 OUTLINE: This is a multicenter, phase I, dose-escalation study followed by a phase II, open-label study. Patients are stratified according to the use of cytochrome P450-inducing anticonvulsants use of anticonvulsant drugs that induce hepatic metabolic enzymes vs use of anticonvulsant drugs that cause modest or no induction of hepatic metabolic enzymes or no use of anticonvulsant drugs. 