Immune checkpoint inhibitors for recurrent ovarian clear cell carcinoma: Real-world outcomes from a Korean multi center study

Abstract

Background. Recurrent ovarian clear cell carcinoma (OCCC) is an aggressive, chemotherapy-resistant subtype with poor prognosis. Given its distinct biology, immune checkpoint inhibitors (ICIs) may offer therapeutic potential. This study aimed to assess the real-world efficacy and safety of ICIs inpatients with recurrent O CCC in South Korea. Methods. We retrospectively investigated the recurrent OCCC patients who treated with ICI at 3 institutions in Korea between 2015 and 2024. We evaluated the objective response rate (ORR), disease control rate (DCR), progression-free survival (PF S), overall survival (OS) and safety. Results. A total of 66 patients with recurrent OCCC were included in the study. Among them, 39 patients (59.1 %) received pembrolizumab, 15 (22.7 %) received nivolumab, 9 (13.7 %) received durvalumab, and 3 (4.5 %) received avelumab. The median age at diagnosis was 51.0 years (range, 27-86), and patients had received a median of 3 prior lines of systemic therapy (range, 1-10), with 46 patients (69.7 %) having previously received anti-angiogenic agents. The best ORR was 6.3%, with 4 patients achieving partial responses. The DCR was 21.9%, including 4 partial responses and 10 cases of stable disease. After a median follow-up of 26.7 months, the median PFS was 2.6 months, and the median OS was 7.8 months. Treatment-related adv erse events (TRAEs) of grade 1-3 occurred in 6 patients (40.9 %). No grade 4 or 5 TRAEs were observed. Conclusions. Although ICIs were well tolerated, their antitumor activity in recurrent OCCC was limited. Further studies are warranted to clarify the therapeutic role of IC Is in this setting. (c) 2025 Elsevier Inc. All rights are reserved, including those for text and data minin g, AI training, and similar technologies.