Toxic priorities at the Enlarged Board of Appeal

The patent at issue in this case has previously been revoked by the Opposition Division. In particular, the Opposition Division found that the patent – which is a divisional – lacks novelty under Article 54(3) EPC in view of its published parent application.

As explained in our earlier article, this situation arises due to the possibility of the subject matter claimed in the divisional having a different effective date to conflicting subject matter in the parent publication.

The Technical Board of Appeal is of the opinion that guidance on the correct application of partial priority is a point of law of fundamental importance and has therefore referred a number of questions (questions 1 to 4) to the Enlarged Board of Appeal on this matter.

Furthermore, the Technical Board of Appeal consider that the secondary issue of whether a parent and divisional application are citable against one another under Article 54(3) EPC is also a point of fundamental importance; accordingly, a further question has also been referred to the Enlarged Board of Appeal on this matter (question 5).

The questions referred to the Enlarged Board are as follows:

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?

Look out for a more detailed analysis of this decision in our next patents newsletter.