Poisonous priority – closer to an answer

20/11/2015

Earlier in the year, we reported a referral to the Enlarged Board of Appeal from the Technical Board of Appeal (T 557/13) on the issue of poisonous priority.

The questions to the Enlarged Board have now been finalised, and 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?

A decision from the Enlarged Board is not expected for at least a year, but we will keep you updated on progress. In the meantime, we would still advise caution, especially when filing a later application that claims priority to an earlier application and if the later application provides for claims of broader scope than in the earlier application.

If you wish to find out more about the above, and how it might affect your patent strategy, please contact us.

This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.