Efficacy and safety of micafungin for treating febrile neutropenia in hematological malignancies.

Less toxic antifungal drugs are required for empirical antifungal therapy. Micafungin is an echinocandin drug that is effective against both Candida and Aspergillus, and preliminary clinical studies have shown good antifungal activity. We prospectively examined the effect and safety of micafungin against febrile neutropenia with suspected fungal infection in 53 patients (median age, 56 years) who had undergone chemotherapy. The administered dose of micafungin was 150 mg/day, and its effect was evaluated as fever resolution as well as the results of chest imaging and serum fungal tests. Micafungin levels were measured on day 4 after the first administration using high-performance liquid chromatography. We also measured trough levels of micafungin. Underlying diseases comprised acute lymphoblastic leukemia (n = 4), acute myeloid leukemia (n = 20), multiple myeloma (n = 3), and non-Hodgkin's lymphoma (n = 26). The overall efficacy of micafungin was 70%. Breakthrough fungal infections were documented in two (3.8%) patients, both of whom died of invasive mycosis. None of the patients were switched to other antifungal drugs due to events unrelated to adverse effects. Plasma levels of micafungin and the degree of hepatic or renal dysfunction did not correlate. Micafungin is safe and effective for the empirical antifungal therapy of febrile neutropenia in patients with hematological malignancies.