The effect of the requested remedy comes first
In 2025Heo10641, decided on 26 August 2026, the Korean Patent Court considered standing to seek invalidation of a patent correction. Patent 1725279 concerned a method for producing polymer microparticles with a network structure. The dispute concerned the correction procedure and standing, not the clinical effectiveness of a filler product.
The second correction added limitations requiring a particle diameter of 20–150 μm and a yield of at least 80% to claims 1 and 7 and affected dependent claims 2, 3 and 5. Following a related disclosure dispute, a distributor that had obtained products for export after the correction in August 2024 sought its invalidation. The tribunal granted the petition on 25 November 2025 in 2025Dang227.
Invalidating a correction is different from invalidating a patent
Patent invalidation ordinarily removes the right retrospectively. Invalidation of a narrowing correction instead treats the correction as never having taken effect, potentially restoring broader claims. Standing therefore depends on whether maintaining the correction causes a direct and actual legal disadvantage to the petitioner.
The exporter was treated as a non-exclusive licensee within the corrected scope. It had no right to exclude other users. While the narrower claims remained in force, the area outside them was already available without that patent restriction. Restoring broader claims could expand licensed scope and associated burdens; that did not itself establish a legal benefit from invalidation.
A commercial disagreement is not necessarily the required legal interest
Arguments about termination of the distribution arrangement, damages and commercial advantage were characterised as indirect economic interests. They did not show the necessary direct legal disadvantage from maintaining the narrowing correction in this case.
The court also considered third parties that may have relied on the narrowed claims: retrospective restoration of broader rights could unsettle that reliance. Where the patentee and petitioner effectively favoured the same outcome, allowing the proceeding without a genuine opposing legal interest would undermine the structure of an inter partes challenge.
The intervener could independently challenge the tribunal decision
Another company participating in the tribunal proceedings challenged the decision. The Korean Patent Act provides a special basis for an intervener’s independent court action; ordinary civil-procedure restrictions on a supporting intervener did not resolve that question. The corrected specification also affected a separate invalidity dispute involving that company.
The patentee was not a party to the court action, and its attempted withdrawal did not end that action. The court set aside the tribunal decision because the exporter’s petition should have been dismissed as inadmissible for lack of standing, rather than allowed on its merits.
Assess standing against the before-and-after claim scope
This judgment does not exclude every non-exclusive licensee from every correction challenge. A different correction and remedy may produce a real legal benefit, including where invalidation would leave a narrower right. The precise claim changes, the requested outcome and the petitioner’s legal position must be analysed together.
Before bringing a challenge, map the original and corrected claims and explain the concrete disadvantage caused by leaving the correction in place. Commercial dissatisfaction, an export relationship or involvement with the product alone does not supply that explanation.
The original figure labels and forms are preserved; the text explains the facts and the court’s reasoning.