The use of higher dose clofarabine in adults with relapsed acute lymphoblastic leukemia

The standard dose of clofarabine is 52 mg/m(2) for pediatrics and 40 mg/m(2) in adults. Clofarabine dosed at 52 mg/m(2) was used in adult patients with refractory ALL to maximize response before allo-HSCT. All patients had a significant response to therapy. Published pharmacokinetic analysis revealed no difference in peak plasma or intracellular concentrations at clofarabine dosed above 40 mg/m(2), yet inhibition of replication in leukemia cells was only sustained over 24 hr at 55 mg/m(2). Despite this, there have been no reports of high dose clofarabine used in this setting. Our experience implies that there may be a niche role for clofarabine in reducing disease burden before allo-HSCT for adults with relapsed ALL. Am. J. Hematol. 84:228-230, 2009. Published 2009 Wiley-Liss, Inc.