The purpose of this study is to investigate E7107 in patients with solid tumors. This is an open label, dose-escalation study of E7107. The maximum tolerated dose (MTD) of the single agent will be established by determining the occurrence of dose limiting toxicities during the first three weeks of therapy (Cycle 1). Patients in this study will be treated at multiple dose levels, starting at 0.6 mg/m^2. Patients will receive E7107 as a 30-minute intravenous infusion on Days 1 and 8 every 21 Days.