bims-tremyl Biomed News
on Therapy resistance biology in myeloid leukemia
Issue of 2022–11–20
thirty-two papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London



  1. Blood. 2022 Nov 17. pii: blood.2022016889. [Epub ahead of print]
      Acute myeloid leukemia (AML) initiation requires multiple rate-limiting mutations to cooperatively reprogram progenitor cell identity. For example, FLT3 Internal Tandem Duplication (FLT3ITD) mutations have been shown to cooperate with a variety of different initiating mutations to reprogram myeloid progenitor fate. These initiating mutations often skew toward either pediatric or adult AML patient populations, though FLT3ITD itself occurs at similar frequencies in both age groups. This raises the question of whether FLT3ITD might induce distinct transcriptional programs and unmask distinct therapeutic vulnerabilities when paired with pediatric, as opposed to adult, initiating mutations. To explore this possibility, we compared AML evolution in mice that carried Flt3ITD/NUP98-HOXD13 (NHD13) or Flt3ITD/Runx1DEL mutation pairs, which are respectively most common pediatric and adult AML. Single cell analyses and epigenome profiling revealed distinct interactions between Flt3ITD and its cooperating mutations. Whereas Flt3ITD and Flt3ITD/Runx1DEL caused aberrant expansion of myeloid progenitors, Flt3ITD/NHD13 drove emergence of a pre-AML population that did not resemble normal hematopoietic progenitors. Differences between Flt3ITD/Runx1DEL and Flt3ITD/NHD13cooperative target gene expression extended to fully transformed AML, as well. Flt3ITD/NHD13 cooperative target genes were enriched in human NUP98-translocated AML. Flt3ITD/NHD13 selectively hijacked type I interferon signaling to drive expansion of the pre-AML population. Blocking interferon signaling delayed AML initiation and extended survival. Thus, common AML driver mutations, such as FLT3ITD, can co-opt different mechanisms of transformation in different genetic contexts. Furthermore, pediatric-biased NUP98 fusions convey actionable interferon dependence.
    DOI:  https://doi.org/10.1182/blood.2022016889
  2. Blood Adv. 2022 Nov 16. pii: bloodadvances.2022007682. [Epub ahead of print]
      Mutated Nucleophosmin 1 (NPM1) is the most common genetic alteration in acute myeloid leukemia (AML), found in approximately 30% of cases. Although mutations in this gene are considered favorable according to current risk stratification guidelines, a large fraction of patients will suffer from relapse, demonstrating the urgent need for new treatment options. Therefore, we aimed to identify cell surface proteins specifically expressed on NPM1)-mutated AML cells, allowing for potential targeting with antibody-based therapies. Herein, we performed an arrayed flow cytometry-based screen directed to 362 cell surface markers. Comparing the cell surface expression on NPM1-mutated AML cells to primitive (CD34+ CD38-) normal bone marrow cells, we identified the complement receptor C3AR as specifically expressed in NPM1-mutated AML. By flow cytometry and single cell RNA-sequencing, we further show that normal hematopoietic stem and progenitor cells lack detectable C3AR gene and protein expression, making it particularly suitable as a target for antibody therapy. We also demonstrate that C3AR in combination with GPR56 distinguishes the leukemic stem cells (LSCs) in NPM1-mutated AML from the normal hematopoietic stem cells, defining the LSC population, as shown by transplantation into immunodeficient mice. Mechanistically, stimulation of C3AR-expressing cells with C3a, the ligand of C3AR, leads to activation of ERK1/2 and increased survival of AML cells, suggesting that this is an important signaling axis in this subtype of AML. Finally, we show that antibodies directed against C3AR efficiently elicit NK cell-mediated killing of primary AML cells ex vivo, highlighting C3AR as a candidate therapeutic target in NPM1-mutated AML.
    DOI:  https://doi.org/10.1182/bloodadvances.2022007682
  3. Cancer. 2022 Nov 17.
      TP53-altered myelodysplastic syndrome with excess blasts and TP53-altered acute myeloid leukemia should be considered under one unifying classification term for their study in clinical trials. Ultimately, such a unification would simplify the screening processes for clinical trials and allow a focus on treating the patient for a genetically defined disorder rather than one based on an arbitrary blast threshold.
    Keywords:  TP53; acute myeloid leukemia (AML); cutoff; excess blasts; myelodysplastic syndrome (MDS); p53
    DOI:  https://doi.org/10.1002/cncr.34535
  4. Leukemia. 2022 Nov 18.
      Chemotherapy-resistant acute myeloid leukemia (AML), frequently driven by clonal evolution, has a dismal prognosis. A genome-wide CRISPR knockout screen investigating resistance to doxorubicin and cytarabine (Dox/AraC) in human AML cell lines identified gene knockouts involving AraC metabolism and genes that regulate cell cycle arrest (cyclin dependent kinase inhibitor 2A (CDKN2A), checkpoint kinase 2 (CHEK2) and TP53) as contributing to resistance. In human AML cohorts, reduced expression of CDKN2A conferred inferior overall survival and CDKN2A downregulation occurred at relapse in paired diagnosis-relapse samples, validating its clinical relevance. Therapeutically targeting the G1S cell cycle restriction point (with CDK4/6 inhibitor, palbociclib and KAT6A inhibitor, WM-1119, to upregulate CDKN2A) synergized with chemotherapy. Additionally, direct promotion of apoptosis with venetoclax, showed substantial synergy with chemotherapy, overcoming resistance mediated by impaired cell cycle arrest. Altogether, we identify defective cell cycle arrest as a clinically relevant contributor to chemoresistance and identify rationally designed therapeutic combinations that enhance response in AML, potentially circumventing chemoresistance.
    DOI:  https://doi.org/10.1038/s41375-022-01755-2
  5. Cancer Med. 2022 Nov 16.
       BACKGROUND: Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) generally confers poor prognosis, however, patient outcomes are heterogeneous. The impact of TP53 allelic state and variant allele frequency (VAF) in AML-MRC remains poorly defined.
    METHODS: We retrospectively evaluated 266 AML-MRC patients who had NGS testing at our institution from 2014 to 2020 and analyzed their clinical outcomes based on clinicopathological features.
    RESULTS: TP53 mutations were associated with cytogenetic abnormalities in 5q, 7q, 17p, and complex karyotype. Prognostic evaluation of TP53MUT AML-MRC revealed no difference in outcome between TP53 double/multi-hit state and single-hit state. Patients with high TP53MUT variant allele frequency (VAF) had inferior outcomes compared to patients with low TP53MUT VAF. When compared to TP53WT patients, TP53MUT patients had inferior outcomes regardless of MRC-defining criteria, TP53 allelic state, or VAF. TP53 mutations and elevated serum LDH were independent predictors for inferior OS and EFS, while PHF6 mutations and transplantation were independent predictors for favorable OS and EFS. NRAS mutation was an independent predictor for favorable EFS.
    CONCLUSIONS: Our study suggests that TP53MUT AML-MRC defines a very-high-risk subentity of AML in which novel therapies should be explored.
    Keywords:  AML risk stratification; AML-MRC; TP53 mutation; next-generation sequencing
    DOI:  https://doi.org/10.1002/cam4.5421
  6. Lancet Haematol. 2022 Nov 09. pii: S2352-3026(22)00292-7. [Epub ahead of print]
       BACKGROUND: Olutasidenib (FT-2102) is a potent, selective, oral, small-molecule inhibitor of mutant isocitrate dehydrogenase 1 (IDH1). The aims for phase 1 of this phase 1/2 study were to assess the safety, pharmacokinetics, pharmacodynamics, and clinical activity of olutasidenib, as monotherapy or in combination with azacitidine, in patients with acute myeloid leukaemia or myelodysplastic syndrome, harbouring mutant IDH1.
    METHODS: In this phase 1/2, multicentre, open-label clinical trial, we enrolled patients aged 18 years or older with acute myeloid leukaemia or intermediate, high, or very high risk myelodysplastic syndrome harbouring mutant IDH1 at 18 study sites in the USA, Australia, France, and Spain. Other key eligibility criteria included Eastern Cooperative Oncology Group performance status 0-2 with adequate liver and renal function. The primary outcomes were dose-limiting toxicities and the maximum tolerated dose, maximum evaluated dose, and the recommended phase 2 dose of olutasidenib. Olutasidenib was administered orally in doses of 150 mg once daily, 150 mg twice per day, and 300 mg once daily. Azacitidine (75 mg/m2) was administered subcutaneously or intravenously daily for 7 days on, 21 days off. The study was ongoing at the data cutoff (Oct 2, 2019) and is registered with ClinicalTrials.gov, NCT02719574.
    FINDINGS: Patients were enrolled between Aug 8, 2016, and Nov 14, 2018. 78 patients received olutasidenib as monotherapy (n=32) or in combination with azacitidine (n=46). The median follow-up was 8·3 months (IQR 3·1-13·3) for monotherapy and 10·1 months (4·2-15·3) for combination therapy. 16 (50%) of 32 patients in the monotherapy group and 24 (52%) of 46 patients in the combination therapy group were women. Most patients were White (26 [81%] for monotherapy and 31 [67%] for combination therapy). No dose-limiting toxicities were reported in the dose-escalation cohorts and 150 mg twice per day was declared the recommended phase 2 dose on the basis of safety, pharmacokinetics and pharmacodynamics, and clinical activity. The most common (≥20%) grade 3-4 treatment-emergent adverse events with monotherapy were thrombocytopenia (nine [28%] of 32 patients), febrile neutropenia (seven [22%] of 32), and anaemia (seven [22%] of 32); and with combination therapy were thrombocytopenia (19 [41%] of 46), febrile neutropenia (13 [28%] of 46), neutropenia (13 [28%] of 46), and anaemia (nine [20%] of 46). 11 (34%) of 32 patients in the monotherapy group and nine (20%) of 46 patients in the combination therapy group died (most commonly from disease progression [three (9%) of 32 and four (9%) of 46]). No deaths were considered study-drug related. For patients with relapsed or refractory acute myeloid leukaemia, 41% (95% CI 21-64; nine of 22) receiving monotherapy and 46% (27-67; 12 of 26) receiving combination therapy had an overall response. For treatment-naive patients with acute myeloid leukaemia, 25% (1-81; one of four) receiving monotherapy and 77% (46-95; ten of 13) receiving combination therapy had an overall response.
    INTERPRETATION: Olutasidenib, with or without azacitidine, was well tolerated and showed meaningful clinical activity in patients with IDH1-mutated acute myeloid leukaemia. The results of this phase 1 study provide rationale for the continued evaluation of olutasidenib in multiple patient populations with myeloid malignancies.
    FUNDING: Forma Therapeutics.
    DOI:  https://doi.org/10.1016/S2352-3026(22)00292-7
  7. Leukemia. 2022 Nov 14.
      The real-world efficacy and safety of gilteritinib was assessed in an ambispective study that included 167 R/R FLT3-mutated AML patients. Among them, 140 received gilteritinib as single agent (cohort B), including 67 previously treated by intensive chemotherapy and midostaurin (cohort C). The main differences in patient characteristics in this study compared to the ADMIRAL trial were ECOG ≥ 2 (83.6% vs. 16.6%), FLT3-TKD mutation (21.0% vs. 8.5%), primary induction failure (15.0% vs. 40.0%) and line of treatment (beyond 2nd in 37.1% vs. 0.0%). The rates of composite complete remission, excluding those that occurred after hematopoietic stem cell transplantation (HSCT), were similar at respectively 25.4% and 27.5% in cohorts B and C. Median overall survival (OS) for these two groups was also similar at respectively 6.4 and 7.8 months. Multivariate analyses for prognostic factors associated with OS identified female gender (HR 1.61), adverse cytogenetic risk (HR 2.52), and allogenic HSCT after gilteritinib (HR 0.13). Although these patients were more heavily pretreated, these real-world data reproduce the results of ADMIRAL and provide new insights into the course of patients previously treated by intensive chemotherapy and midostaurin and beyond the 2nd line of treatment who can benefit from treatment in an outpatient setting.
    DOI:  https://doi.org/10.1038/s41375-022-01742-7
  8. Front Immunol. 2022 ;13 899468
      The management of relapsed or refractory acute myeloid leukemia (AML) continues to be therapeutically challenging. Non-toxic immunotherapy approaches are needed to provide long-term anti-leukemic effects. The goal of this study was to determine whether activated T cells (ATCs) armed with bispecific antibodies (BiAbs) could target and lyse leukemic and leukemic stem cells (LSCs). Anti-CD3 × anti-CD123 BiAb (CD123Bi) and anti-CD3 × anti-CD33GO (gemtuzumab ozogamicin [GO]) BiAb (CD33GOBi) were used to arm ATCs to produce bispecific antibody armed activated T cells (designated CD123 BATs or CD33GO BATs) to target AML cell lines, peripheral blood mononuclear cells from AML patients, and in vivo treatment of AML in xenogeneic NSG mice engrafted with leukemic cells. BATs exhibited high levels of specific cytotoxicity directed at AML cell lines at low 1:1 or 1:2 effector-to-target (E:T) ratios and secrete Th1 cytokines upon target engagement. In vivo study in AML-engrafted NSG mice showed significantly prolonged survival in mice treated with CD33GO BATs (p < 0.0001) or CD123 BATs (p < 0.0089) compared to ATC-treated control mice. Patient samples containing leukemic blasts and LSCs when treated with CD33GO BATs or CD123 BATs for 18 h showed a significant reduction (50%-100%; p < 0.005) in blasts and 75%-100% reduction in LSCs (p < 0.005) in most cases compared to unarmed ATCs. This approach may provide a potent and non-toxic strategy to target AML blasts and LSCs and enhance chemo-responsiveness in older patients who are likely to develop recurrent diseases.
    Keywords:  acute myeloid leukemia; anti-CD123; anti-CD33; bispecific antibodies; targeted T cells
    DOI:  https://doi.org/10.3389/fimmu.2022.899468
  9. Cancer Med. 2022 Nov 16.
      Personalized medicine is a challenge for patients with acute myeloid leukemia (AML). The identification of several genetic mutations in several AML trials led to the creation of a personalized prognostic scoring algorithm known as the Knowledge Bank (KB). In this study, we assessed the prognostic value of this algorithm on a cohort of 167 real life AML patients. We compared KB predicted outcomes to real-life outcomes. For patients younger than 60-year-old, OS was similar in favorable and intermediate ELN risk category. However, KB algorithm failed to predict OS for younger patients in the adverse ELN risk category and for patients older than 60 years old in the favorable ELN risk category. These discrepancies may be explained by the emergence of several new therapeutic options as well as the improvement of allogeneic stem cell transplantation (aHSCT) outcomes and supportive cares. Personalized medicine is a major challenge and predictions models are powerful tools to predict patient's outcome. However, the addition of new therapeutic options in the field of AML requires a prospective validation of these scoring systems to include recent therapeutic innovations.
    Keywords:  acute myeloid leukemia; mutations; personalized medicine; prognosis
    DOI:  https://doi.org/10.1002/cam4.5408
  10. Ann Hematol. 2022 Nov 18.
      We investigated the safety and efficacy of nintedanib added to low-dose cytarabine (LDAC) in a phase 1/2 study in patients 60 years or older with newly diagnosed or relapsed/refractory (r/r) AML ineligible for intensive chemotherapy. The results of the dose-finding phase 1 part have been previously published. Patients were randomized 1:1 to LDAC plus nintedanib or LDAC plus placebo stratified by AML status (newly diagnosed vs r/r). LDAC was applied subcutaneously at 20 mg twice daily on days 1 to 10. Nintedanib/placebo was orally administered twice daily on days 1 to 28 in 28-day cycles. The primary endpoint was overall survival (OS). Between 05/2017 and 09/2019, 31 patients were randomized and 30 were treated, before the study was terminated prematurely due to slow recruitment. Median (range) age of patients was 76 (60-84) years. Twenty-two patients (73%) had r/r AML. Median OS in patients treated with LDAC and nintedanib was 3.4 months, compared with 3.6 months in those treated in the placebo arm, with a HR adjusted for AML status of 1.19 (corresponding confirmatory adjusted 95% CI, 0.55-2.56; univariate log-rank P = 0.96). In the 22 patients with r/r AML, median OS was 3.0 months in the nintedanib and 3.6 months in the placebo arm (P = 0.36). One patient in the nintedanib and two patients in the placebo arm achieved a CR and entered maintenance treatment. Nintedanib showed no superior therapeutic activity over placebo when added to LDAC in elderly AML patients considered unfit for intensive chemotherapy. The trial was registered at clinicaltrials.gov NCT01488344.
    Keywords:  Acute myeloid leukemia; Angiogenesis; Low-dose cytarabine; Nintedanib
    DOI:  https://doi.org/10.1007/s00277-022-05025-0
  11. Ann Hematol. 2022 Nov 15.
      Acute myeloid leukemia (AML) with NPM1 mutation is a distinct genetic entity with favorable outcomes. Nevertheless, emerging evidence suggests that NPM1-mutated AML is still a highly heterogeneous disorder. In this study, 266 patients with AML with NPM1 mutations were retrospectively analyzed to evaluate the associations between variant allele frequency (VAF) of NPM1 mutations, co-mutated genes, measurable residual disease (MRD), and patient outcomes. Multiparameter flow cytometry (MFC) and real-time quantitative polymerase chain reaction (RT-PCR) were used for monitoring MRD. Ultimately, 106 patients were included in the long-term follow-up period. Patients with high NPM1 VAF (≥ 42.43%) had poorer 2-year relapse-free survival (RFS) (55.7% vs. 70.2%, P = 0.017) and overall survival (OS) (63.7% vs. 82.0%, P = 0.027) than those with low VAF. DNMT3A mutations negatively influenced the outcomes of patients with NPM1 mutations. Patients with high DNMT3A VAF or NPM1/DNMT3A/FLT3-ITD triple mutations had shorter RFS and significantly lower OS than that in controls. After two cycles of chemotherapy, patients with positive MFC MRD results had lower RFS (MRD+ vs. MRD-:44.9% vs. 67.6%, P = 0.007) and OS (61.5% vs. 76.6%, P = 0.011) than those without positive MFC MRD results. In multivariate analysis, high NPM1 VAF (hazard ratio [HR] = 2.045; P = 0.034) and positive MRD after two cycles of chemotherapy (HR = 3.289; P = 0.003) were independent risk factors for RFS; MRD positivity after two cycles of chemotherapy (HR = 3.293; P = 0.008) independently predicted the OS of the patients. These results indicate that VAF of both NPM1 gene itself or certain co-occurring gene pre-treatment and MRD post-treatment are potential markers for restratifying the prognoses of patients AML having NPM1 mutations.
    Keywords:  Acute myeloid leukemia; Measurable residual disease; NPM1 mutations; Next-generation sequencing; Prognoses
    DOI:  https://doi.org/10.1007/s00277-022-05033-0
  12. Blood Adv. 2022 Nov 14. pii: bloodadvances.2022008204. [Epub ahead of print]
      Chronic neutrophilic leukemia (CNL) and atypical chronic myeloid leukemia (aCML) are rare myeloid disorders that are challenging with regard to diagnosis and clinical management. To study the similarities and differences of these disorders we undertook a multi-center international study of one of the largest case series (CNL, n=24; aCML, n=37 cases, respectively), focusing on the clinical and mutational profiles (n=53 with molecular data) of these diseases. We found no differences in clinical presentation or outcomes between both entities. As previously described, both CNL and aCML share a complex mutational profile with mutations in genes involved in epigenetic regulation, splicing and signaling pathways. Apart from CSF3R, only EZH2 and TET2 were differentially mutated between them. The molecular profiles support the notion of CNL and aCML being a continuum of the same disease that may fit best within the myelodysplastic/myeloproliferative neoplasms (MDS/MPN). We identified four high-risk mutated genes, specifically CEBPA (β=2.26, HR=9.54, p=0.003), EZH2 (β=1.12, HR=3.062, p=0.009), NRAS (β=1.29, HR=3.63, p=0.048) and U2AF1 (β=1.75, HR=5.74, p=0.013) by multivariate analysis. Our findings underscore the relevance of molecular-risk classification in CNL/aCML as well as the importance of CSF3R mutations in these diseases.
    DOI:  https://doi.org/10.1182/bloodadvances.2022008204
  13. J Cell Mol Med. 2022 Nov 15.
      The transformation biology of secondary acute myeloid leukaemia (AML) from myelodysplastic syndromes (MDSs) is still not fully understood. We performed paired self-controlled sequencing, including targeted, whole exome, and single-cell RNA sequencing, in a cohort of MDS patients to search for AML transformation-related mutations (TRMs). Thirty-nine target genes from paired samples from 72 patients with MDS who had undergone AML transformation were analysed. The targeted sequencing results showed that 64 of 72 (88.9%) patients presented TRMs involving signalling pathway activation, transcription factors, or tumour suppressors. Of the 64 patients, most of the TRMs (62.5%, 40 cases) emerged at the leukaemia transformation point. Paired whole exome sequencing showed some presumptive TRMs, which were not included in the reference targets in three patients. No patient developed AML only by acquiring mutations involved in epigenetic modulation or ribonucleic acid splicing. Single-cell sequencing indicated that the activating cell signalling route was related to TRMs in one paired sample. Targeted sequencing defined TRMs were limited to a small set of seven genes (in the order: NRAS/KRAS, CEBPA, TP53, FLT3, CBL, PTPN11, and RUNX1, accounting for nearly 90.0% of the TRMs). In conclusion, somatic mutations involved in signalling, transcription factors, or tumour suppressors appeared to be a precondition for AML transformation from MDS.
    Keywords:  AML transformation; myelodysplastic syndromes; sequencing; somatic mutations
    DOI:  https://doi.org/10.1111/jcmm.17613
  14. Blood. 2022 Nov 18. pii: blood.2022017865. [Epub ahead of print]
      Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with historically poor outcomes and no worldwide consensus treatment approach. Unique among most hematologic malignancies for its frequent cutaneous involvement, BPDCN also can invade other extramedullary compartments including the central nervous system. Generally affecting older adults, many patients are unfit to receive intensive chemotherapy, and while hematopoietic stem cell transplantation is preferred for younger, fit individuals, not all are eligible. One recent therapeutic breakthrough is that all BPDCNs express CD123 (IL3Rα), and that this accessible surface marker can be pharmacologically targeted. The first-in-class agent for BPDCN, tagraxofusp, which targets CD123, was approved in December 2018 in the United States for patients with BPDCN ages 2 and older. Despite favorable response rates in the frontline setting, many patients still relapse in the setting of monotherapy, and relapsed/refractory BPDCN patient outcomes remain dismal. Therefore, novel approaches targeting both CD123 and other targets are actively being investigated. In order to begin to formally address the state of the field, we formed a new collaborative initiative, the North American BPDCN Consortium (NABC). This group of experts includes a multi-disciplinary panel of hematologists/oncologists, hematopoietic stem cell transplant physicians, pathologists, dermatologists, and pediatric oncologists, and was tasked with defining the current standard of care in the field and identifying the most important research questions and future directions in BPDCN. The position findings of the NABC's inaugural meetings are presented herein.
    DOI:  https://doi.org/10.1182/blood.2022017865
  15. Cancer Lett. 2022 Nov 14. pii: S0304-3835(22)00484-0. [Epub ahead of print] 215997
      Treatment of acute myeloid leukemia (AML) with chemotherapeutic agents fails to eliminate leukemia stem cells (LSC),and thus patients remain at high risk for relapse. Therefore, the identification of agents that target LSC is an important consideration for the development of new therapies. Enhanced glycolysis in LSC contributes to the aggressiveness of AML, which is difficult to be targeted. In this study, we showed that targeting peroxisome-proliferator-activated receptor α (PPARα), a ligand-activated transcription factor by chiglitazar provided a promising therapeutic approach. We first identified that chiglitazar reduced cell viability and proliferation of the leukemia stem-like cells population in AML. Treatment with chiglitazar blocked the ubiquitination of PPARα and increased its expression, resulting in the inhibition of glucose metabolism and apoptosis of AML cells. Consistent with its anti-leukemia stem-like cells activity in vitro, chiglitazar treatment in vivo resulted in the significant killing of leukemia stem-like cells as demonstrated in AML patient-derived xenograft (PDX) models. Mechanistically, PPARα overexpression inhibited the expression and promoter activity of PGK1 through blocking HIF1-α interaction on the PGK1 promoter. Thus, we concluded that targeting PPARα may serve as a novel approach for enhancing stem and progenitor cells elimination in AML.
    Keywords:  Acute myeloid leukemia; Chiglitazar; Glycolysis; HIF1α; Leukemia stem and progenitor cells; PPARα
    DOI:  https://doi.org/10.1016/j.canlet.2022.215997
  16. Cell Death Discov. 2022 Nov 15. 8(1): 457
      Dysregulation of the BCL-2 family is implicated in protecting chronic myeloid leukemia (CML) cells from intracellular damage and BCR::ABL1-inhibition with tyrosine kinase inhibitors (TKIs) and may be a viable therapeutic target in blast phase (BP-)CML, for which treatment options are limited. BH3 mimetics, a class of small molecule inhibitors with high-specificity against the prosurvival members of the BCL-2 family, have displayed clinical promise in the treatment of chronic lymphocytic and acute myeloid leukemia as single agents and in combination with standard-of-care therapies. Here we present the first comparison of inhibition of BCL-2 prosurvival proteins BCL-2, BCL-xL and MCL-1 in combination with a second or third generation TKI, crucially with comparisons drawn between myeloid and lymphoid BP-CML samples. Co-treatment of four BP-CML cell lines with the TKIs nilotinib or ponatinib and either BCL-2 (venetoclax), MCL-1 (S63845) or BCL-xL (A-1331852) inhibitors resulted in a synergistic reduction in cell viability and increase in phosphatidylserine (PS) presentation. Nilotinib with BH3 mimetic combinations in myeloid BP-CML patient samples triggered increased induction of apoptosis over nilotinib alone, and a reduction in colony-forming capacity and CD34+ fraction, while this was not the case for lymphoid BP-CML samples tested. While some heterogeneity in apoptotic response was observed between cell lines and BP-CML patient samples, the combination of BCL-xL and BCR::ABL1 inhibition was consistently effective in inducing substantial apoptosis. Further, while BH3 mimetics showed little efficacy as single agents, dual-inhibition of BCL-2 prosurvival proteins dramatically induced apoptosis in all cell lines tested and in myeloid BP-CML patient samples compared to healthy donor samples. Gene expression and protein level analysis suggests a protective upregulation of alternative BCL-2 prosurvival proteins in response to BH3 mimetic single-treatment in BP-CML. Our results suggest that BH3 mimetics represent an interesting avenue for further exploration in myeloid BP-CML, for which alternative treatment options are desperately sought.
    DOI:  https://doi.org/10.1038/s41420-022-01211-1
  17. Blood. 2022 11 15. pii: blood.2022016835. [Epub ahead of print]
      Clonal hematopoiesis of indeterminate potential (CHIP), also referred to as aging-related clonal hematopoiesis (ARCH), is defined as an asymptomatic clonal expansion of mutant mature hematopoietic cells over 4% of blood leukocytes. CHIP associates with advanced age and increased risk for hematological malignancy, cardiovascular disease and all-cause mortality. Loss-of-function somatic mutations in TET2 are frequent drivers of CHIP. However, the contribution of aging-associated cooperating cell-extrinsic drivers, like inflammation, remains under-explored. Using bone marrow (BM) transplantation and newly developed genetic mosaicism (HSC-SCL-Cre-ERT; Tet2+/flox; R26+/tm6(CAG-ZsGreen1)Hze) mouse models of Tet2+/--driven CHIP, we observed an association between increased Tet2+/- clonal expansion and higher BM levels of the inflammatory cytokine IL-1 upon aging. Administration of IL-1 to mice carrying CHIP led to an IL-1R1-dependent expansion of Tet2+/- hematopoietic stem and progenitor cells (HSPCs) and mature blood cells. This expansion was caused by increased Tet2+/- HSPC cell-cycle progression, increased multilineage differentiation and higher repopulation capacity compared to their WT counterparts. In agreement, IL-1α-treated Tet2+/- HSCs showed increased DNA replication and repair transcriptomic signatures and reduced susceptibility to IL-1α-mediated downregulation of self-renewal genes. Importantly, genetic deletion of IL-1R1 in Tet2+/- HPSC or pharmacological inhibition of IL-1 signaling impaired Tet2+/- clonal expansion, establishing the IL-1 pathway as a relevant and therapeutically targetable driver of Tet2+/- CHIP progression during aging.
    DOI:  https://doi.org/10.1182/blood.2022016835
  18. Blood Cancer J. 2022 Nov 15. 12(11): 153
      Myelodysplastic syndromes (MDS) treated with DNMTI therapy have responses according to the 2006 IWG response criteria. CR responses have had the strongest association with OS. Recently, CR with partial hematologic recovery (CRh; i.e. blasts <5%, ANC > 500, platelets > 50) has been evaluated in AML, but its relevance is unknown in MDS. We identified adult patients with MDS treated with DNMTIs. We assessed best overall response to therapy according to IWG 2006 criteria, and subsequently identified patients meeting CRh criteria from the subgroup with SD or mCR. We evaluated duration of therapy and overall survival according to response. We identified 311 patients with MDS who received treatment between 2007 and 2018. The median age at the time of therapy was 69 years (range 23-91). Median follow up was 60 months. According to IWG 2006, responses included CR (n = 43, 14%), PR (n = 2, 1%), mCR (n = 57, 18%), SD (n = 149, 48%) and PD (n = 60, 19%). 79 patients (25%) achieved HI. A total of 62 patients (20%) met CRh criteria leading to reclassification of mCR (now n = 26, 8%) or SD (now n = 118, 38%). Patients achieving CR had similar time on therapy (median 8.1mo) compared to CRh (median 6mo, HR 1.4, 95% CI 0.9-2.0), and longer than other responses (p < 0.001). OS varied according to response; median OS was similar between CR (23.3mo) and CRh (25mo, HR 1.28 [0.79-2.08]), which was longer than those with mCR (17.2mo, HR 1.71 [0.96-3.05]), SD (16.3mo, HR 1.61 [1.04-2.48]), and PD (8.7mo, HR 3.04 [1.91-4.83]) (p < 0.001). OS associations with CR/CRh were confirmed in multivariable analysis accounting for allogeneic transplant. MDS patients who achieve a CRh response had similar survival and duration on therapy as patients who achieve CR response and superior to other IWG responses. These data support further evaluation of CRh into future response criteria and clinical trials.
    DOI:  https://doi.org/10.1038/s41408-022-00748-9
  19. Cancer Res. 2022 Nov 18. pii: CAN-21-4309. [Epub ahead of print]
      Aberrant RAS/MAPK signaling is a common driver of oncogenesis that can be therapeutically targeted with clinically approved MEK inhibitors. Disease progression on single agent MEK inhibitors is common, however, and combination therapies are typically required to achieve significant clinical benefit in advanced cancers. Here we focused on identifying MEK inhibitor-based combination therapies in neuroblastoma with mutations that activate the RAS/MAPK signaling pathway, which are rare at diagnosis but frequent in relapsed neuroblastoma. A genome-scale CRISPR-Cas9 functional genomic screen was deployed to identify genes that when knocked out sensitize RAS-mutant neuroblastoma to MEK inhibition. Loss of either CCNC or CDK8, two members of the mediator kinase module, sensitized neuroblastoma to MEK inhibition. Furthermore, small molecule kinase inhibitors of CDK8 improved response to MEK inhibitors in vitro and in vivo in RAS-mutant neuroblastoma and other adult solid tumors. Transcriptional profiling revealed that loss of CDK8 or CCNC antagonized the transcriptional signature induced by MEK inhibition. When combined, loss of CDK8 or CCNC prevented the compensatory upregulation of pro-growth gene expression induced by MEK inhibition. These findings propose a new therapeutic combination for RAS-mutant neuroblastoma and may have clinical relevance for other RAS-driven malignancies.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-21-4309
  20. Leukemia. 2022 Nov 15.
      Infants with KMT2A-rearranged B-cell acute lymphoblastic leukemia (ALL) have a dismal prognosis. Survival outcomes have remained static in recent decades despite treatment intensification and novel therapies are urgently required. KMT2A-rearranged infant ALL cells are characterized by an abundance of promoter hypermethylation and exhibit high BCL-2 expression, highlighting potential for therapeutic targeting. Here, we show that hypomethylating agents exhibit in vitro additivity when combined with most conventional chemotherapeutic agents. However, in a subset of samples an antagonistic effect was seen between several agents. This was most evident when hypomethylating agents were combined with methotrexate, with upregulation of ATP-binding cassette transporters identified as a potential mechanism. Single agent treatment with azacitidine and decitabine significantly prolonged in vivo survival in KMT2A-rearranged infant ALL xenografts. Treatment of KMT2A-rearranged infant ALL cell lines with azacitidine and decitabine led to differential genome-wide DNA methylation, changes in gene expression and thermal proteome profiling revealed the target protein-binding landscape of these agents. The selective BCL-2 inhibitor, venetoclax, exhibited in vitro additivity in combination with hypomethylating or conventional chemotherapeutic agents. The addition of venetoclax to azacitidine resulted in a significant in vivo survival advantage indicating the therapeutic potential of this combination to improve outcome for infants with KMT2A-rearranged ALL.
    DOI:  https://doi.org/10.1038/s41375-022-01746-3
  21. Blood. 2022 Nov 18. pii: blood.2021015111. [Epub ahead of print]
      Graft vs. host disease (GVHD) is a major cause of morbidity and mortality following allogeneic hematopoietic transplantation. In experimental models, Interleukin-22 promotes epithelial regeneration and induces innate antimicrobial molecules. We conducted a multicenter single-arm phase 2 study evaluating safety and efficacy of a novel recombinant human Interleukin-22 dimer, F-652, used in combination with systemic corticosteroids for treatment of newly diagnosed lower gastrointestinal acute GVHD (NCT02406651; https://clinicaltrials.gov/ct2/show/NCT02406651). The most common adverse events were cytopenias and electrolyte abnormalities, and there were no dose-limiting toxicities. 19/27 patients (70%; 80% CI: 56-79) achieved a day-28 treatment response, meeting the prespecified primary endpoint. Responders exhibited a distinct fecal microbiota composition characterized by expansion of commensal anaerobes, which correlated with increased overall microbial α-diversity, suggesting improvement of GVHD-associated dysbiosis. This work demonstrates a potential approach for combining immunosuppression with tissue-supportive strategies to enhance recovery of damaged mucosa and promote microbial health in patients with gastrointestinal GVHD. This work was supported by funding from Evive Biotech., The Society of Memorial Sloan Kettering Cancer Center, and the National Institutes of Health.
    DOI:  https://doi.org/10.1182/blood.2021015111
  22. BMC Cancer. 2022 Nov 14. 22(1): 1174
       BACKGROUND: For patients with acute myeloid leukaemia (AML), the only potentially curative treatment is intensive chemotherapy (IC). This is highly toxic, particularly for patients > 60 years, potentially leading to prolonged hospitalisations requiring intensive supportive care, and sometimes treatment-related death. This also results in extensive healthcare costs and negatively impacts quality of life (QoL). Venetoclax with low-dose cytarabine (VEN + LDAC) is a novel, low-intensity treatment for AML patients who cannot receive IC. VEN + LDAC is given as an outpatient and toxicity appears significantly lower than with IC. Analysis of clinical trials performed to date are promising for patients with the genotype NPM1mutFLT3 ITDneg, where remission and survival rates appear comparable to those achieved with IC.
    METHODS: VICTOR is an international, two-arm, open-label, multi-centre, non-inferiority, randomised-controlled phase II trial to assess VEN + LDAC compared to standard of care (IC) as first-line treatment in older patients (initially aged ≥ 60 years) with newly diagnosed AML. The trial will recruit patients with a NPM1mutFLT3 ITDneg genotype; those with a favourable risk in relation to the experimental treatment. University of Birmingham is the UK co-ordinating centre, with national hubs in Aarhus University Hospital, Denmark, and Auckland District Health Board, New Zealand. The primary outcome is molecular event-free survival time where an event is defined as failure to achieve morphological complete response (CR) or CR with incomplete blood count recovery after two cycles of therapy; molecular persistence, progression or relapse requiring treatment change; morphological relapse, or; death. Secondary outcomes include cumulative resource use at 12- and 24-months, and QoL as assessed by EORTCQLQ-C30 and EQ-5D-3L at 3-, 6-, 12-, 18- and 24-months. The trial employs an innovative Bayesian design with target sample size of 156 patients aged > 60 years.
    DISCUSSION: The principle underpinning the VICTOR trial is that the chance of cure for patients in the experimental arm should not be compromised, therefore, an adaptive design with regular checks on accumulating data has been employed, which will allow for a staged expansion of the trial population to include younger patients if, and when, there is sufficient evidence of non-inferiority in older patients.
    TRIAL REGISTRATION: EudraCT: 2020-000,273-24; 21-Aug-2020.
    ISRCTN: 15,567,173; 08-Dec-2020.
    Keywords:  Acute myeloid leukaemia; Adaptive design; Bayesian non-inferiority design; Clinical trial; Low-dose cytarabine; Venetoclax
    DOI:  https://doi.org/10.1186/s12885-022-10221-2
  23. Nat Rev Dis Primers. 2022 Nov 17. 8(1): 74
      Myelodysplastic syndromes (MDS) are a family of myeloid cancers with diverse genotypes and phenotypes characterized by ineffective haematopoiesis and risk of transformation to acute myeloid leukaemia (AML). Some epidemiological data indicate that MDS incidence is increasing in resource-rich regions but this is controversial. Most MDS cases are caused by randomly acquired somatic mutations. In some patients, the phenotype and/or genotype of MDS overlaps with that of bone marrow failure disorders such as aplastic anaemia, paroxysmal nocturnal haemoglobinuria (PNH) and AML. Prognostic systems, such as the revised International Prognostic Scoring System (IPSS-R), provide reasonably accurate predictions of survival at the population level. Therapeutic goals in individuals with lower-risk MDS include improving quality of life and minimizing erythrocyte and platelet transfusions. Therapeutic goals in people with higher-risk MDS include decreasing the risk of AML transformation and prolonging survival. Haematopoietic cell transplantation (HCT) can cure MDS, yet fewer than 10% of affected individuals receive this treatment. However, how, when and in which patients with HCT for MDS should be performed remains controversial, with some studies suggesting HCT is preferred in some individuals with higher-risk MDS. Advances in the understanding of MDS biology offer the prospect of new therapeutic approaches.
    DOI:  https://doi.org/10.1038/s41572-022-00402-5
  24. Front Oncol. 2022 ;12 1017355
       Background: Total Marrow and Lymphoid Irradiation (TMLI) is a promising component of the preparative regimen for hematopoietic cell transplantation in patients with high-risk acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL). Extramedullary (EM) relapse after TMLI is comparable to TBI and non-TBI conditioning regimens. This study evaluates outcomes of patients treated with radiotherapy (RT) with EM relapse previously treated with TMLI.
    Methods: A retrospective analysis of five prospective TMLI trials was performed. TMLI targeted bones and major lymphoid tissues using image-guided tomotherapy, with total dose ranging from 12 to 20 Gy. EM recurrences were treated at the discretion of the hematologist and radiation oncologist using RT ± chemotherapy. Descriptive statistics and survival analysis were then performed on this cohort.
    Results: In total, 254 patients with refractory or relapsed AML or ALL were treated with TMLI at our institution. Twenty-one patients were identified as receiving at least one subsequent course of radiation. A total of 67 relapse sites (median=2 sites/patient, range=1-16) were treated. Eleven relapsed patients were initially treated with curative intent. Following the initial course of subsequent RT, 1-year, 3-year and 5-year estimates of OS were 47.6%, 32.7% and 16.3%, respectively. OS was significantly better in patients treated with curative intent, with median OS of 50.7 months vs 1.6 months (p<0.001). 1-year, 3-year and 5-year estimates of PFS were 23.8%, 14.3% and 14.3%, respectively. PFS was significantly better in patients treated with curative intent, with median PFS of 6.6 months vs 1.3 months (p<0.001). Following RT, 86.6% of the sites had durable local control.
    Conclusions: RT is an effective modality to treat EM relapse in patients with acute leukemia who relapse after HCT achieving high levels of local control. In patients with limited relapse amenable to curative intent, radiation confers favorable long-term survival. Radiation as salvage treatment for EM relapse after HCT warrants further evaluation.
    Keywords:  ALL; AML; HCT role of radiation following TMLI; TMLI; leukemia; radiation; relapse; salvage
    DOI:  https://doi.org/10.3389/fonc.2022.1017355
  25. Blood Adv. 2022 Nov 18. pii: bloodadvances.2022008281. [Epub ahead of print]
      Caregivers of patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT) must cope with substantial caregiving burden, high rates of psychological distress, and diminished quality of life (QOL). However, data describing coping strategies pre-HSCT and the association between coping, QOL, and psychological outcomes in this population are lacking. We conducted a secondary analysis of data collected during a multi-site randomized clinical trial of a supportive care intervention in HSCT recipients and their caregivers. Caregivers completed the Brief COPE, Hospital Anxiety and Depression Scale, and the Caregiver Oncology Quality of Life Questionnaire to measure coping strategies, psychological distress, and QOL, respectively. We grouped coping into two higher order domains: approach-oriented (i.e., emotional support, active coping) and avoidant (i.e., self-blame, denial) We used the median split method to describe the distribution of coping and multivariate linear regression models to assess the relationship between coping and caregiver outcomes. We enrolled 170 caregivers, with a median (range) age of 53 (47-64) years. Most were White (87%), non-Hispanic (96%), and female (77%). Approach-oriented coping was associated with less anxiety (β=-0.210, p=0.003) and depression symptoms (β=-0.160, p=0.009), and better QOL (β=0.526, p=0.002). In contrast, avoidant coping was associated with more anxiety (β=0.687, p<0.001) and depression symptoms (β=0.579, p<0.001), and worse QOL (β=-1.631, p<0.001). Our findings suggest that coping is related to distress and QOL among caregivers of HSCT recipients even pre-transplant. Hence, caregivers of patients with hematologic malignancies undergoing HSCT may benefit from resources that facilitate adaptive coping with the demands of caregiving.
    DOI:  https://doi.org/10.1182/bloodadvances.2022008281
  26. Br J Haematol. 2022 Nov 16.
      High genetic heterogeneity in the human leukocyte antigen (HLA) increases the likelihood of efficient immune response to pathogens and tumours. As measure of HLA diversity, HLA evolutionary divergence (HED) has been shown to predict the response of tumours to immunotherapy and haematopoietic stem cell transplantation (HSCT) in adults. We retrospectively investigated the association of HED with outcomes of 153 paediatric/young adults patients, treated for malignant disorders with HSCT from 9-10/10 HLA-matched unrelated donors. HED was calculated as pairwise genetic distance between alleles in patient HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1, using the locus median to stratify patients with 'high' or 'low' HED. Patients with high HED-B and -DRB1 showed significantly improved disease-free survival (DFS), especially when combined (70.8% vs 53.7% p = 0.008). High HED-B + -DRB1 was also associated with improved overall survival (OS) (82.1 vs 66.4% p = 0.014), and concomitant reduction of non-relapse-mortality (5.1% vs 21.1% p = 0.006). The impact on OS and DFS of combined HED-B + -DRB1 was confirmed in multivariate analysis [hazard ratio (HR) 0.39, p = 0.009; and HR 0.45, p = 0.007 respectively]. Only high HED scores for HLA-DPB1 were associated, in univariate analysis, with reduced incidence of relapse (15.9% vs 31.1%, p = 0.03). These results support HED as prognostic marker in allogeneic HSCT and, if confirmed in larger cohorts, would allow its use to inform clinical risk and potentially influence clinical practice.
    Keywords:  haematopoietic stem cell transplantationhuman leukocyte antigen (HLA)HLA evolutionary divergenceleukaemiapaediatric
    DOI:  https://doi.org/10.1111/bjh.18561