A comparison between allogeneic stem cell transplantation from unmanipulated haploidentical and unrelated donors in acute leukemia

BACKGROUND

In the absence of a HLA-matched related or matched unrelated donor, allogeneic stem cell transplantation (allo-SCT) from mismatched unrelated donors or haploidentical donors are potential alternatives for patients with acute leukemia with an indication to allo-SCT. The objective of this study was to compare the outcome of allo-SCT from T cell-replete haploidentical (Haplo) versus matched (MUD 10/10) or mismatched unrelated donor at a single HLA-locus (MMUD 9/10) for patients with acute leukemia in remission.

METHODS

Two hundred sixty-five adult patients with de novo acute leukemia in first or second remission that received a Haplo-SCT between January 2007 and December 2013 were compared with 2490 patients receiving a MUD 10/10 and 813 receiving a MMUD 9/10. Propensity score weighted analysis was conducted in order to control for disease risk imbalances between the groups.

RESULTS

The weighted 3-year non-relapse mortality and relapse incidence were 29 and 30% for Haplo, 21 and 29% for MUD 10/10, and 29 and 25% for MMUD 9/10, respectively. The weighted 3-year leukemia-free survival (LFS) and overall survival (OS) were 41 and 46% for Haplo, 50 and 56% for MUD 10/10, and 46 and 48% for MMUD 9/10, respectively. Using weighted Cox model, both LFS and OS were significantly higher in transplants from MUD 10/10 compared from those in Haplo but not different between transplants from MMUD 9/10 and Haplo. The type of donor was not significantly associated with neither acute nor chronic graft-versus-host disease.

CONCLUSIONS

Patients with acute leukemia in remission have better outcomes if transplanted from a MUD 10/10. We did not find any significant difference in outcome between transplants from MMUD 9/10 and Haplo, suggesting that both can be equally used in the absence of a 10/10 MUD. KEY POINT 1: Better outcomes using fully (10/10) matched unrelated donor for allo-SCT in acute leukemia in remission. KEY POINT 2: Similar outcomes after allo-SCT from unmanipulated haploidentical graft or mismatched (9/10) unrelated donor in acute leukemia in remission.

Does ex vivo CD34+ positive selection influence outcome after autologous hematopoietic stem cell transplantation in systemic sclerosis patients?

This EBMT Autoimmune Disease Working Party study aimed to evaluate the influence of CD34+ positive graft selection (CD34+) on the outcome of systemic sclerosis (SSc) patients after autologous hematopoietic stem cell transplantation (AHSCT). Clinical and laboratory data from 138 SSc patients at diagnosis, before and after AHSCT were retrospectively analyzed. CD34+ selection was performed in 47.1% (n=65) patients. By multivariate analysis adjusting for all factors differing between the two groups (without or with CD34+), there was no statistically significant difference in terms of overall survival (hazard ratio (HR): 0.98, 95% confidence interval (CI) 0.40-2.39, P=0.96), PFS (HR: 1.55, 95% CI 0.83-2.88, P=0.17) and incidence of relapse or progression (HR: 1.70, 95% CI 0.85-3.38, P=0.13). We demonstrate that CD34+ does not add benefit to the outcome of SSc patient treated with AHSCT. These findings should be further confirmed by prospective randomized trials.

Impact of conditioning with TBI in adult patients with T-cell ALL who receive a myeloablative allogeneic stem cell transplantation: a report from the acute leukemia working party of EBMT

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a therapeutic option for adult patients with T-cell ALL (T-ALL). Meanwhile, few allo-SCT data specific to adult T-ALL have been described thus far. Specifically, the optimal myeloablative conditioning regimen is unknown. In this retrospective study, 601 patients were included. Patients received allo-SCT in CR1, CR2, CR >2 or in advanced disease in 69%, 15%, 2% and 14% of cases, respectively. With an overall follow-up of 58 months, 523 patients received a TBI-based regimen, whereas 78 patients received a chemotherapy-based regimen including IV busulfan-cyclophosphamide (IV Bu-Cy) (n=46). Unlike patients aged ⩾35 years, patients aged <35 years who received a TBI-based regimen displayed an improved outcome compared with patients who received a chemotherapy-based regimen (5-year leukemia-free survival (LFS) of 50% for TBI versus 18% for chemo-only regimen or IV Bu-Cy regimens, P=10(-5) and 10(-4), respectively). In multivariate analysis, use of TBI was associated with an improved LFS (hazard ratio (HR)=0.55 (0.34-0.86), P=0.01) and overall survival (HR=0.54 (0.34-0.87), P=0.01) in patients aged <35 years. In conclusion, younger adult patients with T-ALL entitled to receive a myeloablative allo-SCT may benefit from TBI-based regimens.

Bone marrow or peripheral blood stem cell transplantation from unrelated donors in adult patients with acute myeloid leukaemia, an Acute Leukaemia Working Party analysis in 2262 patients

BACKGROUND

No survival benefit of using blood stem cells instead of bone marrow (BM) has been shown in matched unrelated donor (MUD) transplantation.

DESIGN AND METHODS

In a retrospective registry analysis, we compared the use of blood stem cells (n = 1502) and BM (n = 760) from unrelated donors in patients aged 18-60 years with acute myeloid leukaemia (AML) undergoing myeloablative conditioning between 1997 and 2008. The blood stem cell recipients were older (P < 0.01), had more advanced disease (P < 0.0001) and received less total body irradiation (P < 0.0001) and more antithymocyte globulin (P = 0.01).

RESULTS

Recovery of neutrophils and platelets was faster with blood stem cells (P < 0.0001). The incidence of acute graft-versus-host disease (GVHD) was similar, but there was more chronic GVHD in the blood stem cell group [hazard ratio (HR) = 1.29, P = 0.02]. There were no significant differences in nonrelapse mortality (NRM), relapse incidence and leukaemia-free survival (LFS) between the two groups amongst patients with AML in remission. In patients with advanced leukaemia, NRM was lower (HR = 0.61, P = 0.02) and LFS was prolonged (HR = 0.67, P = 0.002) when blood stem cells were used. At 3 years, LFS for all patients, regardless of remission status, was 41% for both treatment groups. The outcome was not affected after multivariable analysis adjusted for confounders.

CONCLUSION

Blood stem cells compared with BM in MUD transplantation for patients with AML in remission resulted in the same rates of LFS. In patients with advanced leukaemia, the blood stem cell group had reduced NRM and improved LFS.

Status of minimal residual disease determines outcome of autologous hematopoietic SCT in adult ALL

The role of autologous hematopoietic SCT (autoHSCT) in the treatment of high-risk (HR) adult ALL is controversial. In this study, we retrospectively analyzed the results of autoHSCT according to the status of minimal residual disease (MRD) at transplantation, as a joint analysis of the European Study Group for Adult ALL (EWALL). Data on 123 recipients of autoHSCT, aged 31 (16-59) years, with B-lineage (n=77) or T-lineage (n=46) ALL were included. In a cohort of Ph-negative ALL, the probability of leukemia-free survival at 5 years was higher for patients with MRD <0.1% compared with those with MRD > or = 0.1% (57 vs 17%, P=0.0002). The difference was significant for T-lineage ALL (62 vs 8%, P=0.001), and a tendency was observed for B-lineage ALL (54 vs 26%, P=0.17). In a multivariate analysis, adjusted for other potential prognostic factors, high MRD level remained the only independent factor associated with increased risk of failure (risk ratio, 2.8; P=0.0005). We conclude that MRD determines the outcome of autoHSCT in HR adult ALL. Our results suggest the need to reevaluate the role of this treatment option in prospective trials.

Immunogenic disparities of 11 minor histocompatibility antigens (mHAs) in HLA-matched unrelated allogeneic hematopoietic SCT

We determined the alleles of 11 mHAs and investigated the association of immunogenic mHA mismatches between a donor and a recipient with a course of allogeneic hematopoietic SCT (allo-HSCT) from 10/10 alleles HLA-matched unrelated donors in 92 recipients after myeloablative conditioning between 2004 and 2006. The frequency analysis of mHA alleles, genotypes and phenotypes accompanied by appropriate restriction HLA Ags allowed for an estimation of the probability of immunogenic mismatches, which was the highest for HA-1, HA-8 and HY. GVH-directed disparity of mHAs with broad tissue distribution, especially of the sex-related HY Ag, influenced the results of allo-HSCT from HLA-matched unrelated donors by not only increasing the probability of chronic GVHD (cGVHD) but also by decreasing the relapse rate.

Addition of cladribine to daunorubicin and cytarabine increases complete remission rate after a single course of induction treatment in acute myeloid leukemia. Multicenter, phase III study

To assess the efficacy of an original DAC-7 regimen: daunorubicine (DNR) 60 mg/m2/day, days 1-3; cytarabine (AraC) 200 mg/m2/day, days 1-7; cladribine (2-CdA) 5 mg/m2/day, days 1-5, 400 untreated adult acute myeloid leukemia patients (including 63 with preceding myelodysplastic syndrome), aged 45 (16-60) years were randomized to either DAC-7 (n=200) or DA-7 (without 2-CdA, n=200). The overall CR rate equaled 72% for DAC-7 and 69% for DA-7 arm (P=NS). After a single course of DAC-7 induction, the CR rate equaled 64% and was significantly higher compared to 47% in the DA-7 arm (P=0.0009). Median hospitalization time during the induction was 7 days shorter for DAC-7 compared to the DA-7 group (33 vs 40 days, P=0.002). Toxicity was comparable in both groups. The probability of 3-year leukemia-free survival (LFS) for DAC-7 and DA-7 group equaled 43 and 34%, respectively (P=NS). There was a trend toward higher LFS rate for patients aged >40 years receiving DAC-7 compared with DA-7 regimen (44 vs 28%, P=0.05). This study proves that addition of 2-CdA increases antileukemic potency of DNR+AraC regimen, thus resulting in a higher CR rate after one induction cycle when compared to DA-7, without additional toxicity. It shortens hospitalization time and may improve long-term survival in patients aged >40 years.