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Fractionated vs single-dose gemtuzumab ozogamicin with determinants of benefit in older patients with AML: the UK NCRI AML18 trial.
Addition of gemtuzumab ozogamicin (GO) to induction chemotherapy improves outcomes in older patients with acute myeloid leukemia (AML), but it is uncertain whether a fractionated schedule provides additional benefit to a single dose. We randomized 852 older adults (median age, 68-years) with AML/high-risk myelodysplasia to GO on day 1 (GO1) or on days 1 and 4 (GO2) of course 1 induction. The median follow-up period was 50.2 months. Although complete remission (CR) rates after course 1 did not significantly differ between arms (GO2, 63%; GO1, 57%; odds ratio [OR], 0.78; P = .08), there were significantly more patients who achieved CR with a measurable residual disease (MRD)<0.1% (50% vs 41%; OR, 0.72; P = .027). This differential MRD reduction with GO2 varied across molecular subtypes, being greatest for IDH mutations. The 5-year overall survival (OS) was 29% for patients in the GO2 arm and 24% for those in the GO1 arm (hazard ratio [HR], 0.89; P = .14). In a sensitivity analysis excluding patients found to have adverse cytogenetics or TP53 mutations, the 5-year OS was 33% for GO2 and 26% for GO1 (HR, 0.83; P = .045). In total, 228 (27%) patients received an allogeneic transplantation in first remission. Posttransplant OS was superior in the GO2 arm (HR, 0.67; P = .033); furthermore, the survival advantage from GO2 in the sensitivity analysis was lost when data of patients were censored at transplantation. In conclusion, GO2 was associated with a greater reduction in MRD and improved survival in older adults with nonadverse risk genetics. This benefit from GO2 was dependent on allogeneic transplantation to translate the better leukemia clearance into improved survival. This trial was registered at www.isrctn.com as #ISRCTN 31682779.
Genetic and non-genetic mechanisms of inflammation may promote transformation in leukemia.
Non-genetic mechanisms of transformation are still relatively understudied and poorly understood. In this issue of Cell Stem Cell, Muto et al. provide preclinical evidence that loss of TRAF6 expression promotes transformation through a MYC-dependent mechanism that may be modulated by environmental inflammatory signals.
International Consensus Classification of Myeloid Neoplasms and Acute Leukemias: integrating morphologic, clinical, and genomic data.
The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.
Hematopoietic stem cell heterogeneity and age-associated platelet bias are evolutionarily conserved.
Hematopoietic stem cells (HSCs) reconstitute multilineage human hematopoiesis after clinical bone marrow (BM) transplantation and are the cells of origin of some hematological malignancies. Although HSCs provide multilineage engraftment, individual murine HSCs are lineage biased and contribute unequally to blood cell lineages. Here, we performed high-throughput single-cell RNA sequencing in mice after xenograft with molecularly barcoded adult human BM HSCs. We demonstrated that human individual BM HSCs are also functionally and transcriptionally lineage biased. Specifically, we identified platelet-biased and multilineage human HSCs. Quantitative comparison of transcriptomes from single HSCs from young and aged BM showed that both the proportion of platelet-biased HSCs and their level of transcriptional platelet priming increase with age. Therefore, platelet-biased HSCs and their increased prevalence and transcriptional platelet priming during aging are conserved features of mammalian evolution.
A protocol for simultaneous high-sensitivity genotyping and chromatin accessibility profiling in single cells.
Single-cell assay for transposase-accessible chromatin with sequencing (scATAC-seq) resolves the heterogeneity of epigenetic states across cells but does not typically capture exonic mutations, which limits our knowledge of how somatic mutations alter chromatin landscapes. Here, we present a plate-based approach coupling high-sensitivity genotyping of genomic loci with high-content scATAC-seq libraries from the same single cells. We first describe steps for optimization of genotyping primers, followed by detailed guidance on the preparation of both scATAC-seq and single-cell genotyping libraries, fully automated on high-throughput liquid handling platforms. For complete details on the use and execution of this protocol, please refer to Turkalj, Jakobsen et al.1.
Phase III, Randomized, Placebo-Controlled Trial of CC-486 (Oral Azacitidine) in Patients With Lower-Risk Myelodysplastic Syndromes.
PURPOSE: Treatment options are limited for patients with lower-risk myelodysplastic syndromes (LR-MDS). This phase III, placebo-controlled trial evaluated CC-486 (oral azacitidine), a hypomethylating agent, in patients with International Prognostic Scoring System LR-MDS and RBC transfusion-dependent anemia and thrombocytopenia. METHODS: Patients were randomly assigned 1:1 to CC-486 300-mg or placebo for 21 days/28-day cycle. The primary end point was RBC transfusion independence (TI). RESULTS: Two hundred sixteen patients received CC-486 (n = 107) or placebo (n = 109). The median age was 74 years, median platelet count was 25 × 109/L, and absolute neutrophil count was 1.3 × 109/L. In the CC-486 and placebo arms, 31% and 11% of patients, respectively, achieved RBC-TI (P = .0002), with median durations of 11.1 and 5.0 months. Reductions of ≥ 4 RBC units were attained by 42.1% and 30.6% of patients, respectively, with median durations of 10.0 and 2.3 months, and more CC-486 patients had ≥ 1.5 g/dL hemoglobin increases from baseline (23.4% v 4.6%). Platelet hematologic improvement rate was higher with CC-486 (24.3% v 6.5%). Underpowered interim overall survival analysis showed no difference between CC-486 and placebo (median, 17.3 v 16.2 months; P = .96). Low-grade GI events were the most common adverse events in both arms. In the CC-486 and placebo arms, 90% and 73% of patients experienced a grade 3-4 adverse event. Overall death rate was similar between arms, but there was an imbalance in deaths during the first 56 days (CC-486, n = 16; placebo, n = 6), most related to infections; the median pretreatment absolute neutrophil count for the 16 CC-486 patients was 0.57 × 109/L. CONCLUSION: CC-486 significantly improved RBC-TI rate and induced durable bilineage improvements in patients with LR-MDS and high-risk disease features. More early deaths occurred in the CC-486 arm, most related to infections in patients with significant pretreatment neutropenia. Further evaluation of CC-486 in MDS is needed.
The genome-wide impact of trisomy 21 on DNA methylation and its implications for hematopoiesis.
Down syndrome is associated with genome-wide perturbation of gene expression, which may be mediated by epigenetic changes. We perform an epigenome-wide association study on neonatal bloodspots comparing 196 newborns with Down syndrome and 439 newborns without Down syndrome, adjusting for cell-type heterogeneity, which identifies 652 epigenome-wide significant CpGs (P
Identification and Preliminary Structure-Activity Relationship Studies of 1,5-Dihydrobenzo[e][1,4]oxazepin-2(3H)-ones That Induce Differentiation of Acute Myeloid Leukemia Cells In Vitro.
Acute myeloid leukemia (AML) is the most aggressive type of blood cancer, and there is a continued need for new treatments that are well tolerated and improve long-term survival rates in patients. Induction of differentiation has emerged as a promising alternative to conventional cytotoxic chemotherapy, but known agents lack efficacy in genetically distinct patient populations. Previously, we established a phenotypic screen to identify small molecules that could stimulate differentiation in a range of AML cell lines. Utilising this strategy, a 1,5-dihydrobenzo[e][1,4]oxazepin-2(3H)-one hit compound was identified. Herein, we report the hit validation in vitro, structure-activity relationship (SAR) studies and the pharmacokinetic profiles for selected compounds.
Multiple cereblon genetic changes are associated with acquired resistance to lenalidomide or pomalidomide in multiple myeloma.
Emergence of drug resistance to all available therapies is the major challenge to improving survival in myeloma. Cereblon (CRBN) is the essential binding protein of the widely used immunomodulatory drugs (IMiDs) and novel CRBN E3 ligase modulator drugs (CELMoDs) in myeloma, as well as certain proteolysis targeting chimeras (PROTACs), in development for a range of diseases. Using whole-genome sequencing (WGS) data from 455 patients and RNA sequencing (RNASeq) data from 655 patients, including newly diagnosed (WGS, n = 198; RNASeq, n = 437), lenalidomide (LEN)-refractory (WGS, n = 203; RNASeq, n = 176), and pomalidomide (POM)-refractory cohorts (WGS, n = 54; RNASeq, n = 42), we found incremental increases in the frequency of 3 CRBN aberrations, namely point mutations, copy losses/structural variations, and a specific variant transcript (exon 10 spliced), with progressive IMiD exposure, until almost one-third of patients had CBRN alterations by the time they were POM refractory. We found all 3 CRBN aberrations were associated with inferior outcomes to POM in those already refractory to LEN, including those with gene copy losses and structural variations, a finding not previously described. This represents the first comprehensive analysis and largest data set of CBRN alterations in myeloma patients as they progress through therapy. It will help inform patient selection for sequential therapies with CRBN-targeting drugs.
Oncogenic Gata1 causes stage-specific megakaryocyte differentiation delay.
The megakaryocyte/erythroid Transient Myeloproliferative Disorder (TMD) in newborns with Down Syndrome (DS) occurs when N-terminal truncating mutations of the hemopoietic transcription factor GATA1, that produce GATA1short protein (GATA1s), are acquired early in development. Prior work has shown that murine GATA1s, by itself, causes a transient yolk sac myeloproliferative disorder. However, it is unclear where in the hemopoietic cellular hierarchy GATA1s exerts its effects to produce this myeloproliferative state. Here, through a detailed examination of hemopoiesis from murine GATA1s ES cells and GATA1s embryos we define defects in erythroid and megakaryocytic differentiation that occur relatively late in hemopoiesis. GATA1s causes an arrest late in erythroid differentiation in vivo, and even more profoundly in ES-cell derived cultures, with a marked reduction of Ter-119 cells and reduced erythroid gene expression. In megakaryopoiesis, GATA1s causes a differentiation delay at a specific stage, with accumulation of immature, kit-expressing CD41hi megakaryocytic cells. In this specific megakaryocytic compartment, there are increased numbers of GATA1s cells in S-phase of cell cycle and reduced number of apoptotic cells compared to GATA1 cells in the same cell compartment. There is also a delay in maturation of these immature GATA1s megakaryocytic lineage cells compared to GATA1 cells at the same stage of differentiation. Finally, even when GATA1s megakaryocytic cells mature, they mature aberrantly with altered megakaryocyte-specific gene expression and activity of the mature megakaryocyte enzyme, acetylcholinesterase. These studies pinpoint the hemopoietic compartment where GATA1s megakaryocyte myeloproliferation occurs, defining where molecular studies should now be focussed to understand the oncogenic action of GATA1s.
Real-world Effectiveness of Azacitidine in Treatment-Naive Patients With Higher-risk Myelodysplastic Syndromes.
INTRODUCTION: Azacitidine (AZA) is an approved frontline therapy for higher-risk myelodysplastic syndromes (HR-MDS); however, poor survival denotes unmet needs to increase depth/duration of response (DOR). METHODS: This retrospective study with patient chart review evaluated AZA effectiveness in 382 treatment-naive patients with HR-MDS from a US electronic health record (EHR)-derived database. Responses were assessed using International Working Group (IWG) 2006 criteria; real-world equivalents were derived from EHRs. Primary endpoint was IWG 2006-based complete remission rate (CRR). Secondary endpoints were EHR-based CRR, IWG 2006- and EHR-based objective response rates (ORRs), duration of CR, DOR, progression-free survival, time-to-next-treatment, and overall survival (OS). RESULTS: Using IWG 2006 criteria, the CRR was 7.9% (n = 30); median duration of CR was 12.0 months (95% CI, 7.7-15.6). In poor cytogenetic risk (n = 101) and TP53 mutation (n = 46) subgroups, CRRs were 7.9% (n = 8) and 8.7% (n = 4), respectively. ORR was 62.8% (n = 240), including a hematologic improvement rate (HIR) of 46.9% (n = 179). Using EHR-based data, CRR was 3.7% (n = 14); median duration of CR was 13.5 months (95% CI, 4.5-21.5). ORR was 67.8% (n = 259), including an HIR of 29.3% (n = 112). Median follow-up was 12.9 months; median OS was 17.9 months (95% CI, 15.5-21.7). CONCLUSIONS: Consistent with other studies, CRRs and median OS with AZA in treatment-naive patients with HR-MDS were low in this large, real-world cohort. Novel agents/combinations are urgently needed to improve these outcomes in HR-MDS.
A Phenotypic Screen Identifies a Compound Series That Induces Differentiation of Acute Myeloid Leukemia Cells In Vitro and Shows Antitumor Effects In Vivo.
Induction of differentiation is a promising therapeutic strategy against acute myeloid leukemia. However, current differentiation therapies are effective only to specific patient populations. To identify novel differentiation agents with wider efficacy, we developed a phenotypic high-throughput screen with a range of genetically diverse cell lines. From the resulting hits, one chemical scaffold was optimized in terms of activity and physicochemical properties to yield OXS007417, a proof-of-concept tool compound, which was also able to decrease tumor volume in a murine in vivo xenograft model.
A multicenter comparative acute myeloid leukemia study: can we explain the differences in the outcomes in resource-constrained settings?
Outcomes in acute myeloid leukemia (AML) are dependent on patient- and disease-characteristics, treatment, and socioeconomic factors. AML outcomes between resource-constrained and developed countries have not been compared directly. We analyzed two cohorts: from São Paulo state, Brazil (USP, n = 312) and Oxford, United Kingdom (OUH, n = 158). USP cohort had inferior 5-year overall survival compared with OUH (29% vs. 49%, adjusted-p=.027). USP patients have higher early-mortality (23% vs. 6% p
Combined inhibition of XIAP and BCL2 drives maximal therapeutic efficacy in genetically diverse aggressive acute myeloid leukemia.
Aggressive therapy-resistant and refractory acute myeloid leukemia (AML) has an extremely poor outcome. By analyzing a large number of genetically complex and diverse, primary high-risk poor-outcome human AML samples, we identified specific pathways of therapeutic vulnerability. Through drug screens followed by extensive in vivo validation and genomic analyses, we found inhibition of cytosolic and mitochondrial anti-apoptotic proteins XIAP, BCL2 and MCL1, and a key regulator of mitosis, AURKB, as a vulnerability hub based on patient-specific genetic aberrations and transcriptional signatures. Combinatorial therapeutic inhibition of XIAP with an additional patient-specific vulnerability eliminated established AML in vivo in patient-derived xenografts (PDXs) bearing diverse genetic aberrations, with no signs of recurrence during off-treatment follow-up. By integrating genomic profiling and drug-sensitivity testing, this work provides a platform for a precision-medicine approach for treating aggressive AML with high unmet need.
Treatment Intensification With Either Fludarabine, AraC, G-CSF and Idarubicin, or Cladribine Plus Daunorubicin and AraC on the Basis of Residual Disease Status in Older Patients With AML: Results From the NCRI AML18 Trial.
PURPOSE: To evaluate the survival benefit of chemotherapy intensification in older patients with AML who have not achieved a measurable residual disease (MRD)-negative remission. METHODS: Five hundred twenty-three patients with AML (median age, 67 years; range, 51-79) without a flow cytometric MRD-negative remission response after a first course of daunorubicin and AraC (DA; including 165 not in remission) were randomly assigned between up to two further courses of DA or intensified chemotherapy-either fludarabine, cytarabine, granulocyte colony-stimulating factor and idarubicin (FLAG-Ida) or DA with cladribine (DAC). RESULTS: Overall survival (OS) was not improved in the intensification arms (DAC v DA: hazard ratio [HR], 0.74 [95% CI, 0.55 to 1.01]; P = .054; FLAG-Ida v DA: HR, 0.86 [95% CI, 0.66 to 1.12]; P = .270); OS at 3 years was 34%, 46%, and 42% for DA, DAC, and FLAG-Ida, respectively. Early deaths and other adverse events were more frequent with FLAG-Ida (9% day 60 deaths v 4% after DA or DAC; P = .032). Of patients entering random assignment, 131 had MRD unknown status. In this subgroup of patients lacking evidence of residual leukemia by flow cytometry, there was no detectable survival advantage from intensification. A planned sensitivity analysis excluding these patients demonstrated a survival benefit for both DAC (HR, 0.66 [95% CI, 0.46 to 0.93]; P = .018) and FLAG-Ida (HR, 0.72 [95% CI, 0.53 to 0.98]; P = .035); OS at 3 years was 30%, 46%, and 46% for DA, DAC, and FLAG-Ida, respectively. There was a concordant reduction in relapse (DAC v DA: HR, 0.66 [95% CI, 0.45 to 0.98]; P = .039; FLAG-Ida v DA: HR, 0.70 [95% CI, 0.49 to 0.99]; P = .042). DAC benefit was maintained when survival was censored for transplant (P = .042). CONCLUSION: In this study of older patients with AML considered fit and with evidence of residual disease after first induction, chemotherapy intensification improved survival. DAC intensification was better tolerated than FLAG-Ida.
Magrolimab plus azacitidine vs physician's choice for untreated TP53-mutated acute myeloid leukemia: the ENHANCE-2 study.
Patients with TP53-mutated acute myeloid leukemia (AML) have an extremely poor prognosis, necessitating new treatments. The global, randomized, phase 3 ENHANCE-2 trial evaluated the anti-CD47 monoclonal antibody magrolimab plus azacitidine (Magro/Aza) for previously untreated TP53-mutated AML. Patients determined inappropriate for intensive therapy were randomized to receive Magro/Aza or venetoclax plus azacitidine (Ven/Aza); those appropriate for intensive therapy were randomized to receive Magro/Aza or 7+3 induction chemotherapy. Primary endpoint was overall survival (OS) in the non-intensive arm. At interim analysis, non-intensive-arm OS hazard ratio (HR) between treatment groups was 1.191 (95% CI, 0.744-1.906), meeting the study's definition for futility and resulting in study termination. At final analysis, median OS was 4.4 vs 6.6 months (HR, 1.132; 95% CI, 0.783-1.637; P = .5070) in the non-intensive arm (n = 205) and 7.3 vs 11.1 months (HR, 1.434; 95% CI, 0.635-3.239; P = .3798) in the intensive arm (n = 52) between Magro/Aza and control groups, respectively. Incidences of grade ≥3 adverse events (AEs) were similar across Magro/Aza and control groups (non-intensive, n = 194: 96.9% and 95.9%; intensive, n = 50: 92.6% and 95.7%), including grade ≥3 anemia (non-intensive: 27.1% and 23.5%; intensive: 25.9% and 21.7%). Grade ≥3 infections were observed in 50.0% and 53.1% of patients in the non-intensive arm and 44.4% and 65.2% of intensive arm patients. ENHANCE-2 did not meet its primary endpoint of OS in TP53-mutated AML but provides important data informing future studies in this challenging population. This trial was registered at www.clinicaltrials.gov as #NCT04778397.
Genome-wide association study of somatic GATA1s mutations in newborns with Down Syndrome.
Myeloid Leukemia of Down Syndrome (ML-DS) is preceded by a transient neonatal preleukemia driven by somatic mutations in the chromosome X gene GATA1, resulting in a shorter protein isoform (GATA1s). GATA1s mutations occur at high frequency in DS but beyond trisomy 21, risk factors for this preleukemia are unknown. We investigated whether germline genetic variation influences development of GATA1s mutations in DS. Whole-genome sequencing was performed on 434 DS children from the Oxford DS Study previously screened for GATA1s mutations. Following quality control, association tests were conducted separately for disomic autosomes, trisomic chromosome 21, and chromosome X. Regression tests were performed for mutation variant allele frequency or the binary trait (103 GATA1s-positive cases, 326 controls), adjusting for sex and ancestry-related principal components. Genetic ancestry of each subject was inferred and tested for association with GATA1s mutations. We identified three genome-wide significant (P<5x10-8) loci associated with GATA1s mutations. However, these may be false positives as few linked variants showed evidence of association at each locus. No significant associations were detected on chromosome 21 or the GATA1 region on chromosome X. Increasing proportions of South Asian genetic ancestry were associated with an increased risk of GATA1s mutations, with each 10% increase in ancestry associated with a 1.11-fold higher risk of developing GATA1s mutations (P=0.031). Our genetic epidemiology study of somatic GATA1s mutations in DS did not identify strong germline genetic effects. The association with genetic ancestry may relate to unmeasured genetic or nongenetic effects, such as fetal exposures, and warrants further investigation.