Novel Breakthrough in Triple Combination Therapy with Immune Checkpoint Inhibitor, Bevacizumab, and Dose-Reduced Chemotherapy for Patients with Advanced Ovarian Cancer: A Case Series Study

Background Ovarian cancer continues to be the deadliest gynecological malignancy, with surgery and chemotherapy serving as the mainstays of treatment. However, recurrence often develops within several years after initial postoperative chemotherapy due to drug resistance, and the significant toxicity associated with long-term chemotherapy markedly impairs patients’ quality of life. Consequently, there is a pressing clinical need to develop strategies that minimize chemotherapy exposure while preserving efficacy and safety. Case Presentation This study presents three cases of stage IVB ovarian serous carcinoma treated with a triple regimen combining an immune checkpoint inhibitor (ICI), bevacizumab, and chemotherapy with a planned reduction in chemotherapy cycles. All three patients completed the regimen without experiencing treatment-related grade ≥ 3 adverse events. Patient 1 achieved a postoperative complete response, Patient 2 exhibited a partial response, and Patient 3 maintained stable disease. Conclusion Over the past two decades, immunotherapy has advanced rapidly. Although its clinical response rate in ovarian cancer remains relatively low, evidence suggests that combining ICIs with targeted therapy can significantly improve outcomes. This case series offers new insights into the application of immunotherapy in advanced ovarian cancer, highlighting a potential pathway to reduce chemotherapy burden while maintaining therapeutic benefit.