Efficacy, safety and pharmacokinetics of palonosetron in patients receiving highly emetogenic cisplatin-based chemotherapy: a dose-ranging clinical study

Background: Although currently available 5-hydroxytryptamine type 3 receptor (5-HT3) antagonists are effective, not all patients receiving these agents achieve adequate control of chemotherapy-induced nausea and vomiting (CINV). Palonosetron, a potent and highly selective 5-HT3 antagonist with a strong affinity for 5-HT3 and a prolonged plasma elimination half-life, may provide a longer duration of action than other approved agents. Patients and methods: One hundred and sixty-one patients were randomly assigned to receive a single intravenous bolus dose of palonosetron (0.3, 1, 3, 10, 30 or 90 mug/kg) before administration of highly emetogenic chemotherapy, with no pretreatment with corticosteroids. Results: The four highest doses of palonosetron were similarly effective during the first 24h, producing clearly higher complete response (CR) (no emesis, no rescue medication) rates in the 3, 10, 30 and 90 mug/kg groups (46%, 40%, 50% and 46%, respectively) than in the 0.3-1 mug/kg group (24%) of evaluable patients (n = 148). The 3 mug/kg dose was identified as the lowest effective dose. A single dose of palonosetron showed prolonged efficacy in preventing delayed emesis, with approximately one-third of patients who received palonosetron 10 or 30 mug/kg maintaining a CR throughout the 7-day period following chemotherapy administration. Dose-proportional increases in pharmacokinetic parameters and a long plasma half-life (43.7-128 h) were observed. Palonosetron was well-tolerated, with no dose-response effect evident for the incidence or intensity of adverse events. Conclusions: Palonosetron is an effective and well-tolerated agent for the prevention of CINV following highly emetogenic chemotherapy, with 3 and 10 mug/kg identified as the lowest effective palonosetron doses.