In more than 400 older patients with AML who could not receive myeloablative therapy, the incidence of composite complete remission was higher (66.4% vs. 28.3) and the median overall survival was ...longer (14.7 vs. 9.6 months) among patients who received azacitidine plus venetoclax (a B-cell lymphoma 2 antagonist) than among those who received azacitidine alone.
The t(4;11)(q21;q23) fuses mixed-lineage leukemia (MLL) to AF4, the most common MLL-fusion partner. Here we show that MLL fused to murine Af4, highly conserved with human AF4, produces high-titer ...retrovirus permitting efficient transduction of human CD34+ cells, thereby generating a model of t(4;11) pro-B acute lymphoblastic leukemia (ALL) that fully recapitulates the immunophenotypic and molecular aspects of the disease. MLL-Af4 induces a B ALL distinct from MLL-AF9 through differential genomic target binding of the fusion proteins leading to specific gene expression patterns. MLL-Af4 cells can assume a myeloid state under environmental pressure but retain lymphoid-lineage potential. Such incongruity was also observed in t(4;11) patients in whom leukemia evaded CD19-directed therapy by undergoing myeloid-lineage switch. Our model provides a valuable tool to unravel the pathogenesis of MLL-AF4 leukemogenesis.
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•Fusion of MLL to murine Af4 permits faithful modeling of human t(4;11) pro-B ALL•The species of the cell-of-origin determines the lineage of MLL-Af4 leukemia•MLL-fusion proteins drive differential gene expression via specific DNA binding•MLL-fusion leukemia circumvents CD19-directed therapies through lineage plasticity
Lin et al. design a human MLL-mouse Af4 (MLL-Af4) fusion that can transform human CD34+ cells to generate pro-B acute lymphoblastic leukemia (ALL) with the characteristic features of t(4;11) ALL. MLL-Af4 DNA binding drives differential gene expression distinct from MLL-AF9 and confers cells with a lymphoid preference.
Targeting critical epigenetic regulators reverses aberrant transcription in cancer, thereby restoring normal tissue function
. The interaction of menin with lysine methyltransferase 2A (KMT2A), an ...epigenetic regulator, is a dependence in acute leukaemia caused by either rearrangement of KMT2A or mutation of the nucleophosmin 1 gene (NPM1)
. KMT2A rearrangements occur in up to 10% of acute leukaemias and have an adverse prognosis, whereas NPM1 mutations occur in up to 30%, forming the most common genetic alteration in acute myeloid leukaemia
. Here, we describe the results of the first-in-human phase 1 clinical trial investigating revumenib (SNDX-5613), a potent and selective oral inhibitor of the menin-KMT2A interaction, in patients with relapsed or refractory acute leukaemia (ClinicalTrials.gov, NCT04065399). We show that therapy with revumenib was associated with a low frequency of grade 3 or higher treatment-related adverse events and a 30% rate of complete remission or complete remission with partial haematologic recovery (CR/CRh) in the efficacy analysis population. Asymptomatic prolongation of the QT interval on electrocardiography was identified as the only dose-limiting toxicity. Remissions occurred in leukaemias refractory to multiple previous lines of therapy. We demonstrate clearance of residual disease using sensitive clinical assays and identify hallmarks of differentiation into normal haematopoietic cells, including differentiation syndrome. These data establish menin inhibition as a therapeutic strategy for susceptible acute leukaemia subtypes.
Conflicting data exist on the requirement for wild-type MLL1 in MLL-rearranged leukemia. In this issue of Cancer Cell, Chen et al. describe complementary approaches demonstrating that MLL1 is ...dispensable for MLL-fusion-mediated leukemogenesis. They also observe an unexpected role for MLL2 in MLL-rearranged leukemia cells and identify potential therapeutic targets.
Conflicting data exist on the requirement for wild-type MLL1 in MLL-rearranged leukemia. In this issue of Cancer Cell, Chen et al. describe complementary approaches demonstrating that MLL1 is dispensable for MLL-fusion-mediated leukemogenesis. They also observe an unexpected role for MLL2 in MLL-rearranged leukemia cells and identify potential therapeutic targets.
Summary Background The TP53 gene, encoding tumour suppressor protein p53, is located on the short arm of chromosome 17 (17p). Patients with 17p deletion (del17p) chronic lymphocytic leukaemia have ...poor responses and survival after chemoimmunotherapy. We assessed the activity and safety of ibrutinib, an oral covalent inhibitor of Bruton's tyrosine kinase, in relapsed or refractory patients with del17p chronic lymphocytic leukaemia or small lymphocytic lymphoma. Methods We did a multicentre, international, open-label, single-arm study at 40 sites in the USA, Canada, Europe, Australia, and New Zealand. Patients (age ≥18 years) with previously treated del17p chronic lymphocytic leukaemia or small lymphocytic lymphoma received oral ibrutinib 420 mg once daily until progressive disease or unacceptable toxicity. The primary endpoint was overall response in the all-treated population per International Workshop on Chronic Lymphocytic Leukaemia 2008 response criteria modified for treatment-related lymphocytosis. Preplanned exploratory analyses were progression-free survival, overall survival, sustained haematological improvement, and immunological improvement. Patient enrolment is complete, but follow-up is ongoing. Treatment discontinuation owing to adverse events, unacceptable toxicity, or death were collected as a single combined category. This study is registered with ClinicalTrials.gov , number NCT01744691. Findings Between Jan 29, 2013, and June 19, 2013, 145 patients were enrolled. The all-treated population consisted of 144 patients with del17p chronic lymphocytic leukaemia or small lymphocytic lymphoma who received at least one dose of study drug, with a median age of 64 years (IQR 57–72) and a median of two previous treatments (IQR 1–3). At the prespecified primary analysis after a median follow-up of 11·5 months (IQR 11·1–13·8), 92 (64%, 95% CI 56–71) of 144 patients had an overall response according to independent review committee assessment; 119 patients (83%, 95% CI 76–88) had an overall response according to investigator assessment. In an extended analysis with median follow-up of 27·6 months (IQR 14·6–27·7), the investigator-assessed overall response was reported in 120 patients (83%, 95% CI 76–89). 24-month progression-free survival was 63% (95% CI 54–70) and 24-month overall survival was 75% (67–81). Sustained haematological improvement was noted in 72 (79%) of 91 patients with any baseline cytopenia. No clinically relevant changes were noted from baseline to 6 months or 24 months in IgA (median 0·4 g/L at baseline, 0·6 g/L at 6 months, and 0·7 g/L at 24 months), IgG (5·0 g/L, 5·3 g/L, and 4·9 g/L), or IgM (0·3 g/L at each timepoint) concentrations. Common reasons for treatment discontinuation were progressive disease in 34 (24%) patients and adverse events, unacceptable toxicity, or death in 24 (17%) patients. Major bleeding occurred in 13 (9%) patients (11 8% grade 3–4). Grade 3 or worse infections occurred in 43 (30%) patients, including pneumonia in 19 (13%) patients. In the extended analysis, 38 patients died, 18 as a result of adverse events (four pneumonia, three chronic lymphocytic leukaemia, two Richter's syndrome, two sepsis, and one each of acute myocardial infarction, septic shock, encephalopathy, general deterioration in physical health, abnormal hepatic function, myocardial infarction, and renal infarction). Interpretation A high proportion of patients had an overall response to ibrutinib and the risk:benefit profile was favourable, providing further evidence for use of ibrutinib in the most difficult subset of patients with chronic lymphocytic leukaemia or small lymphocytic lymphoma. Ibrutinib represents a clinical advance in the treatment of patients with del17p chronic lymphocytic leukaemia and has been incorporated into treatment algorithms as a primary treatment for these patients. Funding Pharmacyclics LLC, an AbbVie Company.
There is limited evidence on the clinical utility of monitoring measurable residual disease (MRD) in patients with acute myeloid leukemia treated with lower-intensity therapy. Herein, we explored the ...outcomes of patients treated with venetoclax and azacitidine who achieved composite complete remission (CRc; complete remission + complete remission with incomplete hematologic recovery) and MRD < 10
in the VIALE-A trial.
The patients included in this report were treated with venetoclax and azacitidine. Bone marrow aspirate samples for multiparametric flow cytometry assessments were collected for central analysis at baseline, end of cycle 1, and every three cycles thereafter. MRD-negative response was defined as < 1 residual blast per 1,000 leukocytes (< 10
or 0.1%) with an estimated analytic sensitivity of 0.0037%-0.0027%. CRc, duration of remission (DoR), event-free survival (EFS), and overall survival (OS) were assessed. A multivariate Cox regression analysis identified prognostic factors associated with OS.
One hundred sixty-four of one hundred ninety (86%) patients with CRc were evaluable for MRD. MRD < 10
was achieved by 67 of 164 (41%), and 97 of 164 (59%) had MRD ≥ 10
. The median DoR, EFS, and OS were not reached in patients with CRc and MRD < 10
, and the 12-month estimates for DoR, EFS, and OS in this group were 81.2%, 83.2%, and 94.0%. Among patients with CRc and MRD ≥ 10
, the median DoR, EFS, and OS were 9.7, 10.6, and 18.7 months. Multivariate analysis showed that CRc with MRD < 10
was a strong predictor of OS (adjusted hazard ratio = 0.285; 95% CI, 0.159 to 0.510;
< .001).
Patients who achieved CRc and MRD < 10
with venetoclax and azacitidine had longer DoR, EFS, and OS, than responding patients with MRD ≥ 10
.
This analysis represents the longest‐term follow‐up for patients with acute myeloid leukemia (AML) treated with 400 mg of venetoclax plus azacitidine or decitabine. Adults with newly diagnosed AML ...ineligible for intensive chemotherapy were enrolled in an open‐label, non‐randomized, multicenter phase 1b trial of venetoclax with azacitidine (AZA; 75 mg/m2; days 1‐7) or decitabine (DEC; 20 mg/m2; days 1‐5). Endpoints included safety, response rates (complete remission CR, CR with incomplete blood count recovery CRi), response duration and overall survival (OS). The median follow‐up time was 29 and 40 months for patients treated with venetoclax plus AZA and DEC combinations, respectively. Key Grade ≥ 3 AEs (AZA and DEC) were febrile neutropenia (39% and 65%), anemia (30% and 26%), thrombocytopenia (25% and 23%), and neutropenia (20% and 10%). The CR/CRi rate was 71% for venetoclax plus AZA and 74% for venetoclax plus DEC. The median duration of CR/CRi was 21.9 months and 15.0 months, and the median OS was 16.4 months and 16.2 months, for venetoclax plus AZA and DEC, respectively. These results support venetoclax plus hypomethylating agents as highly effective frontline AML therapies for patients unfit for intensive chemotherapy.
To evaluate efficacy and safety of venetoclax + azacitidine among treatment-naïve patients with FLT3-mutant acute myeloid leukemia.
Data were pooled from patients enrolled in a phase III study ...(NCT02993523) that compared patients treated with venetoclax + azacitidine or placebo + azacitidine and a prior phase Ib study (NCT02203773) where patients were treated with venetoclax + azacitidine. Enrolled patients were ineligible for intensive therapy due to age ≥75 years and/or comorbidities. Patients on venetoclax + azacitidine received venetoclax 400 mg orally (days 1-28) and azacitidine (75 mg/m2; days 1-7/28-day cycle). FLT3 mutation was analyzed centrally on pretreatment bone marrow aspirates.
In the biomarker evaluable population, FLT3 mutation was detected in 42 (15%) and 22 (19%) patients in the venetoclax + azacitidine and azacitidine groups. Composite complete remission CRc; complete remission (CR) + CR with incomplete hematologic recovery (CRi) rates (venetoclax + azacitidine/azacitidine) for FLT3-mutant patients were 67%/36%, median duration of remission (DoR) was 17.3/5.0 months, and median OS was 12.5/8.6 months. The CRc rates among FLT3 wild-type patients were 67%/25%, median DoR 18.4/13.4 months, and median OS 14.7/10.1 months. In patients treated with venetoclax + azacitidine, CRc in patients with FLT3-ITD and FLT3-TKD was 63% and 77% and median OS was 9.9 and 19.2 months, and in comutated FLT3-ITD + NPM1 patients, CRc was 70%, median DoR was not reached, and median OS was 9.1 months. There were no unexpected toxicities in the venetoclax + azacitidine group.
When treated with venetoclax + azacitidine, patients with FLT3 mutations and FLT3 wild-type had similar outcomes. Future analyses in larger patient populations may further define the impact of venetoclax + azacitidine in patients harboring FLT3-ITD. See related commentary by Perl and Vyas, p. 2719.
To accurately determine the causes of anemia and proportion of unexplained anemia in a racially diverse cohort of older adults after a comprehensive and standardized evaluation.
We evaluated results ...from a single-institutional university anemia clinic. Patients with anemia, defined as a hemoglobin less than 13.0 g/dL for men and less than 12.0 g/dL for women, underwent a prospective standardized history, physical examination, and laboratory measures, with additional studies including bone marrow examination as indicated. Empiric treatment trials were given for identified deficiencies.
One hundred and seventy-four primarily community-dwelling adults aged 65 years and older were evaluable. African Americans accounted for 69% of patients and whites were 27%. Anemia etiologies included iron deficiency anemia at 25.3%, anemia of chronic inflammation at 9.8%, and hematologic malignancy in 7.5%. Unexplained anemia in the elderly accounted for 43.7% and predominated in both African Americans and whites. The prevalence of iron deficiency anemia and hematologic malignancies did not differ by race. Unexplained anemia in the elderly showed a consistent phenotype composed of a hypoproliferative mild-to-moderate anemia with suppressed serum erythropoietin. Specifically, erythropoietin levels showed no correlation with hemoglobin concentration in unexplained anemia in the elderly (r = -.15, p = .19) as opposed to iron deficiency anemia (r = -.63, p < .0001).
In summary, an intensive hematologic evaluation reveals a wide number of anemia etiologies among older adults, including 7.5% with hematologic malignancies; nevertheless, unexplained anemia in the elderly prevails as the most common category in whites and African Americans.
Even though the Ten-eleven translocation (TET) enzymes catalyze the generation of 5-hydroxymethylcytosines required for lineage commitment and subsequent differentiation of stem cells into erythroid ...cells, the mechanisms that link extracellular signals to TET activation and DNA hydroxymethylation are unknown. We demonstrate that hematopoietic cytokines phosphorylate TET2, leading to its activation in erythroid progenitors. Specifically, cytokine receptor-associated JAK2 phosphorylates TET2 at tyrosines 1939 and 1964. Phosphorylated TET2 interacts with the erythroid transcription factor KLF1, and this interaction with TET2 is increased upon exposure to erythropoietin. The activating JAK2
mutation seen in myeloproliferative disease patient samples and in mouse models is associated with increased TET activity and cytosine hydroxymethylation as well as genome-wide loss of cytosine methylation. These epigenetic and functional changes are also associated with increased expression of several oncogenic transcripts. Thus, we demonstrate that JAK2-mediated TET2 phosphorylation provides a mechanistic link between extracellular signals and epigenetic changes during hematopoiesis. SIGNIFICANCE: Identification of TET2 phosphorylation and activation by cytokine-stimulated JAK2 links extracellular signals to chromatin remodeling during hematopoietic differentiation. This provides potential avenues to regulate TET2 function in the context of myeloproliferative disorders and myelodysplastic syndromes associated with the JAK2
-activating mutation.
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