Prosecution history in claim interpretation at the EPO

Agathon AG v Intercom SRL, Knarr Vertriebs GmbH

Milan Local Division Decision of 5 May 2026¹

A recurring question at the UPC is the degree, if any, to which prosecution history can be relevant to the interpretation of claim scope.  Prosecution history is not among the means of claim interpretation enumerated in the leading Court of Appeal decisions on the topic (10x Genomics v Nanostring,² Amgen v Sanofi,³ Meril v Edwards⁴) and first instance decisions have adopted various approaches in deciding whether the prosecution history should be consulted at all, and if so what weight should be attached to it. However, the Court of Appeal has indicated that applicant assertions during the grant proceedings can be seen as in indication of the view of the person skilled in the art at the filing date (Alexion v Amgen,⁵ confirmed in Philips v Belkin⁶)

This case related to alleged infringement of EP2363263, relating to a tool for injection moulding.  A key issue was the interpretation of feature 1.9 of claim 1 “the second rolling body row (16) abuts an encircling edge (18) concluding the circularly cylindrical surface (17) of the bolt (8)”, and in particular the term “abuts”.  During prosecution before the EPO the patentee had argued that it was essential that the second rolling body row abuts the edge, and the defendants argued that the claim interpretation being argued by the claimant before the UPC was inconsistent with this position.

The LD Milan, referring to the Court of Appeal caselaw, 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.”  While the court primarily interpreted feature 1.9 on the basis of the description of the patent, construing it in the narrower manner contended for by the defendants and rejecting the broader interpretation advanced by the patentee, the prosecution statement was considered to “further confirm the correctness of the interpretation hereby adopted by the Court”.

Ultimately, the patent was found valid in an amended form according to Auxiliary Request 1 submitted in the proceedings, but not infringed by the defendants’ products.

The “indication of the view of the person skilled in the art” is a rather low weight of value to be attached to statements during the grant proceedings, and it seems unlikely that prosecution history will be decisive in UPC cases.

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[1] https://www.unifiedpatentcourt.org/en/node/183254

[2] https://www.unifiedpatentcourt.org/en/node/576

[3] https://www.unifiedpatentcourt.org/en/node/159788

[4] https://www.unifiedpatentcourt.org/en/node/159797

[5] https://www.unifiedpatentcourt.org/en/node/1366

[6] https://www.unifiedpatentcourt.org/en/node/149310

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