, the case law of the EPO (as well as of the national courts of the contracting states of the EPC) has been consistent in its interpretation of the Paris Convention to mean that the right to priority arises from the filing of the priority application and is a joint right in the event that there was more than one priority applicant. 

After hearing arguments on each of the three issues outlined above, the Board of Appeal announced on Thursday afternoon that it was, after all, in a position to reach a conclusion. The conclusion was that:

• The EPO does have jurisdiction to consider the question of whether a party has the legal right to claim priority;
• In the case where a first application was filed by a group of parties, the meaning of “any person who has duly filed” the first application is the group, sharing a single right between them. No subset of the group can claim the priority, without first having assigned to them the share of the right of any party which is not making the claim;
• The EPO does not need to refer to the law of the country in which the priority application was filed, but can determine who is entitled to claim priority with reference to the Paris Convention, the EPC and its own case law.

The Board of Appeal declined to refer any questions to the Enlarged Board of Appeal.

The decision comes as a considerable relief to most European practitioners, who were concerned that it might become almost impossible to assess accurately whether priority had been validly claimed in any given case. It would then have been very hard to identify the prior art for a patent or patent application. This would have made it almost impossible to assess accurately the validity of many patents, at least prior to national litigation (at which point the national law of each country would take effect).

Practitioners should continue to be mindful of the practice in other patent offices when filing a claim to priority. If an application is being filed via the PCT system, there is flexibility in allocating different applicants for different countries, if the approach to claiming priority differs. If you are preparing a PCT application for technology which is important to your client, please don’t hesitate to seek advice from any of us here at Greaves Brewster, to ensure that the priority claim is validly made for any European application which may subsequently arise.

The story will rumble on, however. Although EP2771468 has been revoked, the patentee may file a petition for a review of the Board of Appeal’s decision, which could re-open proceedings. There are a number of related patents and pending applications, some with similar failures in the chain of title for claiming priority. The patentee will, therefore, have further opportunities to present arguments as to why the EPO should change its approach, and may come up with new, creative reasons why it should do so. It seems likely to be a number of years yet before the patent landscape for CRISPR technology is settled.