Recently, the European Patent Office (EPO) revoked one of the Broad Institute´s foundational patents on the CRISP technology.

The CRISP technology is considered a groundbreaking technique in the field of genome engineering. CRISPR-Cas9 has attracted immense attention from the scientific community and is believed to be of great commercial value.

The mention of grant of the European patent in question, EP 2 771 468 B1, was 11 February 2015. The patent was granted to three co-proprietors, namely The Broad Institute, Massachusetts Institute of Technology, and President and Fellows of the Harvard College.

The patent was opposed, and in the present decision issued by the Opposition Division of the EPO at the oral proceedings held January 17, 2018, it upheld its view in the preliminary opinion that the opposed patent did not meet the requirements of the European Patent Convention (EPC).

The European patent derives from the PCT application WO 2014/093712 claiming priority from 12 US provisional patent applications. However, two of the earliest priority founding US provisional patent applications listed an applicant who was not an applicant on the subsequent PCT application and who had not assigned his right to priority to any of the listed applicants on the PCT application. The EPO therefore found that the priority claim was invalid thereby changing the effective filing date of the PCT application to a later effective date. As a consequence, disclosures prior to the later effective filing date of the PCT application were citeable against the granted claims.

The present EPO decision can be understood in the light of European patent law according to which a subsequent patent application may validly claim priority from an earlier application provided that the applicant for the subsequent application is the same as for the earlier application, or that the subsequent application is filed by the successor in title to the applicant of the first application.

This means that when the earlier application has several applicants, i.e. joint applicants, the right to claim priority from the earlier application belongs jointly to the applicants. The joint applicants are considered a single legal entity. Further, if the subsequent application is filed by the successor in title to the earlier applicant(s) the assignment to the successor in title must have taken place before the filing of the subsequent application.

Therefore, in a situation when applicants A, B and C file the earlier application the subsequent application can validly claim priority when it is filed by the applicants A, B and C . Alternatively, the subsequent application can validly claim priority when it is filed by the successor in title to A, B and C provided that the assignment to the successor in title has taken place prior to the filing of the subsequent application.

In the present case, the first two priority founding US provisional patent applications listed the following inventors/applicants: Mr. Zhang; Mr. Cong; Mr. Hsu; Mr. Ran; Mr. Habib; Mr. Cox; Mr. Lin and Mr. Maraffini. Prior to the filing date of the PCT application transfer of priority rights from Mr. Habib, Mr. Lin and Mr. Cox to the Broad Institute and the Massachusetts Institute of Technology took place. The PCT application was filed by the applicants The Broad Institute, Massachusetts Institute of Technology, Mr. Zhang, Mr. Cong, Mr. Hsu and Mr. Ran. After the filing of the PCT application, a change in the indication of the applicants Mr. Zhang, Mr. Cong, Mr. Hsu and Mr. Ran in favour of the Presidents and Fellows of Harvard College was recorded. However, there was no evidence for the transfer of the priority rights of Mr. Maraffini to one of the applicants of the PCT application before its date of filing. Consequently, the Opposition Division found that the first two priority founding US provisional applications and the PCT application did not list the same applicants and the priority claim was therefore held invalid.

It is noted that the patent proprietor argued that the right to claim priority under Article 87 EPC should be interpreted according to national law, and when a US provisional patent application discloses multiple inventions priority can be claimed from such application only from those applicants/inventors who have contributed to one invention which has been claimed also in the subsequent application. However, in its preliminary opinion the EPO stated that “…in both the EPC and Paris Convention systems the decisive factor to a valid claim of priority is the status of the applicant, rather than the substantial entitlement (materielle Berechtigung) to the subject-matter of the first application.”

The Broad Institute has already filed an appeal against the decision by the European Patent Office.