The present decision results from the referral of decision T 557/13 where the patent was revoked in opposition proceedings. In this case, the patent was obtained from a divisional application claiming a genus of the disclosure of the priority application. The Opposition Division applied a narrow interpretation of decision G 2/98 (please see below) and held that the priority claim of the patent was invalid, while the priority claim of the parent application was valid. As a consequence, the parent application constituted prior art under Article 54(3) EPC against the divisional patent. Therefore, the divisional patent lacked novelty in view of its parent application.

In Europe, the Enlarged Board of Appeal decision G 2/98 states that “the use of a generic term or formula in a claim for which multiple priorities are claimed in accordance with Article 88(2), second sentence, EPC is perfectly acceptable under Article 87(1) and 88(3) EPC, provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters.” (Emphasis added.) However, as pointed out in the present referral the interpretation of G 2/98 has diverged. In some cases (e.g. T 665/00, T 1877/08 and T 1496/11) the interpretation has been narrow, holding that the “clearly defined subject-matter” must be separately identified in the claim. In other cases (e.g. T 1222/11 and T 571/10) the interpretation has been broad, holding that the “clearly defined subject-matter” does not need to be specified within the claim as long as it can be identified implicitly.

Thus, the present referral concerned the situation of partial priority in which only part of the subject-matter of a generic ”OR” claim is entitled to the priority date of an earlier patent application.

The following questions were referred to the EBA:

  1. Where a claim of a European patent application or patent encompasses alternative subject-matters by virtue of one or more generic expressions or otherwise (generic "OR"-claim), may entitlement to partial priority be refused under the EPC for that claim in respect of alternative subject-matter disclosed (in an enabling manner) for the first time, directly, or at least implicitly, and unambiguously, in the priority document?
  2. If the answer is yes, subject to certain conditions, is the proviso "provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" in point 6.7 of G 2/98 to be taken as the legal test for assessing entitlement to partial priority for a generic "OR"-claim?
  3. If the answer to question 2 is yes, how are the criteria "limited number" and "clearly defined alternative subject- matters" to be interpreted and applied?
  4. If the answer to question 2 is no, how is entitlement to partial priority to be assessed for a generic "OR"-claim?
  5. If an affirmative answer is given to question 1, may subject-matter disclosed in a parent or divisional application of a European patent application be cited as state of the art under Article 54(3) EPC against subject-matter disclosed in the priority document and encompassed as an alternative in a generic "OR"-claim of the said European patent application or of the patent granted thereon?

The EBA answered question 1 in the negative, and consequently did not deal with questions 2-5. In the reasoning leading to the decision the EBA states that the purpose of the right of priority as established in the European Patent Convention (EPC) is to avoid collision of subject-matter disclosed during the priority period with identical subject-matter in a priority document, the concept of partial priority is present in the European patent system (Articles 88(2) and 88(3) EPC), and that the travaux préparatoires to the EPC 1973 confirm this interpretation.

Importantly, it is stated in the decision that the EPC does not contain other requirements for recognising the right of priority beyond that of the same invention. Thus, from this it can be concluded that the proviso of G 2/98 regarding a limited number of clearly defined alternative subject-matters need not be complied with.

Further, in item 6.4 of the decision, the EBA provides that assessing whether a subject-matter within a generic ”OR” claim should include the following steps.

  1. The first step is to determine the subject-matter disclosed in the priority document that is relevant. This should be done using the disclosure test of G 2/98 and considering explanations provided by the applicant or patent proprietor.
  2. The next step is to examine whether this subject-matter is encompassed by the claim of the application or patent claiming said priority. If the answer is yes, the claim is de facto conceptually divided into two parts, the first corresponding to the invention disclosed directly and unambiguously in the priority document, the second being the remaining part of the subsequent generic "OR"-claim not enjoying this priority but itself giving rise to a right to priority, as laid down in Article 88(3) EPC.

The EBA concludes by stating that although the assessment may be a demanding intellectual exercise, several of the previous decisions have shown that it can be carried out and that there is no need for additional steps or tests.