Absolute oral bioavailability and disposition of deferasirox in healthy human subjects.

ABSTRACT

Deferasirox is a novel iron chelator formulated as tablets for dispersion (suspension) for once-a-day oral administration. The current study evaluated the absolute bioavailability of a single 375-mg oral dose of deferasirox administered in the form of tablets compared with a 130-mg intravenous infusion of deferasirox. Since this was a first-in-man study using the deferasirox intravenous (IV) formulation, the safety and tolerability of the IV formulation was evaluated in a pilot phase with a lower dose (65 mg) in 3 subjects prior to the main phase. The main study phase consisted of 17 healthy male volunteers. Plasma concentrations of deferasirox were measured following each treatment, and pharmacokinetic parameters including absolute oral bioavailability were determined. Absolute oral bioavailability of the deferasirox tablets was 70% (90% confidence interval, 62%-80%). Deferasirox was characterized as having a low plasma clearance of 3.53 (+/- 0.87) L/h. A small volume of distribution of deferasirox at steady state (V(ss)) of 14.37 (+/-2.69 L) was determined, indicating a low tissue distribution.