Palonosetron is nonsuperior to ondansetron in acute phase but provides superior antiemetic control in delayed phase for pediatric patients administered highly emetogenic chemotherapy.

PURPOSE: Chemotherapy-induced nausea and vomiting (CINV) in children remains to be a major side effect despite antiemetic treatment. Palonosetron is a new generation 5-HT3 receptor antagonists effective against acute and delayed nausea and vomiting. This study aimed to compare the therapeutic values of palonosetron and ondansetron in preventing pediatric CINV. METHODS: A prospective, randomized, double-blind, parallel controlled study was conducted in 0-18 years old cancer patients administered highly emetogenic chemotherapy, with different dosage of palonosetron or ondansetron, both followed by dexamethasone. The patients were observed for vomiting and nausea from 0 to 120 hr after chemotherapy initiation. All adverse events (AEs) during the study period were recorded. This study was registered with the Chinese Clinical Trial Registry, number ChiCTR-TRC-14004891. RESULTS: Between August 2014 and July 2016, 565 patients were randomly assigned to receive 5 μg/kg palonosetron (n = 185), 10 μg/kg palonosetron (n = 186), and 3 × 150 μg/kg ondansetron (n = 194), of whom 181, 185, and 189, respectively, were included in the efficacy analysis. Complete response (CR) rates during the acute phase were 69.1, 69.7, and 64.6%, respectively, in the 5 μg/kg palonosetron, 10 μg/kg palonosetron, and ondansetron groups. In the delayed phase, 10 μg/kg palonosetron (CR, 53.5%) showed superiority to 5 μg/kg palonosetron (CR, 39.8%) and ondansetron (CR, 32.8%) groups (P < 0.05). The most frequently observed drug-related AEs were nervous system disorders, mainly headache, with an incidence of 2.8, 2.2, and 2.6% in each group, respectively. CONCLUSION: Combination of palonosetron plus dexamethasone is highly effective in controlling acute and delayed CINV, with palonosetron superior to ondansetron.