Patients receive 6-hydroxymethylacylfulvene (HMAF) IV over 5 minutes on days 1-5. Treatment repeats every 3-4 weeks for at least 2 courses in the absence of disease progression or unacceptable toxicity. Cohorts of 3 patients receive escalating doses of HMAF. The maximum tolerated dose is defined as the dose at which dose limiting toxicity occurs in at least 40% of patients.