Abstract
BACKGROUND: Platinum-refractory ovarian cancer (PROC) is extremely malignant and aggressive. Patients typically have a diminished quality of life and limited survival, with an overall survival (OS) of less than one year. Until early 2024, bevacizumab remains the only targeted agent approved in China for the treatment of PROC. The standard regimen for PROC in China is non-platinum single-agent chemotherapy, or chemotherapy combined with bevacizumab. However, these therapies have not achieved satisfactory clinical outcomes. CASE PRESENTATION: A 63-year-old woman presented with an incidentally detected left neck mass. Ultrasound-guided biopsy revealed high-grade serous ovarian carcinoma. She received first-line bevacizumab plus platinum-based chemotherapy but showed disease progression after two cycles, consistent with platinum-refractory ovarian cancer. After similarly failing second-line gemcitabine therapy (2 cycles), she achieved complete response (CR) and maintained progression-free survival (PFS) for 23.9 months with third-line etoposide combined with anlotinib and sintilimab. CONCLUSION: This case demonstrates that the combination of etoposide, anlotinib, and sintilimab can induce sustained CR in platinum-refractory ovarian cancer, achieving remarkable 23.9-month PFS. The synergistic activity of this regimen successfully reversed multidrug resistance and may redefine third-line therapeutic strategies for this challenging population.