Pharmacokinetics and safety evaluation of oral Palonosetron in Chinese healthy volunteers: A phase 1, open-label, randomized, cross-over study.

Purpose: Palonosetron hydrochloride is a specific 5-HT3 receptor antagonist, used to prevent chemotherapy-induced nausea and vomiting (CINV), and is a known chemical entity currently registered in the oral and IV forms in several countries worldwide.

Methods: Single-center, single-dose, 3-treatment, open-label, randomized, 3-period, phase-I cross-over study, conducted in 18 individuals (16 males and 2 females). The primary objective was to assess the pharmacokinetic profile of Palonosetron 0.25, 0.5 and 0.75mg, after a single, oral administration in Chinese male and female healthy volunteers.

Results: After administration of a single oral dose of 0.25mg, 0.5mg, or 0.75mg palonosetron in Chinese male and female healthy subjects, plasma palonosetron concentrations reached maximum values (C) of 673 ± 151 pg/mL, 1330 ± 258 pg/mL, and 1990 ± 490 pg/mL, respectively, at 3-5 h (t). The plasma elimination half-life for 0.25, 0.5 and 0.75 mg of palonosetron was 41.8±9.72 hours, 44.6±8.59 hours and 42.3±8.51 hours, respectively. Single oral doses of 0.25mg, 0.5mg, or 0.75mg palonosetron were safe and well tolerated among all the 18 subjects involved.

Conclusions: The PK of palonosetron was found to be linear in the dose range of 0.25 to 0.75 mg. Oral palonosetron in doses up to 0.75 mg was well tolerated in healthy Chinese subjects. The PK and safety data obtained from this study were similar to previous phase I studies with IV palonosetron.