Patients are given intravenous drug for 14 days with a 1 day washout period, then 76 weeks of oral medication. To expedite this safety study and still be able to maintain close monitoring of the patient's health, an overlapping dosing regimen is used. After 6 patients have been enrolled and at least 4 have completed 4 weeks of dosing without significant toxic effects, a second group of patients is started at the next dose level.