OUTLINE: This is a dose escalation study of topotecan. Patients receive carboplatin IV continuously and fludarabine IV over 30 minutes on days 1-5, then topotecan IV continuously on days 6-8. Patients with residual leukemia in the bone marrow at day 15 may receive a second induction course. Patients who achieve partial or complete remission after 1-2 induction courses receive 1 consolidation course of fludarabine, carboplatin, and topotecan beginning 4-8 weeks after recovery from induction therapy. Cohorts of 3-6 patients receive escalating doses of topotecan until the maximum tolerated dose (MTD) is determined. The first 3 patients do not receive any topotecan. The MTD is defined as the dose at which no more than 2 of 6 patients experience dose limiting toxicity. Patients are followed monthly for 6 months.