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The prognosis of t(1;19)(q23;p13)/transcription factor 3-pre-B-cell leukaemia homeobox 1 (TCF3-PBXI) in adolescent and adult patients with acute lymphoblastic leukaemia (ALL) treated with measurable residual disease (MRD)-oriented trials remains controversial. In the present study, we analysed the outcome of adolescent and adult patients with t(1;19)(q23;p13) enrolled in paediatric-inspired trials. The patients with TCF3-PBXI showed similar MRD clearance and did not have different survival compared with other B-cell precursor ALL patients. However, patients with TCF3-PBXI had a significantly higher cumulative incidence of relapse, especially among patients aged >= 35 years carrying additional cytogenetic alterations. These patients might benefit from additional/intensified therapy (e.g. immunotherapy in first complete remission with or without subsequent haematopoietic stem cell transplantation).

CD19-directed immunotherapies have revolutionized the treatment of advanced B-cell acute lymphoblastic leukemia (B-ALL). Despite initial impressive rates of complete remission (CR) many patients ultimately relapse. Patients with B-ALL successfully treated with CD19-directed T cells eventually relapse, which, coupled with the early onset of CD22 expression during B-cell development, suggests that preexisting CD34+CD22+CD19− (pre)-leukemic cells represent an “early progenitor origin-related” mechanism underlying phenotypic escape to CD19-directed immunotherapies. We demonstrate that CD22 expression precedes CD19 expression during B-cell development. CD34+CD19−CD22+ cells are found in diagnostic and relapsed bone marrow samples of ∼70% of patients with B-ALL, and their frequency increases twofold in patients with B-ALL in CR after CD19 CAR T-cell therapy. The median of CD34+CD19−CD22+ cells before treatment was threefold higher in patients in whom B-ALL relapsed after CD19-directed immunotherapy (median follow-up, 24 months). Fluorescence in situ hybridization analysis in flow-sorted cell populations and xenograft modeling revealed that CD34+CD19−CD22+ cells harbor the genetic abnormalities present at diagnosis and initiate leukemogenesis in vivo. Our data suggest that preleukemic CD34+CD19−CD22+ progenitors underlie phenotypic escape after CD19-directed immunotherapies and reinforce ongoing clinical studies aimed at CD19/CD22 dual targeting as a strategy for reducing CD19− relapses. The implementation of CD34/CD19/CD22 immunophenotyping in clinical laboratories for initial diagnosis and subsequent monitoring of patients with B-ALL during CD19-targeted therapy is encouraged., The work in P.M. and C.B.’s Laboratory was supported by the European Research Council (CoG-2014-646903, PoC-2018-811220) and the Spanish Ministry of Economy and Competitiveness (SAF2016-80481R, PID2019-108160RB-I00) (P.M.); the ISCIII (ISCIII/FEDER, PI17/01028 and PI20/00822), the Spanish Association against Cancer (AECC), and the FERO Foundation (C.B.). P.M. and J.M.R. acknowledge the support of ISCIII-RICORS within the Next Generation EU program (Plan de Recuperación, Transformación y Resiliencia). N.E. is supported by Cancer Research UK and a Children and Young People’s Cancer Innovation Award (DRCPGM\100058). A.R. is supported by a Wellcome Trust Clinical Research Career Development Fellowship (216632/Z/19/Z). A.O. was supported by ISCIII (PI19/011183). F.S. was supported by AGAUR/Generalitat de Catalunya (SGR288). The single-cell transcriptomic analysis was supported by MRC Discovery award MRCDA 0816-11 and the MRC WIMM Single Cell Facility and MRC-funded Oxford Consortium for Single-Cell Biology (MR/M00919X/1) provided assistance.

The potential prognostic value of conventional karyotyping in adult T-cell acute lymphoblastic leukemia (T-ALL) remains an open question. We hypothesized that a modified cytogenetic classification, based on the number and type of cytogenetic abnormalities, would allow the identification of high-risk adult T-ALL patients. Complex karyotype defined by the presence of >3 cytogenetic alterations identified T-ALL patients with poor prognosis in this study. Karyotypes with >3 abnormalities accounted for 16 % (22/139) of all evaluable karyotypes, corre-sponding to the largest poor prognosis cytogenetic subgroup of T-ALL identified so far. Patients carrying kar-yotypes with >3 cytogenetic alterations showed a significantly inferior response to therapy, and a poor outcome in terms of event-free survival (EFS), overall survival (OS) and cumulative incidence of relapse (CIR), inde-pendently of other baseline characteristics and the end-induction minimal residual disease (MRD) level. Addi-tional molecular analyses of patients carrying >3 cytogenetic alterations showed a unique molecular profile that could contribute to understand the underlying molecular mechanisms of resistance and to evaluate novel tar-geted therapies (e.g. IL7R directed) with potential impact on outcome of adult T-ALL patients.

Despite high complete remission (CR) rates with frontline therapy, relapses are frequent in adults with T-cell acute lymphoblastic leukemia (T-ALL) with limited salvage options. We analyzed the outcomes and prognostic factors for CR to salvage therapy and overall survival (OS) of patients with R/R T-ALL included in two prospective measurable residual disease-oriented trials. Seventy-five patients (70 relapsed, 5 refractory) were identified. Relapses occurred in bone marrow, isolated or combined in 50 patients, and in the central nervous system (CNS; isolated or combined) in 20. Second CR was attained in 30/75 patients (40%). Treatment with FLAG-Ida and isolated CNS relapse were independently associated with a higher CR rate after first salvage therapy. The median OS was 6.2 (95% confidence interval [CI], 3.9–8.6) months, with a 4-year OS probability of 18% (95% CI, 9%–27%). No differences in survival were observed according to the treatment with hematopoietic stem cell transplantation in patients in CR after first salvage therapy. Multivariable analysis showed a ≥12-month interval between first CR and relapse, CR after first salvage therapy and isolated CNS relapse as favorable prognostic factors for OS with hazard ratios (HR) (95% CI) of 1.931 (1.109–3.362), 2.958 (1.640–5.334), and 2.976 (1.157–7.655), respectively. This study confirms the poor outcomes of adults with R/R T-ALL among whom FLAG-Ida was the best of the rescue therapies evaluated. Late relapse, CR after first rescue therapy and isolated CNS relapse showed prognostic impact on survival. More effective rescue therapies are needed in adults with R/R T-ALL., La Caixa" Foundation and ISCIII, Grant/ Award Number: PI19/01828; Generalitat de Catalunya (GRC), Grant/Award Number: 2017 SGR288

INTRODUCTION: The impact of an admission to ICU before stem cell transplantation (SCT) on post-SCT outcome is not well established. PATIENTS AND METHODS: We reviewed the medical records of patients who had received a first SCT between 2000 and 2016 in our institution. The outcome of 22 patients who required ICU admission during chemotherapy prior to SCT (ICU group) was compared with 44 matched patients (1:2) who did not need it (NO-ICU group). RESULTS: There were no differences in transplant complications, in time to neutrophil and platelet recovery or in the length of hospital stay during SCT between the ICU and NO-ICU groups. However, microbiologically documented infections were more common in the ICU group (16/20) than in the NO-ICU group (18/39) (p=.027). The 5-yr overall survival probability (CI 95%) was 49% (28-70%) in the ICU vs. 45% (29-61%) in the NO-ICU group (p=.353), while the 5-yr incidence of non-relapse mortality was 32% (14-52%) and 24% (12-38%) (p=.333), respectively. Six patients (27%) in the ICU group and 8 (18%) in the NO-ICU group required admission to the ICU during or after the SCT procedure (p=.293). Twelve (54%) patients in the ICU and 22 (50%) in the NO-ICU group died, the causes of death were similar in both groups. CONCLUSION: Our results show that admission to the ICU prior to SCT does not have a negative impact on patient outcomes following SCT and should not be considered as an exclusion criterion for SCT.

INTRODUCTION: Inv(3)(q21q26.2)/t(3;3)(q21;q26.2) is a rare poor prognosis cytogenetic abnormality present in acute myeloid leukemia (AML) and other myeloid neoplasms.; OBJECTIVE: The aim of this study was to evaluate the outcome of a cohort of 61 patients with newly diagnosed AML with inv(3)/t(3;3) treated with homogeneous intensive chemotherapy protocols conducted by the Spanish PETHEMA and CETLAM cooperative groups between 1999 and 2017.; METHODS: In this retrospective study the main clinical and biologic parameters were collected. The complete response (CR) rate, the cumulative incidence of relapse (CIR) and the overall survival (OS) were calculated. An analysis of prognostic factors for survival was performed.; RESULTS: Sixty-one patients received induction and only 18 (29%) achieved CR (median age, 46 years). Allogeneic hematopoietic stem cell transplantation (alloHSCT) was performed in 36 patients (59%), 15 with active disease. One and 4-year CIR were 52% and 56%. One and 4-year OS probabilities were 41% and 13%. By multivariate analysis monosomal karyotype (MK) was associated with poorer OS (HR 2.0, p=0.017).; CONCLUSION: Inv(3)/t(3;3) AML is a poor prognosis entity with low response to standard chemotherapy and to alloHSCT because of frequent and early relapse. MK was associated with a poorer prognosis. Improved therapeutic strategies are clearly needed. This article is protected by copyright. All rights reserved.

Introduction Inv(3)(q21.3q26.2)/t(3;3)(q21.3;q26.2) is a rare poor prognosis cytogenetic abnormality present in acute myeloid leukemia (AML) and other myeloid neoplasms. Objective The aim of this study was to evaluate the outcome of a cohort of 61 patients with newly diagnosed AML with inv(3)/t(3;3) treated with homogeneous intensive chemotherapy protocols conducted by the Spanish PETHEMA and CETLAM cooperative groups between 1999 and 2017. Methods In this retrospective study the main clinical and biologic parameters were collected. The complete response (CR) rate, the cumulative incidence of relapse (CIR) and the overall survival (OS) were calculated. An analysis of prognostic factors for survival was performed. Results Sixty-one patients received induction and only 18 (29%) achieved CR (median age, 46 years). Allogeneic hematopoietic stem cell transplantation (alloHSCT) was performed in 36 patients (59%), 15 with active disease. One- and 4-year CIR were 52% and 56%. One- and 4-year OS probabilities were 41% and 13%. By multivariate analysis monosomal karyotype (MK) was associated with poorer OS (HR 2.0,P = .017). Conclusion Inv(3)/t(3;3) AML is a poor prognosis entity with low response to standard chemotherapy and to alloHSCT because of frequent and early relapse. MK was associated with a poorer prognosis. Improved therapeutic strategies are clearly needed.

Minimal residual disease (MRD) assessment is an essential tool in contemporary acute lymphoblastic leukemia (ALL) protocols, being used for therapeutic decisions such as hematopoietic stem cell transplantation in high-risk patients. However, a significant proportion of adult ALL patients with negative MRD still relapse suggesting that other factors (ie, molecular alterations) must be considered in order to identify those patients with high risk of disease progression. We have identified partial IKZF1 gene deletions and CDKN2A/B deletions as markers of disease recurrence and poor survival in a series of uniformly treated adolescent and adult Philadelphia chromosome-negative B-cell progenitor ALL patients treated according to the Programa Espanol de Tratamientos en Hematologia protocols. Importantly, CDKN2A/B deletions showed independent significance of MRD at the end of induction, which points out the need for treatment intensification in these patients despite being MRD-negative after induction therapy.

Native or pegylated (PEG) asparaginase (ASP) are commonly used in treatment of acute lymphoblastic leukemia (ALL), but have been scarcely compared in the same trial in adult patients. Native vs. PEG-ASP administered according to availability in each center were prospectively evaluated in adults with high-risk ALL. Ninety-one patients received native ASP and 35 PEG-ASP in induction. No significant differences were observed in complete remission, minimal residual disease levels after induction and after consolidation, disease-free survival, and overall survival. No significant differences in grades 3-4 toxicity were observed in the induction period, although a trend for higher hepatic toxicity was observed in patients receiving PEG-ASP. In this trial the type of ASP did not influence patient response and outcome.

About 25-35% of adult patients with acute lymphoblastic leukemia show the Philadelphia (Ph) chromosome. Few series have evaluated the prognosis of additional cytogenetic alterations (ACA) to the Ph chromosome. We analyzed the frequency, type and prognostic significance ofACA in adults (18-60 years) treated in the ALL-Ph-08 trial. Fifty-two out of 74 patients (70%) showed ACA and 19 (26%) presented monosomies associated with t(9; 22) (monosomal karyotype, MK). Similar complete response (CR) rate, CR duration, overall survival and event-free survival (EFS) were observed in patients with or without ACA, but patients with MK showed shorter CR duration and EFS than the remaining. On multivariate analysis, the only variable with prognostic impact for CR duration and EFS was the presence of MK (p = .003 and p = .036, respectively). Although ACA associated with the Ph chromosome are frequent, only monosomies were associated with poor prognosis in this group of patients.

The karyotype is an important predictor of outcome in acute lymphoblastic leukemia (ALL). Rearrangements of the 11q23 region involving the KMT2A gene confer an unfavorable prognosis. Forty-six adult ALL patients from the PETHEMA Group treated with risk-adapted protocols, with t(v;11q23) were selected for this study. Complete response (CR) was attained in 38 patients; 25 remained in CR after consolidation. Twelve (48%) received allogeneic hematopoietic stem cell transplantation (HSCT) and 13 delayed intensification and maintenance. The 5-year CR duration probability was 37% (95% CI, 19%-55%). A trend for a longer CR duration was observed in patients undergoing HSCT vs. those receiving chemotherapy. The 5-year overall survival (OS) probability was 20% (95% CI, 5%-35%). The OS was better, albeit not significant, in patients with a MRD level< 0.1% after induction (39% [95% CI, 14%-64%] vs. 13% [95% CI, 0%-36%]). Specific treatment approaches are required to improve the outcome of patients with KMT2A-rearrangements.

BACKGROUNDSome copy number alterations (CNAs) have independent prognostic significance for adults with acute lymphoblastic leukemia (ALL). METHODSThis study analyzed via multiplex ligation-dependent probe amplification the frequency and prognostic impact of CNAs of 12 genetic regions in 142 adolescents and adults with de novo precursor B-cell ALL. RESULTSThe cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletion (59 of 142 or 42%) was the most frequent CNA, and it was followed by Ikaros family zinc finger 1 (IKZF1) losses (49 of 142 or 35%). IKZF1 deletions were more prevalent in Philadelphia chromosome (Ph)-positive ALL and were associated with advanced age and high white blood cell (WBC) counts. The multivariate analysis showed that advanced age and early B-cell factor 1 (EBF1) deletions were associated with chemotherapy resistance in both the whole series (hazard ratios, 0.949 and 0.135, respectively) and the Ph-negative subgroup (hazard ratios, 0.946 and 0.118, respectively). High WBC counts and focal IKZF1 deletions correlated with disease recurrence (hazard ratios, 1.005 and 1.869, respectively), whereas advanced age and CDKN2A/B losses influenced overall survival in both the whole series (hazard ratios, 1.038 and 2.545, respectively) and the Ph-negative subgroup (hazard ratios, 1.044 and 2.105, respectively). CONCLUSIONSDeletions of EBF1, IKZF1, and CDKN2A/B have an independent adverse prognosis for adolescents and adults with B-precursor ALL, and this suggests that these CNAs should be included in the initial risk assessment of ALL. Cancer 2015;121:3809-3817. (c) 2015 American Cancer Society. Deletions of early B-cell factor 1, cyclin-dependent kinase inhibitor 2A/B, and Ikaros family zinc finger 1 are independent markers of a poor prognosis for uniformly treated adolescent and adult patients with B precursor acute lymphoblastic leukemia.

Strategies for reversing graft failure (GF) after allogeneic stem cell transplant (SCT) depend on the options available in each situation. GF was reported in 16 Spanish institutions from January 2006 to July 2011. Primary GF was defined as an absolute neutrophil count (ANC) > 0.5 x 10(9)/L not reached by day + 28 after SCT from peripheral blood (PB) or bone marrow (BM) progenitors and by day + 42 after SCT from unrelated cord blood (UCB) progenitors. Secondary GF was defined as a recurrent ANC < 0.5 x 10(9)/L. Eighty-nine patients with GF were reported, and 80 patients received a second SCT. The 5-year survival probability was 31% (95% confidence interval [CI]: 18-44%), and the incidences of non-relapse mortality and relapse estimated by competing risks were 47% (95% CI: 36-58%) and 21% (95% CI: 4-28%). The strategy adopted to treat GF was heterogeneous, and no approach could be unequivocally recommended for this situation. The prognosis of patients with GF was poor even after successful recovery from GF.

The results of intensive immunochemotherapy were analyzed in human immunodeficiency virus (HIV)-related Burkitt lymphoma/leukemia (BLL) in two cohorts (Spain and Germany). Alternating cycles of chemotherapy were administered, with dose reductions for patients over 55 years. Eighty percent of patients achieved remission, 11% died during induction, 9% failed and 7% died in remission. Four-year overall survival (OS) and progression-free survival (PFS) probabilities were 72% (95% confidence interval [CI]: 62-82%) and 71% (95% CI: 61-81%). CD4 T-cell count < 200/mu L and bone marrow involvement were associated with poor OS (hazard ratio [HR] 3.2 [1.2-8.3] and HR 2.7 [1.1-6.6]) and PFS (HR 3.5 [1.3-9.1] and HR 2.4 [1-5.7]), bone marrow involvement with poor disease-free survival (DFS) (HR 14.4 [1.7-119.7] and Eastern Cooperative Oncology Group (ECOG) score > 2 (odds ratio [OR] 11.9 [1.4-99.9]) with induction death. In HIV-related BLL, intensive immunochemotherapy was feasible and effective, but toxic. Prognostic factors were performance status, CD4 T-cell count and bone marrow involvement.

Genomics; T-cell acute lymphoblastic leukemia Genòmica; leucèmia limfoblàstica aguda de cèl·lules T Genómica; Leucemia linfoblástica aguda de células T Genetic information has been crucial to understand the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL) at diagnosis and at relapse, but still nowadays has a limited value in a clinical context. Few genetic markers are associated with the outcome of T-ALL patients, independently of measurable residual disease (MRD) status after therapy. In addition, the prognostic relevance of genetic features may be modulated by the specific treatment used. We analyzed the genetic profile of 145 T-ALL patients by targeted deep sequencing. Genomic information was integrated with the clinicalbiological and survival data of a subset of 116 adult patients enrolled in two consecutive MRD-oriented trials of the Spanish PETHEMA (Programa Español de Tratamientos en Hematología) group. Genetic analysis revealed a mutational profile defined by DNMT3A/ N/KRAS/ MSH2/ U2AF1 gene mutations that identified refractory/resistant patients. Mutations in the DMNT3A gene were also found in the non-leukemic cell fraction of patients with T-ALL, revealing a possible mutational-driven clonal hematopoiesis event to prime T-ALL in elderly. The prognostic impact of this adverse genetic profile was independent of MRD status on day +35 of induction therapy. The combined worse-outcome genetic signature and MRD on day +35 allowed risk stratification of T-ALL into standard or high-risk groups with significantly different 5- year overall survival (OS) of 52% (95% confidence interval: 37-67) and 17% (95% confidence interval: 1-33), respectively. These results confirm the relevance of the tumor genetic profile in predicting patient outcome in adult T-ALL and highlight the need for novel gene-targeted chemotherapeutic schedules to improve the OS of poor-prognosis T-ALL patients. This project was supported by the AECC (GC16173697BIGA); ISCIII (PI19/01828 and PI19/01183), co-funded by ERDF/ESF, "A way to make Europe"/"Investing in your future", CERCA/Generalitat de Catalunya SGR 2017 288 (GRC)/ “La Caixa”. C Gon-zález-Gil was supported by AGAUR grant (ref: 2020 FI_B2 00210).

Programa para el Tratamiento de Hemopatias Malignas (PETHEMA) Group (Spanish Society of Hematology, SEHH)., The prognosis of t(1;19)(q23;p13)/transcription factor 3-pre-B-cell leukaemia homeobox 1 (TCF3-PBX1) in adolescent and adult patients with acute lymphoblastic leukaemia (ALL) treated with measurable residual disease (MRD)-oriented trials remains controversial. In the present study, we analysed the outcome of adolescent and adult patients with t(1;19)(q23;p13) enrolled in paediatric-inspired trials. The patients with TCF3-PBX1 showed similar MRD clearance and did not have different survival compared with other B-cell precursor ALL patients. However, patients with TCF3-PBX1 had a significantly higher cumulative incidence of relapse, especially among patients aged ≥35 years carrying additional cytogenetic alterations. These patients might benefit from additional/intensified therapy (e.g. immunotherapy in first complete remission with or without subsequent haematopoietic stem cell transplantation)., This work was supported in part by CERCA/Generalitat de Catalunya SGR 2017 288 (GRC), a restricted grant from ‘La Caixa’ and Healthcare Alliance for Resourceful Medicine Offensive against Neoplasms (HARMONY).

© 2021 The Author(s)., The potential prognostic value of conventional karyotyping in adult T-cell acute lymphoblastic leukemia (T-ALL) remains an open question. We hypothesized that a modified cytogenetic classification, based on the number and type of cytogenetic abnormalities, would allow the identification of high-risk adult T-ALL patients. Complex karyotype defined by the presence of ≥3 cytogenetic alterations identified T-ALL patients with poor prognosis in this study. Karyotypes with ≥3 abnormalities accounted for 16 % (22/139) of all evaluable karyotypes, corresponding to the largest poor prognosis cytogenetic subgroup of T-ALL identified so far. Patients carrying karyotypes with ≥3 cytogenetic alterations showed a significantly inferior response to therapy, and a poor outcome in terms of event-free survival (EFS), overall survival (OS) and cumulative incidence of relapse (CIR), independently of other baseline characteristics and the end-induction minimal residual disease (MRD) level. Additional molecular analyses of patients carrying ≥3 cytogenetic alterations showed a unique molecular profile that could contribute to understand the underlying molecular mechanisms of resistance and to evaluate novel targeted therapies (e.g. IL7R directed) with potential impact on outcome of adult T-ALL patients., This project was supported by the AECC (GC16173697BIGA); ISCIII (PI19/01828) co-funded by ERDF/ESF "A way to make Europe"/ "Investing in your future", CERCA/Generalitat de Catalunya SGR 2017 288 (GRC)/ “La Caixa” P. Barba was supported by the Instituto de Salud Carlos III FIS16/01433 and PERIS 2018-2020 from Generalitat de Catalunya (BDNS357800).

On behalf of the PETHEMA Group, Spanish Society of Hematology., [Background]: Pediatric‐based or ‐inspired trials have improved the prognosis of adolescents and young adults (AYA) with Philadelphia chromosome‐negative (Ph‐neg) acute lymphoblastic leukemia (ALL)., [Methods]: This study reports the results of treatment of the ALLRE08 trial, a full pediatric trial for AYA aged 15‐30 years with standard‐risk (SR) ALL., [Results]: From 2008 to 2018, 89 patients (38 adolescents [15‐18 years] and 51 young adults [YA, 19‐30 years], median age: 20 [15‐29] years) were enrolled in the ALLRE08 trial. The complete response (CR) was 95%. Twenty‐two patients were transferred to a high‐risk (HR) protocol because of poor marrow response on day 14 (n = 20) or high‐level of end‐induction minimal residual response (MRD ≥ 0.25%, n = 2). Cumulative incidence of relapse (CIR) at 5 years was 35% (95%CI: 23%‐47%), with significant differences between adolescents and YA: 13% (4%‐28%) vs 52% (34%‐67%), P = .012. No treatment‐related mortality was observed in 66/66 patients following the ALLRE08 trial vs 3/23 patients moved to a HR trial. The estimated 5‐year overall survival (OS) was 74% (95%CI: 63%‐85%), with significantly higher rates for adolescents vs YA: 87% (95%CI: 74%‐100%) vs 63% (46%‐80%), P = .021. Although CIR or OS were lower in patients who were transferred to a HR trial, the differences were not statistically significant (CIR: 34% [21%‐47%] vs 37% [14%‐61%]; OS: 78% [66%‐90%] vs 61% [31%;91%])., [Conclusion]: A full pediatric trial is feasible and effective for AYA with Ph‐neg, SR‐ALL, with better results for adolescents than for YA. Outcome of patients with poor early response rescued with a HR trial was not significantly inferior., We thanks to the following institutions from Spain their support for this paper: ICO‐Hospital Germans Trias i Pujol. Josep Carreras Research Institute. Universitat Autònoma de Barcelona. Hospital Universitari i Politècnic La Fe, Valencia. Hospital Clínico Valencia. Hospital Central de Asturias, Oviedo. Hospital Universitario Virgen del Rocío, Sevilla. Hospital General Universitario de Alicante. Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona. Hospital General Universitario de Castellón. ICO‐Hospital Josep Trueta, Girona. Hospital Dr Peset, Valencia. ICO‐Hospital Duran i Reynals, L'Hospitalet de Llobregat. Hospital Son Espases, Palma de Mallorca. Hospital Clínico Universitario, Cancer Research Center (IBMCC‐CSIC/USAL), Cytometry Service, Salamanca. Hospital San Pedro de Alcántara, Cáceres. Hospital Morales Meseguer, Murcia. Hospital Mútua de Terrassa, Terrassa. Hospital Doce de Octubre, Madrid. Hospital Ramón y Cajal, Madrid. Hospital de Sant Pau, Barcelona. Hospital Arnau de Vilanova, Lleida. Hospital Lucus Augusti, Lugo. ICO‐Hospital Joan XXIII, Tarragona.

We compared outcomes from a single-arm study of blinatumomab in adult patients with B-precursor Ph-negative relapsed/refractory acute lymphoblastic leukemia (R/R ALL) with a historical data set from Europe and the United States. Estimates of complete remission (CR) and overall survival (OS) were weighted by the frequency distribution of prognostic factors in the blinatumomab trial. Outcomes were also compared between the trial and historical data using propensity score methods. The historical cohort included 694 patients with CR data and 1112 patients with OS data compared with 189 patients with CR and survival data in the blinatumomab trial. The weighted analysis revealed a CR rate of 24% (95% CI: 20–27%) and a median OS of 3.3 months (95% CI: 2.8–3.6) in the historical cohort compared with a CR/CRh rate of 43% (95% CI: 36–50%) and a median OS of 6.1 months (95% CI: 4.2–7.5) in the blinatumomab trial. Propensity score analysis estimated increased odds of CR/CRh (OR=2.68, 95% CI: 1.67–4.31) and improved OS (HR=0.536, 95% CI: 0.394–0.730) with blinatumomab. The analysis demonstrates the application of different study designs and statistical methods to compare novel therapies for R/R ALL with historical data.