title: Gemtuzumab ozogamicin as part of reduced-intensity conditioning for allogeneic hematopoietic cell transplantation in patients with relapsed acute myeloid leukemia.
abstract: OBJECTIVE
  Gemtuzumab ozogamicin (GO) has been associated with an increased risk of liver sinusoidal obstruction syndrome (SOS) when applied within 3 months of allogeneic hematopoietic cell transplantation (HCT). We hypothesized that GO might be safe and effective as part of a reduced-intensity conditioning regimen as salvage therapy of CD33+ acute myeloid leukemia.
  
  
  METHODS
  Thirty-one patients with acute myeloid leukemia which relapsed following conventional therapy (n=15), autologous (n=3), or allogeneic (n=13) HCT were included in a prospective phase I/II trial. The preparative regimen contained 6 and 3 mg/m(2) of GO on days -21 and -14 before transplantation, leading to a reduction of marrow blasts in 18 patients (58%). Eight patients received further cytoreductive chemotherapy before conditioning therapy was initiated. Fludarabine-based reduced-intensity (n=11) or nonmyelablative (n=16) conditioning and peripheral blood stem cell infusion from related (n=6) or unrelated (n=21) donors could be done in 27 patients during cytopenia.
  
  
  RESULTS
  Primary engraftment occurred in all evaluable patients. Only one case of reversible hepatic sinusoidal obstruction syndrome was documented. Non-relapse mortality until day 100 was 22% (n=6). The probabilities of overall and disease-free survival at 24 months were 39% and 35%, respectively. Relapse of leukemia occurring between 2 and 24 months after transplantation (median, 8 months) was the major reason for treatment failure and death.
  
  
  CONCLUSIONS
  These data suggest that GO can be combined with reduced-intensity conditioning even after previous autologous or allogeneic HCT.
authors.affiliation: Medizinische Klinik und Poliklinik I, University Hospital, Dresden, Germany. martin.bornhaeuser@uniklinikum-dresden.de
authors.forename: Martin
authors.initials: M
authors.lastname: Bornhäuser
authors.forename: Thomas
authors.initials: T
authors.lastname: Illmer
authors.forename: Uta
authors.initials: U
authors.lastname: Oelschlaegel
authors.forename: Johannes
authors.initials: J
authors.lastname: Schetelig
authors.forename: Rainer
authors.initials: R
authors.lastname: Ordemann
authors.forename: Markus
authors.initials: M
authors.lastname: Schaich
authors.forename: Mathias
authors.initials: M
authors.lastname: Hänel
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schuler
authors.forename: Christian
authors.initials: C
authors.lastname: Thiede
authors.forename: Alexander
authors.initials: A
authors.lastname: Kiani
authors.forename: Uwe
authors.initials: U
authors.lastname: Platzbecker
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ehninger