title: Mobilization of hematopoietic stem cells by plerixafor alone in children: a sequential Bayesian trial.
abstract: BACKGROUND
  The rapid kinetics of hematopoietic stem cells induced by Plerixafor (Mozobil®, Genzyme) should be of particular interest in children. We therefore conducted a prospective trial to determine whether a one-day mobilization by plerixafor alone was efficient enough in children with cancer.
  
  
  METHODS
  Children with solid malignancies were consecutively recruited for this phase-IIA, Bayesian single-center prospective study. Mobilization consisted in one subcutaneous injection of 240 μg plerixafor/kg body weight at 8a.m. (h0). Collection by apheresis began at h5 provided that CD34+count exceeded 10 × 10(6)/L. Our main evaluation criterion was percent of children in which at least 5 × 10(6) CD34+/kg could be collected during the first apheresis.
  
  
  RESULTS
  No patients fulfilled the success criterion, and so a stopping criterion was met after 5 patients. All patients reached the threshold value of 10 × 10(6) CD34+cells/L post-injection and so all were eligible for apheresis. Peak CD34+cell values were ranged from 11 to 44 × 10(6)/L and were reached in 4h to 6h. No side-effects were observed. Median number of CD34+cells collected per patient BW was 1.62 × 10(6)[0.47-3.5]. In 3 of the 5 patients, collection was>1.5 × 10(6) CD34+/kg BW.
  
  
  CONCLUSIONS
  In children, a 'one-day' mobilization regimen consisting of one injection of 240 μg/kg plerixafor alone in hematological steady state provides a faster and shorter mobilization than in adults. This strategy may be an attractive option for completing an insufficient graft. More studies are warranted to optimize the use of plerixafor in children.
authors.affiliation: CHU Clermont-Ferrand, Centre Régional de Cancérologie et Thérapie Cellulaire Pédiatrique, Hôpital Estaing, 63001 Clermont-Ferrand, France; INSERM-CIC 501, 63003 Clermont-Ferrand, France; Clermont Université, Université Clermont-1, Faculté de Médecine, 63001 Clermont-Ferrand, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Chambon
authors.forename: Etienne
authors.initials: E
authors.lastname: Merlin
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Rochette
authors.forename: Bruno
authors.initials: B
authors.lastname: Pereira
authors.forename: Pascale
authors.initials: P
authors.lastname: Halle
authors.forename: François
authors.initials: F
authors.lastname: Deméocq
authors.forename: Justyna
authors.initials: J
authors.lastname: Kanold
mesh_terms: D000293:Adolescent; D001499:Bayes Theorem; D001596:Benzylamines; D002648:Child; D002675:Child, Preschool; D000080027:Cyclams; D005260:Female; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006571:Heterocyclic Compounds / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies
chemical_list: D001596:Benzylamines; D000080027:Cyclams; D006571:Heterocyclic Compounds; C088327:plerixafor
keywords: Apheresis; CXCR4 antagonist; Transplantation