Durable response to pembrolizumab plus axitinib in platinum-resistant ovarian clear cell carcinoma: A case report

Ovarian clear cell carcinoma (OCCC) is a rare and aggressive histologic subtype of epithelial ovarian cancer characterized by intrinsic chemoresistance and limited treatment options in the platinum-resistant setting. Immune checkpoint inhibitors and VEGFR-targeted therapies have demonstrated synergistic activity across multiple malignancies, though their role in OCCC remains incompletely defined. Axitinib is a selective VEGFR1-3 tyrosine kinase inhibitor approved for renal cell carcinoma but not OCCC.

We report a 39-year-old female with FIGO stage IVA platinum-resistant OCCC who achieved durable disease control with pembrolizumab plus axitinib, despite prior mixed response to first-line therapies including bevacizumab. Tumor profiling demonstrated microsatellite stability, low tumor mutational burden, PD-L1 expression (TPS 5%), ARID1A mutation, and TP53 alteration. Serial imaging demonstrated sustained radiographic improvement followed by imaging findings suspicious for disease progression after approximately 23 months of disease control.

This case highlights the potential therapeutic relevance of VEGFR inhibition combined with immune checkpoint blockade in platinum-resistant OCCC. In a setting with limited effective options, this combination strategy may provide meaningful clinical benefit in selected patients.