The Turkish Supreme Court has issued an important decision clarifying the impact of amendments made during European Patent Office (EPO) opposition proceedings on European patents validated in Türkiye.

In its decision dated 15 January 2025 (11th Civil Chamber, Case No. 2024/5746 E., Decision No. 2025/131 K.), the Court confirmed that claim limitations accepted by the EPO must be considered by Turkish courts when assessing the validity of a validated European patent.

Background

The dispute concerned Turkish Patent No. TR 2008/07552 T4, a validated European patent. The claimant sought invalidation of the patent on the grounds that it allegedly lacked novelty and inventive step and that certain claims exceeded the scope of the original disclosure.

During the invalidation proceedings, the corresponding European patent underwent opposition proceedings before the EPO. As a result of those proceedings, a number of claims were deleted and the patent was maintained in a restricted form. The amended claim set was subsequently recognized in Türkiye.

Court’s Assessment

The Court held that where a European patent is maintained in amended form following EPO opposition proceedings, Turkish courts must assess validity based on the restricted claims rather than the original claim set.

Accordingly, claims that had already been removed during the EPO proceedings no longer required examination by the Turkish courts. However, the invalidation action itself did not become moot. Instead, the validity assessment had to continue on the basis of the patent as amended and maintained before the EPO.

After reviewing the restricted claims and the cited prior-art documents, the Court upheld the lower court’s finding that the patent met the requirements of novelty and inventive step and therefore rejected the invalidity claim.

Significance for European Patent Validations in Türkiye

This decision highlights the practical importance of monitoring EPO opposition proceedings even when parallel litigation is ongoing in Türkiye.

The ruling confirms that:

  • Amendments accepted by the EPO may directly affect the scope and outcome of Turkish invalidity proceedings;
  • Turkish courts may assess validity based on the claim set maintained by the EPO;
  • Deletion of claims during EPO proceedings does not automatically render a Turkish invalidation action moot;
  • Developments before the EPO can have direct consequences for validated European patents in Türkiye.

The decision therefore reinforces the need for coordinated patent prosecution and litigation strategies across both European and Turkish proceedings.

Case Reference

Turkish Supreme Court (11th Civil Chamber)
Case No.: 2024/5746 E.
Decision No.: 2025/131 K.
Decision Date: 15 January 2025