Purpose: The aims of this study were to evaluate the safety, efficacy, and pharmacokinetics of repeated doses of palonosetron 0.75 mg on days 1 and 3 in Japanese patients who received highly or moderately emetogenic chemotherapy.
Methods: Twenty- six patients received palonosetron 0.75 mg intravenously before chemotherapy on days 1 and 3 plus dexamethasone (12-16 mg before chemotherapy on day 1 and 4-8 mg on days 2 and 3). The primary endpoints were safety and pharmacokinetics. Pharmacokinetics were evaluated in a subset of patients (n=6). Complete response and complete protection were evaluated as secondary endpoints.
Results: The accumulation ratios for C max and AUClast after the second dose on day 3 were 1.42 and 1.37, respectively. These values were consistent with the theoretical values expected from the half-life of palonosetron on day 1. Almost all of the patients had no nausea or vomiting in the acute phase (complete response (CR) rate, 96.2% [25/26]; CP rate, 92.3% [24/26]). In the delayed phase (24-192 h post-chemotherapy), the complete response and complete protection rates were 76.9% (20/26) and 61.5% (16/26), respectively. Treatment was well tolerated.
Conclusions: This is the first study to report the pharmacokinetics of multiple doses of palonosetron 0.75 mg, given on days 1 and 3, in Japanese patients. Repeated treatment with palonosetron was safe and well tolerated by patients who received highly or moderately emetogenic anticancer chemotherapy.