OBJECTIVES: I. Determine whether a single mitomycin C treatment will suppress expression of one or more proteins associated with the multidrug resistance phenotype in leukemia cells of patients with refractory acute myelogenous leukemia. II. Determine the maximum tolerated dose of a combination of mitomycin C followed 72 hours later by a single dose of mitoxantrone in patients with acute myelogenous leukemia with GM-CSF support. III.

Determine the toxicity profile and pharmokinetics for these combinations of mitomycin C and mitoxantrone. IV.

Determine the ability of this regimen to induce complete response in patients with primary resistant or refractory acute myelogenous leukemia.

OUTLINE: Patients receive mitomycin C by IV bolus on day 1 of treatment. Patients receive mitoxantrone beginning on day 4. One patient each is entered at the first and second dose levels. Dose escalation of mitoxantrone continues in the absence of toxicity. If the patient experiences toxicity at level 1 or 2, then 2 additional patients are entered at that tier. Three patients are entered at all subsequent tiers. At these tiers, if no toxicity is observed, escalation continues. If 1 of the 3 patients experiences toxicity, an additional 3 patients are enrolled at the same dose. If none of these additional patients experiences toxicity, escalation continues; however, if 1 patient has toxicity, the trial is stopped. If 2 or more have toxicities, the dose is de-escalated.

If 2 or more of the original 3 patients have toxicities, the dose is de-escalated. On day 15, patients are treated with sargramostim (GM-CSF) intravenously over 4 hours if the bone marrow is free of residual leukemia; GM-CSF treatment continues until the ANC is greater than 1,500/mm3 for 3 consecutive days.

PROJECTED ACCRUAL: For the pilot study of mitomycin C modulation of multidrug resistance proteins, 12 patients will be accrued. For the phase I study of mitomycin C and mitoxantrone, at least 17 patients will be entered.