EPO Prosecution History in UPC Claim Interpretation: Recent Developments in UPC Practice

1. Introduction

A recent decision from the Milan Local Division in Agathon v Intercom (UPC CFI no. 727/2024, decision of 5 May 2026) provides further insight into an issue that has attracted increasing attention in UPC practice: to what extent may statements made during EPO examination proceedings influence claim interpretation before the UPC?

The case concerned a European patent relating to a centring device for forming tools. While the decision addressed issues including claim construction, novelty, inventive step, and infringement, one aspect of the reasoning appears particularly noteworthy. The Court expressly referred to statements made by the patentee during EPO prosecution proceedings when construing the patent claims.

Although the Court avoided treating prosecution history as formally binding, the decision nevertheless suggests that UPC courts are becoming increasingly willing to consider EPO file history as part of the broader interpretative context.

2. The Court’s Reasoning in Agathon v Intercom

The central dispute concerned the interpretation of claim features relating to the positioning of rolling body rows in the “opened state” of the patented centring device. In particular, the parties disagreed over the meaning of the term “abuts” in feature 1.9 of claim 1.

During prosecution before the EPO, the applicant had argued that it was “essential” or “decisive” for simultaneous preloading that the second rolling body row “abuts” the edge of the cylindrical surface. Before the UPC, however, the patentee advanced a broader interpretation, arguing that the “opened state” should also encompass transitional configurations in which the rolling body row did not yet directly contact the edge.

The Milan Local Division rejected that broader construction. Importantly, the Court expressly referred to the applicant’s earlier submissions during examination and stated:

“Although statements made by the patent proprietor during examination proceedings before the EPO are not binding, they may nevertheless provide further guidance on interpretation as they reflect the possible opinion of the person skilled in the art.”

The Court further observed:

“The applicant’s assertions during the grant proceedings can be seen as an indication of the view of the person skilled in the art at the filing date.”

The prosecution statements were therefore treated as supporting the narrower interpretation ultimately adopted by the Court.

3. The Decision Within the Broader UPC Context

The reasoning in Agathon v Intercom does not appear entirely isolated. The Milan Local Division expressly referred to earlier UPC Court of Appeal decisions, including UPC CoA no. 402/2024 and 405/2024 and UPC CoA no. 534/2024 and 19/2025, as well as UPC CFI no. 630/2025.

At the same time, the Court was careful not to go too far. The decision does not suggest that EPO prosecution history automatically limits claim scope, nor does it establish a doctrine comparable to prosecution history estoppel. Rather, prosecution history was treated as potentially relevant contextual material capable of assisting claim interpretation where appropriate.

The more notable aspect of the decision may therefore be the UPC’s increasing willingness to examine whether positions taken during litigation remain consistent with statements previously made during EPO prosecution.

From a practical perspective, the decision reinforces the importance of EPO examination submissions. Statements describing particular technical features as “essential”, “decisive”, or necessary to distinguish prior art may later reappear in UPC litigation where claim scope becomes disputed.

4. Concluding Remarks

Whether the UPC will eventually develop a more structured approach toward prosecution history remains to be seen. For the moment, Agathon v Intercom appears best understood as another indication that EPO prosecution materials may, at least in some situations, play an increasingly visible role in UPC claim interpretation.

For patent applicants and litigants alike, the decision serves as a useful reminder that arguments advanced during EPO examination proceedings may continue to have relevance long after grant, particularly in technically and linguistically sensitive claim construction disputes before the UPC.