53 Mismatched Unrelated Donor Allo-SCT for AML after Reduced Intensity or Ablative Conditioning Regimen- a Report from the Acute Leukemia Working Party of the EBMT

Track: BMT Tandem "Scientific" Meeting
Saturday, February 14, 2015, 4:45 PM-6:45 PM
Seaport Ballroom DE (Manchester Grand Hyatt)
Bipin N. Savani, MD , Vanderbilt University Medical Center, Nashville, TN
Myriam Labopin, MD , EBMT Paris study office / CEREST-TC, Paris, France
Emmanuelle Polge , Université Pierre et Marie Curie, Paris, France
Nicolaus Kröger, Professor , Dept of Stem Cell Transplantation, University Medical Center Hamburg, Hamburg, Germany
Jurgen Finke, MD , Dept of Medicine, Haematology&Oncology, Allogeneic Stem Cell Transplantation Section, Freiburg University Medical Center, Freiburg, Germany
Gerhard Ehninger , Universitaetsklinikum Dresden, Dresden, Germany
Dietger Niederwieser, MD , University of Leipzig, Leipzig, Germany
Slawomira Kyrcz-Krzemien, MD , Silesian Medical Academy, Katowice, Poland
Rainer Schwerdtfeger, MD, PhD , Department of BMT, DKD - Wiesbaden, Wiesbaden, Germany
Donald W. Bunjes, MD , Department of Internal Medicine III, University of Ulm, Ulm, Germany
Bertrum Glass, MD , Asklepios Klinik St. Georg - Department of Haematology, Hamburg, Germany
Gerard Socié, MD, PhD , Hematology/Transplantation, Hospital Saint Louis, Paris, France
Per T. Ljungman, MD, PhD , Hematology, Karolinska University Hospital, Stockholm, Sweden
Mohamad Mohty, MD, PhD , Department of Haematology, Saint Antoine Hospital, Paris, France
Arnon Nagler, MD , The Chaim Sheba Medical Center, Tel-Hashomer, Division of Hematology and Bone Marrow Transplantation, Ramat-Gan, Israel
Audio File Recorded Presentation

Background: RIC regimens are reported to be associated with equivalent outcome compared to ablative regimens (MAC) but it is unknown  if there are any outcome differences after mismatched (MM) unrelated donor (URD) allo-SCT. We hypothesized that, the historically higher relapse rate after RIC compared to MAC can be abrogated by potent GVL effect using MM URD.

Methods: Patients (pts) who underwent MAC or RIC MM URD transplant from 2000-12 were included in the study. All had donors with available information on HLA MM at one or two loci (9/10 or 8/10). Regimens were classified as MAC or RIC based on EBMT criteria. The Kaplan-Meier estimator, the cumulative incidence function and Cox proportional hazards regression models were used where appropriate.

Results: 1041 pts receiving MAC compared with 883 RIC after MM-URD allo-SCT. Among the MAC, 872 (83.8%) were 9/10 and 169 (16.2%) 8/10 matched and in RIC cohort 754 (85.4%) were 9/10 and 129 (14.6%) were 8/10 matched. Median follow up for MAC and RIC group was 27 and 23 months respectively. MAC recipients were significantly younger (median age 43 vs 57 year), 70% pts were <50 year age in MAC vs only 30% in RIC group (p=0.0001). Significantly higher numbers of pts had sAML (13 vs 10%, p=0.04) and KPS<90% (30 vs 25%, p=0.02) in the RIC group. There were no significant differences in distributions of advanced disease and poor risk cytogenetic among regimens. Commonly used MAC regimens were TBI based (n=369), BuCy (354) and FluBu (143); and in the RIC group regimens were low dose TBI based (n=275), BuFlu (312) and FluMel (178). The MAC group had more frequently marrow as the stem cell source (20 vs 9%; p<0.0001). Percentages of engraftment and grade II-IV aGVHD were not different between the groups. The incidence of cGVHD was higher after RIC (34 vs 29%; p=0.04). There was no statistical difference between MAC vs RIC for OS, LFS, RI and NRM (Figure 1).

The analyses were performed separately for pts <50 and ≥50 year group. Among older cohorts (age ≥50), there was a significant advantage of RIC regimen with higher OS (44.6 vs 37.1%; p=0.01), LFS (40.3 vs 34.3%; p=0.03), decreased NRM (29.6% vs 35.8%; p=0.05), but no differences in RI (p=0.95). A higher cumulative incidence of cGVHD was seen after RIC (37.6 vs 24.3%; p=0.0009). Among younger cohort (age <50), MAC showed no differences in OS, NRM and cGVHD compared to the RIC group.

In multivariate analysis (age ≥50), higher OS (HR 0.78; p=0.01), LFS (HR 0.82; p=0.05), and decreased NRM (HR 0.73; p=0.03) were seen after RIC. RI (HR 0.91; p=0.51) and cGVHD (HR 1.31; p=0.11) were, however, not significantly different. Pts <50 year old showed no differences in OS, LFS, RI, NRM, and cGVHD between MAC or RIC group.

Conclusion: Our study shows no significant outcome difference between RIC and MAC regimens after MM URD allo-SCT in pts younger than 50 years. Furthermore, data support superiority of RIC regimen in older adults receiving transplant from MM URD

Disclosures:
Nothing To Disclose
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