EPO is competent to assess entitlement to priority and will (rebuttably) presume it is in order if the priority claim complies with A.88(1) EPC

Background and the appeal

In T1513/17, a European patent originating from a PCT application was opposed and challenged on the fact that the P/A was different than the applicants on the US provisional priority patent application, which was filed in the name of three inventors. The PCT application named the three inventors as applicants for the US territory only, but for all the other designated states they were not listed among the applicants including the P/A, Alexion Pharmaceuticals. The priority right from only one of the three inventors was assigned to the P/A before filing of the PCT application. As a consequence, the priority claim to the US provisional was found invalid and the patent was refused in view of interfering disclosures published after the filing date of the priority application but prior to the filing date of the patent. In T2719/19, a European patent application that was a 2nd generation divisional application of the patent under appeal in T1513/17, was refused for the same reasons as above.

In both cases, the validity of the priority claim was contested, inter alia, because the P/A was alleged not to be the successor in title having the right of priority within the meaning of Art. 87(1) EPC.

The P/A appealed in both cases and argued that the priority right derived from the priority application was valid. The technical boards in T1513/17 and T2719/19 found that to resolve the situation, it was decisive whether A/P was entitled to priority in line with the EPO-accepted so called “joint applicants approach”, i.e. a situation in which a co-applicant on a subsequent application, who was not an applicant on a priority application, benefits from the priority right to which its co-applicant on the subsequent application is entitled for the reason of being an applicant on the priority application. The technical boards deemed themselves not sufficiently competent to answer if the joint applicants approach applied in the given situation under PCT (i.e. a situation where a PCT application has different applicants for different designated States) and decided to refer the following questions to the Enlarged Board:

1. Does the EPC confer jurisdiction on the EPO to determine whether a party validly claims to be a successor in title as referred to in Art. 87(1)(b) EPC?
2. If question I is answered to the affirmative

Can a party B validly rely on the priority right claimed in a PCT-application for the purpose of claiming priority rights under Art. 87(1) EPC in the case where

1. a PCT-application designates party A as applicant for the US only and party B as applicant for other designated States, including regional European patent protection and
2. the PCT-application claims priority from an earlier patent application that designates party A as the applicant and
3. the priority claimed in the PCT-application is in compliance with Art. 4 of the Paris Convention?

Decision of the Board (of Appeal)

The Board first analysed the internal EPC provisions on priority and concluded that the provisions of Art. 87(1) EPC were identical to the ones of Art. 4A(1) of the Paris Convention (p. 30 of G1/22). Then, the Board considered the Case Law related to Art. 87 EPC in relation to other boards’ decisions on EPO’s jurisdiction over the “right of priority” and its assignment. The Board in particular looked at the application of national law to assess succession in title under Art. 87(1) and noted that EPC contained no conflict for the determination of the applicable national laws except for Art. 60(1) EPC (employee inventions; p. 62). The Board then stressed that in the context of the proceedings before the EPO, a strict distinction should be made between the right to a European patent application (i.e. the legal title to the application and to the ensuing patent), which is subject to national property laws, and the right to benefit from the priority date for that application if the “right of priority” referred to in Article 87(1) EPC is claimed.

The Board agreed that, under Art. 60(3) EPC, the EPO was not competent to assess the applicant’s entitlement to the patent application, but they stressed that this provision, however, did not apply to the right of priority referred to in Article 87(1) EPC, neither directly nor by analogy, because the priority right and its transfer are a matter governed by the autonomous law of the EPC (p. 88-90).

Thus, the Board answered the question (I) by concluding that the EPO was competent to assess an applicant’s entitlement to priority.

When concluding so, the Board therefore endorsed the opinion of the Technical Board T844/18 (concerning a patent owned by the Broad Institute on CRISPR technology), which stated that the explicit listing of the 4 requirements in the Art. 87(1) EPC obliges the EPO to make “no distinction … between the “where”, “what” and “when” requirements … and the “who” requirement”, when assessing the right of priority under this article (p. 91).

Importantly, the Board also stated that the applicant’s entitlement to priority should be presumed to exist if the formal requirements for claiming priority as set out in Art. 88(1) EPC (and the Implementing Regulations) are fulfilled. The Board considered that the presumption was justified because the fulfilment of these requirements should be seen as strong factual evidence (p. 104) of the approval by the priority applicant to the entitlement to priority by the subsequent applicant, for the following reasons: (i) all parties involved normally have an interest that an application may benefit from a priority right, (ii) there are no formal requirements for the transfer of priority rights, and (iii) the applicant of the priority application has to provide support to the applicant claiming priority (e.g. by providing unpublished documents and information that is only available to them at the time when the subsequent application is filed) (p. 112).

Interestingly, the Board also opined that for a valid transfer of priority rights, EPC should not establish higher formal requirements than those established under national laws for the transfer of the right to the patent application. The Board also stated that “the EPO should adapt itself to the lowest standards established under national laws and accept informal or tacit transfers of priority rights under almost any circumstances” (p. 99), and that the EPC should not in particular “require that the assignment of the priority right should be made in writing and/or signed by or on behalf of the parties to the transaction (…) since this would establish a high threshold in view of the national laws” (p. 100). Consequently, it appears that the Board endorsed the position taken in T205/14, (p. 3.6) which was against the application of Art. 72 EPC requirements to the assignment of the right to priority. According to the Board, “Even the requirement that transfer of the right of priority needs to be concluded before the filing of the subsequent European patent application … is questionable” (p. 100).

Further, the Board noted that the presumption of the applicant’s entitlement to priority should be rebuttable since in rare exceptional cases (e.g. instances of bad faith) the priority applicant may have legitimate reasons not to allow the subsequent applicant to rely on the priority (p. 108).

However, the Board also noted that the fact of the existence of this presumption also involves the reversal of the burden of proof; i.e. the party challenging the subsequent applicant’s entitlement to priority is the partly that should prove that this entitlement is missing (p. 110). The Board further clarified that the party challenging the entitlement cannot just raise speculative doubts but must demonstrate specific facts to support serious doubts about the subsequent applicant’s entitlement to priority. The Board also clarified that the rebuttal of the presumption is subject to the autonomous law of the EPC only, just like the existence of the presumption of the applicant’s entitlement to priority. Consequently, the Board stated that there was “no room for the application of national laws on the legal presumptions and their rebuttals” (p. 110), while at the same time, it took the position that “It cannot be excluded, however, that in the context of the rebuttal … national laws (may) need to be considered as well” (p. 133).

Finally, the Board also clarified that “If the requirements under Art. 88(1) EPC are not fulfilled, the subsequent applicant is barred from claiming priority for this reason alone” and that “The fulfilment of these procedural requirements is not covered by the rebuttable presumption” (p. 132).

Importantly, the Board concluded that the presumption applies to cases where the priority applicant is not identical to the subsequent applicant, and regardless of whether the subsequent application is a PCT application.

Consequently, the Board concluded that the rebuttable presumption also applied in the situation described in the referred question II. For this situation, the Board endorsed the interpretation of the joint filing of a PCT application as sufficient proof for an implied agreement on the joint use of the priority right, in particular as no substantial indications to the contrary could be demonstrated in the underlying cases.

The above appears to confirm that in cases where the subsequent application does not name all co-applicants of the earlier application (or their successors in title), there may exist uncertainties about the entitlement to claim priority under Art. 87(1) EPC, which may open such cases to the EPO’s jurisdiction over the assessment of this entitlement (as in the situation underlying e.g. T844/18). As the Board explained (p. 128), this is because the “Co-applicants for the priority application who were not involved in the subsequent application may not be deemed to have consented to the reliance on the priority right by the other co-applicants for the priority application.” At the same time, the Board remarked that “The subsequent applicant(s) may however still be entitled to claim priority since the rebuttable presumption of entitlement does not depend on whether the involved applicants acted as co-applicants at any stage”.

In sum (p. 136), when answering the question II, the Board concluded that “leaves open the validity of the “PCT joint applicants approach” but endorses the concept of an implied agreement”, and that “in the absence of substantial factual indications to the contrary, the joint filing of the subsequent PCT application sufficiently proves that the parties entered into an implied or informal agreement allowing party B to rely on the priority right established by the filing of the priority application by party A”

When referring back to the classical “all applicants” situation (p. 137), the Board also explained that such “agreement cannot be implied if not all of a plurality of priority applicants are applicants or co-applicants for the subsequent application (…). However, the rebuttable presumption of priority entitlement can be applied also in situations where one of the priority applicants is not involved in the filing of the subsequent application. In specific contexts, a priority applicant missing from the subsequent application may have reasons to claim the title to the subsequent application (in proceedings before national courts) or may possess evidence to rebut the presumption of priority entitlement in proceedings before the EPO.”

The Order

In view of the above, the Board answered the referred questions as follows:

1. The European Patent Office is competent to assess whether a party is entitled to claim priority under Article 87(1) EPC. There is a rebuttable presumption under the autonomous law of the EPC that the applicant claiming priority in accordance with Article 88(1) EPC and the corresponding Implementing Regulations is entitled to claim priority.
2. The rebuttable presumption also applies in situations where the European patent application derives from a PCT application and/or where the priority applicant(s) are not identical with the subsequent applicant(s).

 In a situation where a PCT application is jointly filed by parties A and B, (i) designating party A for one or more designated States and party B for one or more other designated States, and (ii) claiming priority from an earlier patent application designating party A as the applicant, the joint filing implies an agreement between parties A and B allowing party B to rely on the priority, unless there are substantial factual indications to the contrary.