Guidance on the Transfer of Priority Rights Required – New Referrals to the Enlarged Board of Appeal

Vera Vallone

Two recent referrals were submitted to the Enlarged Board of Appeal of the European Patent Office (EBoA) earlier this year. Both concern the opposition of patents based on lack of legal entitlement to claim priority. The question is of fundamental importance since the application which names applicants that were not entitled to claim the priority at the date of the application will, under certain circumstances, be rejected for lack of novelty.

The EPO practice involving questions regarding the transfer of priority rights has already been established and is summarized below.

Article 87(1) EPC (also Article 4(A)(1) Paris Convention) provides for the possibility of the priority right to be owned by the successor in title. This is useful and common in situations where the applicant is the inventor and another applicant, e.g. a company (employer or investor/buyer), has filed the subsequent application. The Boards of Appeal of the European Patent Office (BoA) have already decided on a number of cases regarding the transfer of priority rights and as a result, the approach to priority entitlement is rather strict.

The following decision have shaped the legal background for such applications:

• –
  T 1201/14: In general, the transfer of the right of priority (as with all intellectual property rights) is a matter of national law and would have to be ruled on by the respective jurisdiction and under the applicable laws. An exception occurred when the BoA did not accept the transfer of priority rights after the subsequent application, although – under US law – the transfer was retroactive and thus, the assignment was back-dated to a date when the subsequent application was not filed yet. The right of priority, thus, must be completed when filing the subsequent application. It is essential that the applicant would be in possession of the priority right at the date of filing, which cannot be resolved by a transfer with retroactive effect.
• |–
  T 788/05: Where a priority application is filed by two or more applicants, they then build a unity, referred to as a «Legal Unity». Applicants in a legal unity are only able to claim priority together and thus, the same applicants must be listed on the subsequent application.
• –
  T 1933/12: In addition to the above-mentioned «legal unity», if there is an additional applicant listed on the subsequent application, this will generally not interfere with the validity of a priority claim, as long as the original applicants are listed as well.
• –
  T 844/18: Further, when priority claims are being transferred from a legal unity, all applicants of the original application need to transfer their right to claim priority to the applicants of the subsequent application. If this step is ignored, the priority claim will not be valid and – in case of an intervening prior art – will be held invalid based on lack of novelty.

The Joint Applicants Approach was developed in the above-mentioned decision T 1933/12. The BoA summarized the principle in its interlocutory decision T 1513/17 as follows: «The ‹joint applicants approach› concerns, in the most simple case, the situation where a party A is applicant for the priority application and parties A and B are applicants for the subsequent application in which the priority right is invoked. Party B can now benefit from the priority right to which their co-applicant party A is entitled. A separate transfer of the priority right to party B is not needed».

The principle has also found its way into the EPO’s Guidelines for Examination. However, it has so far not been questioned by an interested party. The two present referrals to the EBoA concern this fundamental principle of the Joint Applicants Approach.

The referrals originated from the interlocutory decisions of the BoA in T 1513/17 and T 1219/19. In both cases, a PCT request named two applicants for the European territory, whereas the inventors and applicants of the original US patent (priority patent) were named for the US territory only. Crucially, the right to claim priority was not assigned from all the applicants to all the additional applicants in the subsequent application. In the following, only one of the interlocutory decisions will be addressed in detail, as both conclude in the same fundamental legal question which was referred to the EBoA (see II. 2. below).

The appeal of the patent proprietor in this case derives from the interlocutory decision of the opposition division revoking European patent No. 1 755 674 («the Patent»). The application from which the Patent was granted had originally been filed as an international application under the Patent Cooperation Treaty (PCT) with No. PCT/US2005/017048 and published as WO 2005/110481 (the «PCT application»). It claims priority on the basis of the US provisional patent application No. 60/571,444, filed on 14 May 2004 (the «Priority Application»).

The Priority Application was filed in the name of the inventors (hereinafter inventors A, B and C). The PCT application, on the other hand, names A, B and C as applicants with designation for the United States of America (US) only. Two other applicants (hereinafter «the Company» and «the University») are named in the PCT application as applicants for all designated states except the US. The patent in suit names the Company as patent proprietor and A, B and C as inventors.

The Patent was opposed on the grounds referred to in Article 100(a) EPC (novelty and inventive step) and Article 100(b) and (c) EPC.

The validity of the priority claim was contested, inter alia, because the Company and the University were alleged not to be the applicants or the successors in title of the applicants of the Priority Application. As a consequence, the subject-matter of the claims of the Patent lacked novelty over the disclosure documents (referred to as «the Documents»), all published prior to the filing date of the subsequent patent application.

Figure 1 below provides an overview (without any claim to completeness) of the relevant facts.

As shown in the table above (Figure 1), not all inventors have transferred their priority right to the Company (the appellant) and the University. Thus, the Company and the University were not successors in title. In addition, the disclosure Documents were published prior to the subsequent application. In line with the EPO practice, these facts lead to the conclusion that the subsequent application would lack novely. Consequently, in first instance the claim was found to be invalid, as the right to claim priority has not been assigned from inventors B and C to either the Company or the University.

However, the BoA had some doubts with regards to the applicability of the Joint Applicants Approach, which was brought forward by the appellant. Thus, the BoA formulated two questions.

The following questions were referred to the EBoA:

• I.
  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 Article 87(1)(b) EPC?
• II.
  If question I is answered in 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 Article 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 Article 4 of the Paris Convention?

The first question concerns the general competence of the EPO to determine the validity of a priority claim. In T 844/18 the BoA already held that disregarding the requirement to examine the entitlement to claim priority lacked any legal basis in the EPC. However, as the question has been raised in the past, it will probably be raised again in the future and thus, «The board is also receptive to the argument of the parties that, if questions regarding priority are to be referred to the EBA on a related matter, this is a convenient opportunity to have a final decision on the ‹jurisdiction issue› as well. The board therefore decides to include a question addressing the jurisdiction of the EPO to decide on the entitlement to the priority right».

To answer the first question in the negative would undoubtedly lead to a striking change of the established practice of the EPO and have a significant impact on how the priority is assessed by the EPO in the future.

In the second question, the focus will likely be on whether the Joint Applicants Approach developed for European patents will be integrated in the PCT («PCT Joint Applicants Approach»).

In other words, the case thus concerns the fundamental question of whether the Joint Applicants Approach is applicable to PCT applications, if the named applicants for a PCT application are different for different designated states. Thus, the added applicants would be considered «Joint Applicants» and thus, no assignment of the right to claim priority will be necessary.

The counter-argument in T 1513/17 was based on the fact that as the inventors A, B and C were not named as applicants for the European patent designation, they could not be considered as joined applicants for the European patent designation. The appellant argued that the Joint Applicants Approach should also be applicable to PCT applications. The BoA referred to the approach suggested by the appellant as the «PCT Joint Applicants Approach», although stating that the application in the present case would not be «clear cut». The BoA has considered the interpretation of the EPC, the PCT, the Paris Convention as well as decisions from national courts. Further, the BoA held that although the Joint Applicants Approach would not be applicable in the case at hand, guidance was still needed from the EBoA.

The outcome of the decision will have an impact for any application that names different applicants for different designating states and will be awaited by many interested parties.