UPC preliminary measures: no shift in burden of proof when defendant asserts EPO incorrectly construed claims
Preliminary measures, such as injunctions and seizure of goods, covering all of the Unified Patent Court (UPC) participating member states are a powerful tool for patentees. In UPC_CFI_723/2025, the court looked at where the burden of proof lies when a defendant to an application for preliminary measures does not agree with the claim interpretation applied during examination.
Overview
The patent central to this request for provisional measures relates to orthodontic and dental treatments using aligners and treatment planning software. The defendants, who are direct competitors of the applicant, offer clear aligner orthodontic treatments systems in Europe.
The defendants argued that the “burden of presentation and proof for facts concerning the lack of validity of a patent lies with the defendant” is based on the presumption that the application was thoroughly examined by the EPO before grant.
The defendants asserted that, in this case, the examination of the patent by the EPO was objectively flawed and failed to meet the standard set by the EPC.
However, the court rejected this line of argumentation stating that the fact the defendants do not agree to the claim interpretation applied in examination does not mean that the burden of proof should shift to the patent proprietor. The court emphasised that the defendants are free to bring forward arguments and evidence as to why the claim should be interpreted differently and why this would lead to invalidity of the patent in suit and, thus, they may also rely on prior art that was already assessed by the examiner.
The court provided a detailed analysis of claim construction and went on to conclude that it was more likely than not that the patent is valid. Based on the general principles concerning preliminary measures, the court considered a preliminary injunction to the appropriate and justified.
An additional point of interest in this order is that the court disregarded arguments concerning non-infringement, which were submitted by the defendant for the first time in the rejoinder, on the ground that they were late-filed.
Practice points
The burden of proof remains with the defendant when asserting that the claim interpretation applied by the EPO during examination is incorrect.
Consequently, defendants should be prepared to provide detailed explanations to support any assertions they make that the claim construction used in examination is not valid.
Additionally, parties should ensure that arguments are filed at the earliest opportunity.
Case details at a glance
Jurisdiction: UPC
Decision level: Düsseldorf Local Division
Parties: Align Technology Inc v Angelalign Technoly Inc ao
Date: 12 February 2026
Decision: dycip.com/upc-cfi-723-2025
Related article
UPC preliminary measures: emerging trends, 10 December 2024.
