Bone marrow versus mobilized peripheral blood stem cells in haploidentical transplants using posttransplantation cyclophosphamide.

BACKGROUND: Incidence of graft-versus-host disease (GVHD) in haploidentical bone marrow (BM) transplants using posttransplantion cyclophosphamide (PT-Cy) is low, whereas GVHD using mobilized peripheral blood stem cells (PBSC) ranges between 30% and 40%. METHODS: To evaluate the effect of stem cell source in haploidentical transplantation with PT-Cy, we analyzed 451 patients transplanted for acute myeloid leukemia or acute lymphoblastic leukemia reported to the European Society for Blood and Marrow Transplantation. RESULTS: BM was used in 260 patients, and PBSC were used in 191 patients. The median follow-up was 21 months. Engraftment was lower in BM (92% vs 95%, P < 0.001). BM was associated with a lower incidence of stage II-IV and stage III-IV acute GVHD (21% vs 38%, P ≤ .01; and 4% vs 14%, P < .01, respectively). No difference in chronic GVHD, relapse, or nonrelapse mortality were found for PBSC or BM. The 2-year overall survival (OS) was 55% versus 56% (P = .57) and leukemia-free survival (LFS) was 49% versus 54% (P = .74) for BM and PBSC, respectively. On multivariate analysis, PBSC were associated with an increased risk of stage II-IV (hazard ratio [HR], 2.1; P < .001) and stage III-IV acute GVHD (HR, 3.8; P < .001). For LFS and OS, reduced intensity conditioning was the only factor associated with treatment failure (LFS: HR, 1.40; P = .04) and relapse (HR, 1.62; P = .02). CONCLUSION: In patients with acute leukemia in first or second remission receiving haploidentical transplantation with PT-Cy, the use of PBSC increases the risk of acute GVHD, whereas survival outcomes are comparable. Cancer 2018;124:1428-37. © 2018 American Cancer Society.

Survival advantage of treosulfan plus fludarabine (FT14) compared to busulfan plus fludarabine (FB4) in active acute myeloid leukemia post allogeneic transplantation: an analysis from the European Society for Blood and Marrow Transplantation (EBMT) Acute Leukemia Working Party (ALWP).

We compared FT14 (fludarabine 150-160 mg/m2, treosulfan 42 g/m2) versus FB4 (fludarabine 150-160 mg/m2, busulfan 12.8 mg/kg) in acute myeloid leukemia (AML) transplanted at primary refractory/relapsed disease. We retrospectively studied: (a) adults diagnosed with AML, (b) recipients of first allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated/sibling donor (2010-2020), (c) HSCT with primary refractory/relapsed disease, (d) conditioning regimen with FT14 or FB4. We studied 346 patients, 113 transplanted with FT14, and 233 with FΒ4. FT14 patients were significantly older, more frequently had an unrelated donor and had received a lower dose of fludarabine. Cumulative incidence (CI) of acute graft-versus-host disease (GVHD) grade III-IV and extensive chronic GVHD was similar. With a median follow-up of 28.7 months, 2-year CI of relapse was 43.4% in FT14 versus 53.2% in FB4, while non-relapse mortality (NRM) was respectively 20.8% versus 22.6%. This led to 2-year leukemia-free survival (LFS) of 35.8% for FT14 versus 24.2% in FB4, and overall survival (OS) of 44.4% versus 34%. Adverse cytogenetics and conditioning regimen independently predicted CI of relapse. Furthermore, conditioning regimen was the only independent predictor of LFS, OS, and GVHD-free/relapse-free survival. Therefore, our real-world multicenter study suggests that FT14 is associated with better outcomes in primary refractory/relapsed AML.

Comparison of Outcomes after Unrelated Double-Unit Cord Blood and Haploidentical Peripheral Blood Stem Cell Transplantation in Adults with Acute Myelogenous Leukemia: A Study on Behalf of Eurocord and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

Unmanipulated haploidentical hematopoietic stem cell transplantation (HCT) with post-transplantation cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis (haplo-PTCY) and unrelated double-unit umbilical cord blood transplantation (dUCBT) are feasible options for treating patients with high-risk acute myelogenous leukemia (AML). This study compared outcomes after dUCBT and haplo-HCT using peripheral blood stem cells (PBSCs) in adult patients with AML in complete remission (CR) who underwent transplantation in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers. In a population of adults with de novo AML in first or second CR, we compared outcomes after dUCBT (n = 165) and after haplo-PTCY PBSC (n = 544) performed between January 2013 and December 2018. Patients receiving in vivo antithymocyte globulin, Campath, or ex vivo T cell depletion were excluded. The median follow-up was 33 months for the haplo-PTCY arm and 52 months for the dUCBT arm. No statistically significant differences were observed between the 2 arms in the rates of grade II-IV acute graft-versus-host disease (GVHD) (hazard ratio [HR], 1.31; P = .18), grade III-IV acute GVHD (HR, 1.17; P = .56), chronic GVHD (HR, .86; P = .48), relapse (HR, 1.07; P = .77), nonrelapse mortality (NRM) (HR, .94; P = .77), leukemia-free survival (LFS) (HR, .99; P = .95), or overall survival (OS) (HR, .99; P = .97). Favorable cytogenetic risk was the sole factor predictive of lower relapse incidence (RI). Younger age at transplantation was associated with lower NRM and higher LFS and OS. Both dUCBT and haplo-PTCY with PBSCs can be considered valid approaches for adult AML patients in CR. New strategies should be investigated in both settings to define the most appropriate conditioning regimen and potentially decrease RI and NRM through better immune reconstitution and optimal supportive care.

Post-transplant cyclophosphamide in one-antigen mismatched unrelated donor transplantation versus haploidentical transplantation in acute myeloid leukemia: a study from the Acute Leukemia Working Party of the EBMT.

Whether to choose Haploidentical (Haplo) or one-antigen mismatched unrelated donor (1Ag-MMUD) hematopoietic cell transplantation (HCT) with post-transplant cyclophosphamide (PTCy) remains an unanswered question. We compared PTCy- Haplo-HCT to PTCy-1Ag-MMUD-HCT for acute myeloid leukemia (AML) in complete remission (three groups: 1Ag-MMUD using peripheral blood (1Ag-MMUD-PB; n = 155); Haplo using bone marrow (Haplo-BM; n = 647) or peripheral blood (Haplo-PB; n = 949)). Haplo-BM and Haplo-PB had a higher non-relapse mortality (NRM) compared to 1Ag-MMUD-PB (HR 2.28, 95% CI 1.23-4.24, p < 0.01; HR 2.65, 95% CI 1.46-4.81, p < 0.01, respectively). Haplo groups experienced a lower leukemia-free survival (LFS) compared to 1Ag-MMUD-PB (Haplo-BM: HR 1.51, 95% CI 1.06-2.14, p = 0.02; Haplo-PB: 1.47, 95% CI 1.05-2.05, p = 0.02); overall survival (OS) was also lower in Haplo-HCT (Haplo-BM: HR 1.50, 95% CI 1.02-2.21, p = 0.04; Haplo-PB: HR 1.51, 95% CI 1.05-2.19, p = 0.03). No differences were observed for graft-versus-host/relapse-free survival (GRFS) and relapse incidence (RI). Haplo-BM was associated with a lower risk of grade III-IV acute graft-versus-host disease (GVHD) (HR 0.44, 95% CI 0.24-0.81; p < 0.01), while no statistical differences were observed between groups for grade II-IV aGVHD and for cGVHD. Use of PTCy in 1Ag-MMUD-HCT is a valid alternative to consider when using alternative donors. Larger analysis of 1Ag-MMUD versus Haplo-HCT are warranted.

Prognostic factors for neutrophil engraftment after haploidentical cell transplantation with PT-Cy in patients with acute myeloid leukemia in complete remission, on behalf of the ALWP-EBMT.

The use of haplo-HCT with posttransplant cyclophosphamide (PT-Cy) is a new standard in the treatment of hematological diseases. A paucity of data exists on risk factors for engraftment failure in haplo-HCT with PT-Cy. We analyzed 1939 adults with acute myeloid leukemia (AML) who received a first haplo-HCT from 2010 to 2019. Status at haplo-HCT was first complete remission (CR1) in 72.5% of patients, secondary AML was reported in 9.9%. Median follow-up was 24.4 months and median age at haplo-HCT was 51 years. Stem cell source was bone marrow (BM) in 42% and peripheral blood stem cell (PBSC) in 58%, and 64% of patients received a myeloablative conditioning (MAC) regimen. Cumulative incidence of primary graft failure (GF) was 6%; GF was reported in 110 patients and 54 died before day +30 with no sign of cell recovery. Overall, 33 patients underwent a second HCT in a median time of 45 days and 13 were alive at last follow-up, the 2-year overall survival (OS) after second HCT being 32.4%. In multivariate analysis, factors independently associated with the risk of nonengraftment were: secondary AML (HR 1.30, p = 0.003), use of RIC (HR 1.22, p < 0.001), and use of BM (HR 1.21, p < 0.001). At 2 years, leukemia-free survival (LFS) and OS for the entire population was 55.2% (95% CI: 52.6-57.6) and 60.9% (95% CI: 58.4-63.3), respectively. Incidence of GF after haplo-HCT with PT-Cy is lower than reported T-cell-depleted haplo-HCT. Optimization of conditioning regimen and graft source should be considered for reducing the risk of GF in haplo-HCT recipients using PT-Cy.