Prospective phase II single-center study of the safety of a single very high dose of liposomal amphotericin B for antifungal prophylaxis in patients with acute myeloid leukemia.

Some preclinical and pharmacokinetic studies suggested the variable safety and the potential efficacy of an antifungal prophylaxis with a single high dose of liposomal amphotericin B (L-AmB) in high-risk patients. An open-label, prospective study was conducted with 48 adults receiving induction chemotherapy for acute myeloid leukemia (AML). Patients received a single infusion of 15 mg/kg of body weight L-AmB and, eventually, a second dose after 15 days of persistent neutropenia. The primary objective was tolerability and safety. Efficacy was also evaluated as a secondary endpoint. A pharmacokinetic study was performed with 34 patients in order to evaluate any association of plasma L-AmB levels with toxicity and efficacy. Overall, only 6 patients (12.5%) reported Common Toxicity Criteria (CTC) grade 3 hypokalemia, which was corrected with potassium supplementation in all cases, and no patient developed clinically relevant nephrotoxicity. Mild infusion-related adverse events occurred after 6 of 53 (11.3%) total infusions, with permanent drug discontinuation in only one case. Proven invasive fungal disease (IFD) was diagnosed in 4 (8.3%) patients. The mean AmB plasma levels at 6 h, 24 h, and 7 days after L-AmB administration were 160, 49.5, and 1 mg/liter, respectively. The plasma AmB levels were higher than the mean values of the overall population in 3 patients who developed CTC grade 3 hypokalemia and did not significantly differ from the mean values of the overall population in 3 patients who developed IFD. Our experience demonstrates the feasibility and safety of a single 15-mg/kg L-AmB dose as antifungal prophylaxis in AML patients undergoing induction chemotherapy.