Dose escalation is initially performed without filgrastim (G-CSF). Cohorts of 4-6 patients receive escalating doses of a rebeccamycin analogue and cisplatin until the maximum tolerated dose (MTD) of each drug is determined. The MTD is defined as the highest dose at which less than 2 of 6 patients experience dose limiting toxicity (DLT). If 2 of the first 6 patients experience DLT, then dose escalation proceeds in combination with G-CSF treatment. Patients receive G-CSF subcutaneously daily beginning on day 2 and continuing until blood counts have recovered for 2 days or until approximately day 15. Cohorts of 4-6 patients receive escalating doses of a rebeccamycin analogue and cisplatin as above. The MTD is defined as above.