Don't forget cord blood in non-remission acute myeloid leukaemia!

Transplantation from haploidentical donors is widely used, with progressive reduction of cord blood (CB) as alternative donor. The paper by Matsuda and colleagues, the largest analysing the outcome in non-remission acute myeloid leukaemia (AML) transplanted with haploidentical donor or CB, suggests that CB is still a viable option when considering allogeneic transplantation for advanced AML. Commentary on: Matsuda et al. Comparison of transplant outcomes between haploidentical transplantation and single cord blood transplantation in non-remission acute myeloid leukaemia: A nationwide retrospective study. Br J Haematol. 2023;201:106-113.

Impact of spleen size and splenectomy on outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis: A retrospective analysis by the chronic malignancies working party on behalf of European society for blood and marrow transplantation (EBMT).

The role of spleen size and splenectomy for the prediction of post-allogeneic hematopoietic stem cell transplant (allo-HCT) outcome in myelofibrosis remains under debate. In EBMT registry, we identified a cohort of 1195 myelofibrosis patients transplanted between 2000-2017 after either fludarabine-busulfan or fludarabine-melphalan regimens. Overall, splenectomy was performed in 202 (16.9%) patients and its use decreased over time (28.3% in 2000-2009 vs 14.1% in 2010-2017 period). By multivariate analysis, splenectomy was associated with less NRM (HR 0.64, 95% CI 0.44-0.93, P = .018) but increased risk of relapse (HR 1.43, 95% CI 1.01-2.02, P = .042), with no significant impact on OS (HR 0.86, 95% CI 0.67-1.12, P = .274). However, in subset analysis comparing the impact of splenectomy vs specific spleen sizes, for patients with progressive disease, an improved survival was seen in splenectomised subjects compared to those patients with a palpable spleen length ≥ 15 cm (HR 0.44, 95% CI 0.28-0.69, P < .001), caused by a significant reduction in NRM (HR 0.26, 95% CI 0.14-0.49, P < .001), without significantly increased relapse risk (HR 1.47, 95% CI 0.87-2.49, P = .147). Overall, despite the possible biases typical of retrospective cohorts, this study highlights the potential detrimental effect of massive splenomegaly in transplant outcome and supports the role of splenectomy for myelofibrosis patients with progressive disease and large splenomegaly.

Nonmyeloablative Conditioning Regimen before T Cell Replete Haploidentical Transplantation with Post-Transplant Cyclophosphamide for Advanced Hodgkin and Non-Hodgkin Lymphomas.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a valid option in patients with refractory lymphomas. HLA haploidentical stem cell transplantation (haplo-SCT) expanded the accessibility to allogeneic hematopoietic cell transplantation. The aims of study were to retrospectively assess the toxicity and efficacy of haplo-SCT using nonmyeloablative conditioning in patients with advanced lymphoma. In total, 147 patients with advanced lymphoma at 2 partner institutions were included. Patients received a uniform nonmyeloablative conditioning regimen and graft-versus-host disease (GVHD) prophylaxis. The primary endpoints were progression-free survival (PFS), overall survival (OS), GVHD, nonrelapse mortality, and GVHD, relapse-free survival (GRFS). Median follow-up was 39 months (range, 6 to 114 months). The median age was 46 years (range, 19 to 71 years). Sixty-five percent of patients were in complete remission (CR) at transplantation. Cumulative incidence of grade II to IV acute GVHD was 30% (95% confidence interval [Cl], 23% to 38%). Two-year cumulative incidence of all grades of chronic GVHD was 13% (95% CI, 8% to 20%). Two-year cumulative incidence of disease relapse was 19% (95% CI, 14% to 27%), with a higher incidence in patients not being in CR at allo-HCT (CR versus not CR: 12% versus 33%, P = .006). Two-year PFS, OS, and GRFS were 66% (95% CI, 59-75), 73% (95% CI, 66-81), and 56% (95% CI, 48-65), respectively. Haplo-SCT with post-transplantation cyclophosphamide may be considered a valid option for patients with aggressive lymphoma and deserves further evaluation.

Timing of Post-Transplantation Cyclophosphamide Administration in Haploidentical Transplantation: A Comparative Study on Behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

The timing of immunosuppressive therapy used in combination with post-transplantation cyclophosphamide (PTCY) in haploidentical hematopoietic stem cell transplant (haplo-HSCT) is not standardized. We evaluated the schedules of immunosuppression therapy after haplo-HSCT in 509 patients with acute leukemia receiving PTCY on days +3 and +4 along with tacrolimus (group 1; n = 215), with cyclosporine A (CSA) and mycophenolate mofetil (MMF) from day +5 (group 2; n = 170), or CSA + MMF from day 0 or 1 with PTCY on days +3 and +5 (group 3; n = 124). Compared with the other 2 groups, patients in group 3 were younger (median age, 46 years; P = .02) and more often received bone marrow (77%; P < .01) and a regimen containing thiotepa, fludarabine, and busulfan (84%; P< .01). At 2 years, overall survival was 44% was in group 1, 48% in group 2, and 59% in group 3 (P= .15); leukemia-free survival (LFS) was 43%, 46%, and 53% (P= .05); and refined graft-versus-host disease-free, relapse-free survival (rGRFS) was 33%, 39%, and 36% (P = .02). The incidence of grade II-IV acute GVHD was 25% in group 1, 39% in group 2, and 18% in group 3 (P< .01); incidence of chronic GVHD was 25%, 21%, and 24% (P= .50); relapse incidence was 36%, 37%, and 26% (P= .02); and nonrelapse mortality was 26%, 20%, and 21% (P= .35). On multivariate analysis, early start of immunosuppression therapy at day +1 followed by PTCY was associated with a better LFS (hazard ratio [HR], .58; P= .02) and improved rGRFS (HR, .62; P = .02). In this study, the timing of immunosuppression influenced the outcomes of haplo-HSCT with PTCY. An early start of CSA + MMF with PTCY administered on days +3 and +5 improves LFS and rGRFS.

Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for T Cell Acute Lymphoblastic Leukemia: A Report from the European Society for Blood and Marrow Transplantation Acute Leukemia Working Party.

Allogeneic hematopoietic cell transplantation (HCT) is recommended in high-risk patients with T cell acute lymphoblastic leukemia (T-ALL). For patients without an HLA-identical donor, haploidentical (haplo-) HCT is becoming the leading source of stem cell donation. However, data are scarce on predictive factors for outcome in that setting. We identified 122 adults (20% female; median age, 31 years; range, 18 to 68 years) with T-ALL who underwent haplo-HCT with post-transplantation cyclophosphamide (ptCy) between 2010 and 2017. The median duration of follow-up of living patients was 23 months. The 2-year incidences of relapse and nonrelapse mortality were 45% and 21%, respectively. The 2-year leukemia-free survival (LFS), overall survival (OS), and graft-versus-host disease, relapse-free survival (GRFS) were 34%, 42%, and 27%, respectively. The 2-year LFS and OS were highly influenced by disease status at transplantation, being 49% and 55%, respectively, for patients in first complete remission (CR1); 34% and 50%, respectively, for those in second CR (CR2); and 8% and 12%, respectively, for patients with active disease. On multivariate analysis, only disease status was found to affect LFS and OS. Transplantation in CR2 negatively affected LFS, whereas active disease at the time of haplo-HCT negatively affected LFS and OS. In conclusion, haplo-HCT with ptCy produced encouraging results in this challenging disease, particularly when performed in patients in CR. Despite the limitation of the small sample size, our results were not affected by the type of conditioning, calling into question the need for total body irradiation-based myeloablative conditioning in that setting.

Influence of donor type, stem cell source and conditioning on outcomes after haploidentical transplant for lymphoma - a LWP-EBMT study.

Haploidentical stem cell transplantation (haploSCT) is becoming a major transplant modality for lymphoma. To assess the effects of donor characteristics, stem cell source and conditioning on outcomes, we identified 474 adults with Hodgkin (HL; 240), peripheral T-cell (PTCL; 88), diffuse large B-cell (77), mantle cell (40) or follicular lymphoma (FL; 29), who received haploSCT with post-transplant cyclophosphamide. Median follow-up of alive patients was 32 months. On multivariate analysis, acute graft-versus-host disease (GVHD) grade 2-4 was lower with offspring donors or bone marrow cells, whereas extensive chronic GVHD was higher in partial response at haploSCT or when using sisters, haploidentical donors beyond first degree, or female donors in male patients. Progression-free survival (PFS) was better for FL, HL and PTCL, whereas overall survival (OS) was better for HL and PTCL. Complete remission at haploSCT improved PFS and OS whereas these were negatively affected by cytomegalovirus donor positive/recipient positive status. No other donor characteristics (age, gender, human leucocyte antigen mismatch, ABO incompatibility) affected PFS or OS except use of haploidentical donors beyond first degree, which negatively affected OS. PFS and OS are mostly influenced by disease status and lymphoma subtype, supporting the use of any first degree haploidentical family member as a donor.

Clinical applications of donor lymphocyte infusion from an HLA-haploidentical donor: consensus recommendations from the Acute Leukemia Working Party of the EBMT.

Donor lymphocyte infusion has been used in the management of relapsed hematologic malignancies after allogeneic hematopoietic cell transplantation. It can eradicate minimal residual disease or be used to rescue a hematologic relapse, being able to induce durable remissions in a subset of patients. With the increased use of haploidentical hematopoietic cell transplantation, there is renewed interest in the use of donor lymphocytes to either treat or prevent disease relapse post transplant. Published retrospective and small prospective studies have shown encouraging results with therapeutic donor lymphocyte infusion in different haploidentical transplantation platforms. In this consensus paper, finalized on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we summarize the available evidence on the use of donor lymphocyte infusion from haploidentical donor, and provide recommendations on its therapeutic, pre-emptive and prophylactic use in clinical practice.

Haploidentical related donor compared to HLA-identical donor transplantation for chemosensitive Hodgkin lymphoma patients.

BACKGROUND: Allogeneic stem cell transplantation from haploidentical donor using an unmanipulated graft and post-transplantation cyclophosphamide (PT-Cy) is growing. Haploidentical transplantation with PT-Cy showed a major activity in Hodgkin lymphoma (HL), reducing the relapse incidence. The most important predictive factor of survival and toxicity was disease status before transplantation, which was better in patients with well controlled disease. METHODS: We included 198 HL in complete (CR) or partial remission (PR) before transplantation. Sixty-five patients were transplanted from haploidentical donor and 133 from a HLA identical donor (both sibling and unrelated donors). Survival analysis was defined according to the EBMT criteria. Survival curves were generated by using Kaplan-Meier method and differences between groups were compared by the log rank test or by the log rank test for trend when appropriated. RESULTS: The PFS, OS, and RI were significantly better in patients in CR compared to PR (55% vs 29% p = 0.001, 74% vs 55% p = 0.03, 27% vs 55% p <  0.001, respectively). The 2-year PFS was significantly better for HAPLO than HLA-id (63% vs 37%, p = 0.03), without difference in OS. The 1-year NRM was not different. The 2-year relapse incidence (RI) was lower in the HAPLO group (24% vs 44%, p = 0.008). Patients in CR receiving haplo HSCT showed higher 2-year PFS and lower 2-year RI than those allografted with HLA-id donor (75% vs 47%, p <  0.001 and 11% vs 34%, p < 0.001, respectively). In multivariate analysis, donor type and disease status before transplantation were independent predictors of PFS as well as they predict the risk of relapse. Disease status at transplantation and age were independently associated to OS. CONCLUSIONS: Nonetheless this is a retrospective study, limiting the wide applicability of results, data from this analysis suggest that HLA mismatch can induce a strong graft versus lymphoma effect leading to an enhanced PFS.

Donor-Specific Anti-HLA Antibodies in Haploidentical Stem Cell Transplantation with Post-Transplantation Cyclophosphamide: Risk of Graft Failure, Poor Graft Function, and Impact on Outcomes.

The presence of donor-specific anti-HLA antibodies (DSA) is associated with a 10-fold increased risk of graft failure in haploidentical stem cell transplantation (haplo-SCT). Consensus guidelines from the European Society for Blood and Marrow Transplantation set a mean fluorescence intensity (MFI) >1000 as a cutoff for DSA positivity. In the absence of an alternative donor, it is recommended that patients undergo desensitization therapy, especially with high DSA levels (>5000 MFI). The aim of this study was to analyze the impact of DSA on risk of graft failure and poor graft function, as well as on major outcomes in a consecutive cohort of patients who were systematically screened for DSA before haplo-SCT. A total of 141 consecutive patients were candidates for unmanipulated haplo-SCT with post-transplantation cyclophosphamide (PT-Cy) at our center between January 2012 and January 2018, and 135 were analyzed for the presence of HLA antibodies. Of these 134 patients underwent haplo-SCT. HLA antibodies were detected in 40 patients, including 19 with DSA and 21 without DSA. Ten of the 19 patients with DSA underwent transplantation using that donor, whereas 2 underwent a desensitization program before transplantation. Only 2 patients experienced primary graft failure (1.4 %), both of whom were without DSA. Twenty patients developed a poor graft function (15%). The 3-year overall survival (OS), 3-year progression-free survival (PFS), and 1-year nonrelapse mortality (NRM) were analyzed according to the presence or absence of DSA. No statistically significant difference was found. No impact of the presence of DSA on the risk of developing graft failure and poor graft function was revealed. Major outcomes of transplantation were analyzed separately in patients with poor graft function and those with good graft function. The 3-year OS, 3-year PFS, and 1-year NRM in good graft function and poor graft function populations were 62% versus 20% (P < .0001), 53% versus 20% (P < .0001), and 12% versus 40% (P = .009), respectively. The presence of low-level DSA in the absence of desensitization did not correlate with the risk of developing graft failure and poor graft function. Patients who experienced poor graft function had worse outcomes than patients with good graft function.

Peripheral Blood Hemopoietic Stem Cell Mobilization Regimens in POEMS Syndrome: A Retrospective Study at 2 Hematologic Italian Centers.

Autologous peripheral blood stem cell transplantation should be considered first-line therapy in young patients with POEMS. The best protocol to collect peripheral blood stem cells remains to be defined, because of the disease rarity and the heterogeneity of published case series. We collected clinical and laboratory data from 25 patients undergoing mobilization, of whom 11 were mobilized using cyclophosphamide (CY) followed by granulocyte colony-stimulating factor (G-CSF) and 14 patients using G-CSF. The incidence of poor mobilization was low and not statistically different between the 2 groups. Both schemes (CY plus G-CSF versus G-CSF alone) were able to harvest a sufficient CD34+ cell dose.

Peripheral Blood Stem Cells versus Bone Marrow for T Cell-Replete Haploidentical Transplantation with Post-Transplant Cyclophosphamide in Hodgkin Lymphoma.

Haploidentical stem cell transplantation (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) represents a potential curative strategy for patients with Hodgkin lymphoma (HL) when a matched related or unrelated donor is not available. The role of graft source, either bone marrow (BM) or peripheral blood stem cells (PBSCs), in this setting has not been fully elucidated. We performed a retrospective study on 91 patients with HL to compare the outcome after BM (n = 53) or PBSC (n = 38) transplant. Eighty-nine patients engrafted with no difference between BM and PBSCs in terms of median time for neutrophil (20 versus 20 days, P = .405) and platelet (26 versus 26.5 days, P = .994) engraftment. With a median follow-up of 40.2 months, 100-day cumulative incidences of grades II to IV acute graft-versus host disease (GVHD) and grades II to IV acute GVHD were 24% and 4%, respectively. Graft source was not associated with a different risk of acute GVHD both by univariate and multivariate analyses. Consistently, 1-year cumulative incidence of chronic GVHD was 7% with no differences between the 2 graft types (P = .761). Two-year rates of overall survival (OS), progression-free survival (PFS), nonrelapse mortality, and GVHD/relapse-free survival (GRFS) were 67%, 58%, 20%, and 52%, respectively. By univariate analysis, pretransplant disease status was the main variable affecting all outcomes. By multivariate analysis, PBSCs resulted in a protective factor for OS (hazard ratio [HR], .29; P = .006), PFS (HR, .38; P = .001), and GRFS (HR, .44; P = .020). The other independent variables affecting the final outcome were pretransplant disease status and hematopoietic cell transplant-specific comorbidity index. In conclusion, when planning a haplo-SCT with PT-Cy for patients with poor-risk HL, graft type is an important variable to take into account when selecting the best available donor.

Brentuximab vedotin for recurrent Hodgkin lymphoma after allogeneic hematopoietic stem cell transplantation: A report from the EBMT Lymphoma Working Party.

BACKGROUND: The treatment of patients with Hodgkin lymphoma (HL) who develop disease progression after undergoing allogeneic stem cell transplantation (allo-SCT) remains challenging. METHODS: The authors assessed outcomes in 184 adult patients with HL who developed disease recurrence or progression after a matched related or unrelated allo-SCT at European Society for Blood and Marrow Transplantation-participating centers between 2010 and 2014. RESULTS: Eighty patients who received brentuximab vedotin (BV) salvage therapy were compared with 104 patients who did not. Patients in the BV group were younger (median age of 30 years vs 34 years) and were more likely to receive pretransplant BV (65% vs 46%) or posttransplant donor lymphocyte infusion (66% vs 33%). The 2 groups otherwise were comparable. Patients in the BV group received a median of 6 doses of posttransplant BV, resulting in a complete remission rate of 29%, a partial response rate of 45%, and a stable disease rate of 26%. Response to BV after allo-SCT did not appear to be affected by receipt of pretransplant BV. Despite a longer median follow-up for surviving patients in the BV group (33 months vs 23 months; P<.001), approximately 34% of the original BV cohort were alive and in CR at the time of last follow-up versus 18% in the group that did not receive BV (P=.003). The use of BV before donor lymphocyte infusion was found to be associated with the highest probability of being alive and in CR (40%) at the time of last follow-up. Salvage BV appeared to have no effect on chronic graft-versus-host disease or 1-year overall survival from the time of disease recurrence after allo-SCT (76% vs 67%). CONCLUSIONS: BV is a safe and effective salvage therapy for patients with HL who develop disease recurrence or progression after undergoing allo-SCT, even after prior exposure to BV.

Safety and efficacy of allogeneic hematopoietic stem cell transplant after PD-1 blockade in relapsed/refractory lymphoma.

Anti-programmed cell death protein 1 (PD-1) monoclonal antibodies are being increasingly tested in patients with advanced lymphoma. Following treatment, many of those patients are likely to be candidates for allogeneic hematopoietic stem cell transplant (HSCT). However, the safety and efficacy of HSCT may be affected by prior PD-1 blockade. We conducted an international retrospective analysis of 39 patients with lymphoma who received prior treatment with a PD-1 inhibitor, at a median time of 62 days (7-260) before HSCT. After a median follow-up of 12 months, the 1-year cumulative incidences of grade 2-4 and grade 3-4 acute graft-versus-host disease (GVHD) were 44% and 23%, respectively, whereas the 1-year incidence of chronic GVHD was 41%. There were 4 treatment-related deaths (1 from hepatic sinusoidal obstruction syndrome, 3 from early acute GVHD). In addition, 7 patients developed a noninfectious febrile syndrome shortly after transplant requiring prolonged courses of steroids. One-year overall and progression-free survival rates were 89% (95% confidence interval [CI], 74-96) and 76% (95% CI, 56-87), respectively. One-year cumulative incidences of relapse and nonrelapse mortality were 14% (95% CI, 4-29) and 11% (95% CI, 3-23), respectively. Circulating lymphocyte subsets were analyzed in 17 patients. Compared with controls, patients previously treated with PD-1 blockade had significantly decreased PD-1+ T cells and decreased ratios of T-regulatory cells to conventional CD4 and CD8 T cells. In conclusion, HSCT after PD-1 blockade appears feasible with a low rate of relapse. However, there may be an increased risk of early immune toxicity, which could reflect long-lasting immune alterations triggered by prior PD-1 blockade.

Caspofungin for primary antifungal prophylaxis after T-cell-replete haploidentical stem cell transplantation with post-transplant cyclophosphamide.

OBJECTIVES: T-cell-replete haploidentical stem cell transplantation (Haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) is at high risk of invasive fungal infections (IFI), and anti-mold-active drug is required for primary antifungal prophylaxis (PAP) according to international guidelines. No data are available on the efficacy of caspofungin as PAP in this setting. METHODS: Here, we report our retrospective experience with 103 consecutive patients treated with caspofungin as PAP after Haplo-SCT. Caspofungin was administered only during the pre-engraftment phase. RESULTS: Hundred-day cumulative incidence of proven-probable IFI (PP-IFI) was 8.7% and median day of onset was 19 post-SCT. No patient died of PP-IFI, and overall survival (OS) and non-relapse mortality (NRM) hazard ratio (HR) for patients experiencing IFI were 1.02 (P = 0.9) and 0.7 (P = 0.7), respectively. Three-year overall survival (OS) and 1-year non-relapse mortality (NRM) were 55% and 19%, respectively. By univariate analysis, duration of neutropenic phase and partial remission pre-transplant disease status were associated with increased incidence of IFI, but were not confirmed by multivariate analysis. CONCLUSION: In summary, PAP with caspofungin is an effective strategy for preventing IFI in the context of Haplo-SCT with PT-Cy. Further efforts are required in order to identify more potent strategies able to avoid the occurrence of breakthrough infections.

HLA-Matched Sibling versus Unrelated versus Haploidentical Related Donor Allogeneic Hematopoietic Stem Cell Transplantation for Patients Aged Over 60 Years with Acute Myeloid Leukemia: A Single-Center Donor Comparison.

Haploidentical related donor (HRD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) was developed as a valid option for the treatment of acute myeloid leukemia (AML) in the absence of a matched donor. However, many investigators are reluctant to consider the use of this alternative in elderly patients, anticipating high morbidity. Here, we report a single-center comparison of HRD versus matched sibling donor (MSD) and unrelated donor (UD) allo-HSCT for patients with AML aged ≥60 years. Ninety-four patients (MSD: n = 31; UD: n = 30; HRD: n = 33) were analyzed. The median age was 65 (range, 60 to 73) years. We observed a higher cumulative incidence of grade 3 to 4 acute graft-versus-host disease (GVHD) after UD allo-HSCT (MSD versus UD versus HRD: 3% versus 33% versus 6%, respectively; P = .006). Two-year cumulative incidence of moderate or severe chronic GVHD was 17%, 27%, and 16% in the MSD, UD, and HRD groups, respectively (P = .487). No difference was observed in the 2-year cumulative incidence of relapse or nonrelapse mortality (NRM) (relapse: MSD versus UD versus HRD: 32% versus 25% versus 25%, respectively; P = .411; NRM: MSD versus UD versus HRD: 19% versus 27% versus 24%, respectively; P = .709). At 2 years, progression-free survival, overall survival, and GVHD- and relapse-free survival were 48%, 50%, and 39%, respectively, in the MSD group; 48%, 51%, and 23%, respectively, in the UD group; and 50%, 52%, and 32%, respectively, in the HRD group, without statistically significant differences between the groups. We conclude that HRD allo-HSCT is highly feasible and no less efficient than MSD or UD allo-HSCT in patients with AML aged ≥60 years. Thus, the absence of a HLA-identical donor should not limit the consideration of allo-HSCT for the treatment of AML.

T Cell-Replete Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for Hodgkin Lymphoma Relapsed after Autologous Transplantation: Reduced Incidence of Relapse and of Chronic Graft-versus-Host Disease Compared with HLA-Identical Related Donors.

Allogeneic hematopoietic stem cell transplantation (SCT) represents a potential curative strategy for patients with Hodgkin lymphoma (HL) relapsing after autologous SCT (ASCT), but the incidence of disease relapse is still high. We performed a retrospective study on 64 patients with HL relapsing after ASCT to compare outcomes after HLA-identical SCT (HLAid-SCT; n = 34) and haploidentical SCT with post-transplantation cyclophosphamide (PT-Cy) (Haplo-SCT; n = 30). All patients engrafted, with a significantly shorter median time for neutrophil and platelet engraftment after HLAid compared with Haplo-SCT (14 days versus 19 days and 11 days versus 23 days, respectively; P < .005). With a median follow-up of 47 months, 3-year overall survival (OS), 3 -year progression-free survival (PFS), and 1-year nonrelapse mortality (NRM) were 53%, 44% and 17%, respectively. Recipients of Haplo-SCT were less likely to experience disease relapse (3-year cumulative incidence of relapse, 13% versus 62%; P = .0001) and chronic graft- versus-host disease (GVHD; 3% versus 32%; P = .003), resulting in improved PFS (60% versus 29%; P = .04) and GVHD-free/relapse-free survival (47% versus 17%; P = .06). The 3-year OS did not differ between the 2 groups (56% versus 54%; P not significant), and NRM was higher after Haplo-SCT, but the difference did not reach statistical significance (26% versus 9%; P = .09). On multivariate Cox regression analysis, receipt of Haplo-SCT (hazard ratio [HR], .17; P = .02) and achieving optimal disease control (complete remission before SCT: HR, .6; P < .0001) were the only independent variables associated with a reduced risk of disease relapse. Haplo-SCT is a valid option for patients with HL relapsing after ASCT, with a reduced incidence of relapse compared with HLAid SCT.

Killer Cell Immunoglobulin-Like Receptor-Ligand Mismatch in Donor versus Recipient Direction Provides Better Graft-versus-Tumor Effect in Patients with Hematologic Malignancies Undergoing Allogeneic T Cell-Replete Haploidentical Transplantation Followed by Post-Transplant Cyclophosphamide.

We evaluated the impact of unidirectional donor versus recipient killer cell immunoglobulin-like receptor (KIR)-ligand mismatch (KIR-Lmm) on the outcomes of T cell-replete haploidentical stem cell transplantation (Haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) in a cohort of 144 patients treated for various hematologi diseases. We separately analyzed 81 patients in complete remission (CR group) and 63 with active disease (no CR group) at the time of Haplo-SCT. One-third of patients in each group had KIR-Lmm. In the no CR group, KIR-Lmm was associated with a significantly lower incidence of relapse (hazard ratio, .21; P = .013) and better progression-free survival (hazard ratio, .42; P = .028), with no significant increase in graft-versus-host disease incidence or nonrelapse mortality. In contrast, in the CR group no benefit of KIR-Lmm was observed. Our results encourage considering KIR-Lmm as an additional tool to improve donor selection for T cell-replete Haplo-SCT with PT-Cy, especially in patients with high-risk diseases.

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.

Brentuximab vedotin prior to allogeneic stem cell transplantation in Hodgkin lymphoma: a report from the EBMT Lymphoma Working Party.

Brentuximab vedotin (BV) is an anti-CD30 antibody-drug conjugate. Preliminary data suggest that BV might improve outcomes after allogeneic stem cell transplantation (SCT) for Hodgkin lymphoma (HL) when used as pre-transplant salvage therapy. Between 2010 and 2014, 428 adult patients underwent an allogeneic SCT for classical HL at participating centres of the European Society for Blood and Marrow Transplantation. We compared the outcomes of 210 patients who received BV prior to allogeneic SCT with that of 218 patients who did not receive BV. The median follow-up for survivors was 41 months. Patients in the BV group were more heavily pre-treated (median pre-allograft treatment lines: 4 vs. 3). The two groups were comparable in terms of disease status, performance status, comorbidities, prior autologous SCT, type of donor, conditioning and in vivo T cell depletion. In multivariate analysis, pre-allograft BV had no impact on acute graft-versus-host disease (GVHD), non-relapse mortality, cumulative incidence of relapse, progression-free survival or overall survival (OS), but significantly reduced the risk of chronic GVHD (hazard ratio = 0·64; 95% confidence interval = 0·45-0·92; P < 0·02). Older age, poor performance status, use of pre-transplant radiotherapy and active disease at SCT adversely affected OS. Patients allografted for HL after prior exposure to BV do not have a superior outcome after allogeneic SCT except for a lower risk of chronic GVHD. However, BV may improve the outlook of allogeneic SCT by helping otherwise refractory patients to achieve a more favourable disease status, facilitating allotransplant success.

The early expansion of anergic NKG2Apos/CD56dim/CD16neg natural killer represents a therapeutic target in haploidentical hematopoietic stem cell transplantation.

Natural killer cells are the first lymphocyte population to reconstitute early after non-myeloablative and T cell-replete haploidentical hematopoietic stem cell transplantation with post-transplant infusion of cyclophosphamide. The study herein characterizes the transient and predominant expansion starting from the second week following haploidentical hematopoietic stem cell transplantation of a donor-derived unconventional subset of NKp46neg-low/CD56dim/CD16neg natural killer cells expressing remarkably high levels of CD94/NKG2A. Both transcription and phenotypic profiles indicated that unconventional NKp46neg-low/CD56dim/CD16neg cells are a distinct natural killer cell subpopulation with features of late stage differentiation, yet retaining proliferative capability and functional plasticity to generate conventional NKp46pos/CD56bright/CD16neg-low cells in response to interleukin-15 plus interleukin-18. While present at low frequency in healthy donors, unconventional NKp46neg-low/CD56dim/CD16neg cells are greatly expanded in the seven weeks following haploidentical hematopoietic stem cell transplantation, and express high levels of the activating receptors NKG2D and NKp30 as well as of the lytic granules Granzyme-B and Perforin. Nonetheless, NKp46neg-low/CD56dim/CD16neg cells displayed a markedly defective cytotoxicity that could be reversed by blocking the inhibitory receptor CD94/NKG2A. These data open new and important perspectives to better understand the ontogenesis/homeostasis of human natural killer cells and to develop a novel immune-therapeutic approach that targets the inhibitory NKG2A check-point, thus unleashing natural killer cell alloreactivity early after haploidentical hematopoietic stem cell transplantation.