Comparative efficacy of palonosetron and ondansetron for chemotherapy-induced nausea and vomiting in pediatric and adult populations: A systematic review and meta-analysis of randomized controlled trials

Aim: This systematic review and meta-analysis evaluated the efficacy and safety of palonosetron versus ondansetron for CINV prevention. Methods: A systematic review and meta-analysis of randomized controlled trials comparing palonosetron and ondansetron in patients receiving chemotherapy was conducted. PubMed, Embase, Scopus, and Cochrane CENTRAL were searched until October 2025. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Cochrane ROB 2 tool. Primary outcome was complete response in acute (0–24 h), delayed (24–120 h), and overall (0–120 h) phases. Secondary outcomes included complete control, adverse events, nausea control, rescue medication use, and emetic episodes. Random-effects models were applied, and evidence certainty was assessed using GRADE. This review was registered in PROSPERO (CRD420251172577). Results: Among 11 included studies, all were eligible for meta-analysis. Palonosetron showed higher pooled complete response rates than ondansetron in the acute (RR 1.06; 95% CI 1.02 to 1.11), delayed (RR 1.30; 95% CI 1.17 to 1.43), and overall phases (RR 1.29; 95% CI 1.17 to 1.42). Pooled complete control rates showed improvements mainly in the delayed phase. No significant differences were found in pooled adverse event rates, headache, constipation, rescue medication use, or emetic episodes. Sensitivity analyses confirmed stability of pooled estimates; subgroup analyses showed consistent effects across populations and chemotherapy types. Heterogeneity was low, and certainty of evidence ranged from moderate to high. Conclusions: Palonosetron demonstrates superior pooled complete response rates compared with ondansetron across all phases, with particularly significant improvements in delayed-phase control response, and a comparable safety profile.