Clinical efficacy and safety of arbekacin for high-risk infections in patients with hematological malignancies.

We performed a clinical trial to investigate the efficacy and safety of arbekacin (ABK), a unique aminoglycoside with activity against methicillin-resistant Staphylococcus aureus (MRSA), in patients with hematological malignancies complicated by high-risk infections. ABK was administered intravenously at a dose of approximately 5 mg/kg with various broad-spectrum β-lactams, followed by therapeutic drug monitoring (TDM). A total of 54 febrile or infectious episodes were registered, and TDM was performed in 44 (81%) cases. The absolute neutrophil count was below 500/μl in 49 (91%) cases, and cytotoxic chemotherapy was being administered in 47 (87%) cases. Before initiation of ABK, 52 (96%) patients had received fluoroquinolones (n = 37) and/or broad-spectrum β-lactams (n = 34). There were 10 cases of documented infections including one of MRSA pneumonia, and 44 cases of febrile neutropenia. The efficacy at the end of treatment was 80% for all patients, and efficacy was significantly higher in patients attaining maximum concentrations ≥ 16 µg/ml or receiving TDM-guided dose-adjustment of ABK (n = 19, 95 vs. 71%, P = 0.039). Renal toxicity was observed in six cases (11%) but was generally acceptable. This study demonstrated that TDM-guided ABK administration may be applicable under limited conditions for patients with hematological malignancies.