High-dose liposomal daunorubicin and high-dose cytarabine combination in patients with refractory or relapsed acute myelogenous leukemia

BACKGROUND. Liposomal encapsulation of daunorubicin (DaunoXome, DNX; Nexstar Pharmaceutical, Boulder, CO) changes the pharmacology profile to increase delivery to tumor sites and decrease toxicity. The authors investigated the effect of daunorubicin in combination with ara-C in patients with refractory or recurring acute myelogenous leukemia (AML). PATIENTS AND METHODS. Sixty-two patients with refractory or recurring AML received escalating doses of daunorubicin of 75, 100, 125, or 135 mg/m² daily for 3 days together with ara-C 1 g/m² intravenous continuous infusion daily for 4 days. RESULTS. Eighteen patients (29%) achieved a complete remission (CR) and 7 (11%) a hematologic improvement (i.e., met all criteria for CR except for platelet count < 100 × 109/L) for an overall response rate of 40%. The dose-limiting toxicity was mucositis in 4 in 9 (44%) patients treated at the 150 mg/m² dose level, but minimal at 125 mg/m² (2 of 32, 6%) or 135 mg/m² (1 of 13, 8%). Cardiotoxicity Grade 2 was observed in 4 patients (6%) and Grade 3 or higher in 4 patients (6%). The median CR duration was 63 weeks, and overall survival rate was 25 weeks, with 28% patients alive after 1 year. CONCLUSIONS. The combination of DNX (or liposomal daunorubicin) and ara-C has significant antileukemia activity with acceptable toxicity. Further studies are warranted to investigate the role of high-dose anthracyclines in frontline AML therapy.