High fludarabine exposure and relationship with treatment-related mortality after nonmyeloablative hematopoietic cell transplantation.
Author(s): Long-Boyle JR, Green KG, Brunstein CG, Cao Q, Rogosheske J, Weisdorf DJ, Miller JS, Wagner JE, McGlave PB, Jacobson PA
Affiliation(s): Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN, USA.
Publication date & source: 2011-01, Bone Marrow Transplant., 46(1):20-6. Epub 2010 Apr 12.
Publication type: Clinical Trial; Research Support, N.I.H., Extramural
Despite its common use in nonmyeloablative preparative regimens, the pharmacokinetics of fludarabine are poorly characterized in hematopoietic cell transplantation (HCT) recipients and exposure-response relationships remain undefined. The objective of this study was to evaluate the association between plasma F-ara-A exposure, the systemically circulating moiety of fludarabine, and engraftment, acute GVHD, TRM and OS after HCT. The preparative regimen consisted of CY 50 mg/kg/day i.v. day -6; plus fludarabine 30-40 mg/m(2)/day i.v. on days -6 to -2 and TBI 200 cGy on day -1. F-ara-A pharmacokinetics were carried out with the first dose of fludarabine in 87 adult patients. Median (range) F-ara-A area-under-the-curve (AUC((0-infinity))) was 5.0 mug h/mL (2.0-11.0), clearance 15.3 L/h (6.2-36.6), C(min) 55 ng/mL (17-166) and concentration on day(zero) 16.0 ng/mL (0.1-144.1). Despite dose reductions, patients with renal insufficiency had higher F-ara-A exposures. There was strong association between high plasma concentrations of F-ara-A and increased risk of TRM and reduced OS. Patients with an AUC((0-infinity)) greater than 6.5 mug h/mL had 4.56 greater risk of TRM and significantly lower OS. These data suggest that clinical strategies are needed to optimize dosing of fludarabine to prevent overexposure and toxicity in HCT.
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