Antitumor alkyl ether lipid edelfosine: tissue distribution and pharmacokinetic behavior in healthy and tumor-bearing immunosuppressed mice.

PURPOSE The present study investigates and compares the dose-dependent pharmacokinetics and oral bioavailability of edelfosine in healthy, immunodeficient, and tumor-bearing immunosuppressed mouse animal models, as well as edelfosine uptake and apoptotic activity in the Z-138 mantle cell lymphoma (MCL) cell line. EXPERIMENTAL DESIGN Biodistribution study of edelfosine was done in both BALB/c and severe combined immune deficiency (SCID) mice, and then the in vivo behavior of the drug after i.v. and oral administration was monitored. RESULTS We found that edelfosine is incorporated and induces apoptosis in the Z-138 human mantle cell lymphoma cell line, whereas normal resting peripheral blood human lymphocytes were not affected. In vivo biodistribution studies revealed that accumulation of edelfosine in the tumor of a MCL-bearing mouse animal model was considerably higher (P < 0.01) than in the other organs analyzed. Besides, no statistical differences were observed between the pharmacokinetic parameters of BALB/c and SCID mice. Edelfosine presented slow elimination and high distribution to tissues. Bioavailability for a single oral dose of edelfosine was <10%, but a multiple-dose oral administration increased this value up to 64%. CONCLUSION Our results show that edelfosine is widely scattered across different organs, but it is preferentially internalized by the tumor both in vitro and in vivo. Our data, together with the apoptotic action of the drug on cancer cells, support a rather selective action of edelfosine in cancer treatment, and that multiple oral administration is required to increase oral bioavailability.