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CRISPR – Patent revoked due to unsuccessful transfer of priority rights to Europe
Chris Baxter
Chris Baxter

In a high-stakes opposition in front of the EPO in 2018, granted European patent no. EP2771468 co-owned by the Broad Institute relating to CRISPR technology was revoked due to an unsuccessful transfer of priority rights to Europe. This could have been avoided if appropriate assignments of rights had been in place at the time of filing the PCT application.


CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) was initially known as a general purpose gene-editing tool. Using the enzyme Cas9, this method was transformed into a biomechanical method to selectively cut and modify DNA. As a breakthrough area in biotechnology, with wide-ranging applications that may revolutionise multiple industries, CRISPR promises a global business worth billions of dollars.

Granted European patent EP2771468 entitled “Engineering of systems, methods and optimized guide compositions for sequence manipulation” was a national phase application of PCT application (No. PCT/US2013/074819). The PCT application claimed priority from 12 previously filed US applications.

The PCT application listed The Broad Institute, Inc., MIT and Harvard as applicants. However, three of the applicants and inventors listed on four of the priority documents had assigned their rights to the Rockefeller University of New York and not to any of the three applicants listed on the PCT application, before the PCT application was filed.

The right to claim priority is established by the Paris Convention, which states that any person who has duly filed a patent application, or his successor in title, shall enjoy a right of priority. Hence, the grant of the European patent was opposed on the basis of lack of entitlement to priority under Article 87(1) of the EPC. There were nine opponents, with many of the opponents being straw men.

The patentee wished for the matter to be decided under interpretations of the Paris Convention held under US law as all of the priority documents were filed in the US. This approach may have been more favourable in terms of separately protecting the rights of each applicant listed on the PCT application.

However, the Opposition Division (OD) of the EPO held that the approach proposed by the patentee would cause uncertainty and that it is imperative that applicants and the public at large be provided with legal certainty. The OD stressed that they had been entrusted with the assessment of the validity of a claim to priority, in order to determine patentability requirements, i.e., novelty and inventive step.

The OD found that there was no reason to deviate from established EPO practice. It was decided that the applicants were not legally entitled to claim priority from four priority documents. As claim 1 was not disclosed in any of the remaining eight priority documents, it followed that the claims lacked novelty over prior art documents which had been published after two of the four priority documents. Thus, the patent was revoked.

Transfer of priority rights to Europe at PCT filing

As per recent European decisions, in situations where the applicant(s) of the priority applications are different from the applicant(s) of the subsequent application such as a PCT application, a valid transfer of priority and/or the right to claim priority must be have already taken place at the time of filing the later application, e.g., the PCT application. The rule of thumb is that you cannot use rights that you don’t have.

It is important that the applicants in the later application must together have all of the priority rights in the priority applications.

In many cases, the applicant(s) has/have not decided which countries to designate for entering national phase at the time of filing PCT applications, and so appropriate measures must be in place before the PCT application is filed to ensure that priority rights will be validly transferred to a European national phase application if Europe is designated.

Often the inventors listed on a priority application are also the applicants of the priority application, yet the PCT application is filed in the name of a business or organization. If the correct assignments of rights are not in place before PCT filing, the applicants of the earlier priority application can be listed on the PCT application at filing in addition to any new applicants and valid assignments of rights can be effected to the new applicants later. However, it is understood that this may not be possible in some cases, and it is advisable to consult a patent attorney who will be able to provide options based on the specific situation.

Transfer of priority rights to Australia at PCT filing

Section 15(b) of the Australian Patents Act states that a patent for an invention may be granted to a person who “would, on the grant of a patent for the invention, be entitled to have the patent assigned to the person”. This suggests that relevant assignments of rights to the applicants of an Australian national phase application should be in place before the patent is granted. However, recommended best practice is to ensure that appropriate assignments of rights to the applicants of the PCT are in place before filing of the PCT application.

It is also good practice to ensure that assignments are carried out at an early stage (and preferably soon after filing of the priority applications) to ensure that the original rights holders are still present in the company, in order to avoid having to track down employees or directors or founders that may have moved on.

If you have any questions about any of the above, feel free to get in touch with our patent attorneys.

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About the author
Chris Baxter
Managing Director, Patent & Trade Mark Attorney
Chris Baxter is a Sydney patent and trade mark attorney specialising in software patents, computer patents, medical device patents and engineering patents.

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