Dose escalation will proceed within each hepatic dysfunction group (except in the normal group). Only dose-limiting toxicities (DLTs) that occur during the first cycle of treatment will be used to guide dose escalation. The maximum tolerated dose (MTD) is the highest dose at which no more than one instance of DLT is observed (among 6 patients treated). Once the MTD has been determined for a given hepatic dysfunction group, a maximum of 12 patients will be accrued to this dose level.