OTEC v Steros (UPC_CoA_579/2025)
Decision date:
07 November 2025
Osborne Clarke summary
- Steros is the exclusive licensee of a patent relating to an electrolytic medium and electropolishing process using the electrolytic medium. OTEC manufactures and sells electropolishing machines and electrolytic mediums for them in some UPC contracting states, including Germany. In June 2025, Steros obtained a preliminary injunction in the Hamburg LD against OTEC.
- OTEC appealed this decision and requested that the order be set aside, the injunction lifted and for Steros to bear the costs of the proceedings. OTEC had previously requested suspensive effect for the appeal under Rule 223 RoP, which had been rejected.
- The appeal turned on the interpretation of one claim feature, which related to the presence of non-conductive fluid. OTEC argued that the attacked embodiment contained one same electrolyte liquid inside and outside the particles that is a conductive oil-in-water-type emulsion with a water-type continuous phase and oily micelles. It maintained that the conductivity of the liquid should be assessed by measuring the emulsion as a whole, which shows that there is no non-conductive fluid according to claim 1 of the patent, and not, as Hamburg LD did, by separating the ingredients of the emulsion and assessing the conductivity of both phases separately to identify the presence of a non-conductive fluid.
- The court confirmed the principles on claim construction. The patent claim is not only the starting point but the decisive basis for determining the protective scope of a European patent under Article 69 EPC in conjunction with the Protocol on the Interpretation of Article 69 EPC. The interpretation of a patent claim does not depend solely on the strict, literal meaning of the wording used. Rather, citing Nanostring v 10x Genomics, the description and the drawings must always be used as explanatory aids for the interpretation of the patent claim and not only to resolve any ambiguities in the patent claim.
- The Court of Appeal agreed with OTEC – when considering an emulsion as the non-conductive fluid under the claim, the electrical conductivity of the overall emulsion was to be assessed, not that of each ingredient in the emulsion as the Hamburg LD had done.
- Steros had sought to demonstrate that the skilled person, on the basis of a table in the patent specification and their common general knowledge, would understand that the table presented an embodiment of a non-conductive fluid within the meaning of the relevant claim feature having an electrical conductivity above a certain level. Steros relied primarily on the results of experiments it conducted for the purposes of the present litigation and the Court of Appeal rejected this, clarifying that experimental data that are not disclosed in the patent specification are, as a general rule, not relevant to the interpretation of the patent claims.
- OTEC's appeal was successful. Based on the Court of Appeal's interpretation of the claim, it found that it was more likely than not that that the patent was not infringed. As such, it did not need to consider validity.
- The first instance order was set aside, Steros' application for provisional measures was rejected and therefore the preliminary injunction was lifted and Steros was ordered to bear the costs of the first instance and appeal proceedings.
Issue
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