UPC CoA’s added-matter test (similar to EPO gold standard) results in reversal, patent claim invalidation: expert v. Seoul Viosys

Context:

• Case at hand: Last year, the Unified Patent Court’s (UPC) Dusseldorf Local Division (LD) granted Seoul Viosys an injunction over an LED-related patent against expert, a reseller of Emporia smartphones for senior citizens (October 10, 2024 ip fray article).
• Precedent: In an Abbott v. SiBio case, the UPC’s Court of Appeal (CoA) reversed (February 19, 2025 ip fray article) a denial of provisional measures (i.e., preliminary injunction (PI)) by the Hague LD (June 25, 2024 ip fray article). Without referencing the European Patent Office’s (EPO) “gold standard” for identifying impermissibly added subject matter, the CoA’s second panel spelled out a test that one could describe as materially consistent with EPO case law, though it sparked debate (Section 1 of our February 22, 2025 UPC Roundup).

What’s new: Yesterday (October 2, 2025), the CoA’s second panel reached the question of added matter in expert v. Seoul Viosys, resulting in another reversal (PDF (in German)), though not in connection with a PI. The patent-in-suit, EP3926698 (“light emitting diode”), was deemed invalid due to added matter. The decision lays out an added-matter standard in one headnote, and clarifies in a second headnote that for divisionals the test is applied with respect to both the original application of the patent-in-suit and the original Patent Cooperation Treaty (PCT) application that entered into the regional phase and constitutes the parent application of the divisional in question. In this case, the patentee sought to capture infringements of a kind that the CoA does not consider to find sufficient support in the two relevant applications.

Direct impact: Seoul Viosys has definitively lost the case, short of a miracle in the form of a rehearing (which the company may not even request in the first place).

Wider ramifications: The debate over whether the UPC or the EPO has a more rigid added-matter standard will continue (and may not end anytime soon). The CoA’s second panel has now disagreed with first-instance panels on added matter twice, first deeming a patent likely valid that the court below considered likely invalid, and then (yesterday) invalidating the claims-in-suit contrary to the lower court’s view.