Clofarabine: in pediatric patients with acute lymphoblastic leukemia.

Clofarabine is a purine nucleoside analog that inhibits DNA synthesis and repair. Its effects are mediated via the inhibition of ribonucleotide reductase and DNA polymerase. Clofarabine also disrupts the integrity of mitochondrial membranes, resulting in programmed cell death. In 61 pediatric patients with relapsed or refractory acute lymphoblastic leukemia treated with clofarabine 52 mg/m2 infused intravenously over 2 hours once daily for 5 days every 2-6 weeks, rates of complete remission, complete remission without platelet recovery, and partial remission were 12%, 8%, and 10%, respectively. Data are from two non-comparative, multicenter, phase II studies. The most common adverse events associated with clofarabine 52 mg/m2 once daily for 5 days every 2-6 weeks in 96 patients with acute myelogenous or lymphoblastic leukemia (combined analysis of phase I/II trials) were hematologic events (including anemia, leukopenia, thrombocytopenia, neutropenia, and febrile neutro-penia), gastrointestinal events (including vomiting, nausea, and diarrhea), infections, and transient elevations in liver enzymes. Capillary leak syndrome or systemic inflammatory response syndrome was reported in four patients.