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This article discusses the case of a 57-year-old male with acute lymphoblastic leukemia (ALL) who experienced severe liver toxicity after receiving pegaspargase, a type of asparaginase used in ALL treatment. The patient's liver function tests increased, and high levels of asparaginase activity were detected in the serum. To address this toxicity, the patient underwent plasmapheresis, a procedure to remove asparaginase from the circulation. This intervention resulted in a rapid decrease in asparaginase activity and normalization of liver function. The authors suggest that plasmapheresis should be considered in the treatment of severe asparaginase toxicities. [Extracted from the article]

We present the case of a 58-year-old female patient who presented with an extramedullary B-ALL relapse after prior allogenic HSCT and blinatumomab therapy. The patient died from complications of a drug-induced acute liver failure after a salvage therapy combining inotuzumab ozogamicin (InO)-based induction followed by consolidation with high dose MTX and pegaspargase based on the GMALL protocol for older ALL patients. After a diagnosis of the extramedullary relapse in the form of a retro vesical chloroma, the patient received an individualized multi-agent chemotherapy based on induction chemotherapy for older patients in combination with InO. After four administrations of InO, in combination with vincristine, dexamethasone, cytarabine, and cyclophosphamide, CT-imaging showed a reduction in volume of the chloroma and response to therapy. Consolidation with high-dose methotrexate and pegaspargase was administered. The patient developed toxic liver damage manifested by hyperbilirubinemia and progressive hepatic encephalopathy. The diagnostic criteria for VOD were met, and therapy with defibrotide was initiated. Liver biopsy revealed no histological signs of VOD but instead steatohepatitis indicative of drug-induced toxicity. The patient ultimately died of hemorrhagic shock through postinterventional hemorrhage after liver biopsy. In conclusion, although InO shows promising results in the therapy of r/r ALL with and without additional chemotherapy, the combination with MTX and pegaspargase in an intensively pretreated patient with relapse after HCST may impart an increased risk for liver-related toxicity. Special caution is required when assessing fitness for further liver toxic regimens. A key takeaway is also the reminder that InO can cause liver damage not only in the form of VOD but also through direct hepatocellular toxicity. [ABSTRACT FROM AUTHOR]

The translocation t(1;19)(q23;p13) with the resulting chimeric TCF3::PBX1 gene is the third most prevalent recurrent chromosomal translocation in acute lymphoblastic leukemia and accounts for 3–5% of cases. The molecular background of this translocation has been incompletely studied, especially in adult cases. We characterized the chromosomal breakpoints of 49 patients with TCF3::PBX1 and the corresponding reciprocal PBX1::TCF3 breakpoints in 15 cases at the molecular level, thus providing an extensive molecular overview of this translocation in a well-defined study patient population. Breakpoints were found to be remarkably clustered not only in TCF3 but also in PBX1. No association with DNA repeats or putative cryptic recombination signal sequence sites was observed. A simplified detection method for breakpoint identification was developed and the feasibility of patient-specific chromosomal break sites as molecular markers for detecting measurable residual disease (MRD) was explored. A highly sensitive generic real-time PCR for MRD assessment using these breakpoint sequences was established that could serve as a useful alternative to the classical method utilizing rearranged immune gene loci. This study provides the first extensive molecular data set on the chromosomal breakpoints of the t(1;19)/TCF3::PBX1 aberration in adult ALL. Based on the obtained data a generic MRD method was developed that has several theoretical advantages, including an on average higher sensitivity and a greater stability of the molecular marker in the course of disease. [ABSTRACT FROM AUTHOR]

Introduction: The malignant transformation leading to a maturation arrest in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) occurs early in B-cell development, in a pro-B or pre-B cell, when somatic recombination of variable (V), diversity (D), and joining (J) segment immunoglobulin (IG) genes and the B-cell rescue mechanism of VH replacement might be ongoing or fully active, driving clonal evolution. In this study of newly diagnosed BCP-ALL, we sought to understand the mechanistic details of oligoclonal composition of the leukemia at diagnosis, clonal evolution during follow-up, and clonal distribution in different hematopoietic compartments. Methods: Utilizing high-throughput sequencing assays and bespoke bioinformatics we identified BCP-ALL-derived clonally-related IGH sequences by their shared 'DNJ-stem'. Results: We introduce the concept of 'marker DNJ-stem' to cover the entirety of, even lowly abundant, clonally-related family members. In a cohort of 280 adult patients with BCP-ALL, IGH clonal evolution at diagnosis was identified in onethird of patients. The phenomenon was linked to contemporaneous recombinant and editing activity driven by aberrant ongoing DH/VH-DJH recombination and VH replacement, and we share insights and examples for both. Furthermore, in a subset of 167 patients with molecular subtype allocation, high prevalence and high degree of clonal evolution driven by ongoing DH/VH-DJH recombination were associated with the presence of KMT2A gene rearrangements, while VH replacements occurred more frequently in Ph-like and DUX4 BCP-ALL. Analysis of 46 matched diagnostic bone marrow and peripheral blood samples showed a comparable clonal and clonotypic distribution in both hematopoietic compartments, but the clonotypic composition markedly changed in longitudinal follow-up analysis in select cases. Thus, finally, we present cases where the specific dynamics of clonal evolution have implications for both the initial marker identification and the MRD monitoring in follow-up samples. Discussion: Consequently, we suggest to follow the marker DNJ-stem (capturing all family members) rather than specific clonotypes as the MRD target, as well as to follow both VDJH and DJH family members since their respective kinetics are not always parallel. Our study further highlights the intricacy, importance, and present and future challenges of IGH clonal evolution in BCP-ALL. [ABSTRACT FROM AUTHOR]

Background: A lower baseline bone marrow blast percentage (bBMB%) is associated with better outcomes in patients with B‐cell acute lymphoblastic leukemia (B‐ALL) receiving blinatumomab. The objective of this analysis was to investigate the association between bBMB% and treatment outcomes in relapsed/refractory (R/R) B‐ALL. Methods: Data from five trials of blinatumomab for R/R B‐ALL were pooled for analyses. Patients were placed in one of three groups: group 1, ≥50% bBMBs; group 2, ≥25% to <50% bBMBs; group 3, ≥5% to <25% bBMBs. Response and survival outcomes were compared between groups. Results: Data from 683 patients (166 pediatric, 517 adult) were analyzed. Collectively, patients in groups 2 and 3 had significantly higher odds of achieving a complete remission (CR) (odds ratio [OR], 3.50 [95% confidence interval (CI), 2.23–5.48] and 3.93 [95% CI, 2.50–6.18], respectively; p <.001) and minimal/measurable residual disease response (OR, 2.61 and 3.37, respectively; p <.001) when compared with group 1 (reference). Groups 2 and 3 had a 37% and 46% reduction in the risk of death (hazard ratio [HR], 0.63 and 0.54, respectively; p <.001) and a 41% and 43% reduction in the risk of an event (relapse or death) (HR, 0.59 and 0.57, respectively; p <.001) compared with group 1. No significant differences in response or survival outcomes were observed between groups 2 and 3. Seven of nine patients whose bBMB% was lowered to <50% with dexamethasone achieved CR with blinatumomab. Conclusion: Any bBMB% <50% was associated with improved efficacy following blinatumomab treatment for R/R B‐ALL. Patients with a baseline leukemia burden of <50% bone marrow blasts achieved better outcomes with blinatumomab compared with those who had ≥50% blasts. There was no statistical difference in clinical outcomes with blinatumomab in patients who had ≥5% to <50% bone marrow blasts at baseline. [ABSTRACT FROM AUTHOR]

FAT atypical cadherin 1 (FAT1), a transmembrane protein, is frequently mutated in various cancer types and has been described as context-dependent tumor suppressor or oncogene. The FAT1 gene is mutated in 12–16% of T-cell acute leukemia (T-ALL) and aberrantly expressed in about 54% of T-ALL cases contrasted with absent expression in normal T-cells. Here, we characterized FAT1 expression and profiled the methylation status from T-ALL patients. In our T-ALL cohort, 53% of patient samples were FAT1 positive (FAT1pos) compared to only 16% FAT1 positivity in early T-ALL patient samples. Aberrant expression of FAT1 was strongly associated with FAT1 promotor hypomethylation, yet a subset, mainly consisting of TLX1-driven T-ALL patient samples showed methylation-independent high FAT1 expression. Genes correlating with FAT1 expression revealed enrichment in WNT signaling genes representing the most enriched single pathway. FAT1 knockdown or knockout led to impaired proliferation and downregulation of WNT pathway target genes (CCND1, MYC, LEF1), while FAT1 overexpressing conveyed a proliferative advantage. To conclude, we characterized a subtype pattern of FAT1 gene expression in adult T-ALL patients correlating with promotor methylation status. FAT1 dependent proliferation and WNT signaling discloses an impact on deeper understanding of T-ALL leukemogenesis as a fundament for prospective therapeutic strategies. [ABSTRACT FROM AUTHOR]

Background: B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a genetically heterogenous malignancy with poor prognosis in relapsed adult patients. The genetic basis for relapse in aneuploid subtypes such as near haploid (NH) and high hyperdiploid (HeH) BCP-ALL is only poorly understood. Pathogenic genetic alterations remain to be identified. To this end, we investigated the dynamics of genetic alterations in a matched initial diagnosis-relapse (ID-REL) BCP-ALL cohort. Here, we firstly report the identification of the novel genetic alteration CYB5Aalt, an alternative transcript of CYB5A, in two independent cohorts. Methods: We identified CYB5alt in the RNAseq-analysis of a matched ID-REL BCP-ALL cohort with 50 patients and quantified its expression in various molecular BCP-ALL subtypes. Findings were validated in an independent cohort of 140 first diagnosis samples from adult BCP-ALL patients. Derived from patient material, the alternative open reading frame of CYB5Aalt was cloned (pCYB5Aalt) and pCYB5Aalt or the empty vector were stably overexpressed in NALM-6 cells. RNA sequencing was performed of pCYB5Aalt clones and empty vector controls followed by differential expression analysis, gene set enrichment analysis and complementing cell death and viability assays to determine functional implications of CYB5Aalt. Results: RNAseq data analysis revealed non-canonical exon usage of CYB5Aalt starting from a previously undescribed transcription start site. CYB5Aalt expression was increased in relapsed BCP-ALL and its occurrence was specific towards the shared gene expression cluster of NH and HeH BCP-ALL in independent cohorts. Overexpression of pCYB5Aalt in NALM-6 cells induced a distinct transcriptional program compared to empty vector controls with downregulation of pathways related to reported functions of CYB5A wildtype. Interestingly, CYB5A wildtype expression was decreased in CYB5Aalt samples in silico and in vitro. Additionally, pCYB5Aalt NALM-6 elicited a more resistant drug response. Conclusions: Across all age groups, CYB5Aalt was the most frequent secondary genetic event in relapsed NH and HeH BCP-ALL. In addition to its high subgroup specificity, CYB5Aalt is a novel candidate to be potentially implicated in therapy resistance in NH and HeH BCP-ALL. This is underlined by overexpressing CYB5Aalt providing first evidence for a functional role in BCL2-mediated apoptosis. [ABSTRACT FROM AUTHOR]

Background: Blinatumomab is a BiTE® immuno‐oncology therapy indicated for the treatment of patients with relapsed or refractory (r/r) B‐cell precursor (BCP) acute lymphoblastic leukemia (ALL). Aims: To assess the efficacy and safety of blinatumomab as first salvage versus second or later salvage in patients with r/r BCP ALL. Materials & Methods: Patient‐level pooled data were used for this analysis. In total, 532 adults with r/r BCP ALL treated with blinatumomab were included (first salvage, n = 165; second or later salvage, n = 367). Results: Compared with patients who received blinatumomab as second or later salvage, those who received blinatumomab as first salvage had a longer median overall survival (OS; 10.4 vs. 5.7 months; HR, 1.58; 95% CI, 1.26–1.97; P <.001) and relapse‐free survival (10.1 vs. 7.3 months; HR, 1.38; 95% CI, 0.98–1.93; P =.061), and higher rates of remission (n = 89 [54%] vs. n = 150 [41%]; odds ratio, 0.59; 95% CI, 0.41–0.85; P =.005), minimal residual disease response (n = 68 [41%] vs. n = 118 [32%]), and allogeneic hematopoietic stem cell transplant (alloHSCT) realization (n = 60 [36%] vs. n = 88 [24%]), and alloHSCT in continuous remission (n = 33 [20%] vs. n = 52 (14%]). In a subgroup analysis, there was no apparent effect of prior alloHSCT on median OS in either salvage group. The safety profile of blinatumomab was generally similar between the groups; however, cytokine release syndrome, febrile neutropenia, and infection were more frequent with second or later salvage than with first salvage. Discussion: In this pooled analysis, the logistic regression analyses indicated greater benefit with blinatumomab as first salvage than as second or later salvage, as evident by the longer median OS, longer median RFS, and higher rates of remission. Conclusion: Overall, blinatumomab was beneficial as first salvage and as second or later salvage, but the effects were favorable as first salvage. [ABSTRACT FROM AUTHOR]

Background: Patients with relapsed/refractory (R/R) Philadelphia chromosome–positive (Ph+) acute lymphoblastic leukemia (ALL) have a poor prognosis and limited treatment options. Methods: The efficacy of inotuzumab ozogamicin (InO), a humanized anti‐CD22 monoclonal antibody conjugated to the cytotoxic antibiotic calicheamicin, was evaluated in R/R ALL patients in the phase 1/2 study 1010 (NCT01363297) and open‐label, randomized, phase 3 study 1022 (INO‐VATE; NCT01564784). This analysis focused specifically on Ph+ R/R ALL patients. In study 1022, Ph+ patients were randomly assigned 1:1 to InO (n = 22) or standard intensive chemotherapy (SC) (n = 27) and 16 Ph+ patients in study 1010 received InO. Results: In study 1022, rates of complete remission/complete remission with incomplete hematologic recovery (CR/CRi) and minimal residual disease (MRD) negativity (patients achieving CR/CRi) were higher with InO (CR/CRi = 73%; MRD = 81%) versus SC (CR/CRi = 56%; MRD = 33%). The corresponding rates in study 1010 were 56% (CR/CRi) and 100% (MRD). The hematopoietic stem cell transplantation (HSCT) rate in study 1022 was 41% versus 19% for InO versus SC; however, there was no benefit in overall survival (median OS: 8.7 vs 8.4 months; hazard ratio, 1.17 [95% CI, 0.64‐2.14]). The probability of being event‐free (progression‐free survival) at 12 months was greater with InO versus SC (20.1% vs 4.8%). Conclusion: Given the substantial improvement in responses and rates of HSCT, InO is an important treatment option for patients with R/R Ph+ ALL. Future studies need to consider better characterization of disease characteristics, more sensitive MRD measurements, MRD‐directed therapy before HSCT, and potentially combination therapies, including tyrosine kinase inhibitors. An analysis of 65 patients with relapsed/refractory Philadelphia chromosome‐positive acute lymphoblastic leukemia shows that patients receiving inotuzumab ozogamicin (InO) have higher rates of complete remission/complete remission with incomplete hematologic recovery, minimal residual disease negativity, and subsequent hematopoietic stem cell transplantation than those receiving standard intensive chemotherapy (SC). Although this does not result in prolonged progression‐free survival or overall survival compared with SC, InO remains an important treatment option for patients with resistant and difficult‐to–treat disease. [ABSTRACT FROM AUTHOR]

Background: Blinatumomab is a CD19 BiTE (bispecific T‐cell engager) immuno‐oncology therapy that mediates the lysis of cells expressing CD19. Methods: A pooled analysis of long‐term follow‐up data from 2 phase 2 studies that evaluated blinatumomab in heavily pretreated adults with Philadelphia chromosome–negative, relapsed/refractory B‐cell precursor acute lymphoblastic leukemia was conducted. Results: A total of 259 patients were included in the analysis. The median overall survival (OS) among all patients, regardless of response, was 7.5 months (95% confidence interval [CI], 5.5‐8.5 months); the median follow‐up time for OS was 36.0 months (range, 0.3‐60.8 months). The median relapse‐free survival (RFS) among patients who achieved a complete remission (CR) or complete remission with partial hematologic recovery (CRh) in the first 2 cycles (n = 123) was 7.7 months (95% CI, 6.2‐10.0 months); the median follow‐up time for RFS was 35.0 months (range, 9.5‐59.5 months). OS and RFS plateaued with 3‐year rates of 17.7% and 23.4%, respectively. The cumulative incidence function of the time to relapse, with death not due to relapse considered a competing risk, for patients who achieved a CR/CRh within 2 cycles of treatment also plateaued with a 3‐year relapse rate of 59.3%. For patients who achieved a CR/CRh with blinatumomab followed by allogeneic hematopoietic stem cell transplantation while in continuous CR, the median OS was 18.1 months (95% CI, 10.3‐30.0 months) with a 3‐year survival rate of 37.2%. Conclusions: These data suggest that long‐term survival is possible after blinatumomab therapy. Lay Summary: Immuno‐oncology therapies such as blinatumomab activate the patient's own immune system to kill cancer cells.This study combined follow‐up data from 2 blinatumomab‐related clinical trials to evaluate long‐term survival in patients with relapsed and/or refractory B‐cell precursor acute lymphoblastic leukemia at high risk for unfavorable outcomes.Among patients who achieved a deep response with blinatumomab, one‐third lived 3 years or longer. These findings suggest that long‐term survival is possible after treatment with blinatumomab. Patients achieving remission after blinatumomab can have a durable response. The survival plateau indicates a high probability of a cure in those patients responding to blinatumomab and alive after 3 years. [ABSTRACT FROM AUTHOR]

Minimal residual disease (MRD) is the strongest predictor of relapse in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In BLAST study (NCT01207388), adults with BCP-ALL in remission with MRD after chemotherapy received blinatumomab, a CD19 BiTE® immuno-oncotherapy, 15 µg/m2/day for up to four 6-week cycles (4 weeks continuous infusion, 2 weeks off). Survival was evaluated for 110 patients, including 74 who received HSCT in continuous complete remission. With a median follow-up of 59·8 months, median survival (months) was 36·5 (95% CI: 22.0–not reached [NR]). Median survival was NR (29.5–NR) for complete MRD responders (n = 84) and 14.4 (3.8–32.3) for MRD non-responders (n = 23; p = 0.002); after blinatumomab and HSCT, median survival was NR (25.7–NR) (n = 61) and 16.5 (1.1–NR) (n = 10; p = 0.065), respectively. This final analysis suggests complete MRD response during blinatumomab treatment is curative. Post-hoc analysis of study data suggests while post blinatumomab HSCT may be beneficial in appropriate patients, long-term survival without HSCT is also possible. [ABSTRACT FROM AUTHOR]

The GMALL07/2003 protocol introduced pegylated E. coli asparaginase (PEG-ASNase) frontline for adults with acute lymphoblastic leukemia (ALL). PEG-ASNase (500 U/m2, 1000 U/m2, or 2000 U/m2) was given once in induction and as part of three HD-MTX/PEG-ASNase cycles with two PEG-ASNase doses every other week in consolidation. PEG-ASNase activities were monitored in 1363 serum samples from 304 ALL patients. The overall rate of silent inactivation was low (5%) and did not differ between induction and consolidation. The successful targeting of PEG-ASNase activities ≥100 U/L depended on protocol and dose. Overall PEG-ASNase activities were higher during consolidation compared to induction. To target PEG-ASNase activities ≥100 U/L for 14 day with a single dose in induction, 2000 U/m2 was more preferable than 1000 U/m2 or 500 U/m2. During consolidation with two administrations every other week, 1000 U/m2 and 2000 U/m2 were similarly effective in sustaining PEG-ASNase ≥100 U/L activities over 14 days. [ABSTRACT FROM AUTHOR]

Background: Blinatumomab, a bispecific T-cell-engaging (BiTE®) immuno-oncology therapy, demonstrated superior overall survival versus standard-of-care chemotherapy (SOC) in adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R ALL) in the phase 3 TOWER study. Herein, the authors reported clinical features and outcomes for those patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) after treatment with blinatumomab.Methods: In the TOWER study, adults with R/R ALL were randomized 2:1 to receive blinatumomab or SOC. Study treatment consisted of 2 cycles of induction with blinatumomab or SOC followed by consolidation and maintenance therapy. At any time after the first cycle, patients who were eligible for HSCT could proceed to HSCT.Results: Of the 97 patients who underwent HSCT during the study, baseline characteristics generally were comparable and donor types were similar between the patients treated with blinatumomab (65 patients) and those receiving SOC (32 patients). There was no evidence to suggest that the survival benefit of HSCT differed between the patients treated with blinatumomab and those receiving SOC (P = .68). On the basis of descriptive statistics, a survival benefit of HSCT versus no HSCT was not observed in patients who achieved complete remission with full, partial, or incomplete hematologic recovery with blinatumomab (odds ratio, 1.17; 95% CI, 0.54-2.53). The best outcomes were achieved in patients with no prior salvage therapy and with minimal residual disease response to blinatumomab regardless of on-study HSCT status.Conclusions: Survival was found to be driven by response to study treatment and by salvage status regardless of on-study HSCT status. These data should be interpreted with caution because the current study was not designed to prospectively assess survival outcomes associated with HSCT after blinatumomab.Lay Summary: Evidence before this study: Blinatumomab is associated with superior morphologic and molecular response rates and superior overall outcome when compared with standard of care chemotherapy in adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia. Added value of this study: The best outcomes with blinatumomab were observed in patients who achieved minimal residual disease remission in first salvage treatment regardless of subsequent allogeneic stem cell transplantation (HSCT). Implications of all the available evidence: Patients achieving CR/CRh/CRi following blinatumomab can have a durable response with or without HSCT. [ABSTRACT FROM AUTHOR]

Objectives: Detectable minimal residual disease (MRD) after therapy for acute lymphoblastic leukemia (ALL) is the strongest predictor of hematologic relapse. This study evaluated outcomes of patients with B-cell precursor ALL with MRD of ≥10−4 Methods: Study population was from ALL study groups in Europe managed in national study protocols 2000–2014. MRD was measured by polymerase chain reaction or flow cytometry. Patients were age ≥15 years at initial ALL diagnosis. Patients were excluded if exposed to blinatumomab within 18 months of baseline or prior alloHSCT. Results: Of 272 patients in CR1, baseline MRD was ≥10−1, 10−2 to <10−1, 10−3 to <10−2, and 10−4 to <10−3 in 15 (6%), 71 (26%), 109 (40%), and 77 (28%) patients, respectively. Median duration of complete remission (DoR) was 18.5 months (95% confidence interval [CI], 11.9–27.2), median relapse-free survival (RFS) was 12.4 months (95% CI, 10.0–19.0) and median overall survival (OS) was 32.5 months (95% CI, 23.6–48.0). Lower baseline MRD level (P ≤.0003) and white blood cell count <30,000/µL at diagnosis (P ≤.0053) were strong predictors for better RFS and DoR. Allogeneic hematopoietic stem cell transplantation (alloHSCT) was associated with longer RFS (hazard ratio [HR], 0.59; 95% CI, 0.41–0.84) and DoR (HR, 0.43; 95% CI, 0.29–0.64); the association with OS was not significant (HR, 0.72; 95% CI, 0.50–1.05). Discussion: In conclusion, RFS, DoR, and OS are relatively short in patients with MRD-positive ALL, particularly at higher MRD levels. AlloHSCT may improve survival but has limitations. Alternative approaches are needed to improve outcomes in MRD-positive ALL. [ABSTRACT FROM AUTHOR]

Background: Inotuzumab ozogamicin (InO) is an antibody-drug conjugate used for adults with relapsed/refractory B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). The INotuzumab Ozogamicin trial to inVestigAte Tolerability and Efficacy (INO-VATE) previously reported improved outcomes with InO versus standard-of-care (SoC) chemotherapy. This article reports the final INO-VATE results (≥2 years of follow-up) and additional analyses of patient characteristics associated with improved outcomes.Methods: Between August 27, 2012, and January 4, 2015, this multicenter, parallel, open-label, phase 3 trial randomized 326 adults with relapsed/refractory ALL to InO (n = 164) or SoC (n = 162); 307 received 1 or more doses of the study drug (164 in the InO arm and 143 in the SoC arm).Results: The complete remission (CR)/complete remission with incomplete hematologic recovery (CRi) rate was higher with InO versus SoC (73.8% vs 30.9%; 1-sided P < .0001), with consistent CR/CRi rates across patient subgroups. The median overall survival (OS) was 7.7 months with InO and 6.2 months with SoC, with 2-year OS rates of 22.8% and 10.0%, respectively (overall hazard ratio, 0.75; 97.5% confidence interval [CI], 0.57-0.99; 1-sided P = .0105). The predictors of OS with InO were the best minimal residual disease status, baseline platelet count, duration of first remission, achievement of CR/CRi, and follow-up hematopoietic stem cell transplantation (HSCT; all 2-sided P values < .05). More InO arm patients proceeded directly to HSCT after achieving CR/CRi before any follow-up induction therapy (39.6% [95% CI, 32.1%-47.6%] vs 10.5% [6.2%-16.3%]; 1-sided P < .0001). The most frequent all-grade and grade 3 or higher adverse events in both arms were hematologic. Veno-occlusive disease (VOD)/sinusoidal obstruction syndrome (SOS) was more frequent with InO (23 of 164 [14.0%] vs 3 of 143 [2.1%]).Conclusions: In patients with relapsed/refractory BCP ALL in INO-VATE, InO was associated with a greater likelihood of CR/CRi across key patient subgroups, and it served as a bridge to HSCT. Potential VOD/SOS risk factors must be considered when InO treatment decisions are being made. [ABSTRACT FROM AUTHOR]

Acute leukemias of ambiguous lineage represent a heterogeneous group of rare, poorly characterized leukemias with adverse outcome. No larger studies have yet performed a combined approach of molecular and clinical characterization of acute undifferentiated leukemia (AUL) and biphenotypic acute leukemia (BAL) in adults. Here we describe 16 adults with AUL and 26 with BAL and performed mutational as well as expression studies of genes with prognostic impact in acute leukemia ( BAALC, ERG, MN1, WT1, and IGFBP7). AUL showed overexpression of these genes compared to T-lymphoblastic leukemia (T-ALL), B-precursor ALL, and to acute myeloid leukemia (AML). Genotype alterations were not detectable in AUL. BAL samples were characterized by frequent WT1 mutations (18 %) and BCR-ABL translocations (30 %). ALL-based treatment protocols induced complete remissions in 40 % and AML-like therapies in 22 % of AUL/BAL patients. The outcome in both groups was very poor; a long-term survival was only observed in patients undergoing allogeneic stem cell transplantation (SCT). Our findings indicate that AUL and BAL share important molecular and high-risk features of both myeloid and lymphoid leukemias. BAL patients exhibited genetic alterations, which can be targeted therapeutically. Importantly, ALL therapy might be more effective than AML protocols and AUL/BAL patients should be considered for allogeneic SCT. [ABSTRACT FROM AUTHOR]

Wilms’ tumor gene 1 (WT1) is gaining increasing attention as a therapeutic target molecule due to its common expression in acute leukemias and its involvement in cell proliferation. Here, we reported on WT1 messenger RNA expression levels at diagnosis in a series of 238 adult acute lymphoblastic leukemia (ALL) samples of various subtypes and clinical outcome. WT1 expression was found in 219 out of 238 ALL samples (92%). Compared to a cohort of acute myeloid leukemia patients, the median WT1 expression level in ALL was significantly lower with large variations among different ALL subgroups. Specifically, WT1 expression levels were low in mature B-ALL and highest in ALL cases with co-expression of myeloid markers, making it a useful therapeutic target molecule in adult ALL with the exception of mature B-ALL. Cox regression analysis, considering ALL phenotype as well as molecular-cytogenetic subsets, revealed no independent prognostic role of WT1 expression level for disease-free and overall survival. [ABSTRACT FROM AUTHOR]

Background: Combined inhibition of phosphatidylinositol 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) complexes may be an efficient treatment for acute leukemia. The primary objective of this phase I single center open label study was to determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of the dual pan-class I PI3K and mTOR inhibitor BEZ235 in patients with advanced leukemia. Methods: Herein patients > 18 years of age who had relapsed or showed refractory leukemia were treated with BEZ235 (orally at 300–400 mg BID (cohort − 1/1)) to assess safety, tolerability, preliminary efficacy and pharmacokinetic (PK). Adverse events data and serious adverse events were analyzed and haematological and clinical biochemistry toxicities were assessed from laboratory test parameters. Response was assessed for the first time at the end of cycle 1 (day 29) and after every subsequent cycle. Pharmacokinetic and pharmacodynamic analyses of BEZ235 were also included (BEZ235 plasma levels, phosphorylation of AKT, S6 and 4EBP1). On statistics this trial is a multiple ascending dose study in which a following variant of the 3 + 3 rule ("Rolling Six"), a minimum of 6 and a maximum of 12 patients was recruited for the dose escalation and another 5 were planned for the expansion phase. Results: Twenty-four patients with ALL (n = 11) or AML (n = 12) or CML-BP (n = 1) were enrolled. All patients had failed one (n = 5) or more lines of therapy (n = 5) and 14 patients were in refractory / refractory relapse. No formal MTD was defined, stomatitis and gastrointestinal toxicity at 400 mg BID dose was considered incompatible with prolonged treatment. The RP2D of BEZ235 was defined as 300 mg BID. Four of 24 patients showed clinical benefit. Twenty-two of 24 patients discontinued because of progression, (median time to progression 27 days (4d-112d). There was no association between PK parameters and efficacy or tolerability. Conclusions: Combined inhibition of PI3K and mTOR inhibits a clinically meaningful driver pathway in a small subset of patients with ALL, with no benefit in patients with AML. Trial registration: ClinicalTrials.gov, identifier NCT01756118. retrospectively registered 19th December 2012, https://clinicaltrials.gov/ct2/show/NCT01756118. [ABSTRACT FROM AUTHOR]

• Subgroup data were analyzed in patients with ALL enrolled in INO-VATE (NCT01564784). • The analysis was based on MRD status at end of treatment with inotuzumab ozogamicin. • MRD-negative patients with complete remission had improved survival vs MRD-positive. • MRD-negative patients treated in 1st salvage experienced the most survival benefit. • The best outcomes were seen in these patients who proceeded to stem cell transplant. Minimal residual disease (MRD) negativity is a key prognostic indicator of outcome in acute lymphocytic leukemia. In the INO-VATE trial (clinicaltrials.gov identifier: NCT01564784), patients with relapsed/refractory acute lymphocytic leukemia who received inotuzumab versus standard chemotherapy achieved greater remission and MRD-negativity rates as well as improved overall survival: hazard ratio 0.75, one-sided P = 0.0105. The current analysis assessed the prognostic value of MRD negativity at the end of inotuzumab treatment. All patients who received inotuzumab (n = 164) were included. Among patients with complete remission/complete remission with incomplete hematologic response (CR/CRi; n = 121), MRD-negative status (by multiparametric flow cytometry) was defined as <1 × 10–4 blasts/nucleated cells. MRD negativity was achieved in 76 patients at the end of treatment. Compared with MRD-positive, MRD-negative status with CR/CRi was associated with significantly improved overall survival and progression-free survival, respectively: hazard ratio (97.5% confidence interval; one-sided P- value) 0.512 (97.5% CI [0.313–0.835]; P = 0.0009) and 0.423 (97.5% CI [0.256–0.699]; P < 0.0001). Median overall survival was 14.1 versus 7.2 months, in the MRD-negative versus MRD-positive groups. Patients in first salvage who achieved MRD negativity at the end of treatment experienced significantly improved survival versus that seen in MRD-positive patients, particularly for those patients who proceeded to stem cell transplant. Among patients with relapsed/refractory acute lymphocytic leukemia who received inotuzumab, those with MRD-negative CR/CRi had the best survival outcomes. [ABSTRACT FROM AUTHOR]

• Blinatumomab treatment resulted in a complete remission (CR)/CR with partial hematologic recovery of peripheral blood counts rate of 45% within the first 2 cycles. • The incidence of adverse events was similar in patients with and those without previous allogeneic hematopoietic stem cell transplantation. • Blinatumomab appears to be an effective salvage therapy in this patient population. Patients with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) following allogeneic hematopoietic stem cell transplantation (alloHSCT) have a poor prognosis, and alternative therapies are needed for this patient population. Blinatumomab, a bispecific T cell engager immunotherapy, was evaluated in an open-label, single-arm, phase II study of adults with R/R Philadelphia chromosome-negative B cell precursor ALL and resulted in a rate of complete remission (CR) or CR with partial hematologic recovery of peripheral blood counts (CRh) of 43% within 2 treatment cycles. We conducted an exploratory analysis to determine the efficacy and safety of blinatumomab in 64 patients who had relapsed following alloHSCT before enrollment in the phase II study. Forty-five percent of the patients (29 of 64) achieved a CR/CRh within the first 2 cycles of treatment, 22 of whom had a minimal residual disease (MRD) response (including 19 with a complete MRD response). After 1 year and 3 years of follow-up, the median relapse-free survival was 7.4 months for patients who achieved CR/CRh in the first 2 cycles, and the median overall survival was 8.5 months; overall survival rate (Kaplan-Meier estimate) was 36% at 1 year and 18% at 3 years. Grade 3 and 4 adverse events were reported in 20 patients (31%) and 28 patients (44%), respectively, with grade 3 and 4 neurologic events in 8 and 2 patients, respectively, and grade 3 cytokine release syndrome in 2 patients. Eight patients had fatal adverse events, including 5 due to infections. Seven patients had grade ≤ 3 graft-versus-host disease during the study, none of which resulted in the discontinuation of blinatumomab or hospitalization. Our data suggest that blinatumomab is an effective salvage therapy in this patient population. [ABSTRACT FROM AUTHOR]

• Salvage with inotuzumab can provide a bridge to transplant in relapsed/refractory acute lymphoblastic leukemia. • A high chance of achieving minimal residual disease negativity also exists with inotuzumab ozogamicin (InO). • Data from 2 InO trials were used to find factors related to post-transplant survival. • Best survival was in those who had first transplant upon remission after inotuzumab. Attaining complete remission of acute lymphoblastic leukemia (ALL) before hematopoietic stem cell transplantation (HSCT) correlates with better post-transplant outcomes. Inotuzumab ozogamicin (InO), an anti-CD22 antibody conjugated to calicheamicin, has shown significantly higher rates of remission, minimal residual disease negativity, and HSCT versus standard chemotherapy in treating relapsed/refractory (R/R) ALL. We investigated the role of previous transplant and proceeding directly to HSCT after remission as factors in determining post-transplant survival in the setting of InO treatment for R/R ALL. The analyzed population comprised InO-treated patients who proceeded to allogeneic HSCT in 2 clinical trials (phase 1/2: NCT01363297 and phase 3: NCT01564784). Overall survival (OS) was defined as time from HSCT to death (any cause). Of 236 InO-treated patients, 101 (43%) proceeded to allogeneic HSCT and were included in this analysis. Most received InO as first salvage (62%); 85% had no previous HSCT. Median (95% confidence interval [CI]) post-transplant OS was 9.2 months (5.1, not evaluable) with 2-year survival probability (95% CI) of 41% (32% to 51%). In first-HSCT patients (n = 86), median (95% CI) post-transplant OS was 11.8 months (5.9, not evaluable) with 2-year survival probability (95% CI) of 46% (35% to 56%); some patients relapsed and needed additional treatment before HSCT (n = 28). Those who went directly to first HSCT upon remission with no additional salvage/induction treatment (n = 73) fared best: median post-transplant OS was not reached with a 2-year survival probability (95% CI) of 51% (39% to 62%). In patients with R/R ALL, InO followed by allogeneic HSCT provided an optimal long-term survival benefit among those with no previous HSCT who went directly to transplant after remission. [ABSTRACT FROM AUTHOR]