A Confirmation of the Importance of Properly Assigning the Right to Claim Priority for Validly Transferring an Entitlement to Claim Priority Before the EPO
The reasons underlying the long-awaited decision T844/17 revoking European patent EP 2 771 468 (the “CRISPR-Cas9 patent”) have been rendered by the European Patent Office Board of Appeals. Although the decision may appear shocking because the patent at issue is considered to be a pioneer patent of one of the most important biotech inventions of our time, the decision is nevertheless in line with European Patent Office practice as established at least since decisions T 328/07 and T 788/05 relating to the transfer of the right of priority.
The reasons underlying the long-awaited decision T844/17 revoking European patent EP 2 771 468 (the “CRISPR-Cas9 patent”) have been rendered in writing by the European Patent Office (EPO) Board of Appeals in early November. Although the decision may appear shocking because the patent at issue counts as a pioneer patent of one of the most important biotech inventions of our time, the decision is nevertheless in line with the EPO practice as established at least since decisions T 328/07 and T 788/05 relating to the transfer of the right of priority were issued.
The CRISPR-Cas9 patent relates to the CRISPR/Cas9 genome editing technique, standing for Clustered Regularly Interspaced Short Palindromic Repeats, a.k.a. “molecular scissors,” which contributed to the Nobel Prize in Chemistry in 2020. Despite the importance of this invention, since the validity of the priority thereof was relevant to the determination of patentability of the claimed invention, the applicants had to prove their entitlement to the right of priority. They were unable to persuade the Board of Appeal of such entitlement based on the submitted evidence.
The CRISPR/Cas9 patent derived from a PCT application claiming the priority of twelve provisional US applications P1-P12. Under US law, since the central provisions of the Leahy-Smith America Invents Act (AIA) took effect, for PCT applications filed on or after 16 September 2012, inventors no longer have to be indicated as applicants for the purposes of the US designation. Instead, the assignee or other person to whom the inventor is under an obligation to assign the invention, or who otherwise shows sufficient proprietary interest in the matter, may be indicated as the applicant for the US designation.
This was not yet settled, however, at the time of filing the CRISPR/Cas9 patent, for which the inventors had to also be applicants of the US priority applications. Additionally, since the multiple inventions described in the twelve US priority applications were split into later multiple PCT applications, only the inventors responsible for the respective inventions in each PCT application were named as PCT inventors and, under the US practice, also as applicants. Some applicants were therefore left out of some of the PCT applications, including the one from which the CRISPR/Cas9 patent derived, compared to the priority US provisional applications, without there being any transfer of priority rights from the omitted applicants.
The PCT application subsequently entered the European regional phase. However, under EPO case law, if only some of the applicants of a priority application are also applicants of a later (in the present case, PCT) application, a transfer of the priority right to the remaining applicants has to be made. Under EPO practice, the right or entitlement to claim priority is considered as a separate right, that may be transferred independently of the patent or application. In particular, the successor in title of the subsequent application must prove that the transfer occurred before the filing date of the subsequent application claiming priority to the first application (see EPO Guidelines A-III, 6.1). No retroactive transfer is recognized, even when a national law would allow it, as confirmed by decisions T 1201/14 or T 577/11.
Hence, in the case at issue, since the priority right transfer was concluded after the PCT application was filed for four priority applications P1, P2, P5 and P12, the priority right was lost under Article 87 EPC, because of lack of identity of the filing “person” (in this case, the community of joint applicants). This led to documents D3 and D4, i.e., references published in Science and Nature - after the priority date but before the filing date of the relevant PCT application - becoming prior art relevant under Article 54(2) EPC and the ultimate downfall of the CRISPR/Cas9 patent in Europe.
Beyond the core legal question, which was “If A and B filed a first application and if A alone files the subsequent application, can priority be valid in the absence of assignment of the priority right from B to A?”, to which the answer was "No" as in previous decisions rendered by different EPO Boards of Appeal, the Board also clarified the following aspects:
- rather than the national courts, the EPO is competent to assess and decide who is entitled to priority, since examining the validity of the priority right amounts to a formal examination rather than a decision on a property right;
- under Art. 87(1) EPC, which is based on Article 4A of the Paris Convention for the Protection of Industrial Property, the expression “any person” in “any person who has duly filed… ” is the translation from the French word “celui,” and therefore should not be interpreted as “whoever” but instead as “all applicants.” Originally, among other goals, the Paris Convention was intended to create a system preventing each of the applicants to independently dispose of their entitlement to claim priority;
- the Paris Convention is the law which determines who “any person” is, not the “national law” (in this case, US law). In fact, within the context of the European Patent Convention (EPC), applicants and patentees from non-member states are treated in the same way as applicants and patentees from member states. The appellants are mistaken, said the Board, when they argue that this principle requires the EPO to treat applicants and patentees from non-member states in the same way as they would have been treated in their home country.
No questions were referred to the Enlarged Board of Appeal, since the Board adopted without exception a consistent interpretation of Art. 87(1) EPC. While decision T844/17 is perhaps unsurprising, given the EPO's longstanding practice, the decision provides a confirmation on the EPO’s strict approach when assessing a valid transfer of priority. This decision also proves that the transfer of the priority right should not be overlooked, all the more that this aspect is handled quite differently in other jurisdictions.
We thus refer you further to the end of our previous article on decision T 577/11, which lists some precautions that should be taken when filing a European application (be it a direct European application or a PCT application susceptible of entering the European regional phase) in the name of one or more applicants which are not identical to the applicant(s) of a previous application from which the European application claims priority.
