IP Information & News

CRISPR-Cas9 – from gene editing to EPO patent law editing?

A recent EPO decision on a gene editing patent opposition provides a useful reminder that getting the filing formalities correct is as important as getting the science correct.

The sequencing of the human genome has created opportunities to improve human health. For example, identification of certain mutations in genomic DNA may help in the diagnosis, prevention and/or treatment of gene-linked conditions such as cancer, cystic fibrosis or haemophilia. The advantages to human health of being able to edit genomic DNA to remove mutations that cause disease are clear.

One promising genome editing technology is based on CRISPR-Cas9. CRISPR-Cas9 is a system that normally protects bacteria from viral invasion, which can be exploited to target specific parts of the genome for cutting and optionally pasting DNA sequences of interest. In view of the promise of this life sciences technology, the related commercial and patent landscapes are being vigorously contested.


On 17 January 2018, the opposition division of the EPO revoked EP2771468, a patent granted to the Broad Institute, Massachusetts Institute of Technology and Harvard University relating to CRISPR-Cas9 technology. The full details of the case will be available when the written decision is issued by the EPO.

The patent had been opposed by nine opponents, based on a number of grounds. However, as noted in a press release from the Broad Institute the decision did not focus on the “substantive merits” of the invention. Rather, the case turned on the validity of the priority claims of the patent application.

The application, which named three institutional applicants, claimed priority from twelve prior applications. Some of the priority applications named the inventors personally as applicants, whose rights to claim priority were not transferred to the applicants named on the opposed application before the filing date. The opposition division held that this lack of timely transfer rendered the priority claims from the earliest inventor-owned priority applications invalid, in a decision that is consistent with current European practice. As a result, disclosures made between the earliest lost priority date and the deemed-valid earliest priority date became relevant for the assessment of patentability of EP2771468, and the patent was revoked for lack of novelty.

The Patentees have filed a notice of appeal against the decision announced at the end of the oral proceedings. The grounds of appeal have not yet been filed as the full reasons for the decision have not yet issued. However, the likely focus of the appeal is apparent from the comments filed with the Patentees’ notice of appeal and the present opposition proceedings to date. The appeal will likely focus on a re-assessment of the law concerning the jurisdiction of the EPO to assess priority entitlement as well as the current interpretation of the relevant provisions of the EPC and the Paris Convention. Thus, the Patentees may challenge the way in which the EPO applies the international legal basis for priority claims. Accordingly, the Patentees may seek to “edit” current and much-tested legal practice at the EPO as deftly as they can edit the genome.

The general legal issues of this case are not unique. Formal priority issues are often the first focus of European patent attorneys seeking to attack patents in third party observations, oppositions or revocation proceedings. The present decision marks the first of many EPO patent opposition decisions that are pending on CRISPR-Cas9 technology. Indeed, there are pending opposition proceedings on a number of cases in the present patent family citing the same priority issues in respect of the same priority documents.

The outcome of the appeal will be critical to forming the commercial landscape of gene editing technology in Europe as well as to determining the outcome of other EPO cases, regardless of technical field, for which formal priority is an issue.

While we await the outcome, the present case provides a reminder to ensure priority claims are valid according to current practice. In particular, those applicants who wish to avoid issues at the EPO should ensure that the applicants on their European patent applications, or on their PCT applications from which European patent applications will be derived, own the right to claim priority from the claimed priority applications at the application filing date.

For more information on how to ensure that your priority claim is correct, or securing protection for your biotechnology inventions, get in touch with me at sjm@udl.co.uk.

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