No more poisonous priority / poisonous divisionals at the EPO

The Enlarged Board of Appeal of the EPO has taken a long awaited decision regarding poisonous divisionals – ending self-collision of patents/patent applications once and for all. The decision G1/15 can be found here. …

Common sense has prevailed! Very much to the relief of patentees and practitioners.

A more liberal approach to partial priority

In addressing the questions referred for consideration, the Enlarged Board has held:

“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), entitlement to partial priority may not be refused under the EPC for that claim in respect of alternative subject-matter disclosed (in an enabling manner) for the first time, directly, at least implicitly, and unambiguously, in the priority document.”

A test for partial priority is presented that in practice should mean the end for poisonous priority and poisonous divisionals in Europe.

A Two-step test for partial priority

The Paragraph 6.4 of the decision sets out the two-step test to be applied in assessing whether subject matter within a generic “OR” claim is entitled to partial priority:

Step 1

Determine the subject matter in the priority document that is relevant to the intervening disclosure. This is to be performed in accordance with the disclosure test (i.e. the existing “gold standard” – what is directly and unambiguously derivable from the priority document as a whole) and in view of explanations from the applicant/patentee as to what the skilled person would have derived from the priority document.

Step 2

Determine whether this subject matter is encompassed by the claim of the application or patent claiming the priority. If it is, the claim is conceptually divided into two parts, each entitled to different priority dates.