Incorporating immune checkpoint inhibitors in epithelial ovarian cancer

Therapeutic interventions for epithelial ovarian cancer (EOC) have increased greatly over the last decade but improvements outside of biomarker selected therapies have been limited. There remains a pressing need for more effective treatment options that can prolong survival and enhance the quality of life of patients with EOC. In contrast to the significant benefits of immunotherapy with immune checkpoint inhibitors (CPI) seen in many solid tumors, initial experience in EOC suggests limited efficacy of CPIs monotherapy.

A systematic review of phase III studies testing the role of CPIs in ovarian cancer was performed.

Seven randomized trials testing CPIs in newly diagnosed (n = 3) and recurrent (n = 4) EOC are evaluated. Overall, those trials included data of 5671 patients. Single-agent PD-L1 inhibitor trials have not shown significant efficacy in newly diagnosed ovarian cancer. Triplet maintenance with bevacizumab plus olaparib and durvalumab is associated with longer progression-free survival than maintenance with bevacizumab alone in patients without tumor BRCA mutations. CPIs were not effective in platinum-sensitive (n = 1031) and platinum-resistant (n = 1420) EOC.

The value of adding CPI to standard treatment including poly (ADP-ribose) polymerase (PARP) inhibitors with or without bevacizumab remains unclear and is being addressed in ongoing clinical trials. The combination of cytotoxic T-lymphocyte associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) inhibitors may enhance the efficacy of immunotherapy in EOC and studies are underway to investigate the combination of CPI with other emerging treatment modalities. PROSPERO registration ID: CRD42024536017.