Combined Phase 1 pharmacokinetic data at nelarabine doses of 104 to 2,900 mg/ m2 indicate that mean (%CV) clearance (Cl) values for nelarabine are 138 l/ h/ m2 (104%) and 125 l/ h/ m2 (214%) in adult and paediatric patients, respectively, on day 1 (n = 65 adults, n = 21 paediatric patients).