title: Should busulfan therapeutic range be narrowed in pediatrics? Experience from a large cohort of hematopoietic stem cell transplant children.
abstract: Busulfan, the corner stone of hematopoietic stem cell transplantation regimens, has a narrow therapeutic window. Therapeutic drug monitoring (TDM)-guided dosing to reach the conventional area under the concentration-time curve (AUC) target range of 900-1500 μmol min/L is associated with better outcomes. We report our experience with busulfan TDM in a large cohort of children. The aims were to investigate the relevance of using a more restricted therapeutic range and investigate the association between busulfan therapeutic range and clinical outcome. This study includes 138 children receiving 16 doses of intravenous busulfan, with the first dose assigned based on weight and doses adjusted to a local AUC target range of 980-1250 μmol min/L. Busulfan TDM combined with model-based dose adjustment was associated with an increased probability of AUC target attainment, for both target range: 90.8% versus 74.8% for the conventional target range and 66.2% versus 43.9% for the local target range (P<0.001). The median follow-up was 56.2 months. Event-free survival was 88.5%, overall survival was 91.5% and veno-occlusive disease occurred in 18.3% of patients. No difference was observed for clinical outcomes depending on the selected target range. Pharmacokinetic monitoring and individualization of busulfan dosage regimen are useful in improving target attainment, but using a restricted target range has no impact on clinical outcomes.
authors.affiliation: Hematology Department, Institute of Pediatric Hematology and Oncology, and Hospices Civils de Lyon, Lyon, France.|Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Lyon 1, Villeurbanne, France.
authors.forename: M
authors.initials: M
authors.lastname: Philippe
authors.affiliation: Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Lyon 1, Villeurbanne, France.|ISPB - Faculté de Pharmacie de Lyon, Université Lyon 1, Lyon, France.|Service Pharmaceutique, Groupement Hospitalier de Gériatrie, Hospices Civils de Lyon, Lyon, France.
authors.forename: S
authors.initials: S
authors.lastname: Goutelle
authors.affiliation: ISPB - Faculté de Pharmacie de Lyon, Université Lyon 1, Lyon, France.|Laboratoire de Ciblage Thérapeutique en Cancérologie, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre Bénite, France.
authors.forename: J
authors.initials: J
authors.lastname: Guitton
authors.affiliation: Laboratoire de Pharmacologie, University Hospital Centre, Grenoble, France.
authors.forename: X
authors.initials: X
authors.lastname: Fonrose
authors.affiliation: Hematology Department, Institute of Pediatric Hematology and Oncology, and Hospices Civils de Lyon, Lyon, France.
authors.forename: C
authors.initials: C
authors.lastname: Bergeron
authors.affiliation: Clinique de Pédiatrie, Hôpital Couple Enfant, University Hospital Centre, Grenoble, France.
authors.forename: P
authors.initials: P
authors.lastname: Girard
authors.affiliation: Hematology Department, Institute of Pediatric Hematology and Oncology, and Hospices Civils de Lyon, Lyon, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Bertrand
authors.affiliation: Hematology Department, Institute of Pediatric Hematology and Oncology, and Hospices Civils de Lyon, Lyon, France.|Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Lyon 1, Villeurbanne, France.
authors.forename: N
authors.initials: N
authors.lastname: Bleyzac
mesh_terms: D000293:Adolescent; D000328:Adult; D064591:Allografts; D002066:Busulfan / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D002066:Busulfan