Efficacy of PD-1/PDL-1 inhibitors for ovarian cancer: a systematic review and network meta-analysis

Randomized controlled trials (RCTs) have assessed the efficacy of anti-programmed cell death 1 (PD- 1)/programmed cell death ligand 1 (PD-L1), alone or combined with other therapies, for ovarian cancer. However, the optimal strategy remains unclear. This study evaluated their effectiveness as monotherapy and in combination.
We conducted a systematic review and Frequentist network meta-analysis (NMA) by searching PubMed, ScienceDirect, Web of Science, Scopus, Cochrane Library, and Clinicaltrials.gov databases. This analysis included RCTs comparing PD-L1/PD-1 inhibitors, alone or in combination with other therapies.
Six studies involving 3,895 patients and eight treatment combinations were included. PD1/PDL1 inhibitors plus chemotherapy and PD1/PDL1 inhibitors plus ipilimumab showed the greatest progression-free survival (PFS) benefit (hazard ratio (HR) = 0.82, 95% confidence interval [CI]: 0.52–1.07; HR = 0.82, 95% CI:0.51–1.33) and overall survival (OS) (HR = 0.85, 95% CI:0.64–1.14; HR = 0.83, 95% CI:0.45–1.54). These combinations also improved overall response rates (ORR), especially with chemotherapy (OR = 3.06; 95% CI:1.42–6.60). Subgroup analysis suggested that PD-1/PD-L1 inhibitors plus chemotherapy provided the best PFS and OS in PD-L1-positive patients.
Combining PD-1/PD-L1 inhibitors with chemotherapy or ipilimumab improved survival in ovarian cancer. However, PD-L1 expression may be a valuable biomarker for predicting the efficacy of PD-1/PD-L1 checkpoint inhibitors.
This systematic review was preregistered in PROSPERO (CRD42022342057). Available from: https://www.crd.york.ac.uk/PROSPERO/view/CRD42022347967.
Ovarian cancer is a serious disease that is often discovered too late. In recent years, researchers have developed new treatments called immune checkpoint inhibitors, including programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors. These medicines help the body’s immune system fight cancer more effectively. Although they work well in other types of cancer, it is still unclear how effective they are in ovarian cancer.This study looked at six clinical trials that tested these treatments in women with ovarian cancer. Researchers have compared different combinations to determine which one works best. They found that combining immune checkpoint inhibitors with chemotherapy or with another medicine called ipilimumab helped patients live longer and slowed the growth of the cancer. These combinations worked better than chemotherapy alone.Women whose tumors had high levels of a protein called PD-L1 showed even better results. These findings indicate that testing for PD-L1 could help doctors choose the best treatment for each patient. Overall, this study suggests that combining immune-based treatments with other therapies could help some women with ovarian cancer. The results are promising, but more research is needed.