Reduced intensity versus myeloablative conditioning for MDS: long-term results of an EBMT phase III study (RICMAC).

Short-term outcome of myeloablative (MAC) and reduced intensity (RIC) conditioning in the prospective randomized international EBMT RICMAC study in patients with myelodyplastic syndrome (MDS) was comparable but longer follow up is lacking. Patients with MDS aged 18-65 years were randomized to receive MAC (N = 64) with busulfan/cyclophosphamide or RIC (n = 65) with busulfan/fludarabine followed by stem cell transplantation -(HCT) from HLA matched or mismatched donor. After a median follow-up of 6.2 (0.4-12.5) years, 10-year OS and RFS were 54.0% and 43.9% for RIC and 44.4% and 44.2% for MAC (p = 0.15 and p = 0.78), respectively. Since the first report, 6 patients died on NRM, 4 after RIC, and 2 after MAC. Similarly, 8 patients relapsed (4 in each arm), increasing the number of relapsed patients to 28. The second HCT was performed in 18 pts, 8 in the MAC, and 10 in the RIC arm. In a multivariate analysis, ECOG status and chemotherapy prior to HCT were independent risk factors for OS and RFS, ECOG and low cytogenetic risk for NRM and chemotherapy prior to HCT for RI. Patients with low cytogenetic risk had better OS [p = 0.002], RFS [p = 0.02], and NRM (p = 0.015) after RIC as compared to MAC.

Transplantation for myelofibrosis patients in the ruxolitinib era: a registry study from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire.

In this SFGM-TC registry study, we report the results after stem cell transplantation (HSCT) in 305 myelofibrosis patients, in order to determine potential risk factors associated with outcomes, especially regarding previous treatment with ruxolitinib. A total of 102 patients were transplanted from an HLA-matched-sibling donor (MSD), and 143 patients received ruxolitinib. In contrast with previous studies, our results showed significantly worse outcomes for ruxolitinib patients regarding overall survival (OS) and non-relapse mortality (NRM), especially in the context of unrelated donors (URD). When exploring reasons for potential confounders regarding the ruxolitinib effect, an interaction between the type of donor and the use of ATG was found, therefore subsequent analyses were performed separately for each type of donor. Multivariable analyses did not confirm a significant negative impact of ruxolitinib in transplantation outcomes. In the setting of URD, only age and Fludarabine-Melphalan (FM) conditioning were associated with increased NRM. For MSD, only Karnoksfy <70% was associated with reduced OS. However, a propensity score analysis showed that ruxolitinib had a negative impact on OS but only in non-responding patients, consistent with previous data. To conclude, with all the precautions due to confounders and bias, ruxolitinib itself does not appear to increase mortality after HSCT.

Bone marrow graft versus peripheral blood graft in haploidentical hematopoietic stem cells transplantation: a retrospective analysis in1344 patients of SFGM-TC registry.

The use of peripheral blood (PB) or bone marrow (BM) stem cells graft in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis remains controversial. Moreover, the value of adding anti-thymoglobulin (ATG) to PTCy is unknown. A total of 1344 adult patients received an unmanipulated haploidentical transplant at 37 centers from 2012 to 2019 for hematologic malignancy. We compared the outcomes of patients according to the type of graft, using a propensity score analysis. In total population, grade II-IV and III-IV acute GVHD (aGVHD) were lower with BM than with PB. Grade III-IV aGVHD was lower with BM than with PB + ATG. All outcomes were similar in PB and PB + ATG groups. Then, in total population, adding ATG does not benefit the procedure. In acute leukemia, myelodysplastic syndrome and myeloproliferative syndrome (AL-MDS-MPS) subgroup receiving non-myeloablative conditioning, risk of relapse was twice greater with BM than with PB (51 vs. 22%, respectively). Conversely, risk of aGVHD was greater with PB (38% for aGVHD II-IV; 16% for aGVHD III-IV) than with BM (28% for aGVHD II-IV; 8% for aGVHD III-IV). In this subgroup with intensified conditioning regimen, risk of relapse became similar with PB and BM but risk of aGVHD III-IV remained higher with PB than with BM graft (HR = 2.0; range [1.17-3.43], p = 0.012).

In the era of Bortezomib-based Induction, intensification of Melphalan-based conditioning with Bortezomib does not improve Survival Outcomes in newly diagnosed Multiple Myeloma: a study from the Chronic Malignancies Working Party of the EBMT.

Bortezomib (Vel)- Melphalan 200 mg/m2 (Mel200) (Vel-Mel) has been utilised to intensify conditioning in autologous hematopoietic stem cell transplantation (AHCT) for multiple myeloma (MM). This EBMT registry-based study compared Vel-Mel with Mel200 during upfront AHCT. Between 2010 and 2017, MM patients who received Vel-Mel (n = 292) conditioning were compared with 4,096 Mel200 patients in the same 58 centres. Pre-AHCT, compared to Mel200 patients, Vel-Mel patients had similar International Staging System (ISS) scores and cytogenetic risk profiles; a similar proportion had received bortezomib-based induction (85% and 87.3%, respectively) though they were younger with a better performance status. Vel-Mel patients were more likely to achieve CR post-induction (40.6% vs 20.3%, p < 0.001) and by day 100 of AHCT (CR/VGPR: 70.2 % vs. 57.2%, p < 0.001). There was no difference in 3-year PFS (49% vs 46%, p = 0.06) or early post-AHCT mortality. In multivariable analysis, Vel-Mel associated with inferior PFS (HR: 1.69 (1.27-2.25, p < 0.001) and OS (HR:1.46 (1.14-1.86,p = 0.002), similar to negative effects on PFS of advanced ISS (HR:1.56 (1.33-1.83, p < 0.001), high-risk cytogenetics (HR:1.43(1.18-1.74, p < 0.001) and poor post-induction response(<=PR)(HR: 1.43(1.25-1.62, p < 0.001) Overall, despite superior pre- and post-AHCT responses, there was no improvement in PFS or OS following Vel-Mel. This data supports the findings of the smaller prospective IFM study.

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia with hyperdiploid complex karyotype.

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the best consolidation strategy for acute myeloid leukemia (AML) with complex karyotype (CK). However, CK is a heterogenous and highly diverse entity. Numerical abnormalities have been associated with a controversial prognosis and AML with only multiple numerical abnormalities known as pure hyperdiploid karyotype (HDK) may have a distinct prognosis after allo-HCT compared to non-pure HDK CK AML. A total of 236 patients were identified within the EBMT registry as having HDK comprising 95 pure (pHDK) and 141 with other cytogenetic abnormalities (HDK+). The 2-year probability of leukemia-free survival (LFS) was 50% for pHDK and 31% for HDK+ (p = 0.003). The 2-year probability of overall survival (OS) was 57% for pHDK and 36% for HDK+ (p = 0.007). The 2-year cumulative incidence of relapse (RI) was 22% for pHDK and 44% for HDK+ (p = 0.001). The 2-year probability of graft-versus-host disease (GvHD)-free and relapse-free survival (GRFS) was 36% for pHDK and 21% for HDK+ (p = 0.01). On multivariate analysis, pHDK remained associated with significantly better LFS, OS and GRFS and lower RI (all p-values <0.004). pHDK AML constitutes probably a distinct cytogenetic entity from HDK+ or other non-hyperdiploid CK AML with better outcomes after allo-HCT.

Product Attributes of CAR T-cell Therapy Differentially Associate with Efficacy and Toxicity in Second-line Large B-cell Lymphoma (ZUMA-7).

Treatment resistance and toxicities remain a risk following chimeric antigen receptor (CAR) T-cell therapy. Herein, we report pharmacokinetics, pharmacodynamics, and product and apheresis attributes associated with outcomes among patients with relapsed/refractory large B-cell lymphoma (LBCL) treated with axicabtagene ciloleucel (axi-cel) in ZUMA-7. Axi-cel peak expansion associated with clinical response and toxicity, but not response durability. In apheresis material and final product, a naive T-cell phenotype (CCR7+CD45RA+) expressing CD27 and CD28 associated with improved response durability, event-free survival, progression-free survival, and a lower number of prior therapies. This phenotype was not associated with high-grade cytokine release syndrome (CRS) or neurologic events. Higher baseline and postinfusion levels of serum inflammatory markers associated with differentiated/effector products, reduced efficacy, and increased CRS and neurologic events, thus suggesting targets for intervention. These data support better outcomes with earlier CAR T-cell intervention and may improve patient care by informing on predictive biomarkers and development of next-generation products. SIGNIFICANCE: In ZUMA-7, the largest randomized CAR T-cell trial in LBCL, a naive T-cell product phenotype (CCR7+CD45RA+) expressing CD27 and CD28 associated with improved efficacy, decreased toxicity, and a lower number of prior therapies, supporting earlier intervention with CAR T-cell therapy. In addition, targets for improvement of therapeutic index are proposed. This article is featured in Selected Articles from This Issue, p. 4.

Influence of invasive aspergillosis during acute leukaemia treatment on survival after allogeneic stem cell transplantation: a prospective study of the EBMT Infectious Diseases Working Party.

Background: Infections are the main reason for mortality during acute leukaemia treatment and invasive aspergillosis (IA) is a major concern. Allogeneic stem cell transplantation (alloSCT) is a standard therapy and often is the only live-saving procedure in leukaemia patients. The profound immunodeficiency occurring after alloSCT led to high IA-associated mortality in the past. Therefore, patients with IA were historically considered transplant-ineligible. Recently, there has been improvement of anti-fungal management including novel anti-fungal agents. As a result, more leukaemia patients with IA are undergoing alloSCT. Outcome has not been prospectively assessed. Methods: We performed a prospective study in acute leukaemia patients undergoing alloSCT to analyse the impact of a prior history of probable or proven IA (pre-SCT IA). The primary endpoint was 1-year non-relapse mortality (NRM). Relapse free survival and overall survival were analysed as secondary endpoints. Findings: 1439 patients were included between 2016 and 2021. The incidence of probable or proven pre-SCT IA was 6.0% (n = 87). The cumulative incidence of 1-year NRM was 17.3% (95% CI 10.2-26.0) and 11.2% (9.6-13.0) for patients with and without pre-SCT IA. In multivariate analyses the hazard ratio (HR) for 1-year NRM was 2.1 (1.2-3.6; p = 0.009) for patients with pre-SCT IA. One-year relapse-free survival was inferior in patients with pre-SCT IA (59.4% [48.3-68.9] vs. 70.4 [67.9-72.8]; multivariate HR 1.5 [1.1-2.1]; p = 0.02). Consequently, 1-year overall survival was lower in patients with pre-SCT IA: (68.8% [57.8-77.4] vs. 79.0% [76.7-81.1]; multivariate HR 1.7 [1.1-2.5]; p = 0.01). Interpretation: Pre-SCT IA remains to be significantly associated with impaired alloSCT outcome. On the other hand, more than two thirds of patients with pre-SCT IA were alive at one year after alloSCT. IA is not anymore an absolute contraindication for alloSCT because the majority of patients with IA who undergo alloSCT benefit from this procedure. Funding: There was no external funding source for this study.

HLA haplotype frequencies and diversity in patients with hemoglobinopathies.

The genetic diversity of the human leukocyte antigen (HLA) system was shaped by evolutionary constraints exerted by environmental factors. Analyzing HLA diversity may allow understanding of the underlying pathways and offer useful tools in transplant setting. The aim of this study was to investigate the HLA haplotype diversity in patients with sickle cell disease (SCD, N = 282) or ß-thalassemia (ß-Thal, N = 60), who received hematopoietic cell transplantation (HCT) reported to Eurocord and the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC). We identified 405 different HLA-A-B-DRB1 haplotypes in SCD and 108 in ß-Thal patients. Using data from African and European populations of the "1000 Genomes Project" for comparison with SCD and ß-Thal, respectively, we found that the haplotypes HLA-A*30-B*14-DRB1*15 (OR 7.87, 95% CI: 1.66-37.3, p b = 0.035), HLA-A*23-B*08 (OR 6.59, 95% CI: 1.8-24.13, p b = 0.023), and HLA-B*14-DRB1*15 (OR 10.74, 95% CI: 3.66-31.57, p b = 0.000) were associated with SCD, and the partial haplotypes HLA-A*30-B*13 and HLA-A*68-B*53 were associated with ß-Thal (OR 4.810, 95% CI: 1.55-14.91, p b = 0.033, and OR 17.52, 95% CI: 2.81-184.95, p b = 0.011). Our results confirm the extreme HLA genetic diversity in SCD patients likely due to their African ancestry. This diversity seems less accentuated in patients with ß-Thal. Our findings emphasize the need to expand inclusion of donors of African descent in HCT donor registries and cord blood banks.

Allogeneic hematopoietic stem cell transplantation for adults with therapy-related acute myeloid leukaemia: a retrospective multicentre study on behalf of the SFGM-TC.

We report the results from a multicentre retrospective study of 220 adult patients who underwent allogeneic hematopoietic stem cell transplantation (alloHSCT) for therapy-related acute myeloid leukaemia (t-AML). Median age at t-AML diagnosis was 56 years, with a prior history of haematological (45%) or breast (34%). Median time from cytotoxic exposure to t-AML diagnosis was 54.7 months. At transplant, around 20% of patients had measurable residual disease and 3% of patients were not in complete remission. The median follow-up was 21.4 months (Q1-Q3, 5.9-52.8). At 12 months, overall survival (OS), event-free survival (EFS), and graft-versus-host-disease (GVHD)-free-relapse-free survival (GRFS) were 60.7% (95% CI 54.6-67.5), 52.8% (95% CI 46.5-68.4), and 44.1% (95% CI 37.6-51.8), respectively. At 5 years, OS, EFS, and GRFS were 44.1% (95% CI 37.4-52.1), 40.4% (95% CI 33.9-48.1), and 35.3% (95% CI 28.8-43.3), respectively. At last follow-up, 44% of patients were in complete remission (n = 96) and transplant-related mortality accounted for 21% of all deaths (n = 119). Multivariable analysis revealed that uncontrolled t-AML at transplant was associated with lower EFS (HR 1.94, 95% CI 1.0-3.7, p = 0.041). In conclusion, alloHSCT for t-AML shows encouraging results and offers additional opportunity with the emergence of novel pre-graft therapies.

Epidemiology, Outcomes, and Complement Gene Variants in Secondary Thrombotic Microangiopathies.

BACKGROUND: The identification of complement defects as major drivers of primary atypical hemolytic uremic syndrome (HUS) has transformed the landscape of thrombotic microangiopathies (TMAs), leading to the development of targeted therapies and better patient outcomes. By contrast, little is known about the presentation, genetics, and outcomes of TMA associated with specific diseases or conditions, also referred to as secondary TMA. METHODS: In this study, we assessed the relative incidence, clinical and genetic spectra, and long-term outcomes of secondary TMA versus other TMAs in consecutive patients hospitalized with a first episode of TMA from 2009 to 2019 at two European reference centers. RESULTS: During the study period, 336 patients were hospitalized with a first episode of TMA. Etiologies included atypical HUS in 49 patients (15%), thrombotic thrombocytopenic purpura (TTP) in 29 (9%), shigatoxin-associated HUS in 70 (21%), and secondary TMA in 188 (56%). The main causes of secondary TMA were hematopoietic stem-cell transplantation ( n =56, 30%), solid-organ transplantation ( n =44, 23%), and malignant hypertension ( n =25, 13%). Rare variants in complement genes were identified in 32 of 49 patients (65%) with atypical HUS and eight of 64 patients (13%) with secondary TMA; pathogenic or likely pathogenic variants were found in 24 of 49 (49%) and two of 64 (3%) of them, respectively ( P < 0.001). After a median follow-up of 1157 days, death or kidney failure occurred in 14 (29%), eight (28%), five (7%), and 121 (64%) patients with atypical HUS, TTP, shigatoxin-associated HUS, and secondary TMA, respectively. Unadjusted and adjusted Cox regressions showed that patients with secondary TMA had the highest risk of death or kidney failure (unadjusted hazard ratio [HR], 3.35; 95% confidence interval [CI], 1.85 to 6.07; P < 0.001; adjusted HR, 4.11; 95% CI, 2.00 to 8.46; P < 0.001; considering atypical HUS as reference). CONCLUSIONS: Secondary TMAs represent the main cause of TMA and are independently associated with a high risk of death and progression to kidney failure.

Multipotent mesenchymal stromal cells as treatment for poor graft function after allogeneic hematopoietic cell transplantation: A multicenter prospective analysis.

Introduction: Poor graft function (PGF) is a rare but serious complication of allogeneic hematopoietic cell transplantation (alloHCT). Due to their hematopoietic supporting properties and immune regulatory effects, multipotent mesenchymal stromal cells (MSC) could be considered a good candidate to help to restore bone marrow (BM) niches homeostasis and facilitate hematopoiesis after alloHCT. Methods: We prospectively assessed the efficacy and safety of ex-vivo expanded BM-derived MSC from third-party donor in a series of 30 patients with prolonged severe cytopenia and PGF after alloHCT. This multicenter trial was registered at www.clinicaltrials.gov (#NTC00603330). Results: Within 90 days post-MSC infusion, 53% (95% CI, 35 - 71%) of patients improved at least one cytopenia (overall response, OR) and 37% (95% CI, 19 - 54%) achieved a complete hematological response (CR: absolute neutrophil count, ANC >0.5 x 109/L, Hb > 80g/L and platelet count > 20 x 109/L with transfusion independence). Corresponding response rates increased to 67% (95% CI, 50 - 84%) OR and 53% (95% CI, 35 - 71%) CR within 180 days after MSC infusion. A significant decrease in red blood cells and platelets transfusion requirement was observed after MSC (median of 30-days transfusion requirement of 0.5 and 0 from d90-120 post-MSC versus 5 and 6.5 before MSC, respectively, p ≤0.001). An increase in ANC was also noted by day +90 and +180, with 3/5 patients with severe neutropenia having recovered an ANC > 1 x 109/L within the 90-120 days after MSC infusion. Overall survival at 1 year post-MSC was 70% (95% CI, 55.4 - 88.5), with all but one of the patients who achieved CR being alive. A single infusion of third-party MSC appeared to be safe, with the exception of one deep vein thrombotic event possibly related to the intervention. Discussion: In conclusion, a single i.v. infusion of BM-derived MSC from third party donor seemed to improve hematological function after alloHCT, although spontaneous amelioration cannot be excluded. Comparative studies are warranted to confirm these encouraging results.

CYAD-01, an autologous NKG2D-based CAR T-cell therapy, in relapsed or refractory acute myeloid leukaemia and myelodysplastic syndromes or multiple myeloma (THINK): haematological cohorts of the dose escalation segment of a phase 1 trial.

BACKGROUND: CYAD-01 is an autologous chimeric antigen receptor (CAR) T-cell product based on the natural killer (NK) group 2D (NKG2D) receptor, which binds eight ligands that are overexpressed in a wide range of haematological malignancies but are largely absent on non-neoplastic cells. Initial clinical evaluation of a single infusion of CYAD-01 at a low dose in patients with relapsed or refractory acute myeloid leukaemia, myelodysplastic syndromes, and multiple myeloma supported the feasibility of the approach and prompted further evaluation of CYAD-01. The aim of the present study was to determine the safety and recommended phase 2 dosing of CYAD-01 administered without preconditioning or bridging chemotherapy. METHODS: The multicentre THINK study was an open-label, dose-escalation, phase 1 study for patients with relapsed or refractory acute myeloid leukaemia, myelodysplastic syndromes, or multiple myeloma, after at least one previous line of therapy. Patients were recruited from five hospitals in the USA and Belgium. The dose-escalation segment evaluated three dose levels: 3 × 108 (dose level one), 1 × 109 (dose level two), and 3 × 109 (dose level three) cells per infusion with a 3 + 3 Fibonacci study design using a schedule of three infusions at 2-week intervals followed by potential consolidation treatment consisting of three additional infusions. The occurrence of dose-limiting toxicities post-CYAD-01 infusion was assessed as the primary endpoint in the total treated patient population. The trial was registered with ClinicalTrials.gov, NCT03018405, and EudraCT, 2016-003312-12, and has been completed. FINDINGS: Between Feb 6, 2017, and Oct 9, 2018, 25 patients were registered in the haematological dose-escalation segment. Seven patients had manufacturing failure for insufficient yield and two had screening failure. 16 patients were treated with CYAD-01 (three with multiple myeloma and three with acute myeloid leukaemia at dose level one; three with acute myeloid leukaemia at dose level two; and six with acute myeloid leukaemia and one with myelodysplastic syndromes at dose level three). Median follow-up was 118 days (IQR 46-180). Seven patients (44%) had grade 3 or 4 treatment-related adverse events. In total, five patients (31%) had grade 3 or 4 cytokine release syndrome across all dose levels. One dose-limiting toxicity of cytokine release syndrome was reported at dose level three. No treatment-related deaths occurred, and the maximum tolerated dose was not reached. Three (25%) of 12 evaluable patients with relapsed or refractory acute myeloid leukaemia or myelodysplastic syndromes had an objective response. Among responders, two patients with acute myeloid leukaemia proceeded to allogeneic haematopoietic stem-cell transplantation (HSCT) after CYAD-01 treatment, with durable ongoing remissions (5 and 61 months). INTERPRETATION: Treatment with a multiple CYAD-01 infusion schedule without preconditioning is well tolerated and shows anti-leukaemic activity, although without durability outside of patients bridged to allogeneic HSCT. These phase 1 data support the proof-of-concept of targeting NKG2D ligands by CAR T-cell therapy. Further clinical studies with NKG2D-based CAR T-cells are warranted, potentially via combinatorial antigen targeted approaches, to improve anti-tumour activity. FUNDING: Celyad Oncology.

Outcome after allogeneic stem cell transplantation with haploidentical versus HLA-matched donors in patients with higher-risk MDS.

Allogeneic hematopoietic stem cell transplantation remains the best curative option for higher-risk myelodysplastic syndrome. The presence of monosomal karyotype and/or complex karyotype abnormalities predicts inferior survival after allo-SCT in MDS patients. Haploidentical allo-SCT has been increasingly used in acute leukemia (AL) and has similar results as using HLA-matched donors, but data on higher-risk MDS is sparse. We compared outcomes in 266 patients with higher-risk MDS after HLA-matched sibling donor (MSD, n = 79), HLA-matched unrelated donor (MUD, n = 139) and HLA haploidentical donor (HID, n = 48) from 2010 to 2019. Median donor age differed between the three groups (p < 0.001). The overall survival was significantly different between the three groups with a better OS observed in the MUD group (p = 0.014). This observation could be explained by a higher progression-free survival with MUD (p = 0.014). The cumulative incidence of grade 2-4 acute GvHD was significantly higher in the HID group (p = 0.051). However, in multivariable analysis, patients transplanted using an HID had comparable mortality to patients transplanted using a MUD (subdistribution hazard ratio [sHR]: 0.58 [0.32-1.07]; p = 0.080) and a MSD ([sHR]: 0.56 [0.28-1.11]; p = 0.094). MUD do not remain a significant positive predictor of survival, suggesting that beyond the donor-recipient HLA matching, the donor age might impact recipient outcome.

Late relapse after hematopoietic stem cell transplantation for acute leukemia: a retrospective study by SFGM-TC.

Late relapse (LR) after allogeneic hematopoietic stem cell transplantation (AHSCT) for acute leukemia is a rare event (nearly 4.5%) and raises the questions of prognosis and outcome after salvage therapy. We performed a retrospective multicentric study between January 1, 2010, and December 31, 2016, using data from the French national retrospective register ProMISe provided by the SFGM-TC (French Society for Bone Marrow Transplantation and Cellular Therapy). We included patients presenting with LR, defined as a relapse occurring at least 2 years after AHSCT. We used the Cox model to identify prognosis factors associated with LR. During the study period, a total of 7582 AHSCTs were performed in 29 centers, and 33.8% of patients relapsed. Among them, 319 (12.4%) were considered to have LR, representing an incidence of 4.2% for the entire cohort. The full dataset was available for 290 patients, including 250 (86.2%) with acute myeloid leukemia and 40 (13.8%) with acute lymphoid leukemia. The median interval from AHSCT to LR was 38.2 months (interquartile range [IQR], 29.2 to 49.7 months), and 27.2% of the patients had extramedullary involvement at LR (17.2% exclusively and 10% associated with medullary involvement). One-third of the patients had persistent full donor chimerism at LR. Median overall survival (OS) after LR was 19.9 months (IQR, 5.6 to 46.4 months). The most common salvage therapy was induction regimen (55.5%), with complete remission (CR) obtained in 50.7% of cases. Ninety-four patients (38.5%) underwent a second AHSCT, with a median OS of 20.4 months (IQR, 7.1 to 49.1 months). Nonrelapse mortality after second AHSCT was 18.2%. The Cox model identified the following factors as associated with delay of LR: disease status not in first CR at first HSCT (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.04 to 1.64; P = .02) and the use of post-transplantation cyclophosphamide (OR, 2.23; 95% CI, 1.21 to 4.14; P = .01). Chronic GVHD appeared to be a protective factor (OR, .64; 95% CI, .42 to .96; P = .04). The prognosis of LR is better than in early relapse, with a median OS after LR of 19.9 months. Salvage therapy associated with a second AHSCT improves outcome and is feasible, without creating excess toxicity.

Fludarabine versus cyclophospamide in combination with myeloablative total body irradiation as conditioning for patients with acute myeloid leukemia treated with allogeneic hematopoietic cell transplantation. A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

Total body irradiation (TBI) at a dose of 12 Gy combined with cyclophosphamide (CyTBI12Gy) is one of the standard myeloablative regimens for patients with acute myeloid leukemia (AML) treated with allogeneic hematopoietic cell transplantation (allo-HCT). In clinical practice, cyclophosphamide may be substituted with fludarabine (FluTBI12Gy) to reduce toxicity. We retrospectively compared outcomes of CyTBI12Gy with FluTBI12Gy for patients with AML treated in complete remission (CR) with allo-HCT from either a matched sibling or unrelated donor. Of 1684 adults who met inclusion criteria, 109 patients in each group were included in a matched-pair analysis. The cumulative incidence of relapse at 2 years was 25% in the FluTBI12Gy compared to 28% in the CyTBI12Gy group (p = .44) while non-relapse mortality (NRM) was 17% versus 19%, (p = .89) respectively. The rates of leukemia-free survival and overall survival were 65% versus 54% (p = .28) and 70% versus 60.5% (p = .17). Cumulative incidence of grade 2-4 acute graft-versus-host disease (GVHD) was significantly lower for FluTBI12Gy than CyTBI12Gy (16% vs. 34%, p = .005), while the incidences of grade 3-4 acute GVHD and chronic GVHD did not differ significantly. The probability of GVHD and relapse-free survival was 49% in the FluTBI12Gy and 41% in the CyTBI12Gy group (p = .17). We conclude that for patients with AML treated with allo-HCT in CR, cyclophosphamide may be substituted with fludarabine in a regimen based on TBI at a dose of 12 Gy without negative impact on the efficacy. FluTBI12Gy is associated with reduced risk of grade 2-4 acute GVHD and encouraging survival rates.

On Behalf of the SFGM-TC: Prophylactic Donor Lymphocyte Infusion in Patients Treated with Allogeneic Stem-Cell Transplantation for High-Risk Myelodysplastic Syndrome and Acute Myeloid Leukemia.

INTRODUCTION: Allogeneic hematopoietic stem-cell transplantation (allo-HSCT) remains the best curative option for high-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Unfortunately, it is still associated with a significant risk of relapse due to mechanisms of escape from the control of alloreactive T cells. Repetitive adjuvant donor lymphocyte infusion (DLI), termed prophylactic DLI (proDLI), as an effective strategy in preventing relapse is still debated. METHODS: We performed a retrospective multicenter study to evaluate the efficacy of proDLI in allografted AML and MDS. We identified 56 patients treated with proDLI (DLI planned in full chimeras without any sign of disease relapse) and matched them to 167 patients in control group, (DLI performed for mixed chimerism or positive minimal residual disease) based on similar age, initial disease, cytogenetic prognosis, and conditioning intensity. RESULTS: In univariate analysis, the incidence of severe aGVHD at 100 days and incidence of all grades of chronic GVHD 1 year after allo-HSCT were similar in the two groups. We also observed a trend of higher 3-year RI (52.61% [95% confidence interval 25.99-79.23]) in the proDLI group versus the control group (29.31% [20.28-38.34], p = 0.067). However, 3-year overall survival (p = 0.892), progression-free survival (p = 0.239), and nonrelapse mortality (p = 0.343) were similar between the two groups. In multivariate analysis, the only factor influencing overall and progression-free survival was anti-thymocyte globulin administration during the conditioning regimen. CONCLUSION: The proDLI strategy had an acceptable toxicity profile but did not improve patient outcomes compared to the pre-emptive strategy.

Comparison of autologous and allogeneic hematopoietic cell transplantation strategies in patients with primary plasma cell leukemia, with dynamic prediction modeling.

Primary plasma cell leukemia (pPCL) is a rare and challenging malignancy. There are limited data regarding optimum transplant approaches. We therefore undertook a retrospective analysis from 1998-2014 of 751 patients with pPCL undergoing one of four transplant strategies; single autologous transplant (single auto), single allogeneic transplant (allo-first) or a combined tandem approach with an allogeneic transplant following an autologous transplant (auto-allo) or a tandem autologous transplant (auto-auto). To avoid time bias, multiple analytic approaches were employed including Cox models with time-dependent covariates and dynamic prediction by landmarking. Initial comparisons were made between patients undergoing allo-first (n=70) versus auto-first (n=681), regardless of a subsequent second transplant. The allo-first group had a lower relapse rate (45.9%, 95% confidence interval [95% CI]: 33.2-58.6 vs. 68.4%, 64.4-72.4) but higher non-relapse mortality (27%, 95% CI: 15.9-38.1 vs. 7.3%, 5.2-9.4) at 36 months. Patients who underwent allo-first had a remarkably higher risk in the first 100 days for both overall survival and progression-free survival. Patients undergoing auto-allo (n=122) had no increased risk in the short term and a significant benefit in progression-free survival after 100 days compared to those undergoing single auto (hazard ratio [HR]=0.69, 95% CI: 0.52- 0.92; P=0.012). Auto-auto (n=117) was an effective option for patients achieving complete remission prior to their first transplant, whereas in patients who did not achieve complete remission prior to transplantation our modeling predicted that auto-allo was superior. This is the largest retrospective study reporting on transplantation in pPCL to date. We confirm a significant mortality risk within the first 100 days for allo-first and suggest that tandem transplant strategies are superior. Disease status at time of transplant influences outcome. This knowledge may help to guide clinical decisions on transplant strategy.

Combining blinatumomab and donor lymphocyte infusion in B-ALL patients relapsing after allogeneic hematopoietic cell transplantation: a study of the SFGM-TC.

Relapsed B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic stem cell transplantation (allo-HCT) still represents a major concern with poor outcomes. The aim of this study is to compare the efficacy and safety of blinatumomab and donor lymphocyte infusion (DLI) versus blinatumomab alone in this setting. This is a multicenter retrospective study from centers of SFGM-TC. All transplanted patients who received blinatumomab salvage therapy were included. Patients who received DLI from 1 month before to 100 days after the starting of blinatumomab were included in the blina-DLI group. Seventy-two patients were included. Medium follow-up was 38 months. Fifty received blinatumomab alone and 22 the association blinatumomab-DLI. Two-year overall survival (OS) was 31% in the blinatumomab group and 43% in the blinatumomab-DLI group (p = 0.31). Studying DLI as a time dependent variable, PFS did not significantly differ between the 2 groups (HR:0.7, 95% CI: 0.4-1.5). In multivariate analysis, DLI was not a prognostic factor for OS, progression-free survival and progression/relapse incidence. Adverse events and graft-versus-disease rates were comparable in the 2 groups. In conclusion, adding DLI between 1 month before and 100 days after start of blinatumomab is safe and does not seem to improve outcomes in B-ALL patients who relapsed after allo-HCT.