CRISPR-based techniques have revolutionized the field of gene editing in recent years. The Broad Institute is at the forefront of this technology and holds many of the original patents. However, the validity of some of those patents has been challenged at the European Patent Office (EPO) and developments this week are a blow to the Broad Institute’s patent coverage in Europe.

The Broad Institute’s CRISPR-Cas9 European patent (EP2771468) was granted in 2015, but it was then opposed and subsequently revoked by the EPO’s Opposition Division on the basis that the patent lacks novelty over prior art that was published during the priority year. Although the patent claimed priority from a number of US provisional applications, there was a discrepancy between an inventor/applicant named on one of the US provisional applications and the final PCT application. Consequently, the Opposition Division concluded that the priority claim is invalid (and hence the invalidating prior art became citable). The Broad Institute subsequently filed an Appeal against the Opposition Division’s decision; this Appeal was heard over the last 4 days.

Whilst the decision of the Opposition Division is consistent with the large body of EPO case law on priority, by the middle of this week it seemed that the case was set to drag on as the Appeal Board indicated its intention to refer some questions on priority to the Enlarged Board of Appeal. The Appeal Board suggested that the issues at the heart of this case, namely the right to claim priority from an earlier application under Article 87 EPC, are of such fundamental importance that consideration by the Enlarged Board of Appeal was justified.

However, following further arguments from both sides, the Appeal Board concluded that it was able to decide on the issues without input from the Enlarged Board. Unfortunately for the Broad Institute, the Appeal Board upheld the decision of the Opposition Division and dismissed the appeal. Thus, the patent is revoked.

The Broad Institute has acknowledged that the same priority issue also affects some of its other European patents. Thus, it would seem that the validity of those patents may also be at risk of revocation unless the EPO changes its position on the interpretation of Article 87 EPC.

Given that the Appeal Board decided not to refer questions on this issue to the Enlarged Board of Appeal, the Enlarged Board will not have the opportunity to consider whether the current interpretation of Article 87 EPC is correct unless it is requested to do so by the President of the EPO. However, the President’s power to refer a point of law to the Enlarged Board of Appeal is limited to situations where two Boards of Appeal have given different decisions on that question. As the EPO case law on priority is largely consistent, such a referral may arguably be beyond the scope of the President’s authority.

There will be a number of entities currently paying license fees to the Broad Institute to work this technology in Europe who will be wondering whether those payments need to continue in view of this week’s decision. However, as noted above, the Broad Institute has many patents in this field, the majority of which are unlikely to be affected by the priority issue considered in the present case. Thus, it would be advisable for licensees to consider whether their activities are covered by other patents in the Broad Institute’s portfolio before stopping or renegotiating license fee payments. As the decision only affects the European patent(s), consideration will also need to be given to activities outside Europe, where equivalent patents may still be in force.

Whilst this chapter of the CRISPR patent story has reached a conclusion, it would seem that the saga is set to continue. I can’t wait to find out what happens next…


“Today, the EPO Board of Appeal dismissed the Broad Institute’s appeal of an earlier Opposition Division decision which denied the Broad’s reliance on its U.S. priority provisional application for one patent in Europe based on a technical formality.”