bims-tremyl 2023-08-13 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2023–08–13
35 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

FLT3 inhibitors as MRD-guided salvage treatment for molecular failure in FLT3 mutated AML.
Treating accelerated and blast phase myeloproliferative neoplasms: progress and challenges.
Etoposide plus cytarabine versus cyclophosphamide or melphalan in busulfan-based preparative regimens for autologous stem cell transplantation in adults with acute myeloid leukemia in first complete remission: a study from the Acute Leukemia Working Party of the EBMT.
MRD as Biomarker for Response to Donor Lymphocyte Infusion after Allogeneic Hematopoietic Cell Transplantation in Patients with AML.
Real-world experience with ponatinib therapy in chronic phase chronic myeloid leukemia: impact of depth of response on survival and prior exposure to nilotinib on arterial occlusive events.
Cigarette smoke stimulates clonal expansion of Jak2V617F and Tet2-/- cells.
Discordant Pathologic Diagnoses of Myelodysplastic Neoplasms and Their Implications for Registries and Therapies.
Utilization of Serial Next-Generation Sequencing Among Patients Receiving CPX-351 for Newly Diagnosed Acute Myeloid Leukemia.
Different niches for stem cells carrying the same oncogenic driver affect pathogenesis and therapy response in myeloproliferative neoplasms.
Combination strategies to overcome drug resistance in FLT+ acute myeloid leukaemia.
Mutational Profile Enables the Identification of a High-Risk Subgroup in Myelodysplastic Syndromes with Isolated Trisomy 8.
The relevance of the hematopoietic niche for therapy resistance in acute myeloid leukemia.
Real-World Experience With CPX-351 Treatment for Acute Myeloid Leukemia in England: An Analysis From the National Cancer Registration and Analysis Service.
Associations Between Cancer Predisposition Mutations and Clonal Hematopoiesis in Patients With Solid Tumors.
Modulating the immune system as a therapeutic target for myelodysplastic syndromes and acute myeloid leukemia.
Antibody targeting of mutant calreticulin in myeloproliferative neoplasms.
Inhibition of METTL3 results in a cell-intrinsic interferon response that enhances anti-tumour immunity.
BCL2L1 inhibitor A-1331852 inhibits MCL1 transcription and triggers apoptosis in acute myeloid leukemia cells.
Pacritinib is a potent ACVR1 inhibitor with significant anemia benefit in patients with myelofibrosis.
Validation of the molecular international prognostic scoring system in patients with myelodysplastic syndromes defined by international consensus classification.
Cox proportional hazards deep neural network identifies peripheral blood complete remission to be at least equivalent to morphologic complete remission in predicting outcomes of patients treated with azacitidine-A prospective cohort study by the AGMT.
Clinical Characteristics and Outcomes of Patients with Primary and Secondary Myelofibrosis According to the Genomic Classification Using Targeted Next-Generation Sequencing.
Treatment with midostaurin and other FLT3 targeting inhibitors is associated with an increased risk of cardiovascular adverse events in patients who underwent allogeneic hematopoietic stem cell transplantation with FLT3-mutated AML.
Leukocytes carrying Clonal Hematopoiesis of Indeterminate Potential (CHIP) Mutations invade Human Atherosclerotic Plaques.
Late fetal hematopoietic failure results from ZBTB11 deficiency despite abundant HSC specification.
Genotype, Oxidase Status, and Preceding Infection or Autoinflammation Do Not Affect Allogeneic HCT Outcomes for CGD.
PTEN regulates hematopoietic lineage plasticity via PU.1-dependent chromatin accessibility.
Food for thought (and CML survival).
Prognostication and risk stratification of patients with myelodysplastic syndromes.
Heterogeneity in leukemia cells that escape drug-induced senescence-like state.
Discovery of Small-Molecule TIM-3 Inhibitors for Acute Myeloid Leukemia Using Pharmacophore-Based Virtual Screening.
A membrane-associated MHC-I inhibitory axis for cancer immune evasion.
A HIF independent oxygen-sensitive pathway for controlling cholesterol synthesis.
Transcriptomic comparison of bone marrow CD34 + cells and peripheral blood neutrophils from ET patients with JAK2 or CALR mutations.
Clinical outcome of therapy-related acute myeloid leukemia patients. Real-life experience in a University Hospital and a Cancer Center in France.

Leukemia. 2023 Aug 09.

FLT3 inhibitors as MRD-guided salvage treatment for molecular failure in FLT3 mutated AML.

Jad Othman, Nicola Potter, Katya Mokretar, David Taussig, Anjum Khan, Pramila Krishnamurthy, Anne-Louise Latif, Paul Cahalin, James Aries, Mariam Amer, Edward Belsham, Eibhlin Conneally, Charles Craddock, Dominic Culligan, Mike Dennis, Caroline Duncan, Sylvie D Freeman, Caroline Furness, Amanda Gilkes, Paraskevi Gkreka, Katherine Hodgson, Wendy Ingram, Manish Jain, Andrew King, Steven Knapper, Panagiotis Kottaridis, Mary Frances McMullin, Unmesh Mohite, Loretta Ngu, Jenny O'Nions, Katharine Patrick, Tom Rider, Wing Roberts, Marianne Tang Severinsen, Neill Storrar, Tom Taylor, Nigel H Russell, Richard Dillon.

Patients with FLT3-mutated AML have a high relapse rate and suboptimal outcomes. Many have co-mutations suitable for measurable residual disease (MRD) monitoring by RT-qPCR and those destined to relapse can be identified by high or rising levels of MRD, called molecular failure. This provides a window for pre-emptive intervention, but there is little evidence to guide treatment. The use of FLT3 inhibitors (FLT3i) appears attractive but their use has not yet been evaluated. We identified 56 patients treated with FLT3i at molecular failure. The FLT3 mutation was an ITD in 52, TKD in 7 and both in 3. Over half of patients had previously received midostaurin. Molecular failure occurred at a median 9.2 months from diagnosis and was treated with gilteritinib (n = 38), quizartinib (n = 7) or sorafenib (n = 11). 60% achieved a molecular response, with 45% reaching MRD negativity. Haematological toxicity was low, and 22 patients were bridged directly to allogeneic transplant with another 6 to donor lymphocyte infusion. 2-year overall survival was 80% (95%CI 69-93) and molecular event-free survival 56% (95%CI 44-72). High-sensitivity next-generation sequencing for FLT3-ITD at molecular failure identified patients more likely to benefit. FLT3i monotherapy for molecular failure is a promising strategy which merits evaluation in prospective studies.

DOI: https://doi.org/10.1038/s41375-023-01994-x
Ther Adv Hematol. 2023 ;14 20406207231177282

Treating accelerated and blast phase myeloproliferative neoplasms: progress and challenges.

Helen O Ajufo, Julian A Waksal, John O Mascarenhas, Raajit K Rampal.

  Myeloproliferative neoplasms (MPNs) are a group of clonal hematologic malignancies that include polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). MPNs are characterized by activating mutations in the JAK/STAT pathway and an increased risk of transformation to an aggressive form of acute leukemia, termed MPN-blast phase (MPN-BP). MPN-BP is characterized by the presence of ⩾20% blasts in the blood or bone marrow and is almost always preceded by an accelerated phase (MPN-AP) defined as ⩾10-19% blasts in the blood or bone marrow. These advanced forms of disease are associated with poor prognosis with a median overall survival (mOS) of 3-5 months in MPN-BP and 13 months in MPN-AP. MPN-AP/BP has a unique molecular landscape characterized by increased intratumoral complexity. Standard therapies used in de novo acute myeloid leukemia (AML) have not demonstrated improvement in OS. Allogeneic hematopoietic stem cell transplant (HSCT) remains the only curative therapy but is associated with significant morbidity and mortality and infrequently utilized in clinical practice. Therefore, an urgent unmet need persists for effective therapies in this advanced phase patient population. Here, we review the current management and future directions of therapy in MPN-AP/BP.

Keywords:  accelerated phase; blast phase; myeloproliferative neoplasms; novel therapeutics

DOI:  https://doi.org/10.1177/20406207231177282
Bone Marrow Transplant. 2023 Aug 08.

Etoposide plus cytarabine versus cyclophosphamide or melphalan in busulfan-based preparative regimens for autologous stem cell transplantation in adults with acute myeloid leukemia in first complete remission: a study from the Acute Leukemia Working Party of the EBMT.

Jaime Sanz, Myriam Labopin, Thomas Pabst, Jurjen Versluis, Gwendolyn Van Gorkom, Ellen Meijer, Tobias Gedde-Dahl, Juan Montoro, William Arcese, Jose Antonio Pérez-Simón, Nicolaas Schaap, Johan Maertens, Radovan Vrhovac, Francesco Lanza, Norbert Claude Gorin, Mohamad Mohty, Fabio Ciceri.

We retrospectively compared the impact of the conditioning regimen in adult patients with acute myeloid leukemia (AML) in first complete remission (CR1) that received high-dose myeloablative chemotherapy followed by autologous stem cell transplantation (ASCT) from 2010 to 2021 with either high-dose cytarabine, etoposide and busulfan (BEA), busulfan with cyclophosphamide (BUCY) or busulfan and high-dose melphalan (BUMEL) registered in the EBMT database. Overall 1560 patients underwent ASCT, of which 156, 1143 and 261 received BEA, BUCY and BUMEL, respectively. Compared to BUCY and BUMEL, BEA patients were younger (p < 0.001) and less frequently had NPM1 mutations (p = 0.03). Transplant outcomes at 5 years with BEA, BUCY and BUMEL were: cumulative incidence of relapse 41.8%, 46.6% and 51.6%; non-relapse mortality (NRM) 1.5%, 5.2% and 7.3%; probability of leukemia-free survival (LFS) 56.7%, 48.2% and 41.1%; and overall survival (OS) 71.3%, 62.3% and 56%, respectively. In multivariable analysis the BEA regimen showed significant improvement in OS compared to BUCY (hazard ratio [HR] 0.65; 95% CI, 0.42-0.83; p = 0.048) and BUMEL (HR 0.59; 95% CI, 0.37-0.94; p = 0.029). In conclusion, high-dose myeloablative combination chemotherapy with BEA offered improved outcomes compared to classical BUCY or BUMEL in patients with AML in CR1 undergoing ASCT.

DOI: https://doi.org/10.1038/s41409-023-02075-4
Cancers (Basel). 2023 Aug 01. pii: 3911. [Epub ahead of print]15(15):

MRD as Biomarker for Response to Donor Lymphocyte Infusion after Allogeneic Hematopoietic Cell Transplantation in Patients with AML.

Katrin Teich, Michael Stadler, Razif Gabdoulline, Jyoti Kandarp, Clara Wienecke, Bennet Heida, Piroska Klement, Konstantin Büttner, Letizia Venturini, Martin Wichmann, Wolfram Puppe, Christian Schultze-Florey, Christian Koenecke, Gernot Beutel, Matthias Eder, Arnold Ganser, Michael Heuser, Felicitas Thol.

  Donor lymphocyte infusions (DLIs) can directly target leukemic cells through a graft-versus-leukemia effect and play a key role in the prevention and management of relapse after allogeneic hematopoietic cell transplantation (alloHCT). Predictors of response to DLIs are not well established. We evaluated measurable residual disease (MRD) before, 30 and 90 days after DLI treatment as biomarkers of response. MRD was assessed by next-generation sequencing in 76 DLI-treated acute myeloid leukemia patients. MRD status before DLI treatment was independently prognostic for event-free survival (EFS, p < 0.001) and overall survival (OS, p < 0.001). Within 90 days of DLI treatment, 73% of MRD+ patients converted to MRD- and 32% of patients without remission achieved remission. MRD status 90 days after DLI treatment was independently prognostic for the cumulative incidence of relapse (CIR, p = 0.011) and relapse-free survival (RFS, p = 0.001), but not for OS. To evaluate the role of DLI treatment in MRD- patients, 23 MRD- patients who received DLIs were compared with a control cohort of 68 MRD- patients not receiving DLIs. RFS (p = 0.23) and OS (p = 0.48) were similar between the two cohorts. In conclusion, MRD is prognostic before (EFS, OS) and after (CIR, RFS) DLI treatment and may help in the selection of patients who benefit most from DLIs.

Keywords:  allogeneic hematopoietic cell transplantation (alloHCT); donor lymphocyte infusions (DLIs); measurable residual disease (MRD); targeted graft-versus-leukemia (GvL) effect

DOI:  https://doi.org/10.3390/cancers15153911
Blood Cancer J. 2023 Aug 11. 13(1): 122

Real-world experience with ponatinib therapy in chronic phase chronic myeloid leukemia: impact of depth of response on survival and prior exposure to nilotinib on arterial occlusive events.

Maymona G Abdelmagid, Aref Al-Kali, Mark R Litzow, Kebede H Begna, William J Hogan, Mirinal S Patnaik, Shahrukh K Hashmi, Michelle A Elliott, Hassan Alkhateeb, Omer S Karrar, Farah Fleti, Mohammed H Elnayir, Candido E Rivera, Hemant S Murthy, James M Foran, Mohamed A Kharfan-Dabaja, Talha Badar, David S Viswanatha, Kaaren K Reichard, Naseema Gangat, Ayalew Tefferi.

We surveyed the performance of ponatinib, as salvage therapy, in a real-world setting of chronic phase chronic myeloid leukemia (CML-CP). Among 55 consecutive patients (median age 49 years) with relapsed/refractory CML-CP, 35 (64%) had failed ≥3 tyrosine kinase inhibitors (TKIs), 35 (64%) were pre-treated with nilotinib, and 14 (28%) harbored ABL1T315I. At start of ponatinib (median dose 30 mg/day), 40 patients were already in complete hematologic (CHR), 4 in complete cytogenetic (CCyR), 3 in major molecular (MMR) remission, while 8 had not achieved CHR (NR). Ponatinib improved the depth of response in 13 (33%), 3 (75%), 2 (66%), and 4 (50%) patients with CHR, CCyR, MMR, and NR, respectively (p = 0.02). At a median follow-up of 42 months, 13 (23%) deaths, 5 (9%) blast transformations, and 25 (45%) allogeneic transplants were recorded. Five/10-year post-ponatinib survival was 77%/58% with no significant difference when patients were stratified by allogeneic transplant (p = 0.94), ponatinib-induced deeper response (p = 0.28), or a post-ponatinib ≥CCyR vs CHR remission state (p = 0.25). ABL1T315I was detrimental to survival (p = 0.04) but did not appear to affect response. Prior exposure to nilotinib was associated with higher risk of arterial occlusive events (AOEs; 11% vs 0%; age-adjusted p = 0.04). Ponatinib starting/maintenance dose (45 vs 15 mg/day) did not influence either treatment response or AOEs. Our observations support the use of a lower starting/maintenance dose for ponatinib in relapsed/refractory CML-CP but a survival advantage for deeper responses was not apparent and treatment might not overcome the detrimental impact of ABL1T315I on survival. The association between prior exposure to nilotinib and a higher risk of post-ponatinib AOEs requires further validation.

DOI: https://doi.org/10.1038/s41408-023-00891-x
Front Oncol. 2023 ;13 1210528

Cigarette smoke stimulates clonal expansion of Jak2V617F and Tet2-/- cells.

Gajalakshmi Ramanathan, Jane H Chen, Nitya Mehrotra, Tiffany Trieu, Aaron Huang, Eduard Mas, Jessica E Monterrosa Mena, Bishop Bliss, David A Herman, Michael T Kleinman, Angela G Fleischman.

   Introduction: Somatic mutations in myeloid growth factor pathway genes, such as JAK2, and genes involved in epigenetic regulation, such as TET2, in hematopoietic stem cells (HSCs) leads to clonal hematopoiesis of indeterminate potential (CHIP) which presents a risk factor for hematologic malignancy and cardiovascular disease. Smoking behavior has been repeatedly associated with the occurrence of CHIP but whether smoking is an environmental inflammatory stressor in promoting clonal expansion has not been investigated.
Methods: We performed in vivo smoke exposures in both wildtype (WT) mice and transplanted mice carrying Jak2V617F mutant and Tet2 knockout (Tet-/-) cells to determine the impact of cigarette smoke (CS) in the HSC compartment as well as favoring mutant cell expansion.
Results: WT mice exposed to smoke displayed increased oxidative stress in long-term HSCs and suppression of the hematopoietic stem and progenitor compartment but smoke exposure did not translate to impaired hematopoietic reconstitution in primary bone marrow transplants. Gene expression analysis of hematopoietic cells in the bone marrow identified an imbalance between Th17 and Treg immune cells suggesting a local inflammatory environment. We also observed enhanced survival of Jak2V617F cells exposed to CS in vivo and cigarette smoke extract (CSE) in vitro. WT bone marrow hematopoietic cells from WT/Jak2V617F chimeric mice exposed to CS demonstrated an increase in neutrophil abundance and distinct overexpression of bone marrow stromal antigen 2 (Bst2) and retinoic acid early transcript 1 (Raet1) targets. Bst2 and Raet1 are indicative of increased interferon signaling and cellular stress including oxidative stress and DNA damage, respectively. In chimeric mice containing both WT and Tet2-/- cells, we observed an increased percentage of circulating mutant cells in peripheral blood post-cigarette smoke exposure when compared to pre-exposure levels while this difference was absent in air-exposed controls.
Conclusion: Altogether, these findings demonstrate that CS results in an inflamed bone marrow environment that provides a selection pressure for existing CHIP mutations such as Jak2V617F and Tet2 loss-of-function.

Keywords:  cigarette smoke; clonal hematopoiesis; inflammation; myeloproliferative neoplasm; reactive oxygen species

DOI:  https://doi.org/10.3389/fonc.2023.1210528
Blood Adv. 2023 Aug 08. pii: bloodadvances.2023010061. [Epub ahead of print]

Discordant Pathologic Diagnoses of Myelodysplastic Neoplasms and Their Implications for Registries and Therapies.

Edward Gorak, Michael Otterstatter, Tareq Al Baghdadi, Nancy Gillis, James M Foran, Jane Jijun Liu, Rafael Bejar, Steven D Gore, Steven H Kroft, Alexandra M Harrington, Wael Saber, Daniel T Starczynowski, Dana E Rollison, Ling Zhang, Lynn C Moscinski, Steffanie H Wilson, Jason Thompson, Christine Borchert, Seth Sherman, Donnie Hebert, Mary Ellen Walker, Eric Padron, Amy DeZern, Mikkael A Sekeres.

Myelodysplastic neoplasms (MDS) are a collection of hematopoietic disorders with widely variable prognoses and treatment options. Accurate pathologic diagnoses present challenges due to interobserver variability in interpreting morphology and quantifying dysplasia. We compared local clinical site diagnoses with central, adjudicated review from 918 participants enrolled in the ongoing National Heart, Lung, and Blood Institute National MDS Natural History Study (NCT02775383), a prospective observational cohort study of participants with suspected MDS or MDS/myeloproliferative neoplasms (MPNs). Locally, 264 (29%) were diagnosed as having MDS, 15 (2%) MDS/MPN overlap, 62 (7%) idiopathic cytopenia of undetermined significance (ICUS), 0 (0%) acute myeloid leukemia (AML) with <30% blasts, and 577 (63%) other. Approximately one-third of cases were reclassified following central review with 266 (29%) diagnosed as MDS, 45 (5%) MDS/MPN overlap, 49 (5%) ICUS, 15 (2%) AML <30%, and 543 (59%) other. Site miscoding errors accounted for over half (53%) of the local misdiagnoses, leaving a true misdiagnosis rate of 15% overall, 21% for MDS. Therapies were reported in 37% of patients, including 43% of patients with MDS, 49% of MDS/MPN, and 86% of AML <30% blasts. Treatment rates were lower (25%) in cases with true discordance in diagnosis compared to those where local and central diagnoses agreed (40%), and receipt of inappropriate therapy occurred in 7% of misdiagnosed cases. Discordant diagnoses were frequent, which has implications for the accuracy of study-related and national registries and can lead to inappropriate therapy.

DOI: https://doi.org/10.1182/bloodadvances.2023010061
Clin Lymphoma Myeloma Leuk. 2023 Jul 26. pii: S2152-2650(23)00211-2. [Epub ahead of print]

Utilization of Serial Next-Generation Sequencing Among Patients Receiving CPX-351 for Newly Diagnosed Acute Myeloid Leukemia.

Akriti G Jain, Somedeb Ball, Luis E Aguirre, Katherine A Tobon, Onyee Chan, Eric Padron, Andrew Kuykendall, Rami Komrokji, David Sallman, Jeffrey E Lancet, Kendra Sweet.

   BACKGROUND: The phase III trial that led to the approval of CPX-351 for treating secondary acute myeloid leukemia (sAML) in 2017 did not study the effect of specific mutations on outcomes.
METHODS: This retrospective study was done to evaluate the effect of next-generation sequencing (NGS) results at the time of best response and before allogeneic stem cell transplant (alloSCT) in patients treated with CPX-351 as frontline therapy for sAML between 2017 and 2021.
RESULTS: The most common mutations seen were DNMT3A (n = 17, 29.8%), SRSF2 (n = 13, 22.8%), RUNX1 (n = 13, 22.8%), TET2 (n = 9, 15.8%), ASXL1 (n = 9, 15.8%), and BCOR (n = 9, 15.8%). Median OS (mOS) for the entire cohort was 47 months. Though 64.7% patients cleared the DNMT3A mutation, only 44.4% and 22.2% of patients cleared the TET2 and ASXL1 mutations, respectively. The mOS for patients who cleared their mutations vs. for those who did not was not significantly longer (46 vs. 30 months; P = .991). The relapse-free survival (RFS) for patients who cleared mutations was numerically longer compared to those who had persistent mutations; however, this did not reach statistical significance (44 months vs. 26 months; P = .786).
CONCLUSION: This is the first study reporting NGS at best response and before alloSCT and its effect on OS and RFS. We found that OS and RFS were numerically longer among patients who cleared mutations; however, this did not reach statistical significance. In addition, alloSCT led to improved RFS irrespective of mutational clearance.

Keywords:  AML; Mutations; NGS; Secondary acute myeloid leukemia; Vyxeos

DOI:  https://doi.org/10.1016/j.clml.2023.07.002
Nat Cancer. 2023 Aug 07.

Different niches for stem cells carrying the same oncogenic driver affect pathogenesis and therapy response in myeloproliferative neoplasms.

Elodie Grockowiak, Claudia Korn, Justyna Rak, Veronika Lysenko, Adrien Hallou, Francesca M Panvini, Matthew Williams, Claire Fielding, Zijian Fang, Eman Khatib-Massalha, Andrés García-García, Juan Li, Reema A Khorshed, Sara González-Antón, E Joanna Baxter, Anjali Kusumbe, Bridget S Wilkins, Anna Green, Benjamin D Simons, Claire N Harrison, Anthony R Green, Cristina Lo Celso, Alexandre P A Theocharides, Simón Méndez-Ferrer.

Aging facilitates the expansion of hematopoietic stem cells (HSCs) carrying clonal hematopoiesis-related somatic mutations and the development of myeloid malignancies, such as myeloproliferative neoplasms (MPNs). While cooperating mutations can cause transformation, it is unclear whether distinct bone marrow (BM) HSC-niches can influence the growth and therapy response of HSCs carrying the same oncogenic driver. Here we found different BM niches for HSCs in MPN subtypes. JAK-STAT signaling differentially regulates CDC42-dependent HSC polarity, niche interaction and mutant cell expansion. Asymmetric HSC distribution causes differential BM niche remodeling: sinusoidal dilation in polycythemia vera and endosteal niche expansion in essential thrombocythemia. MPN development accelerates in a prematurely aged BM microenvironment, suggesting that the specialized niche can modulate mutant cell expansion. Finally, dissimilar HSC-niche interactions underpin variable clinical response to JAK inhibitor. Therefore, HSC-niche interactions influence the expansion rate and therapy response of cells carrying the same clonal hematopoiesis oncogenic driver.

DOI: https://doi.org/10.1038/s43018-023-00607-x
Cancer Cell Int. 2023 Aug 11. 23(1): 161

Combination strategies to overcome drug resistance in FLT+ acute myeloid leukaemia.

Jingmei Yang, Ran Friedman.

   BACKGROUND: Acute myeloid leukaemia (AML) remains difficult to treat despite the development of novel formulations and targeted therapies. Activating mutations in the FLT3 gene are common among patients and make the tumour susceptible to FLT3 inhibitors, but resistance to such inhibitors develops quickly.
METHODS: We examined combination therapies aimed at FLT3+-AML, and studied the development of resistance using a newly developed protocol. Combinations of FLT3, CDK4/6 and PI3K inhibitors were tested for synergism.
RESULTS: We show that AML cells express CDK4 and that the CDK4/6 inhibitors palbociclib and abemaciclib inhibit cellular growth. PI3K inhibitors were also effective in inhibiting the growth of AML cell lines that express FLT3-ITD. Whereas resistance to quizartinib develops quickly, the combinations overcome such resistance.
CONCLUSIONS: This study suggests that a multi-targeted intervention involving a CDK4/6 inhibitor with a FLT3 inhibitor or a pan-PI3K inhibitor might be a valuable therapeutic strategy for AML to overcome drug resistance. Moreover, many patients cannot tolerate high doses of the drugs that were studied (quizartinib, palbociclib and PI3K inhibitors) for longer periods, and it is therefore of high significance that the drugs act synergistically and lower doses can be used.

Keywords:  Acute myeloid leukemia; Alpelisib; Combination treatment; Copanlisib; Drug synergism; Duvelisib; FLT3-ITD; Gilteritinib; Idelalisib; Targeted therapy

DOI:  https://doi.org/10.1186/s12935-023-03000-x
Cancers (Basel). 2023 Jul 27. pii: 3822. [Epub ahead of print]15(15):

Mutational Profile Enables the Identification of a High-Risk Subgroup in Myelodysplastic Syndromes with Isolated Trisomy 8.

Sofía Toribio-Castelló, Sandra Castaño, Ángela Villaverde-Ramiro, Esperanza Such, Montserrat Arnán, Francesc Solé, Marina Díaz-Beyá, María Díez-Campelo, Mónica Del Rey, Teresa González, Jesús María Hernández-Rivas.

  Trisomy 8 (+8) is the most frequent trisomy in myelodysplastic syndromes (MDS) and is associated with clinical heterogeneity and intermediate cytogenetic risk when found in isolation. The presence of gene mutations in this group of patients and the prognostic significance has not been extensively analyzed. Targeted deep sequencing was performed in a cohort of 79 MDS patients showing isolated +8. The most frequently mutated genes were: TET2 (38%), STAG2 (34.2%), SRSF2 (29.1%) and RUNX1 (26.6%). The mutational profile identified a high-risk subgroup with mutations in STAG2, SRSF2 and/or RUNX1, resulting in shorter time to acute myeloid leukemia progression (14 months while not reached in patients without these mutations, p < 0.0001) and shorter overall survival (23.7 vs. 46.3 months, p = 0.001). Multivariate analyses revealed the presence of mutations in these genes as an independent prognostic factor in MDS showing +8 isolated (HR: 3.1; p < 0.01). Moreover, 39.5% and 15.4% of patients classified as low/intermediate risk by the IPSS-R and IPSS-M, respectively, were re-stratified as a high-risk subgroup based on the mutational status of STAG2, SRSF2 and RUNX1. Results were validated in an external cohort (n = 2494). In summary, this study validates the prognosis significance of somatic mutations shown in IPSS-M and adds STAG2 as an important mutated gene to consider in this specific subgroup of patients. The mutational profile in isolated +8 MDS patients could, therefore, offer new insights for the correct management of patients with a higher risk of leukemic transformation.

Keywords:  AML progression; NGS; isolated trisomy 8; myelodysplastic syndromes; prognostic stratification

DOI:  https://doi.org/10.3390/cancers15153822
Int J Cancer. 2023 Aug 11.

The relevance of the hematopoietic niche for therapy resistance in acute myeloid leukemia.

Catana Allert, Carsten Müller-Tidow, Maximilian Felix Blank.

  The expansion of acute myeloid leukemia (AML) blasts not only suppresses normal hematopoiesis, but also alters the microenvironment. The interplay of different components of the bone marrow gives rise to altered metabolic states and activates signaling pathways which lead to resistance and impede effective therapy. Therefore, the underlying processes and mechanisms represent attractive therapeutic leverage points for overcoming therapy resistance in AML. Here, we briefly discuss resistance mechanisms based on cell interactions and secreted soluble factors in the hematopoietic niche and provide an overview of niche-related therapeutic targets currently undergoing preclinical and clinical investigation which may help improve the outcome in AML therapy.

Keywords:  cell adhesion-mediated drug resistance; niche related therapies; soluble factor-mediated drug resistance

DOI:  https://doi.org/10.1002/ijc.34684
Clin Lymphoma Myeloma Leuk. 2023 Jul 11. pii: S2152-2650(23)00212-4. [Epub ahead of print]

Real-World Experience With CPX-351 Treatment for Acute Myeloid Leukemia in England: An Analysis From the National Cancer Registration and Analysis Service.

Alex Legg, Alexandrina Lambova, Anne Broe, Julia Levy, Greg Medalla.

   BACKGROUND: CPX-351 demonstrated improved overall survival (OS) versus conventional 3 + 7 daunorubicin/cytarabine chemotherapy in a registrational phase III study in older patients with newly diagnosed, high-risk secondary acute myeloid leukemia (AML). This retrospective, population-based cohort study aimed to describe and compare the characteristics and survival outcomes of younger (<60 years) versus older (≥60 years) patients with AML treated with CPX-351 in England.
PATIENTS AND METHODS: The study included adults aged ≥18 years diagnosed with AML in England between January 2013 and March 2022, and treated with CPX-351 in routine clinical practice (patients who received CPX-351 in a clinical trial were excluded). Patient records were sourced from the population-level cancer analysis system database available through the National Cancer Registration and Analysis Service.
RESULTS: Of 353 included patients, 104 (29.5%) were <60 years. With a median follow-up of 10.9 months from diagnosis, the estimated median OS was 12.9 months overall, 17.3 months for adults <60 years and 11.7 months for those ≥60 years. All-cause mortality by Day 30 from diagnosis was 6% overall, 4% for adults <60 years and 6% for those ≥60 years. Hematopoietic cell transplantation (HCT) was received by 54% of adults <60 years and 38% of those ≥60 years after CPX-351, with median OS landmarked from the HCT date not yet reached for either age subgroup.
CONCLUSION: This study provides real-world survival outcomes data suggesting that CPX-351 is an effective treatment for both younger (<60 years) and older (≥60 years) adults with AML.

Keywords:  AML; Cancer Analysis System; Chemotherapy; Mortality; Survival

DOI:  https://doi.org/10.1016/j.clml.2023.07.003
JCO Precis Oncol. 2023 Aug;7 e2300070

Associations Between Cancer Predisposition Mutations and Clonal Hematopoiesis in Patients With Solid Tumors.

Sebastià Franch-Expósito, Miika Mehine, Ryan N Ptashkin, Kelly L Bolton, Chaitanya Bandlamudi, Preethi Srinivasan, Linda Zhang, Margaret A Goodell, Erika Gedvilaite, Kamal Menghrajani, Pablo Sánchez-Vela, Diana Mandelker, Elizabeth Comen, Larry Norton, Ryma Benayed, Teng Gao, Elli Papaemmanuil, Barry Taylor, Ross Levine, Kenneth Offit, Zsofia Stadler, Michael F Berger, Ahmet Zehir.

PURPOSE: Clonal hematopoiesis (CH), the expansion of clones in the hematopoietic system, has been linked to different internal and external features such as aging, genetic ancestry, smoking, and oncologic treatment. However, the interplay between mutations in known cancer predisposition genes and CH has not been thoroughly examined in patients with solid tumors.
METHODS: We used prospective tumor-blood paired sequencing data from 46,906 patients who underwent Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) testing to interrogate the associations between CH and rare pathogenic or likely pathogenic (P/LP) germline variants.
RESULTS: We observed an enrichment of CH-positive patients among those carrying P/LP germline mutations and identified a significant association between P/LP germline variants in ATM and CH. Germline and CH comutation patterns in ATM, TP53, and CHEK2 suggested biallelic inactivation as a potential mediator of clonal expansion. Moreover, we observed that CH-PPM1D mutations, similar to somatic tumor-associated PPM1D mutations, were depleted in patients with P/LP germline mutations in the DNA damage response (DDR) genes ATM, CHEK2, and TP53. Patients with solid tumors and harboring P/LP germline mutations, CH mutations, and mosaicism chromosomal alterations might be at an increased risk of developing secondary leukemia while germline variants in TP53 were identified as an independent risk factor (hazard ratio, 36; P < .001) for secondary leukemias.
CONCLUSION: Our results suggest a close relationship between inherited variants and CH mutations within the DDR genes in patients with solid tumors. Associations identified in this study might translate into enhanced clinical surveillance for CH and associated comorbidities in patients with cancer harboring these germline mutations.

DOI: https://doi.org/10.1200/PO.23.00070
Biochem Cell Biol. 2023 Aug 11.

Modulating the immune system as a therapeutic target for myelodysplastic syndromes and acute myeloid leukemia.

Caroline M Putnam, Lahari Kondeti, Meredith B A Kesler, Melinda E Varney.

Modulating the immune system to treat diseases, including myeloid malignancies, has resulted in the development of a multitude of novel therapeutics in recent years. Myelodysplastic syndromes or neoplasms (MDS) and acute myeloid leukemia (AML) are hematologic malignancies that arise from defects in hematopoietic stem and progenitor cells (HSPCs). Dysregulated immune responses, especially in innate immune and inflammatory pathways, are highly associated with the acquisition of HSPC defects in MDS and AML pathogenesis. In addition to utilizing the immune system in immunotherapeutic interventions such as CAR-T cell therapy, vaccines, and immune checkpoint inhibitors, mitigating dysregulation of innate immune and inflammatory responses in MDS and AML remains a priority in slowing the initiation and progression of these myeloid malignancies. This review provides a comprehensive summary of the current progress of diverse strategies to modulate the immune system in the treatment of MDS and AML.

DOI: https://doi.org/10.1139/bcb-2022-0374
J Cell Mol Med. 2023 Aug 07.

Antibody targeting of mutant calreticulin in myeloproliferative neoplasms.

Frederike Kramer, Ann Mullally.

Mutations in calreticulin are one of the key disease-initiating mutations in myeloproliferative neoplasms (MPN). In MPN, mutant calreticulin translates with a novel C-terminus that leads to aberrant binding to the extracellular domain of the thrombopoietin receptor, MPL. This cell surface neoantigen has become an attractive target for immunological intervention. Here, we summarize recent advances in the development of mutant calreticulin targeting antibodies as a novel therapeutic approach in MPN.

DOI: https://doi.org/10.1111/jcmm.17896
Cancer Discov. 2023 Aug 07. pii: CD-23-0007. [Epub ahead of print]

Inhibition of METTL3 results in a cell-intrinsic interferon response that enhances anti-tumour immunity.

Andrew A Guirguis, Yaara Ofir-Rosenfeld, Kathy Knezevic, Wesley Blackaby, David Hardick, Yih-Chih Chan, Ali Motazedian, Andrea Gillespie, Dane Vassiliadis, Enid Yn Lam, Kevin Tran, Byron Andrews, Michael E Harbour, Lina Vasiliauskaite, Claire J Saunders, Georgia Tsagkogeorga, Aleksandra Azevedo, Joanna Obacz, Ewa S Pilka, Marie Carkill, Laura MacPherson, Elanor N Wainwright, Brian Liddicoat, Benjamin J Blyth, Mark R Albertella, Oliver Rausch, Mark A Dawson.

Therapies that enhance anti-tumour immunity have altered the natural history of many cancers. Consequently, leveraging non-overlapping mechanisms to increase immunogenicity of cancer cells remains a priority. Using a novel enzymatic inhibitor of the RNA methyltransferase, METTL3, we demonstrate a global decrease in N6-methyladenosine (m6A) results in double-stranded RNA formation and a profound cell-intrinsic interferon response. Through unbiased CRISPR screens, we establish dsRNA-sensing and interferon signalling are primary mediators that potentiate T-cell killing of cancer cells following METTL3 inhibition. We show in a range of immunocompetent mouse models that whilst METTL3 inhibition is equally efficacious to anti-PD1 therapy, the combination has far greater pre-clinical activity. Using SPLINTR barcoding, we demonstrate that anti-PD1 and METTL3 inhibition target distinct malignant clones and the combination of these therapies overcome clones insensitive to the single agents. These data provide the molecular and pre-clinical rationale for employing METTL3 inhibitors to promote anti-tumour immunity in the clinic.

DOI: https://doi.org/10.1158/2159-8290.CD-23-0007
Biochem Pharmacol. 2023 Aug 08. pii: S0006-2952(23)00329-5. [Epub ahead of print] 115738

BCL2L1 inhibitor A-1331852 inhibits MCL1 transcription and triggers apoptosis in acute myeloid leukemia cells.

Jing-Ting Chiou, Yu-Ying Wu, Yuan-Chin Lee, Long-Sen Chang.

  BH3 mimetics exert anticancer activity by inhibiting anti-apoptotic BCL2 proteins. However, accumulating evidence indicates that the off-target effects of these drugs tightly modulates their anticancer activities. In this study, we investigated whether the BCL2L1 inhibitor A-1331852 induced the death of U937 acute myeloid leukemia (AML) cells through a non-BCL2L1-targeted effect. A-1331852-induced apoptosis in U937 cells was characterized by increased ROS production, downregulation of MCL1, and loss of mitochondrial membrane potential. Ectopic expression of MCL1 alleviated A-1331852-induced mitochondrial depolarization and cytotoxicity in U937 cells. A-1331852-induced ROS production increased p38 MAPK phosphorylation and inhibited MCL1 transcription. Inhibition of p38 MAPK activation restored MCL1 expression in A-1331852-treated cells. A-1331852 triggered p38 MAPK-mediated Cullin 3 downregulation, which in turn increased PP2Acα expression, thereby reducing CREB phosphorylation. A-1331852 reduced the binding of CREB to the MCL1 promoter, leading to the inhibition of CREB-mediated MCL1 transcription. Furthermore, A-1331852 acted synergistically with the BCL2 inhibitor ABT-199 to induce U937 and ABT-199-resistant U937 cell death by inhibiting MCL1 expression. A similar phenomenon caused A-1331852-induced MCL1 downregulation and cytotoxicity in AML HL-60 cells. Collectively, our data suggest that A-1331852 shows an off-target effect of inhibiting MCL1 transcription, ultimately leading to U937 and HL-60 cell death.

Keywords:  A-1331852; Apoptosis; BH3 mimetic; MCL1; Off-target effect

DOI:  https://doi.org/10.1016/j.bcp.2023.115738
Blood Adv. 2023 Aug 08. pii: bloodadvances.2023010151. [Epub ahead of print]

Pacritinib is a potent ACVR1 inhibitor with significant anemia benefit in patients with myelofibrosis.

Stephen T Oh, Ruben A Mesa, Claire N Harrison, Prithviraj Bose, Aaron T Gerds, Vikas Gupta, Bart L Scott, Jean-Jacques Kiladjian, Alessandro Lucchesi, Tim Kong, Sarah A Buckley, Shanthakumar Tyavanagimatt, Bryan G Harder, Karisse Roman-Torres, Jennifer Smith, Adam R Craig, John O Mascarenhas, Srdan Verstovsek.

In patients with cytopenic myelofibrosis, treatment with the JAK2/IRAK1 inhibitor pacritinib was associated with anemia benefit in the phase 3 PERSIST-2 study. The impact of pacritinib on transfusion independence (TI) has not been previously described, nor has the mechanism by which pacritinib improves anemia been elucidated. As it has been previously postulated that inhibition of activin A receptor, type 1 (ACVR1) / activin receptor-like kinase-2 (ALK2) improves anemia in patients with myelofibrosis via suppression of hepcidin production, we assessed the relative inhibitory potency of pacritinib compared to other JAK2 inhibitors against ACVR1. Pacritinib inhibited ACVR1 with greater potency (IC50 = 16.7 nM; Cmax:IC50 = 12.7) than momelotinib (IC50 = 52.5 nM; Cmax:IC50 = 3.2), fedratinib (IC50 = 273 nM; Cmax:IC50 = 1.0), or ruxolitinib (IC50 >1000; Cmax:IC50 <0.01). Pacritinib's inhibitory activity against ACVR1 was corroborated via inhibition of downstream SMAD signaling in conjunction with marked suppression of hepcidin production. Among patients on PERSIST-2 who were not TI at baseline based on Gale criteria, a significantly greater proportion became TI on pacritinib compared to best available therapy (37% vs. 7%, P=0.001), and significantly more had a ≥50% reduction in transfusion burden (49% vs. 9%, P<0.0001). These data indicate that the anemia benefit of the JAK2/IRAK1 inhibitor pacritinib may be a function of potent ACVR1 inhibition.

DOI: https://doi.org/10.1182/bloodadvances.2023010151
Blood Cancer J. 2023 Aug 09. 13(1): 120

Validation of the molecular international prognostic scoring system in patients with myelodysplastic syndromes defined by international consensus classification.

Wan-Hsuan Lee, Ming-Tao Tsai, Cheng-Hong Tsai, Feng-Ming Tien, Min-Yen Lo, Mei-Hsuan Tseng, Yuan-Yeh Kuo, Ming-Chih Liu, Yi-Tsung Yang, Jui-Che Chen, Jih-Luh Tang, Hsun-I Sun, Yi-Kuang Chuang, Liang-In Lin, Wen-Chien Chou, Chien-Chin Lin, Hsin-An Hou, Hwei-Fang Tien.

Myelodysplastic syndromes (MDS) have varied prognoses and require a risk-adapted treatment strategy for treatment optimization. Recently, a molecular prognostic model (Molecular International Prognostic Scoring System [IPSS-M]) that combines clinical parameters, cytogenetic abnormalities, and mutation topography was proposed. This study validated the IPSS-M in 649 patients with primary MDS (based on the 2022 International Consensus Classification [ICC]) and compared its prognostic power to those of the IPSS and revised IPSS (IPSS-R). Overall, 42.5% of the patients were reclassified and 29.3% were up-staged from the IPSS-R. After the reclassification, 16.9% of the patients may receive different treatment strategies. The IPSS-M had greater discriminative potential than the IPSS-R and IPSS. Patients with high, or very high-risk IPSS-M might benefit from allogeneic hematopoietic stem cell transplantation. IPSS-M, age, ferritin level, and the 2022 ICC categorization predicted outcomes independently. After analyzing demographic and genetic features, complementary genetic analyses, including KMT2A-PTD, were suggested for accurate IPSS-M categorization of patients with ASXL1, TET2, STAG2, RUNX1, SF3B1, SRSF2, DNMT3A, U2AF1, and BCOR mutations and those classified as MDS, not otherwise specified with single lineage dysplasia/multi-lineage dysplasia based on the 2022 ICC. This study confirmed that the IPSS-M can better risk-stratified MDS patients for optimized therapeutic decision-making.

DOI: https://doi.org/10.1038/s41408-023-00894-8
Am J Hematol. 2023 Aug 07.

Cox proportional hazards deep neural network identifies peripheral blood complete remission to be at least equivalent to morphologic complete remission in predicting outcomes of patients treated with azacitidine-A prospective cohort study by the AGMT.

Lisa Pleyer, Marc Vaisband, Manuel Drost, Michael Pfeilstöcker, Reinhard Stauder, Sonja Heibl, Heinz Sill, Michael Girschikofsky, Margarete Stampfl-Mattersberger, Angelika Pichler, Bernd Hartmann, Andreas Petzer, Martin Schreder, Clemens A Schmitt, Sonia Vallet, Thomas Melchardt, Armin Zebisch, Petra Pichler, Nadja Zaborsky, Sigrid Machherndl-Spandl, Dominik Wolf, Felix Keil, Jan Hasenauer, Julian Larcher-Senn, Richard Greil.

The current gold standard of response assessment in patients with myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and acute myeloid leukemia (AML) is morphologic complete remission (CR) and CR with incomplete count recovery (CRi), both of which require an invasive BM evaluation. Outside of clinical trials, BM evaluations are only performed in ~50% of patients during follow-up, pinpointing a clinical need for response endpoints that do not necessitate BM assessments. We define and validate a new response type termed "peripheral blood complete remission" (PB-CR) that can be determined from the differential blood count and clinical parameters without necessitating a BM assessment. We compared the predictive value of PB-CR with morphologic CR/CRi in 1441 non-selected, consecutive patients diagnosed with MDS (n = 522; 36.2%), CMML (n = 132; 9.2%), or AML (n = 787; 54.6%), included within the Austrian Myeloid Registry (aMYELOIDr; NCT04438889). Time-to-event analyses were adjusted for 17 covariates remaining in the final Cox proportional hazards (CPH) model. DeepSurv, a CPH neural network model, and permutation-based feature importance were used to validate results. 1441 patients were included. Adjusted median overall survival for patients achieving PB-CR was 22.8 months (95%CI 18.9-26.2) versus 10.4 months (95%CI 9.7-11.2) for those who did not; HR = 0.366 (95%CI 0.303-0.441; p < .0001). Among patients achieving CR, those additionally achieving PB-CR had a median adjusted OS of 32.6 months (95%CI 26.2-49.2) versus 21.7 months (95%CI 16.9-27.7; HR = 0.400 [95%CI 0.190-0.844; p = .0161]) for those who did not. Our deep neural network analysis-based findings from a large, prospective cohort study indicate that BM evaluations solely for the purpose of identifying CR/CRi can be omitted.

DOI: https://doi.org/10.1002/ajh.27046
Cancers (Basel). 2023 Jul 31. pii: 3904. [Epub ahead of print]15(15):

Clinical Characteristics and Outcomes of Patients with Primary and Secondary Myelofibrosis According to the Genomic Classification Using Targeted Next-Generation Sequencing.

Marta Garrote, Mónica López-Guerra, Eduardo Arellano-Rodrigo, María Rozman, Sara Carbonell, Francesca Guijarro, Marta Santaliestra, Ana Triguero, Dolors Colomer, Francisco Cervantes, Alberto Álvarez-Larrán.

  Myelofibrosis (MF) is a heterogeneous disease regarding its mutational landscape, clinical presentation, and outcomes. The aim of our work is to evaluate the genomic classification of MF considering whether it is primary or secondary. One-hundred seventy-five patients, 81 with primary MF (PMF) and 94 with secondary MF (SMF) were hierarchically allocated into eight molecular groups. We found that TP53 disruption/aneuploidy (n = 16, 9%) was more frequent (12% versus 6%) and showed higher allele burden (57% versus 15%, p = 0.01) in SMF than in PMF, and was associated with shorter survival (median 3.5 years). Mutations in chromatin/spliceosome genes (n = 72, 41%) represented the most frequent genomic group in PMF. Homozygous JAK2 mutation (n = 40, 23%) was enriched with old patients with SMF after long-standing polycythemia vera, whereas MF with heterozygous JAK2 mutation (n = 22, 13%) was similarly distributed among PMF and SMF. MF with CALR mutation (n = 19, 11%) predominated in post-essential thrombocythemia MF. The remaining genomic groups were infrequent. TP53 disruption, chromatin/spliceosome mutation, and homozygous JAK2 mutation were associated with significantly shorter survival and higher risk of progression. In conclusion, genomic classification reveals different pathogenic pathways between PMF and SMF and provides relevant information regarding disease phenotype and outcomes.

Keywords:  genomic classification; myelofibrosis; myeloproliferative neoplasms; personalized medicine; prognosis

DOI:  https://doi.org/10.3390/cancers15153904
Ann Hematol. 2023 Aug 08.

Treatment with midostaurin and other FLT3 targeting inhibitors is associated with an increased risk of cardiovascular adverse events in patients who underwent allogeneic hematopoietic stem cell transplantation with FLT3-mutated AML.

Anjali Cremer, Julius C Enssle, Saskia Pfaff, Khouloud Kouidri, Fabian Lang, Christian Brandts, Andreas Zeiher, Sebastian Cremer, Björn Steffen, Hubert Serve, Gesine Bug.

  The addition of midostaurin to standard chemotherapy has improved survival in patients with FLT3-mutated AML. However, the impact of midostaurin and other FLT3 inhibitors (FLT3i) on cardiovascular adverse events (CAEs) has not been studied in patients who underwent allogeneic hematopoietic stem cell transplantation in a real-world setting. We reviewed 132 patients with AML who were treated with intensive induction therapy and consecutive allogeneic stem cell transplantation at our institution (42 FLT3-mutated AML and 90 with FLT3 wildtype). We identified treatment with midostaurin and/or FLT3i as an independent risk factor for CAEs not resulting in higher non-relapse mortality (NRM) or impaired overall survival (OS). Hence, close monitoring for CAEs is warranted for these patients.

Keywords:  Acute myeloid leukemia; Allogeneic stem cell transplantation; Cardiac toxicities; Targeted FLT3 inhibitor therapy

DOI:  https://doi.org/10.1007/s00277-023-05396-y
medRxiv. 2023 Jul 26. pii: 2023.07.22.23292754. [Epub ahead of print]

Leukocytes carrying Clonal Hematopoiesis of Indeterminate Potential (CHIP) Mutations invade Human Atherosclerotic Plaques.

Moritz von Scheidt, Sabine Bauer, Angela Ma, Ke Hao, Thorsten Kessler, Baiba Vilne, Ying Wang, Chani J Hodonsky, Saikat K B Ghosh, Michal Mokry, Hua Gao, Kenji Kawai, Atsushi Sakamoto, Juliane Kaiser, Dario Bongiovanni, Julia Fleig, Lilith Oldenbuettel, Zhifen Chen, Aldo Moggio, Hendrik B Sager, Judith S Hecker, Florian Bassermann, Lars Maegdefessel, Clint L Miller, Wolfgang Koenig, Andreas M Zeiher, Stefanie Dimmeler, Matthias Graw, Christian Braun, Arno Ruusalepp, Nicholas J Leeper, Jason C Kovacic, Johan L M Björkegren, Heribert Schunkert.

Background: Leukocyte progenitors derived from clonal hematopoiesis of undetermined potential (CHIP) are associated with increased cardiovascular events. However, the prevalence and functional relevance of CHIP in coronary artery disease (CAD) are unclear, and cells affected by CHIP have not been detected in human atherosclerotic plaques.
Methods: CHIP mutations in blood and tissues were identified by targeted deep-DNA-sequencing (DNAseq: coverage >3,000) and whole-genome-sequencing (WGS: coverage >35). CHIP-mutated leukocytes were visualized in human atherosclerotic plaques by mutaFISH TM . Functional relevance of CHIP mutations was studied by RNAseq.
Results: DNAseq of whole blood from 540 deceased CAD patients of the Munich cardIovaScular StudIes biObaNk (MISSION) identified 253 (46.9%) CHIP mutation carriers (mean age 78.3 years). DNAseq on myocardium, atherosclerotic coronary and carotid arteries detected identical CHIP mutations in 18 out of 25 mutation carriers in tissue DNA. MutaFISH TM visualized individual macrophages carrying DNMT3A CHIP mutations in human atherosclerotic plaques. Studying monocyte-derived macrophages from Stockholm-Tartu Atherosclerosis Reverse Networks Engineering Task (STARNET; n=941) by WGS revealed CHIP mutations in 14.2% (mean age 67.1 years). RNAseq of these macrophages revealed that expression patterns in CHIP mutation carriers differed substantially from those of non-carriers. Moreover, patterns were different depending on the underlying mutations, e.g. those carrying TET2 mutations predominantly displayed upregulated inflammatory signaling whereas ASXL1 mutations showed stronger effects on metabolic pathways.
Conclusions: Deep-DNA-sequencing reveals a high prevalence of CHIP mutations in whole blood of CAD patients. CHIP-affected leukocytes invade plaques in human coronary arteries. RNAseq data obtained from macrophages of CHIP-affected patients suggest that pro-atherosclerotic signaling differs depending on the underlying mutations. Further studies are necessary to understand whether specific pathways affected by CHIP mutations may be targeted for personalized treatment.

DOI: https://doi.org/10.1101/2023.07.22.23292754
Blood Adv. 2023 Aug 11. pii: bloodadvances.2022009580. [Epub ahead of print]

Late fetal hematopoietic failure results from ZBTB11 deficiency despite abundant HSC specification.

Huimin Cao, Shalin H Naik, Daniela Amann-Zalcenstein, Peter Hickey, Agus Salim, Benjamin Cao, Susan K Nilsson, M Cristina Keightley, Graham J Lieschke.

Hematopoiesis produces all the diverse blood cell lineages to meet basal needs and the sudden demands of injury or infection. Rapid response to such challenges requires expansion of specific lineages then prompt return to balanced steady-state levels, necessitating tightly coordinated regulation. We previously identified a requirement for the Zinc finger and BTB-domain containing 11 (ZBTB11) transcription factor in definitive hematopoiesis from a forward genetic screen for zebrafish myeloid mutants. To understand its relevance to mammalian systems, we extended these studies to mouse. When Zbtb11 was deleted in the hematopoietic compartment, embryos died at embryonic day (E) 18.5 with hematopoietic failure. Zbtb11 hematopoietic knockout (Zbtb11hKO) hematopoietic stem cells (HSCs) were overabundantly specified at E14.5 through E17.5 compared to controls. Overspecification was accompanied by loss of stemness, inability to differentiate into committed progenitors and mature lineages in fetal liver, failure to seed fetal bone marrow and total hematopoietic failure. Zbtb11hKO HSCs did not proliferate in vitro and were constrained in cell cycle progression, demonstrating a cell-intrinsic role for Zbtb11 in proliferation and cell cycle regulation in mammalian HSCs. scRNAseq analysis identified Zbtb11-deficient HSCs were underrepresented in an erythroid-primed subpopulation and showed downregulation of oxidative phosphorylation (OXPHOS) pathways and dysregulation of genes associated with the hematopoietic niche. We have identified a cell-intrinsic requirement for Zbtb11-mediated gene regulatory networks in sustaining a pool of maturation-capable hematopoietic stem and progenitor cells.

DOI: https://doi.org/10.1182/bloodadvances.2022009580
Blood. 2023 Aug 10. pii: blood.2022019586. [Epub ahead of print]

Genotype, Oxidase Status, and Preceding Infection or Autoinflammation Do Not Affect Allogeneic HCT Outcomes for CGD.

Jennifer W Leiding, Danielle E Arnold, Suhag H Parikh, Brent R Logan, Rebecca A Marsh, Linda M Griffith, Ruizhe Wu, Sharon Kidd, Kanwaldeep K Mallhi, Deepak Chellapandian, Stephanie Si Lim, Eyal Grunebaum, Emilia Liana Falcone, Luis Murguia-Favela, Debbi Grossman, Vinod K Prasad, Jennifer R Heimall, Fabien Touzot, Lauri Burroughs, Jack Bleesing, Neena Kapoor, Jasmeen Dara, Olatundun Williams, Malika Kapadia, Benjamin R Oshrine, Jeffrey J Bednarski, Ahmad Rayes, Hey Chong, Geoffrey D E Cuvelier, Lisa R Forbes Satter, Caridad Martinez, Mark T Vander Lugt, Lolie C Yu, Shanmuganathan Chandrakasan, Avni Joshi, Susan E Prockop, Blachy J Dávila Saldaña, Victor Aquino, Larisa Broglie, Christen L Ebens, Lisa M Madden, Kenneth DeSantes, Jordan Milner, Hemalatha G Rangarajan, Ami Shah, Alfred P Gilio, Alan P Knutsen, Holly K Miller, Theodore B Moore, Pamela Graham, Andrea Bauchat, Nancy J Bunin, Pierre Teira, Aleksandra Petrovic, Sharat Chandra, Hisham Abdel-Azim, Morna Dorsey, Olga Birbrayer, Morton J Cowan, Christopher C Dvorak, Elie Haddad, Donald B Kohn, Luigi D Notarangelo, Sung-Yun Pai, Jennifer M Puck, Michael A Pulsipher, Troy R Torgerson, Harry L Malech, Elizabeth M Kang.

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by life-threatening infections and inflammatory conditions. Hematopoietic cell transplantation (HCT) is the definitive treatment for CGD, but questions remain regarding patient selection and impact of active disease on transplant outcomes. We performed a multi-institutional retrospective and prospective study of 391 patients with CGD treated either conventionally (non-HCT;n=151) enrolled from 2004-2018 or who underwent HCT (n=240) from 1996-2018. Median follow-up post-HCT was 3.7 years with a 3-year overall survival of 82% and event-free survival of 69%. In multivariate analysis, Lansky/Karnofsky score <90 and use of HLA-mismatched donors negatively impacted survival. Age, genotype, and oxidase status did not impact outcomes. Pre-HCT, patients had higher infection density, higher frequency of non-infectious lung and liver disease, and more steroid use compared to conventionally-treated patients, yet these issues did not adversely affect HCT survival. Presence of pre-HCT inflammatory conditions was associated with chronic graft versus host disease. Graft failure or receipt of second HCT occurred in 17.6% and was associated with melphalan-based conditioning and/or early mixed chimerism. By 3-5 years post-HCT, patients had improved growth and nutrition, resolved infections and inflammatory disease, and lower rates of anti-microbial prophylaxis or corticosteroid use compared to both their baseline and to conventionally-treated patients. HCT leads to durable resolution of CGD symptoms and lowers burden of disease. Patients with active infection or inflammation are candidates for transplant; HCT should be considered prior to the development of co-morbidities that could impact performance status. Clinical trial # NCT02082353.

DOI: https://doi.org/10.1182/blood.2022019586
Cell Rep. 2023 Aug 09. pii: S2211-1247(23)00978-6. [Epub ahead of print]42(8): 112967

PTEN regulates hematopoietic lineage plasticity via PU.1-dependent chromatin accessibility.

Zihan Xu, Libing He, Yilin Wu, Lu Yang, Cheng Li, Hong Wu.

  PTEN loss in fetal liver hematopoietic stem cells (HSCs) leads to alterations in myeloid, T-, and B-lineage potentials and T-lineage acute lymphoblastic leukemia (T-ALL) development. To explore the mechanism underlying PTEN-regulated hematopoietic lineage choices, we carry out integrated assay for transposase-accessible chromatin using sequencing (ATAC-seq), single-cell RNA-seq, and in vitro culture analyses using in vivo-isolated mouse pre-leukemic HSCs and progenitors. We find that PTEN loss alters chromatin accessibility of key lineage transcription factor (TF) binding sites at the prepro-B stage, corresponding to increased myeloid and T-lineage potentials and reduced B-lineage potential. Importantly, we find that PU.1 is an essential TF downstream of PTEN and that altering PU.1 levels can reprogram the chromatin accessibility landscape and myeloid, T-, and B-lineage potentials in Ptennull prepro-B cells. Our study discovers prepro-B as the key developmental stage underlying PTEN-regulated hematopoietic lineage choices and suggests a critical role of PU.1 in modulating the epigenetic state and lineage plasticity of prepro-B progenitors.

Keywords:  CP: Immunology; CP: Molecular biology; PTEN; PU.1; chromatin accessibility; lineage plasticity

DOI:  https://doi.org/10.1016/j.celrep.2023.112967
Blood. 2023 Aug 10. 142(6): 502-504

Food for thought (and CML survival).

Maiko Sezaki, Gang Huang.

DOI: https://doi.org/10.1182/blood.2023021051
Blood. 2023 Aug 10. pii: blood.2023020081. [Epub ahead of print]

Prognostication and risk stratification of patients with myelodysplastic syndromes.

Amy DeZern, Peter L Greenberg.

Risk stratification and prognostication are crucial for the appropriate management of patients with myelodysplastic syndromes or myelodysplastic neoplasms (MDS), for whom expected survival can vary from a few months to more than 10 years. For the past five decades, patients with MDS have been classified into higher-risk versus lower-risk disease phenotypes using sequentially developed clinical prognostic scoring systems. Factors such as morphologic dysplasia, clinical hematologic parameters, cytogenetics, and more recently, mutational information, have been captured in prognostic scoring systems which refine risk stratification and guide therapeutic management in MDS patients. This review will describe the progressive evolution and improvement of these systems to the current Molecular International Prognostic Scoring System (IPSS-M).

DOI: https://doi.org/10.1182/blood.2023020081
Cell Death Dis. 2023 08 05. 14(8): 503

Heterogeneity in leukemia cells that escape drug-induced senescence-like state.

David Miller, Kyra Kerkhofs, Farnoosh Abbas-Aghababazadeh, Sahib Singh Madahar, Mark D Minden, Josée Hébert, Benjamin Haibe-Kains, Mark A Bayfield, Samuel Benchimol.

Erythropoietin (EPO) suppresses drug-induced apoptosis in EPO-receptor-positive leukemia cells and allows cells to persist after drug treatment by promoting cellular senescence. Importantly a small proportion of senescent cells can re-enter the cell cycle and resume proliferation after drug treatment, resulting in disease recurrence/persistence. Using a single-cell assay to track individual cells that exit a drug-induced senescence-like state, we show that cells exhibit asynchronous exit from a senescent-like state, and display different rates of proliferation. Escaped cells retain sensitivity to drug treatment, but display inter-clonal variability. We also find heterogeneity in gene expression with some of the escaped clones retaining senescence-associated gene expression. Senescent leukemia cells exhibit changes in gene expression that affect metabolism and senescence-associated secretory phenotype (SASP)-related genes. Herein, we generate a senescence gene signature and show that this signature is a prognostic marker of worse overall survival in AML and multiple other cancers. A portion of senescent leukemia cells depend on lysosome activity; chloroquine, an inhibitor of lysosome activity, promotes senolysis of some senescent leukemia cells. Our study indicates that the serious risks associated with the use of erythropoietin-stimulating agents (ESAs) in anemic cancer patients may be attributed to their ability to promote drug-tolerant cancer cells through the senescence program.

DOI: https://doi.org/10.1038/s41419-023-06015-4
J Med Chem. 2023 Aug 11.

Discovery of Small-Molecule TIM-3 Inhibitors for Acute Myeloid Leukemia Using Pharmacophore-Based Virtual Screening.

Somaya A Abdel-Rahman, Valerij Talagayev, Szymon Pach, Gerhard Wolber, Moustafa T Gabr.

T-cell immunoglobulin and mucin domain 3 (TIM-3) is a negative immune checkpoint that represents a promising target for cancer immunotherapy. Although encouraging results have been observed for TIM-3 inhibition in the context of acute myeloid leukemia (AML), targeting TIM-3 is currently restricted to monoclonal antibodies (mAbs). To fill this gap, we implemented a pharmacophore-based screening approach to identify small-molecule TIM-3 inhibitors. Our approach resulted in the identification of hit compounds with TIM-3 binding affinity. Subsequently, we used the structure-activity relationship (SAR) by a catalog approach to identify compound A-41 with submicromolar TIM-3 binding affinity. Remarkably, A-41 demonstrated the ability to block TIM-3 interactions with key ligands and inhibited the immunosuppressive function of TIM-3 using an in vitro coculture assay. This work will pave the way for future drug discovery efforts aiming at the development of small-molecule inhibitors TIM-3 for AML.

DOI: https://doi.org/10.1021/acs.jmedchem.3c00960
Cell. 2023 Aug 02. pii: S0092-8674(23)00783-3. [Epub ahead of print]

A membrane-associated MHC-I inhibitory axis for cancer immune evasion.

Xufeng Chen, Qiao Lu, Hua Zhou, Jia Liu, Bettina Nadorp, Audrey Lasry, Zhengxi Sun, Baoling Lai, Gergely Rona, Jiangyan Zhang, Michael Cammer, Kun Wang, Wafa Al-Santli, Zoe Ciantra, Qianjin Guo, Jia You, Debrup Sengupta, Ahmad Boukhris, Hongbing Zhang, Cheng Liu, Peter Cresswell, Patricia L M Dahia, Michele Pagano, Iannis Aifantis, Jun Wang.

  Immune-checkpoint blockade has revolutionized cancer treatment, but some cancers, such as acute myeloid leukemia (AML), do not respond or develop resistance. A potential mode of resistance is immune evasion of T cell immunity involving aberrant major histocompatibility complex class I (MHC-I) antigen presentation (AP). To map such mechanisms of resistance, we identified key MHC-I regulators using specific peptide-MHC-I-guided CRISPR-Cas9 screens in AML. The top-ranked negative regulators were surface protein sushi domain containing 6 (SUSD6), transmembrane protein 127 (TMEM127), and the E3 ubiquitin ligase WWP2. SUSD6 is abundantly expressed in AML and multiple solid cancers, and its ablation enhanced MHC-I AP and reduced tumor growth in a CD8+ T cell-dependent manner. Mechanistically, SUSD6 forms a trimolecular complex with TMEM127 and MHC-I, which recruits WWP2 for MHC-I ubiquitination and lysosomal degradation. Together with the SUSD6/TMEM127/WWP2 gene signature, which negatively correlates with cancer survival, our findings define a membrane-associated MHC-I inhibitory axis as a potential therapeutic target for both leukemia and solid cancers.

Keywords:  MHC-I; SUSD6; T cell; TMEM127; WWP2; antigen presentation; cancer; immune evasion; lysosomal degradation; ubiquitination

DOI:  https://doi.org/10.1016/j.cell.2023.07.016
Nat Commun. 2023 08 09. 14(1): 4816

A HIF independent oxygen-sensitive pathway for controlling cholesterol synthesis.

Anna S Dickson, Tekle Pauzaite, Esther Arnaiz, Brian M Ortmann, James A West, Norbert Volkmar, Anthony W Martinelli, Zhaoqi Li, Niek Wit, Dennis Vitkup, Arthur Kaser, Paul J Lehner, James A Nathan.

Cholesterol biosynthesis is a highly regulated, oxygen-dependent pathway, vital for cell membrane integrity and growth. In fungi, the dependency on oxygen for sterol production has resulted in a shared transcriptional response, resembling prolyl hydroxylation of Hypoxia Inducible Factors (HIFs) in metazoans. Whether an analogous metazoan pathway exists is unknown. Here, we identify Sterol Regulatory Element Binding Protein 2 (SREBP2), the key transcription factor driving sterol production in mammals, as an oxygen-sensitive regulator of cholesterol synthesis. SREBP2 degradation in hypoxia overrides the normal sterol-sensing response, and is HIF independent. We identify MARCHF6, through its NADPH-mediated activation in hypoxia, as the main ubiquitin ligase controlling SREBP2 stability. Hypoxia-mediated degradation of SREBP2 protects cells from statin-induced cell death by forcing cells to rely on exogenous cholesterol uptake, explaining why many solid organ tumours become auxotrophic for cholesterol. Our findings therefore uncover an oxygen-sensitive pathway for governing cholesterol synthesis through regulated SREBP2-dependent protein degradation.

DOI: https://doi.org/10.1038/s41467-023-40541-1
BMC Genom Data. 2023 Aug 07. 24(1): 40

Transcriptomic comparison of bone marrow CD34 + cells and peripheral blood neutrophils from ET patients with JAK2 or CALR mutations.

Ana Guijarro-Hernández, José Luis Vizmanos.

   BACKGROUND: Essential thrombocythemia (ET) is one of the most common types of Ph-negative myeloproliferative neoplasms, an infrequent group of blood cancers that arise from a CD34 + hematopoietic stem cell (HSC) in the bone marrow (BM) primarily due to driver mutations in JAK2, CALR or MPL. These aberrations result in an overproduction of mature myeloid cells in peripheral blood (PB). To date, no targeted therapies have been approved for ET patients, so the study of the molecular mechanisms behind the disease and the identification of new therapeutic targets may be of interest. For this reason, in this study, we have compared the transcriptomic profile of undifferentiated CD34 + cells and mature myeloid cells from ET patients (CALR and JAK2-mutated) and healthy donors deposited in publicly available databases. The study of the similarities and differences between these samples might help to better understand the molecular mechanisms behind the disease according to the degree of maturation of the malignant clone and the type of mutation and ultimately help identify new therapeutic targets for these patients.
RESULTS: The results show that most of the altered hallmarks in neutrophils were also found in CD34 + cells. However, only a few genes showed a similar aberrant expression pattern in both types of cells. We have identified a signature of six genes common to patients with CALR and JAK2 mutations (BPI, CRISP3, LTF, MMP8, and PTGS1 upregulated, and PBXIP1 downregulated), a different signature of seven genes for patients with CALR mutations (BMP6, CEACAM8, ITK, LCN2, and PRG2 upregulated, and MAN1A1 and MME downregulated) and a signature of 13 genes for patients with JAK2 mutations (ARG1, CAST, CD177, CLEC5A, DAPP1, EPS15, IL18RAP, OLFM4, OLR1, RIOK3, SELP, and THBS1 upregulated, and IGHM downregulated).
CONCLUSIONS: Our results highlight transcriptomic similarities and differences in ET patients according to the degree of maturation of the malignant clone and the type of mutation. The genes and processes altered in both CD34 + cells and mature neutrophils may reveal altered sustained processes that could be studied as future therapeutic targets for ET patients.

Keywords:  Bone marrow; CALR; Essential thrombocythemia; JAK2; Myeloproliferative neoplasms; Peripheral blood

DOI:  https://doi.org/10.1186/s12863-023-01142-5
Cancer Med. 2023 Aug 07.

Clinical outcome of therapy-related acute myeloid leukemia patients. Real-life experience in a University Hospital and a Cancer Center in France.

Amine Belhabri, Mael Heiblig, Stephane Morisset, Liliana Vila, Clémence Santana, Emmanuelle Nicolas-Virelizier, Sandrine Hayette, Isabelle Tigaud, Adriana Plesa, Hélène Labussiere-Wallet, Mohamad Sobh, Anne-Sophie Michallet, Balsat Marie, Franck-Emmanuel Nicolini, Yann Guillermin, Fossard Gaëlle, Laure Lebras, Philippe Rey, Lucie Jauffret-Bertholon, Marie-Charlotte Laude, Loron Sandrine, Mauricette Michallet.

   BACKGROUND: t-AML occurs after a primary malignancy treatment and retains a poor prognosis.
AIMS: To determine the impact of primary malignancies, therapeutic strategies, and prognostic factors on clinical outcomes of t-AML.
RESULTS: A total of 112 adult patients were included in this study. Fifty-Five patients received intensive chemotherapy (IC), 33 non-IC, and 24 best supportive care. At t-AML diagnosis, 42% and 44% of patients presented an unfavorable karyotype and unfavorable 2010 ELN risk profile, respectively. Among treated patients (n = 88), 43 (49%) achieved complete remission: four out of 33 (12%) and 39 out of 55 (71%) in non-IC and IC groups, respectively. With a median follow-up of 5.5 months, the median overall survival (OS) and disease-free survival (DFS) for the whole population were 9 months and 6.3 months, respectively, and for the 88 treated patients 13.5 months and 8.2 months, respectively. Univariate analysis on OS and DFS showed a significant impact of high white blood cells (WBC) and blast counts at diagnosis, unfavorable karyotype and ELN classification. Multivariate analysis showed a negative impact of WBC count at diagnosis and a positive impact of chemotherapy on OS and DFS in the whole population. It also showed a negative impact of previous auto-HCT and high WBC count on OS and DFS and of IC on OS in treated patients which disappeared when we considered only confounding variables (age, previous cancers, marrow blasts, and 2010 ELN classification). In a pair-matched analysis comparing IC treated t-AML with de novo AML, there was no difference of OS and DFS between the two populations.
CONCLUSION: We showed, in this study that t-AML patients with unfavorable features represented almost half of the population. Best outcomes obtained in patients receiving IC must be balanced by known confounding variables and should be improved by using new innovative agents and therapeutic strategies.

Keywords:  clinical outcome; real-life management; therapy-related AML

DOI:  https://doi.org/10.1002/cam4.6322