Measurable residual disease (MRD; previously termed minimal residual disease) is an independent, postdiagnosis, prognostic indicator in acute myeloid leukemia (AML) that is important for risk ...stratification and treatment planning, in conjunction with other well-established clinical, cytogenetic, and molecular data assessed at diagnosis. MRD can be evaluated using a variety of multiparameter flow cytometry and molecular protocols, but, to date, these approaches have not been qualitatively or quantitatively standardized, making their use in clinical practice challenging. The objective of this work was to identify key clinical and scientific issues in the measurement and application of MRD in AML, to achieve consensus on these issues, and to provide guidelines for the current and future use of MRD in clinical practice. The work was accomplished over 2 years, during 4 meetings by a specially designated MRD Working Party of the European LeukemiaNet. The group included 24 faculty with expertise in AML hematopathology, molecular diagnostics, clinical trials, and clinical medicine, from 19 institutions in Europe and the United States.
Blinatumomab, a bispecific monoclonal antibody construct that enables CD3-positive T cells to recognize and eliminate CD19-positive acute lymphoblastic leukemia (ALL) blasts, was approved for use in ...patients with relapsed or refractory B-cell precursor ALL on the basis of single-group trials that showed efficacy and manageable toxic effects.
In this multi-institutional phase 3 trial, we randomly assigned adults with heavily pretreated B-cell precursor ALL, in a 2:1 ratio, to receive either blinatumomab or standard-of-care chemotherapy. The primary end point was overall survival.
Of the 405 patients who were randomly assigned to receive blinatumomab (271 patients) or chemotherapy (134 patients), 376 patients received at least one dose. Overall survival was significantly longer in the blinatumomab group than in the chemotherapy group. The median overall survival was 7.7 months in the blinatumomab group and 4.0 months in the chemotherapy group (hazard ratio for death with blinatumomab vs. chemotherapy, 0.71; 95% confidence interval CI, 0.55 to 0.93; P=0.01). Remission rates within 12 weeks after treatment initiation were significantly higher in the blinatumomab group than in the chemotherapy group, both with respect to complete remission with full hematologic recovery (34% vs. 16%, P<0.001) and with respect to complete remission with full, partial, or incomplete hematologic recovery (44% vs. 25%, P<0.001). Treatment with blinatumomab resulted in a higher rate of event-free survival than that with chemotherapy (6-month estimates, 31% vs. 12%; hazard ratio for an event of relapse after achieving a complete remission with full, partial, or incomplete hematologic recovery, or death, 0.55; 95% CI, 0.43 to 0.71; P<0.001), as well as a longer median duration of remission (7.3 vs. 4.6 months). A total of 24% of the patients in each treatment group underwent allogeneic stem-cell transplantation. Adverse events of grade 3 or higher were reported in 87% of the patients in the blinatumomab group and in 92% of the patients in the chemotherapy group.
Treatment with blinatumomab resulted in significantly longer overall survival than chemotherapy among adult patients with relapsed or refractory B-cell precursor ALL. (Funded by Amgen; TOWER ClinicalTrials.gov number, NCT02013167 .).
Minimal residual disease (MRD) is highly prognostic in pediatric B-precursor acute lymphoblastic leukemia (B-ALL). In Children's Oncology Group high-risk B-ALL study AALL0232, we investigated MRD in ...subjects randomized in a 2 × 2 factorial design to receive either high-dose methotrexate (HD-MTX) or Capizzi methotrexate (C-MTX) during interim maintenance (IM) or prednisone or dexamethasone during induction. Subjects with end-induction MRD ≥0.1% or those with morphologic slow early response were nonrandomly assigned to receive a second IM and delayed intensification phase. MRD was measured by 6-color flow cytometry in 1 of 2 reference labs, with excellent agreement between the two. Subjects with end-induction MRD <0.01% had a 5-year event-free survival (EFS) of 87% ± 1% vs 74% ± 4% for those with MRD 0.01% to 0.1%; increasing MRD amounts was associated with progressively worse outcome. Subjects converting from MRD positive to negative by end consolidation had a relatively favorable 79% ± 5% 5-year disease-free survival vs 39% ± 7% for those with MRD ≥0.01%. Although HD-MTX was superior to C-MTX, MRD retained prognostic significance in both groups (86% ± 2% vs 58% ± 4% for MRD-negative vs positive C-MTX subjects; 88% ± 2% vs 68% ± 4% for HD-MTX subjects). Intensified therapy given to subjects with MRD >0.1% did not improve either 5-year EFS or overall survival (OS). However, these subjects showed an early relapse rate similar to that seen in MRD-negative ones, with EFS/OS curves for patients with 0.1% to 1% MRD crossing those with 0.01% to 0.1% MRD at 3 and 4 years, thus suggesting that the intensified therapy altered the disease course of MRD-positive subjects. Additional interventions targeted at the MRD-positive group may further improve outcome. This trial was registered at www.clinicaltrials.gov as #NCT00075725.
•MRD measured by flow cytometry is prognostic in childhood B-ALL even with more effective high-dose methotrexate therapy.•Intensive therapy in MRD-positive patients altered the timing of relapse but did not overcome the poor prognostic significance of MRD.
Patients with acute myeloid leukemia (AML) who are in morphologic complete remission are typically considered separately from patients with active disease (ie, ≥ 5% marrow blasts by morphology) in ...treatment algorithms for allogeneic hematopoietic cell transplantation (HCT), which implies distinct outcomes for these two groups. It is well recognized that the presence of minimal residual disease (MRD) at the time of transplantation is associated with adverse post-HCT outcome for those patients in morphologic remission. This effect of pre-HCT MRD prompted us to compare outcomes in consecutive patients in MRD-positive remission with patients with active AML who underwent myeloablative allogeneic HCT at our institution.
We retrospectively studied 359 consecutive adults with AML who underwent myeloablative allogeneic HCT from a peripheral blood or bone marrow donor between 2006 and 2014. Pre-HCT disease staging included 10-color multiparametric flow cytometry on bone marrow aspirates in all patients. Any level of residual disease was considered to be MRD positive.
Three-year relapse estimates were 67% in 76 patients in MRD-positive morphologic remission and 65% in 48 patients with active AML compared with 22% in 235 patients in MRD-negative remission. Three-year overall survival estimates were 26%, 23%, and 73% in these three groups, respectively. After multivariable adjustment, MRD-negative remission status remained statistically significantly associated with longer overall and progression-free survival as well as lower risk of relapse compared with MRD-positive morphologic remission status or having active disease, with similar outcomes between the latter two groups.
The similarities in outcomes between patients in MRD-positive morphologic remission and those with active disease at the time of HCT support the use of treatment algorithms that use MRD- rather than morphology-based disease assessments.
Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a high-risk subtype characterized by genomic alterations that activate cytokine receptor and kinase signaling. We examined ...the frequency and spectrum of targetable genetic lesions in a retrospective cohort of 1389 consecutively diagnosed patients with childhood B-lineage ALL with high-risk clinical features and/or elevated minimal residual disease at the end of remission induction therapy. The Ph-like gene expression profile was identified in 341 of 1389 patients, 57 of whom were excluded from additional analyses because of the presence of BCR-ABL1 (n = 46) or ETV6-RUNX1 (n = 11). Among the remaining 284 patients (20.4%), overexpression and rearrangement of CRLF2 (IGH-CRLF2 or P2RY8-CRLF2) were identified in 124 (43.7%), with concomitant genomic alterations activating the JAK-STAT pathway (JAK1, JAK2, IL7R) identified in 63 patients (50.8% of those with CRLF2 rearrangement). Among the remaining patients, using reverse transcriptase polymerase chain reaction or transcriptome sequencing, we identified targetable ABL-class fusions (ABL1, ABL2, CSF1R, and PDGFRB) in 14.1%, EPOR rearrangements or JAK2 fusions in 8.8%, alterations activating other JAK-STAT signaling genes (IL7R, SH2B3, JAK1) in 6.3% or other kinases (FLT3, NTRK3, LYN) in 4.6%, and mutations involving the Ras pathway (KRAS, NRAS, NF1, PTPN11) in 6% of those with Ph-like ALL. We identified 8 new rearrangement partners for 4 kinase genes previously reported to be rearranged in Ph-like ALL. The current findings provide support for the precision-medicine testing and treatment approach for Ph-like ALL implemented in Children's Oncology Group ALL trials.
•Ph-like ALL is characterized by a diverse array of genetic alterations activating cytokine receptor and tyrosine kinase signaling.•Pediatric patients with Ph-like ALL can be identified in real time for effective treatment stratification.
Diamond Blackfan anemia (DBA) and myelodysplastic syndrome (MDS) with isolated del(5q) are severe macrocytic anemias; although both are associated with impaired ribosome assembly, why the anemia ...occurs is not known. We cultured marrow cells from DBA (n = 3) and del(5q) MDS (n = 6) patients and determined how heme (a toxic chemical) and globin (a protein) are coordinated. We show that globin translation initiates slowly, whereas heme synthesis proceeds normally. This results in insufficient globin protein, excess heme and excess reactive oxygen species in early erythroid precursors, and CFU-E (colony-forming unit-erythroid)/proerythroblast cell death. The cells that can more rapidly and effectively export heme or can slow heme synthesis preferentially survive and appropriately mature. Consistent with these observations, treatment with 10 μM succinylacetone, a specific inhibitor of heme synthesis, improved the erythroid cell output of DBA and del(5q) MDS marrow cultures by 68 to 95% (P = 0.03 to 0.05), whereas the erythroid cell output of concurrent control marrow cultures decreased by 4 to 13%. Our studies demonstrate that erythropoiesis fails when heme exceeds globin. Our data further suggest that therapies that decrease heme synthesis (or facilitate heme export) could improve the red blood cell production of persons with DBA, del(5q) MDS, and perhaps other macrocytic anemias.
Abstract Minimal residual disease (MRD) after therapy has unequivocal prognostic value in acute leukemia. Over the past 20 years, a number of techniques have evolved into routine laboratory tools to ...detect MRD, most notably, multiparametric flow cytometry (MFC) and quantitative polymerase chain reaction (PCR)-based molecular methods. There is growing evidence that the presence of MRD detected by MFC or molecular methods provides independent prognostic information and is associated with an increased risk of relapse and shortened survival. However, the predictive value of MRD may be affected by a lack of consensus as to the timing for assessment, the methodology used, and interlaboratory variation in test performance. Herein, we review the methodological principles of MRD assays, discuss the clinical implications of monitoring MRD for risk stratification and directing further therapy, and suggest potential areas for future investigation.
Glucocorticoid (GC) resistance is a poor prognostic factor in T‐cell acute lymphoblastic leukaemia (T‐ALL). Interleukin‐7 (IL‐7) mediates GC resistance via GC‐induced upregulation of IL‐7 receptor ...(IL‐7R) expression, leading to increased pro‐survival signalling. IL‐7R reaches the cell surface via the secretory pathway, so we hypothesized that inhibiting the translocation of IL‐7R into the secretory pathway would overcome GC resistance. Sec61 is an endoplasmic reticulum (ER) channel that is required for insertion of polypeptides into the ER. Here, we demonstrate that KZR‐445, a novel inhibitor of Sec61, potently attenuates the dexamethasone (DEX)‐induced increase in cell surface IL‐7R and overcomes IL‐7‐induced DEX resistance.
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