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Hematopoietic stem cells (HSC) must balance self-renewal and differentiation to provide sufficient primitive cells to sustain hematopoiesis, while generating more mature cells with specialized capabilities. The enhanced self-renewal capacity of primitive HSCs enables their ability to sustain hematopoiesis throughout decades of life and their ability to repopulate a host when used therapeutically in bone marrow transplantation. However, hematopoietic cell perturbations resulting in unchecked self-renewal participate in leukemogenesis. While mechanisms governing self-renewal are still being uncovered, they are thought to bear relationship to the malignant process in a variety of tumor types and may therefore provide useful therapeutic targets in putative cancer stem cells. This review discusses molecular mechanisms recently defined to participate in HSC governance and highlights features of stem cell interactions with the microenvironment that may help guide therapies directed at HSCs.Leukemia (2004) 18, 1760-1768. doi:10.1038/sj.leu.2403515 Published online 30 September 2004 [ABSTRACT FROM AUTHOR]

Background: TP53-mutated acute myeloid leukaemia is associated with poor outcomes. Eprenetapopt (APR-246) is a first-in-class, small-molecule p53 reactivator. We aimed to evaluate the combination of eprenetapopt and venetoclax with or without azacitidine in patients with TP53-mutated acute myeloid leukaemia., Methods: This phase 1, multicentre, open-label, dose-finding and cohort expansion study was done at eight academic research hospitals in the USA. Inclusion criteria were age of at least 18 years; at least one pathogenic TP53 mutation; treatment-naive acute myeloid leukaemia according to the 2016 WHO classification; an ECOG performance status of 0-2; and a life expectancy of at least 12 weeks. In dose-finding cohort 1 patients received previous therapy with hypomethylating agents for myelodysplastic syndromes. In dose-finding cohort 2, previous use of hypomethylating agents was not permitted. Treatment cycles were 28 days. Patients in cohort 1 received intravenous eprenetapopt 4·5 g/day on days 1-4 and oral venetoclax 400 mg/day on days 1-28; those in cohort 2 also received subcutaneous or intravenous azacitidine 75 mg/m 2 on days 1-7. The expansion part of the study proceeded with patients enrolled as in cohort 2. Primary endpoints were safety in all cohorts (assessed in patients receiving at least one dose of assigned treatment) and complete response in the expansion cohort (assessed in patients who completed at least one treatment cycle and had at least one post-treatment clinical response assessment). The trial is registered with ClinicalTrials.gov, NCT04214860, and is complete., Findings: Between Jan 3, 2020, and July 22, 2021, 49 patients were enrolled across all cohorts. Six patients were initially enrolled into each of dose-finding cohorts 1 and 2; after no dose-limiting toxicities were observed, cohort 2 was expanded to enrol an additional 37 patients. The median age was 67 years (IQR 59-73). 24 (49%) of 49 patients were female and 25 (51%) male, and 40 (82%) were White. At data cutoff (Oct 1, 2021), the median length of follow-up was 9·5 months (IQR 6·1-11·5). No dose-limiting toxicities were recorded and the recommended phase 2 dose for eprenetapopt combinations was 4·5 g/day on days 1-4. Across all patients, adverse events of grade 3 or worse occurring in at least 20% of patients were febrile neutropenia (23 [47%] of 49 patients), thrombocytopenia (18 [37%] patients), leukopenia (12 [25%] patients), and anaemia (11 [22%] patients). Treatment-related serious adverse events occurred in 13 (27%) of 49 patients and there was one (2%) treatment-related death (sepsis). 25 (64%, 95% CI 47-79) of 39 patients had an overall response with eprenetapopt and venetoclax with azacytidine; 15 (38%, 23-55) had a complete response., Interpretation: Eprenetapopt and venetoclax with azacitidine had an acceptable safety profile and encouraging activity, supporting further frontline evaluation of this combination in the treatment of TP53-mutated acute myeloid leukaemia., Funding: Aprea Therapeutics., Competing Interests: Declaration of interests GG-M reports research funding from Aprea Therapeutics. ADG reports research funding from Aprea Therapeutics; consulting fees from AbbVie, Aptose Biosciences, Astellas Pharma, Daiichi Sankyo, and Genentech; honoraria from AbbVie and Dava Oncology; and advisory board membership for AbbVie. ESW reports consulting fees from Pfizer, Jazz Pharmaceuticals, and Takeda. JKA reports research funding from Astellas Pharma and OPEN Health Group. ATF reports grants from Agios Pharmaceuticals/Servier, Celgene/Bristol-Myers Squibb (BMS), and AbbVie; and consulting fees from Pfizer, Trillium Health Partners, AbbVie, Kura Oncology, Blueprint Medicines, Genentech, Novartis, Trovagene, Agios Pharmaceuticals/Servier, Celgene/BMS, MorphoSys, Kite Pharma, Foghorn Therapeutics, Takeda, Amgen, Seattle Genetics, NewLink Genetics, Forty Seven, Ipsen, ImmunoGen, Mablytics, PureTech Health, Forma Therapeutics, Daiichi Sankyo, EnClear Therapies, and Astellas Pharma. OO reports research funding from Aprea Therapeutics; grants from AbbVie, Agios Pharmaceuticals, Astex, AstraZeneca, BMS, Celgene, CTI BioPharma, Daiichi Sankyo, Incyte, Janssen Pharmaceuticals, Kartos Therapeutics, Loxo Oncology, Novartis, NS Pharma, and Oncotherapy Sciences; advisory board membership for BMS, Celgene, Novartis, Taiho Pharmaceutical, and Kymera Therapeutics; membership of a data safety monitoring board for Threadwell Therapeutics; and leadership as Vice Chair of the medical advisory board of the Aplastic Anemia and MDS International Foundation. Kxs consulting fees from Astellas Pharma, BMS, Gilead Sciences, and Novartis and advisory board membership for BerGenBio, Curis, and Mablytics. GJR reports research funding from Aprea Therapeutics; grants from Janssen Pharmaceuticals; and consulting fees from Actinium Pharmaceuticals, Agios Pharmaceuticals, Amgen, Astellas Pharma, AstraZeneca, BMS, Blueprint Medicines, bluebird bio, Catamaran Bio, Celgene, Daiichi Sankyo, GlaxoSmithKline, Helsinn, Janssen Pharmaceuticals, Jasper Therapeutics, Jazz Pharmaceuticals, Mesoblast, Novartis, Pfizer, Roche, Syndax Pharmaceuticals, Takeda, and Trovagene. JL reports consulting fees from AbbVie, Agios Pharmaceuticals, Astellas Pharma, BerGenBio, Boxer Capital, Celgene, Daiichi Sankyo, The Dedham Group, ElevateBio, Jasper Therapeutics, Jazz Pharmaceuticals, Millenium Pharmaceuticals, Novartis, and Servier. DKH, AW, and ECA report employment with Aprea Therapeutics. HK reports grants from AbbVie, Amgen, Ascentage Pharma, BMS, Daiichi Sankyo, ImmunoGen, Jazz Pharmaceuticals, and Novartis and honoraria from AbbVie, Amgen, Amphista Therapeutics, Ascentage Pharma, Astellas Pharma, Biologix Pharma, Curis, Ipsen Biopharmaceuticals, KAHR Medical, Labcorp, Novartis, Pfizer, Shenzhen TargetRx, Stemline Therapeutics, and Takeda. DAS reports research funding from Aprea Therapeutics and Jazz Pharmaceuticals; consulting fees from AbbVie, Takeda, Zentalis Pharmaceuticals, and Molecular Partners; speakers bureaus from BMS and Incyte; and advisory board membership for AvenCell, Jasper Therapeutics, bluebird bio, BMS, Shattuck Labs, Intellia Therapeutics, Novartis, Gilead Sciences, Janssen Pharmaceuticals, Curis, Syndax Pharmaceuticals, Agios Pharmaceuticals, and Servier. All other authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Outcomes are poor in TP53 -mutant (m TP53 ) acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), even after allogeneic hematopoietic stem-cell transplant (HCT). Eprenetapopt (APR-246) is a first-in-class, small-molecule p53 reactivator., Patients and Methods: We conducted a phase II, multicenter, open-label trial to assess efficacy and safety of eprenetapopt combined with azacitidine as maintenance therapy after HCT (ClinicalTrials.gov identifier: NCT03931291). Patients with m TP53 MDS or AML received up to 12 cycles of eprenetapopt 3.7 g once daily intravenously on days 1-4 and azacitidine 36 mg/m 2 once daily intravenously/subcutaneously on days 1-5 in 28-day cycles. The primary outcomes were relapse-free survival (RFS) and safety., Results: Of the 84 patients screened for eligibility before HCT, 55 received a transplant. Thirty-three patients ultimately received maintenance treatment (14 AML and 19 MDS); the median age was 65 (range, 40-74) years. The median number of eprenetapopt cycles was 7 (range, 1-12). With a median follow-up of 14.5 months, the median RFS was 12.5 months (95% CI, 9.6 to not estimable) and the 1-year RFS probability was 59.9% (95% CI, 41 to 74). With a median follow-up of 17.0 months, the median overall survival (OS) was 20.6 months (95% CI, 14.2 to not estimable) and the 1-year OS probability was 78.8% (95% CI, 60.6 to 89.3). Thirty-day and 60-day mortalities from the first dose were 0% and 6% (n = 2), respectively. Acute and chronic (all grade) graft-versus-host disease adverse events were reported in 12% (n = 4) and 33% (n = 11) of patients, respectively., Conclusion: In patients with m TP53 AML and MDS, post-HCT maintenance therapy with eprenetapopt combined with azacitidine was well tolerated. RFS and OS outcomes were encouraging in this high-risk population.

Background: We conducted a phase I, multicenter, open-label, dose-finding, and expansion study to determine the safety and preliminary efficacy of eprenetapopt (APR-246) combined with pembrolizumab in patients with advanced/metastatic solid tumors (ClinicalTrials.gov NCT04383938)., Patients and Methods: For dose-finding, requirements were non-central nervous system primary solid tumor, intolerant to/progressed after ≥1 line of treatment, and eligible for pembrolizumab; for expansion: (i) gastric/gastroesophageal junction tumor, intolerant to/progressed after first-line treatment, and no prior anti-programmed cell death receptor-1 (PD-1)/programmed death-ligand 1 (PD-L1) therapy; (ii) bladder/urothelial tumor, intolerant to/progressed after first-line cisplatin-based chemotherapy, and no prior anti-PD-1/PD-L1 therapy; (iii) non-small-cell lung cancer (NSCLC) with previous anti-PD-1/PD-L1 therapy. Patients received eprenetapopt 4.5 g/day intravenously (IV) on days 1-4 with pembrolizumab 200 mg IV on day 3 in each 21-day cycle. Primary endpoints were dose-limiting toxicity (DLT), adverse events (AEs), and recommended phase II dose (RP2D) of eprenetapopt., Results: Forty patients were enrolled (median age 66 years; range 27-85) and 37 received eprenetapopt plus pembrolizumab. No DLTs were reported and the RP2D for eprenetapopt in combination was 4.5 g/day IV on days 1-4. The most common eprenetapopt-related AEs were dizziness (35.1%), nausea (32.4%), and vomiting (29.7%). AEs leading to eprenetapopt discontinuation occurred in 2/37 patients (5.4%). In efficacy-assessable patients (n = 29), one achieved complete response (urothelial cancer), two achieved partial responses (NSCLC, urothelial cancer), and six patients had stable disease., Conclusions: The eprenetapopt plus pembrolizumab combination was well tolerated with an acceptable safety profile and showed clinical activity in patients with solid tumors., Competing Interests: Disclosure HP reports research funding from Ambrx, Aprea Therapeutics, Array BioPharma, BJ Bioscience, Bristol Myers Squibb, Daiichi Pharmaceutical, Eli Lilly, Elicio Therapeutics, EMD-Serono, Genentech, GlaxoSmithKline, Gossamer Bio, Hoffman-LaRoche, Hutchison MediPharma, ImmuneOncia Therapeutics, Incyte, Jounce Therapeutics, Mabspace Biosciences, MacroGenics, Merck, Mirati, Novartis, Oncologie, PsiOxus Therapeutics, Puma Biotechnology, Regeneron Pharmaceuticals, Seattle Genetics, Synermore Biologics, TopAlliance Biosciences, Turning Point Therapeutics, Vedanta Biosciences, and Xencor Inc. GIS reports research funding from Eli Lilly, Merck KGaA/EMD-Serono, Merck, and Sierra Oncology, and has served on advisory boards for Pfizer, Eli Lilly, G1 Therapeutics, Merck KGaA/EMD-Serono, Sierra Oncology, Bicycle Therapeutics, Fusion Pharmaceuticals, Cybrexa Therapeutics, Astex, Ipsen, Bayer, Angiex, Daiichi Sankyo, Seattle Genetics, Boehringer Ingelheim, ImmunoMet, Asana, Artios, Atrin, Concarlo Holdings, Syros, Zentalis, CytomX Therapeutics, Blueprint Medicines, Kymera Therapeutics, Janssen and Xinthera, and holds a patent entitled, ‘Dosage regimen for sapacitabine and seliciclib’, also issued to Cyclacel Pharmaceuticals, and a pending patent, entitled, ‘Compositions and Methods for Predicting Response and Resistance to CDK4/6 Inhibition’, together with Liam Cornell. XG reports consulting or advisory roles for Exelix, Bayer, Guardant Health, and Flare Therapeutics, and research funding (to institution) from Arvinas, Exelixis, Pfizer, Harpoon therapeutics, Aprea Therapeutics, Takeda, Aravive, Merck, Poseida therapeutics, TopAlliance BioSciences Inc., Janssen, Novartis, and Silverback Therapeutics. AM reports participation on an advisory board for QED Therapeutics and Taiho Oncology. JS reports research funding from Aprea Therapeutics, Macrogenics, Rafael Therapeutics, Xencor, Cardiff Oncology, Merus Therapeutics, Daiichi-Sanyko, and Amgen, and consulting for Advanced Accelerated Applications, Ipsen, Pfizer, Taiho, Tersera, Natera, and Cancer Expert Now. MF reports participation on an advisory board for Mirati, AstraZeneca, Pfizer, and Beigene. PS reports participation on an advisory board for Janssen, EMD Soreno, Aveo, and Seattle Genetics. LG reports participation in scientific advisory boards for Xilio, Surface Oncology, Mersana, Beigene, Bristol Myers Squibb, Eisai, and Tentarix; consultancy for Tempus, TwentyEight-Seven Therapeutics, and Pliant Therapeutics; and is a member of the Board of Directors for Bright Peak Therapeutics. AG reports research support (drugs) from Aprea Therapeutics and consultancy for Adivo Associates. DH, PDG, AW, ECA, and MMA report current employment and equity holder (publicly traded company) with Aprea Therapeutics. SD reports receiving honoraria for consultancy for AAA/Novartis, Ipsen, and TerSera Therapeutics. EED reports grants from Bayer Pharmaceuticals, Immunocore, Amgen, NCI, Aileron Therapeutics, Compugen, TRACON Pharmaceuticals, Unum Therapeutics, Immunomedics, Bolt Biotherapeutics, Aprea Therapeutics, Bellicum Pharmaceuticals, PMV Pharma, Triumvira, Seagen, Mereo BioPharma, and Sanofi, Astex Therapeutics during the conduct of the study, and personal fees and other from Bolt Biotherapeutics and Catamaran Bio outside the submitted work. AA has declared no conflicts of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: Approximately 20% of patients with TP53 -mutant myelodysplastic syndromes (MDS) achieve complete remission (CR) with hypomethylating agents. Eprenetapopt (APR-246) is a novel, first-in-class, small molecule that restores wild-type p53 functions in TP53 -mutant cells., Methods: This was a phase Ib/II study to determine the safety, recommended phase II dose, and efficacy of eprenetapopt administered in combination with azacitidine in patients with TP53 -mutant MDS or acute myeloid leukemia (AML) with 20%-30% marrow blasts (ClinicalTrials.gov identifier: NCT03072043)., Results: Fifty-five patients (40 MDS, 11 AML, and four MDS/myeloproliferative neoplasms) with at least one TP53 mutation were treated. The overall response rate was 71% with 44% achieving CR. Of patients with MDS, 73% (n = 29) responded with 50% (n = 20) achieving CR and 58% (23/40) a cytogenetic response. The overall response rate and CR rate for patients with AML was 64% (n = 7) and 36% (n = 4), respectively. Patients with only TP53 mutations by next-generation sequencing had higher rates of CR (69% v 25%; P = .006). Responding patients had significant reductions in TP53 variant allele frequency and p53 expression by immunohistochemistry, with 21 (38%) achieving complete molecular remission (variant allele frequency < 5%). Median overall survival was 10.8 months with significant improvement in responding versus nonresponding patients by landmark analysis (14.6 v 7.5 months; P = .0005). Overall, 19/55 (35%) patients underwent allogeneic hematopoietic stem-cell transplant, with a median overall survival of 14.7 months. Adverse events were similar to those reported for azacitidine or eprenetapopt monotherapy, with the most common grade ≥ 3 adverse events being febrile neutropenia (33%), leukopenia (29%), and neutropenia (29%)., Conclusion: Combination treatment with eprenetapopt and azacitidine is well-tolerated yielding high rates of clinical response and molecular remissions in patients with TP53 -mutant MDS and oligoblastic AML., Competing Interests: David A. SallmanConsulting or Advisory Role: Celyad, Agios, Abbvie, Aprea AB, Bristol-Myers Squibb, Gilead Sciences, Intellia Therapeutics, Kite Pharma, Magenta Therapeutics, Novartis, SyndaxSpeakers' Bureau: Agios, Incyte, Bristol-Myers SquibbResearch Funding: Celgene, Jazz PharmaceuticalsPatents, Royalties, Other Intellectual Property: Intellectual Property Patent for LB-100 in MDS Amy E. DeZernConsulting or Advisory Role: Celgene, Novartis, Gilead SciencesResearch Funding: Celgene, Astex PharmaceuticalsTravel, Accommodations, Expenses: Abbvie Guillermo Garcia-ManeroHonoraria: Celgene, Astex Pharmaceuticals, Acceleron Pharma, Helssin, AbbvieConsulting or Advisory Role: Celgene, Astex Pharmaceuticals, Acceleron Pharma, Jazz Pharmaceuticals, Bristol-Myers Squibb, Helsinn TherapeuticsResearch Funding: Celgene, Astex Pharmaceuticals, Amphivena, Helsinn Therapeutics, Novartis, Abbvie, Bristol-Myers Squibb, Onconova Therapeutics, H3 Biomedicine, Merck David P. SteensmaStock and Other Ownership Interests: Arrowhead Pharmaceuticals, Sage TherapeuticsHonoraria: Daiichi Sankyo, Summer Road, Stemline Therapeutics, Celgene, Astex PharmaceuticalsConsulting or Advisory Role: Pfizer, Janssen Oncology, Agios, Onconova Therapeutics, Geron, Astex PharmaceuticalsResearch Funding: Aprea AB, Celgene/BMS, H3 Biomedicine Gail J. RobozConsulting or Advisory Role: Amphivena, Janssen, Amgen, Astex Pharmaceuticals, Celgene, Genoptix, MedImmune, Novartis, Pfizer, Abbvie, Argenx, Array BioPharma, Bayer, Celltrion, Jazz Pharmaceuticals, Orsenix, Genentech/Roche, Sandoz, Actinium Pharmaceuticals, Astellas Pharma, Eisai, Bayer, Daiichi Sankyo, MEI Pharma, Otsuka, Takeda, Roche, Agios, Trovagene, GlaxoSmithKline, Bristol-Myers Squibb, Helsinn Therapeutics, MesoblastResearch Funding: Abbvie, Agios, Astex Pharmaceuticals, Celgene, CTI, Karyopharm Therapeutics, MedImmune, MEI Pharma, Moffitt, Novartis, Onconova Therapeutics, Pfizer, Sunesis Pharmaceuticals, Tensha Therapeutics, Cellectis, Janssen, AmphivenaTravel, Accommodations, Expenses: Amphivena, Astex Pharmaceuticals, Janssen, Pfizer, Array BioPharma, Novartis, Abbvie, Jazz Pharmaceuticals, Celgene, Celltrion, Roche/Genentech, Sandoz, Bayer, Clovis Oncology, Amgen, Sunesis Pharmaceuticals, Eisai, Agios Mikkael A. SekeresConsulting or Advisory Role: Celgene, Millennium, Syros PharmaceuticalsResearch Funding: Takeda, Pfizer, Bristol-Myers Squibb Thomas CluzeauConsulting or Advisory Role: Abbvie, Agios, Bristol-Myers Squibb, Jazz Pharmaceuticals, Novartis, Roche, Takeda, Syros PharmaceuticalsSpeakers' Bureau: Novartis, Amgen, Sanofi, Astellas PharmaTravel, Accommodations, Expenses: Bristol-Myers Squibb, Novartis, Pfizer, Sanofi Kendra L. SweetLeadership: ImmtechConsulting or Advisory Role: Astellas Pharma, Bristol-Myers Squibb, Novartis, Takeda, Stemline TherapeuticsResearch Funding: Incyte Kathy L. McGrawResearch Funding: Genentech, Celgene Eric PadronHonoraria: Stemline Therapeutics, Blueprint MedicinesSpeakers' Bureau: Novartis, Taiho PharmaceuticalResearch Funding: Incyte, Bristol-Myers Squibb, Kura Oncology Greg KorbelEmployment: Aprea Therapeutics, IncLeadership: Aprea Therapeutics, IncStock and Other Ownership Interests: Aprea Therapeutics, Inc Eyal C. AttarEmployment: Agios, Aprea ABLeadership: Aprea ABStock and Other Ownership Interests: Agios, Aprea ABConsulting or Advisory Role: TeladocTravel, Accommodations, Expenses: Aprea AB, Agios Hagop M. KantarjianHonoraria: Abbvie, Amgen, ARIAD, Bristol-Myers Squibb, Immunogen, Orsenix, Pfizer, Agios, Takeda, Actinium PharmaceuticalsResearch Funding: Pfizer, Amgen, Bristol-Myers Squibb, Novartis, ARIAD, Astex Pharmaceuticals, Abbvie, Agios, Cyclacel, Immunogen, Jazz Pharmaceuticals Jeffrey E. LancetStock and Other Ownership Interests: ArvinasConsulting or Advisory Role: Jazz Pharmaceuticals, Astellas Pharma, Abbvie, Agios, BerGenBio, Daiichi Sankyo, ElevateBioResearch Funding: Pfizer Pierre FenauxHonoraria: CelgeneResearch Funding: Celgene Alan F. ListHonoraria: Celgene, Aileron Therapeutics, Cellular Biomedicine GroupConsulting or Advisory Role: Celgene, Cellular Biomedicine Group, Aileron Therapeutics, Acceleron Pharma, International Personalized Cancer Center, Precision Biosciences, CTI BioPharma Corp, Prelude TherapeuticsResearch Funding: CelgeneTravel, Accommodations, Expenses: Celgene, Cellular Biomedicine GroupOther Relationship: Thousand Talents Award Rami S. KomrokjiStock and Other Ownership Interests: AbbvieConsulting or Advisory Role: Novartis, Incyte, Bristol-Myers Squibb, Jazz Pharmaceuticals, Abbvie, Geron, Acceleron PharmaSpeakers' Bureau: Jazz Pharmaceuticals, Bristol-Myers Squibb, AgiosTravel, Accommodations, Expenses: Incyte, Jazz Pharmaceuticals, Bristol-Myers Squibb, AgiosNo other potential conflicts of interest were reported.

Isocitrate dehydrogenase 1 ( IDH1 ) and 2 ( IDH2 ) mutations in Myeloid Neoplams (MNs) exhibit DNA hypermethylation via 2-hydroxyglutarate (2HG) over-production. Clinical impact of azacitidine (AZA) remains inconsistent in IDH1/2 -mutated MNs and the potential of serum 2HG as a suitable marker of response to AZA is unknown. To address these questions, we retrospectively analyzed 93 MNs patients (78 AML, 11 MDS, 4 CMML) with IDH1 / 2 mutations treated with AZA. After a median of 5 cycles of AZA, overall response rate was 28% (including 15% complete remission) and median OS was 12.3 months (significantly shorter in AML compared to MDS/CMML patients). In multivariate analysis of AML patients, DNMT3A mutation was associated with shorter OS while IDH1/2 mutation subtypes had no independent impact. No difference was observed in serum 2HG levels upon AZA treatment between responding and refractory patients suggesting that serum 2HG cannot be used as a surrogate marker of AZA response.

Isocitrate dehydrogenase (IDH) 1 and 2 mutations result in overproduction of D-2-hydroxyglutarate (2-HG) and impaired cellular differentiation. Ivosidenib, a targeted mutant IDH1 (mIDH1) enzyme inhibitor, can restore normal differentiation and results in clinical responses in a subset of patients with mIDH1 relapsed/refractory (R/R) acute myeloid leukemia (AML). We explored mechanisms of ivosidenib resistance in 174 patients with confirmed mIDH1 R/R AML from a phase 1 trial. Receptor tyrosine kinase (RTK) pathway mutations were associated with primary resistance to ivosidenib. Multiple mechanisms contributed to acquired resistance, particularly outgrowth of RTK pathway mutations and 2-HG-restoring mutations (second-site IDH1 mutations, IDH2 mutations). Observation of multiple concurrent mechanisms in individual patients underscores the complex biology of resistance and has important implications for rational combination therapy design. This trial was registered at www.clinicaltrials.gov as #NCT02074839., (© 2020 by The American Society of Hematology.)

Purpose: Isocitrate dehydrogenase (IDH) mutations lead to formation of the oncometabolite 2-hydroxyglutarate (2-HG), which is elevated in several solid and liquid tumors. Ivosidenib (AG-120) is a targeted, potent, oral inhibitor of the mutant IDH1 protein. We describe detailed pharmacokinetics and pharmacodynamics of ivosidenib in patients with advanced hematologic malignancies with an IDH1 mutation treated in a phase I study (ClinicalTrials.gov NCT02074839)., Methods: Patients received single and multiple oral doses of ivosidenib from 100 mg twice daily to 1200 mg once daily (QD) in 28-day continuous cycles. Concentrations of ivosidenib and 2-HG in plasma, and 2-HG in bone marrow, were assessed at routine intervals. Plasma 4β-hydroxycholesterol/cholesterol ratios were assessed as a marker of CYP3A activity., Results: Ivosidenib was rapidly absorbed and slowly eliminated (half-life 72-138 h) after single and multiple dosing. Ivosidenib exhibited dose- and time-dependent pharmacokinetics, with exposure increasing sub-proportionally to dose, and clearance increasing with increasing dose. Plasma 2-HG concentrations were maximally and persistently inhibited in the majority of patients receiving 500-mg QD ivosidenib, to concentrations close to those observed in healthy subjects. Ivosidenib pharmacokinetics were not affected by mild or moderate renal impairment, mild hepatic impairment, age, weight, sex, race, or co-administration of weak CYP3A4 inhibitors or inducers. Moderate-to-strong CYP3A4 inhibitors decreased ivosidenib clearance. Ivosidenib also induced CYP3A enzyme activity, with increases in 4β-hydroxycholesterol/cholesterol ratios of 119-168% at 500-mg QD ivosidenib., Conclusions: Ivosidenib 500-mg QD has favorable pharmacokinetic and pharmacodynamic profiles in patients with advanced hematologic malignancies with an IDH1 mutation., Clinical Trial Registration: ClinicalTrials.gov NCT02074839.

Background: Mutations in isocitrate dehydrogenase-2 (IDH2) occur in around 5% of patients with myelodysplastic syndromes. Neomorphic activity of mutant IDH2 proteins results in hypermethylation of DNA and histones, leading to blocked haemopoietic differentiation. Enasidenib, an inhibitor of mutated IDH2 proteins, induces responses in patients with IDH2-mutated, relapsed or refractory acute myeloid leukaemia. We aimed to establish the clinical outcomes of enasidenib monotherapy in a subgroup of patients with myelodysplastic syndromes harbouring mutations in IDH2 from the AG221-C-001 trial., Methods: The multicentre, open-label, phase 1-2 AG221-C-001 trial enrolled patients with advanced haematological malignancies (2008 WHO criteria) harbouring an IDH2 mutation. The present study is a subgroup analysis of patients with IDH2-mutated myelodysplastic syndromes in the phase 1 dose-escalation and expansion portions of the trial. Patients with myelodysplastic syndromes were aged 18 years or older with an ECOG performance status score of 2 or lower, and were relapsed or refractory to, or ineligible for, standard treatments. Patients received oral doses of enasidenib at 60-300 mg per day in repeated 28-day treatment cycles. In this subgroup analysis, we focused on the safety and activity of enasidenib as main outcomes. Overall response rate, duration of response, and overall and event-free survival analyses were by intention-to-treat. Safety was assessed in all participants who received at least one dose of study drug in terms of treatment-emergent adverse events. The AG221-C-001 trial is registered on ClinicalTrials.gov, NCT01915498, status ongoing but closed to recruitment., Findings: 17 patients with myelodysplastic syndromes harbouring an IDH2 mutation (median age, 67·0 years [IQR 60·5-73·0]) were enrolled between Feb 18, 2014, and Sept 1, 2015. At data cutoff (Oct 1, 2018), after a median follow-up of 11·0 months (IQR 6·8-23·0), all patients had discontinued enasidenib, with a median of 3 treatment cycles (2-15) for all patients (five [29%] received ≥12 cycles). At entry, three (18%) patients had relapsed after allogeneic stem-cell transplants, 13 (76%) had previously received therapy with hypomethylating agents, and ten (59%) had received at least two previous therapies. No dose-limiting toxicities were reported. The most common treatment-emergent adverse events were diarrhoea and nausea (in nine [53%] patients each). Most common grade 3-4 treatment-emergent adverse events were indirect hyperbilirubinaemia (in six [35%] patients), pneumonia (in five [29%] patients), and thrombocytopaenia (in four [24%] patients). Serious treatment-emergent adverse events in more than one patient were pneumonia (in five [29% patients); tumor lysis syndrome (in three [18%] patients); and sepsis, atrial flutter, indirect hyperbilirubinaemia, cerebral hemorrhage, and mental status change (in two [12%] patients each). No treatment-related deaths occurred. An overall response was achieved in 9 patients (53% [95% CI 28-77]), with a median duration of response of 9·2 months (95% CI 1·0-not reached). Six (46%) of 13 patients previously treated with hypomethylating agents responded. Median overall survival was 16·9 months (95% CI 1·5-32·3), and median event-free survival was 11·0 months (1·5-16·7)., Interpretation: Enasidenib is generally well tolerated and can induce responses in patients with mutant IDH2 myelodysplastic syndromes, including in those who have had previous therapy with hypomethylating agents. Testing for IDH2 mutations in myelodysplastic syndromes is essential for identifying patients who might benefit from enasidenib therapy, including those patients in whom conventional treatments have been unsuccessful., Funding: Celgene and Agios Pharmaceuticals., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Ivosidenib (AG-120) is an oral, targeted agent that suppresses production of the oncometabolite 2-hydroxyglutarate via inhibition of the mutant isocitrate dehydrogenase 1 (IDH1; mIDH1) enzyme. From a phase 1 study of 258 patients with IDH1-mutant hematologic malignancies, we report results for 34 patients with newly diagnosed acute myeloid leukemia (AML) ineligible for standard therapy who received 500 mg ivosidenib daily. Median age was 76.5 years, 26 patients (76%) had secondary AML, and 16 (47%) had received ≥1 hypomethylating agent for an antecedent hematologic disorder. The most common all-grade adverse events were diarrhea (n = 18; 53%), fatigue (n = 16; 47%), nausea (n = 13; 38%), and decreased appetite (n = 12; 35%). Differentiation syndrome was reported in 6 patients (18%) (grade ≥3 in 3 [9%]) and did not require treatment discontinuation. Complete remission (CR) plus CR with partial hematologic recovery (CRh) rate was 42.4% (95% confidence interval [CI], 25.5% to 60.8%); CR 30.3% (95% CI, 15.6% to 48.7%). Median durations of CR+CRh and CR were not reached, with 95% CI lower bounds of 4.6 and 4.2 months, respectively; 61.5% and 77.8% of patients remained in remission at 1 year. With median follow-up of 23.5 months (range, 0.6-40.9 months), median overall survival was 12.6 months (95% CI, 4.5-25.7). Of 21 transfusion-dependent patients (63.6%) at baseline, 9 (42.9%) became transfusion independent. IDH1 mutation clearance was seen in 9/14 patients achieving CR+CRh (5/10 CR; 4/4 CRh). Ivosidenib monotherapy was well-tolerated and induced durable remissions and transfusion independence in patients with newly diagnosed AML. This trial was registered at www.clinicaltrials.gov as #NCT02074839., (© 2020 by The American Society of Hematology.)

The preferred post-remission therapy for older patients with acute myeloid leukemia (AML) in first complete remission (CR1) remains uncertain. In this retrospective, multicenter study, we compared the outcomes for older AML patients (age 60-77 years) receiving allogeneic hematopoietic cell transplantation (alloHCT) (n = 431) with those treated on prospective National Clinical Trials Network induction and nontransplantation chemotherapy (CT) consolidation trials (n = 211). AlloHCT patients were younger (median age: 64.2 versus 67.9 years, p < 0.001), but more frequently had high-risk AML (high WBC, secondary AML, and unfavorable cytogenetics). Overall survival (OS) was worse in alloHCT during the first 9 months after CR1 (HR = 1.52, p = 0.02), but was significantly better thereafter (HR = 0.53, p < 0.0001) relative to CT. Treatment-related mortality (TRM) following HCT was worse in the first 9 months (HR = 2.8, 95% CI: 1.5-5.2, p = 0.0009), while post-HCT relapse was significantly less frequent beyond 9 months (HR = 0.42, 95% CI: 0.29-0.61, p < 0.0001). Despite higher early TRM, alloHCT recipients had superior long-term OS [29% (24-34%) versus CT 13.8% (9-21%) at 5 years]. Although this is a retrospective analysis with potential biases, it indicates that alloHCT led to heightened early risks from TRM, yet reduced relapse and superior long-term survival relative to CT in older AML patients in CR1.

Older adults with acute myeloid leukemia (AML) who are not fit for standard chemotherapy historically have poor outcomes. Approximately 12-15% of older patients with AML harbor isocitrate dehydrogenase 2 (IDH2) gene mutations. Enasidenib is an oral inhibitor of mutant IDH2 proteins. Among 39 patients with newly diagnosed mutant-IDH2 AML who received enasidenib monotherapy in this phase I/II trial, median age was 77 years (range 58-87) and 23 patients (59%) had had an antecedent hematologic disorder. The median number of enasidenib treatment cycles was 6.0 (range 1-35). The most common treatment-related adverse events were indirect hyperbilirubinemia (31%), nausea (23%), and fatigue, decreased appetite, and rash (18% each). Treatment-related grade 3-4 cytopenias were reported for eight patients (21%); there was no treatment-related grade 3-4 infections. Twelve patients achieved a response (overall response rate 30.8% [95% CI 17.0%, 47.6%]), including seven patients (18%) who attained complete remission. At a median follow-up of 8.4 months, the median duration of any response was not reached (NR). Median overall survival for all patients was 11.3 months (95% CI 5.7, 15.1), and was NR for responders. Oral, outpatient targeted treatment with enasidenib may benefit older adults with newly diagnosed mutant-IDH2 AML who are not candidates for cytotoxic regimens.

Approximately 8% to 19% of patients with acute myeloid leukemia (AML) have isocitrate dehydrogenase-2 ( IDH2 ) mutations, which occur at active site arginine residues R140 and R172. IDH2 mutations produce an oncometabolite, 2-hydroxyglutarate (2-HG), which leads to DNA and histone hypermethylation and impaired hematopoietic differentiation. Enasidenib is an oral inhibitor of mutant-IDH2 proteins. This first-in-human phase 1/2 study evaluated enasidenib doses of 50 to 650 mg/d, administered in continuous 28-day cycles, in patients with mutant- IDH2 hematologic malignancies. Overall, 214 of 345 patients (62%) with relapsed or refractory (R/R) AML received enasidenib, 100 mg/d. Median age was 68 years. Forty-two patients (19.6%) attained complete remission (CR), 19 patients (10.3%) proceeded to an allogeneic bone marrow transplant, and the overall response rate was 38.8% (95% confidence interval [CI], 32.2-45.7). Median overall survival was 8.8 months (95% CI, 7.7-9.6). Response and survival were comparable among patients with IDH2 -R140 or IDH2 -R172 mutations. Response rates were similar among patients who, at study entry, were in relapse (37.7%) or were refractory to intensive (37.5%) or nonintensive (43.2%) therapies. Sixty-six (43.1%) red blood cell transfusion-dependent and 53 (40.2%) platelet transfusion-dependent patients achieved transfusion independence. The magnitude of 2-HG reduction on study was associated with CR in IDH2 -R172 patients. Clearance of mutant- IDH2 clones was also associated with achievement of CR. Among all 345 patients, the most common grade 3 or 4 treatment-related adverse events were hyperbilirubinemia (10%), thrombocytopenia (7%), and IDH differentiation syndrome (6%). Enasidenib was well tolerated and induced molecular remissions and hematologic responses in patients with AML for whom prior treatments had failed. The study is registered at www.clinicaltrials.gov as #NCT01915498., (© 2019 by The American Society of Hematology.)

Novel treatment strategies are needed for older patients with acute myeloid leukemia (AML). This randomized phase 2 trial compared the efficacy and safety of 20 mg/m 2 of IV decitabine on days 1 to 10 alone (arm A) with those of 1.3 mg/m 2 of subcutaneous bortezomib (arm B) on days 1, 4, 8, and 11 for up to 4 10-day cycles followed by monthly 5-day cycles. Previously untreated AML patients age ≥60 years (excluding those with FLT3 mutations and favorable-risk cytogenetics) without restrictions in performance status (PS) or organ function were eligible. Median age was 72.4 years (range, 60.5-92.3 years); 31 patients (19%) had baseline PS ≥2, 35 (22%) had an antecedent hematological disorder, 58 had (39%) adverse cytogenetics, and 7 (5%) and 23 (14%) had abnormal cardiac or renal function. There were no statistically significant differences in overall survival (OS) or responses between the 2 treatment arms. The overall response rate (complete remission + complete remission with incomplete blood count recovery) was 39% (n = 64), with median OS of 9.3 months. Nineteen responders (31%) underwent allogeneic stem cell transplantation. The most common adverse event was febrile neutropenia, and there were no unexpected toxicities. Adding bortezomib to decitabine did not improve outcomes, but responses were better than those in previous trials using 5-day decitabine cycles. This trial was registered at www.clinicaltrials.gov as #NCT01420926., (© 2018 by The American Society of Hematology.)

Importance: Enasidenib mesylate, a mutant isocitrate dehydrogenase 2 (IDH2) protein inhibitor that promotes differentiation of leukemic myeloblasts, was recently approved by the US Food and Drug Administration for use in relapsed/refractory (R/R) mutant IDH2 acute myeloid leukemia (AML). During the first study of enasidenib in humans, a minority of patients with advanced myeloid neoplasms experienced unexpected signs/symptoms of a differentiation syndrome (DS), a potentially lethal entity., Objective: To characterize IDH-inhibitor-associated DS (IDH-DS) and its effective management., Design, Setting, and Participants: Using data obtained from a multicenter, open-label, pivotal phase 1/2 study of enasidenib, a differentiation syndrome review committee retrospectively evaluated potential cases of IDH-DS in enasidenib-treated patients with R/R AML. Data were collected between August 27, 2013, and October 14, 2016. The committee identified and agreed on signs and symptoms characteristic of IDH-DS and developed an algorithm for identification and treatment. Among 281 patients with R/R AML enrolled in the trial, the committee identified 72 patients for review based on investigator-reported cases of DS (n = 33) or reported adverse events or signs and symptoms characteristic of IDH-DS., Interventions: Treatment with enasidenib at a dosage of 50 to 650 mg/d was evaluated during the dose-escalation phase, and a dosage of 100 mg/d was used in the phase 1 expansion and phase 2, all in continual 28-day cycles., Main Outcomes and Measures: Unexpected adverse events of IDH-DS during the phase 1/2 study., Results: Thirty-three of the 281 patients (11.7%) were identified as having possible or probable IDH-DS. Median age of those 33 patients was 70 years (range, 38-80 years); 20 (60.6%) were male. The most frequent manifestations were dyspnea, fever, pulmonary infiltrates, and hypoxia. Median time to onset was 30 days (range, 7-129 days). Patients who experienced IDH-DS were less likely to have less than 20% bone marrow blasts (6% vs 22%, P = .04) and more likely to have undergone fewer previous anticancer regimens (median, 1.0 [range, 1-4] vs 2.0 [range, 1-14], P = .05) at study entry than those who did not. Thirteen patients (39.4%) had concomitant leukocytosis. Isocitrate dehydrogenase differentiation syndrome was effectively managed with systemic corticosteroids. The enasidenib regimen was interrupted for 15 patients (45.5%), but permanent discontinuation of treatment was not required., Conclusions and Relevance: Isocitrate dehydrogenase differentiation syndrome is a recognizable and potentially lethal clinical entity, occurring in approximately 12% of enasidenib-treated patients with mutant-IDH2 R/R AML. It requires prompt recognition and management. As use of mutant IDH inhibitors increases, these findings and recommendations are increasingly germane to care of patients with mutant-IDH neoplasms., Trial Registration: clinicaltrials.gov Identifier: NCT01915498.

Background: Mutations in the gene encoding isocitrate dehydrogenase 1 ( IDH1) occur in 6 to 10% of patients with acute myeloid leukemia (AML). Ivosidenib (AG-120) is an oral, targeted, small-molecule inhibitor of mutant IDH1., Methods: We conducted a phase 1 dose-escalation and dose-expansion study of ivosidenib monotherapy in IDH1-mutated AML. Safety and efficacy were assessed in all treated patients. The primary efficacy population included patients with relapsed or refractory AML receiving 500 mg of ivosidenib daily with at least 6 months of follow-up., Results: Overall, 258 patients received ivosidenib and had safety outcomes assessed. Among patients with relapsed or refractory AML (179 patients), treatment-related adverse events of grade 3 or higher that occurred in at least 3 patients were prolongation of the QT interval (in 7.8% of the patients), the IDH differentiation syndrome (in 3.9%), anemia (in 2.2%), thrombocytopenia or a decrease in the platelet count (in 3.4%), and leukocytosis (in 1.7%). In the primary efficacy population (125 patients), the rate of complete remission or complete remission with partial hematologic recovery was 30.4% (95% confidence interval [CI], 22.5 to 39.3), the rate of complete remission was 21.6% (95% CI, 14.7 to 29.8), and the overall response rate was 41.6% (95% CI, 32.9 to 50.8). The median durations of these responses were 8.2 months (95% CI, 5.5 to 12.0), 9.3 months (95% CI, 5.6 to 18.3), and 6.5 months (95% CI, 4.6 to 9.3), respectively. Transfusion independence was attained in 29 of 84 patients (35%), and patients who had a response had fewer infections and febrile neutropenia episodes than those who did not have a response. Among 34 patients who had a complete remission or complete remission with partial hematologic recovery, 7 (21%) had no residual detectable IDH1 mutations on digital polymerase-chain-reaction assay. No preexisting co-occurring single gene mutation predicted clinical response or resistance to treatment., Conclusions: In patients with advanced IDH1-mutated relapsed or refractory AML, ivosidenib at a dose of 500 mg daily was associated with a low frequency of grade 3 or higher treatment-related adverse events and with transfusion independence, durable remissions, and molecular remissions in some patients with complete remission. (Funded by Agios Pharmaceuticals; ClinicalTrials.gov number, NCT02074839 .).

Patients with relapsed AML have a poor prognosis and limited responses to standard chemotherapy. Lenalidomide is an immunomodulatory drug that may modulate anti-tumor immunity. We performed a study to evaluate the safety and tolerability of lenalidomide with mitoxantrone, etoposide and cytarabine (MEC) in relapsed/refractory AML. Adult patients with relapsed/refractory AML were eligible for this phase I dose-escalation study. We enrolled 35 patients using a "3 + 3" design, with a 10 patient expansion cohort at the maximum tolerated dose (MTD). Lenalidomide was initially given days 1-14 and MEC days 4-8; due to delayed count recovery, the protocol was amended to administer lenalidomide days 1-10. The dose of lenalidomide was then escalated starting at 5 mg/d (5-10-25-50). The primary objective was tolerability and MTD determination, with secondary outcomes including overall survival (OS). The MTD of lenalidomide combined with MEC was 50 mg/d days 1-10. Among the 35 enrolled patients, 12 achieved complete remission (CR) (34%, 90%CI 21-50%); 30-day mortality was 6% and 60-day mortality 13%. The median OS for all patients was 11.5 months. Among 17 patients treated at the MTD, 7 attained CR (41%); the median OS was not reached while 12-month OS was 61%. Following therapy with MEC and lenalidomide, patient CD4+ and CD8+ T-cells demonstrated increased inflammatory responses to autologous tumor lysate. The combination of MEC and lenalidomide is tolerable with an RP2D of lenalidomide 50 mg/d days 1-10, yielding encouraging response rates. Further studies are planned to explore the potential immunomodulatory effect of lenalidomide and MEC., (© 2017 Wiley Periodicals, Inc.)

Purpose Azacitidine is standard, first-line therapy in higher-risk myelodysplastic syndromes (MDS). Whether azacitidine-based combinations with lenalidomide or vorinostat produce superior overall response rates (ORRs) to azacitidine is not known. Patients and Methods North American Intergroup Study S1117 is a phase II/III trial that randomly assigned patients with higher-risk MDS and chronic myelomonocytic leukemia (CMML) 1:1:1 to azacitidine (75 mg/m 2 /day on days 1 to 7 of a 28-day cycle); azacitidine plus lenalidomide (10 mg/day on days 1 to 21); or azacitidine plus vorinostat (300 mg twice daily on days 3 to 9). The primary phase II end point was improved ORR. Results Of 277 patients from 90 centers, 92 received azacitidine, 93 received azacitidine plus lenalidomide, and 92 received azacitidine plus vorinostat. Median age was 70 years (range, 28 to 93 years), 85 patients (31%) were female, and 53 patients (19%) had CMML. Serious adverse events were similar across arms, although combination-arm patients were more likely to undergo nonprotocol-defined dose modifications ( P < .001).With a median follow-up of 23 months (range, 1 to 43 months), the ORR was 38% for patients receiving azacitidine, 49% for azacitidine plus lenalidomide ( P = .14 v azacitidine), and 27% for azacitidine plus vorinostat ( P = .16 v azacitidine). For patients with CMML, ORR was higher for azacitidine plus lenalidomide versus azacitidine (68% v 28%, P = .02) but similar for all arms across cytogenetic subgroups, as was remission duration and overall survival. ORR was higher with mutations in DNMT3A and lower for SRSF2, whereas ORR duration improved with fewer mutations. Lenalidomide dose reduction was associated with worse overall survival (hazard ratio, 1.30; P = .05). Conclusion Patients with higher-risk MDS treated with azacitidine-based combinations had similar ORR to azacitidine monotherapy, although patients with CMML benefitted from azacitidine plus lenalidomide. The efficacy of combination regimens may have been affected by dose modifications.

Aberrant expression of aurora kinase A is implicated in the genesis of various neoplasms, including acute myeloid leukemia. Alisertib, an aurora A kinase inhibitor, has demonstrated efficacy as monotherapy in trials of myeloid malignancy, and this efficacy appears enhanced in combination with conventional chemotherapies. In this phase I, dose-escalation study, newly diagnosed patients received conventional induction with cytarabine and idarubicin, after which alisertib was administered for 7 days. Dose escalation occurred via cohorts. Patients could then receive up to four cycles of consolidation, incorporating alisertib, and thereafter alisertib maintenance for up to 12 months. Twenty-two patients were enrolled. One dose limiting toxicity occurred at dose level 2 (prolonged thrombocytopenia), and the recommended phase 2 dose was established at 30mg twice daily. Common therapy-related toxicities included cytopenias and mucositis. Only three (14%) patients had persistent disease at mid-cycle, requiring "5+2" reinduction. The composite remission rate (complete remission and complete remission with incomplete neutrophil recovery) was 86% (nineteen of twenty-two patients; 90% CI 68-96%). Among those over age 65 and those with high-risk disease (secondary acute leukemia or cytogenetically high-risk disease), the composite remission rate was 88% and 100%, respectively. The median follow up was 13.5 months. Of those treated at the recommended phase 2 dose, the 12-month overall survival and progression-free survival were 62% (90% CI 33-81%) and 42% (90% CI 17-65%), respectively. Alisertib is well tolerated when combined with induction chemotherapy in acute myeloid leukemia, with a promising suggestion of efficacy. ( clinicaltrials.gov Identifier:01779843 )., (Copyright© Ferrata Storti Foundation.)

Background: Outcomes among older patients with acute lymphoblastic leukemia remain poor. This study sought to determine the efficacy of an intensified, multi-agent approach derived from a Dana-Farber consortium trial in younger adults for patients older than 50 years (trial identifier NCT00973752)., Methods: The primary endpoint was overall survival (OS) at 1 year. Patients received induction chemotherapy with vincristine, prednisone, doxorubicin, and pegylated asparaginase. Imatinib was incorporated for Philadelphia chromosome-positive disease. After induction, the first consolidation incorporated clofarabine. Patients in remission could proceed to allogeneic hematopoietic cell transplantation (HCT) after induction and consolidation I. Those not receiving HCT went on to receive central nervous system, consolidation II, and continuation phases of treatment., Results: Thirty patients were enrolled: 19 achieved a complete remission (CR) after induction and 1 achieved CR after consolidation I for a CR rate of 67%. Sixteen patients underwent HCT. The proportion surviving at 1 year was 63%, and this met the primary endpoint. The 2-year OS rate was 52% (n = 30), and the 2-year disease-free survival rate was 52% for patients achieving CR (n = 20). There was no survival advantage among those undergoing HCT. Therapy-related hyperbilirubinemia prompted adjustments and limitations to asparaginase dosing., Conclusions: Intensified chemotherapy can result in improved outcomes in comparison with historical data. Additional studies of similarly intensive regimens are warranted in this population. Cancer 2016;122:2379-2388. © 2016 American Cancer Society., (© 2016 American Cancer Society.)

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are key metabolic enzymes, converting isocitrate to α-ketoglutarate (αKG).IDH1 and IDH2 mutations have been identified in multiple tumor types, including gliomas and myeloid malignancies such as acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Here we provide an overview of the function of normal and mutated IDH, discuss the role of IDH mutations in tumorigenesis and progression and review the key clinical considerations when treating IDH-mutated tumors based on emerging clinical data from mutant IDH1/2 inhibitor trials. IDH1 and IDH2 mutations confer neomorphic activity in the mutant protein, resulting in the conversion of αKG to the oncometabolite, D-2-hydroxyglutarate (2-HG). The subsequent accumulation of 2-HG results in epigenetic dysregulation via inhibition of αKG-dependent histone and DNA demethylases, and a block in cellular differentiation. There is growing preclinical and clinical evidence suggesting that IDHmutations are involved in neoplasia. Furthermore, preclinical studies assessing small molecule inhibitors of mutant IDH1/2 enzymes have provided proof of concept that this approach decreases intracellular 2-HG levels, reverses epigenetic dysregulation and induces cellular differentiation. Phase I studies of mutant IDH inhibitors are currently ongoing in patients with IDH-mutant hematologic and solid tumors, with early data in hematologic tumors suggesting a manageable safety profile as well as clinical benefit, with a mechanism of action based on differentiation of malignant cells. Inhibition of mutant IDH shows promise as a treatment approach in hematologic malignancies, with further development ongoing in solid tumors and glioma. The mutant IDH inhibitors may have clinical utility both as single agents and in combination strategies that target additional oncogenic pathways., (© The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Health care utilization in older adults (age ≥60 years) with acute myeloid leukemia (AML) has not been well studied., Methods: We conducted a retrospective analysis of 330 consecutive older patients who were diagnosed with AML between May 1, 2005 and December 23, 2011, at 2 hospitals in Boston to examine their health care utilization and end-of-life care. Using multivariable logistic and linear regression models adjusting for covariates, we also compared health care utilization between patients who received intensive induction chemotherapy (n = 197; cytarabine/ anthracycline combination) versus nonintensive chemotherapy (n = 133; single-agent therapy)., Results: The median number of hospitalizations for the entire cohort was 4.2 (range, 1-18 hospitalizations). Patients who died spent a mean of 28.3% of their life after diagnosis in the hospital and 13.8% of their life attending outpatient clinic appointments. Although the majority of patients (87.9%) died during the 2-year follow-up period, a minority received palliative care (16.2%) or hospice (23.1%) services. Within 30 days of death, 84.5% of patients were hospitalized, and 61% died in the hospital. Among the patients who died, those who received intensive induction therapy (vs nonintensive therapy) spent 30% more of their life after diagnosis in the hospital (P < .0001) and were less likely to receive hospice services (odds ratio, 0.45; P = .05)., Conclusions: The current findings highlight the intensity of health care utilization among older patients with AML, regardless of treatment modality. Despite the poor prognosis, palliative care and hospice services are rarely used. Future work should study novel health care delivery models to optimize care throughout the course of illness and at the end of life., (© 2015 American Cancer Society.)

Isolated myeloid sarcoma (MS) is a rare extramedullary presentation of acute myeloid leukemia (AML). Little is known about MS outcomes due to its rarity. A population-based analysis of MS using the Survival, Epidemiology, and End Results (SEER) database was performed. We identified 345 patients, aged 15 or older, diagnosed with isolated MS between 1973 and 2010. Overall survival (OS) was calculated and compared between MS and non-MS AML using the log-rank test. Survival was also evaluated based upon the primary site of disease presentation. The 3-year survival rate for MS (0.319; 95% confidence interval [CI]: 0.267-0.371) was greater than for non-MS AML (0.172; 95% CI: 0.168-0.175). There was variation in survival based on the site of involvement. The survival rates for isolated MS involving the pelvis/genitourinary organs, eyes/gonads and gastrointestinal mucosa appeared to be slightly improved when compared to primary sites of soft tissues, lymphatic/hematopoietic tissues or nervous system.

Advancements in sequencing techniques have led to the discovery of numerous genes not previously implicated in acute myeloid leukemia (AML) biology. Further in vivo studies are necessary to discern the biological impact of these mutations. Murine models, the most commonly used in vivo system, provide a physiologic context for the study of specific genes. These systems have provided deep insights into the role of genetic translocations, mutations, and dysregulated gene expression on leukemia pathogenesis. This review focuses on the phenotype of newly identified genes, including NPM1, IDH1/2, TET2, MLL, DNMT3A, EZH2, EED, and ASXL1, in mouse models and the implications on AML biology., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We performed a retrospective population-based study using the SEER database to assess survival trends in CBF-AML between 2000 and 2010. Median OS increased from 16 months in 2000-2002 to 25 months in 2006-2008 (P=0.002). The 3-year OS rate for patients with inv(16) was 57.3%, but in t(8;21) was only 35.5%. Patients aged 75-84 had worse survival than patients aged 15-44 (HR 5.61, P=0.0002). Black race was associated with higher mortality (HR 1.50, P=0.03). Compared to clinical trial outcomes, CBF-AML survival is poorer in the general population, particularly among African Americans and the elderly, and in t(8;21) compared to inv(16) AML., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Aa total of 105 patients (age ≥18 years) with newly diagnosed low or intermediate risk acute promyelocytic leukaemia (APL) were treated with a standard induction and consolidation regimen including arsenic trioxide (ATO). Sixty-eight patients who were polymerase chain reaction (PCR) negative for PML-RARA post-consolidation were randomized to either 1 year of maintenance with tretinoin, mercaptopurine and methotrexate, or observation. Enrollment in this non-inferiority trial was stopped prematurely due to slow accrual. With a median follow up of 36·1 months, the overall survival of the 105 patients was 93%, and there have been no relapses in the patients randomized to maintenance or observation. These results demonstrate that cures can be expected in >90% of patients with low and intermediate risk APL and suggest that maintenance therapy may not be needed if patients are treated with an intensive post-remission regimen including ATO. This trial was registered at clinicaltrials.gov as #NCT00492856., (© 2014 John Wiley & Sons Ltd.)

We conducted a phase I dose escalation study to determine the maximal tolerated dose of bortezomib that could be combined with standard dose lenalidomide in patients with MDS or AML. Treatment consisted of bortezomib (IV) on Days 1, 4, 8, and 11 and lenalidomide 10mg daily (PO) days 1-21 in 28 day cycles for up to 9 cycles. 23 patients (14 MDS/CMML, 9 AML) were enrolled. The maximally tested dose of bortezomib, 1.3mg/m(2), was tolerable in this regimen. Responses were seen in patients with MDS and AML. Further testing of this regimen is planned., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Acute myeloid leukemia (AML) is more common and more lethal among patients over the age of 60. Increased body mass index (BMI) has been associated with a higher incidence of various malignancies, including AML. We sought to determine whether patient BMI at the time of AML diagnosis is related to overall survival (OS) among elderly patients. We identified 97 patients with AML diagnosed after the age of 60 and treated with cytarabine-based induction chemotherapy. The median age was 68 years (range 60-87); 52% of patients were male, and our study population was predominantly white (89% of patients). The median OS for all patients was 316 days (95% CI 246-459). The hazard ratio for mortality was increased among patients with a BMI < 25 compared to BMI ≥ 30 (HR 2.14, P = 0.009, 95% CI 1.21-3.77), as well as with older age (HR 1.76, P = 0.015, 95% CI 1.12-2.79) and with secondary versus de novo disease (HR 1.95, P = 0.006, 95% CI 1.21-3.14). After multivariable analysis, we did not find a significant association between OS and other potential confounders such as coronary artery disease or diabetes among these patients. We conclude that increased BMI was independently associated with improved OS among older AML patients at our institution., (Copyright © 2013 Wiley Periodicals, Inc.)

Comparisons of myeloablative conditioning versus reduced-intensity conditioning (RIC) have demonstrated a tradeoff between relapse and toxicity. Dose intensity across RIC regimens vary and may affect treatment outcomes. In this retrospective analysis, we investigated the effect of i.v. busulfan dosing (total dose 3.2 mg/kg versus 6.4 mg/kg) in RIC regimens that combined fludarabine and busulfan on outcomes in patients who were undergoing hematopoietic stem cell transplantation (HSCT) for myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). A total of 217 consecutive patients with MDS or AML underwent first busulfan and fludarabine RIC peripheral blood stem cell transplantation from well-matched related or unrelated donors at our institutions between 2004 and 2009. Of the 217 patients, 135 patients received Bu1 (3.2 mg/kg of busulfan) and 82 patients received Bu2 (6.4 mg/kg of busulfan), both with daily fludarabine (30 mg/m(2)/day for 4 days). The choice of RIC regimen was based on temporal institutional standard, enrollment on protocols, and physician choice. Patients had similar characteristics with a few notable differences: Patients who received Bu1 were younger (median age 61 versus 64 years, P < . 001), received more single-antigen mismatched unrelated grafts (14.1% versus 1.2%, P < . 001), received more sirolimus-based graft-versus-host disease (GVHD) prophylaxis regimens (63% versus 45%, P < .0001), received less antithymocyte globulin for GVHD prophylaxis (0% versus 22%, P < .001), and had less enrollment on a clinical trial that used prophylactic rituximab for the prevention of chronic GVHD (2.2% versus 11.0%, P = .011). Clinical disease status was similar between the groups. Median follow-up for survivors was 4.4 years for Bu1 and 3.2 years for Bu2. Because of the differences in characteristics, the 2 groups were compared with the adjustment of a propensity score that predicted Bu2 to account for measured differences. The day +200 cumulative incidence rates of grades II to IV acute GVHD (Bu1, 17%, versus Bu2, 8.5%; hazard ratio [HR], .56; 95% confidence interval [CI], .22 to 1.41; P = .22) or grades III to IV acute GVHD (Bu1, 6.7%, versus Bu2, 4.9%) were not different. The 2-year cumulative incidence of chronic GVHD was not significantly different between Bu1 and Bu2 (41.5% versus 28%, respectively; HR, .70; CI, .42 to 1.17; P = .09). Two-year nonrelapse mortality rates were similar for Bu1 and Bu2 (8.9% versus 9.8%, respectively; HR, .80; CI, .29 to 2.21; P = .67). Two-year progression-free survival and overall survival were also similar between Bu1 and Bu2 (progression-free survival: 40.6% versus 39.3%, respectively; HR, .82; CI, .57 to 1.30; P = .33; and overall survival: 47.4% versus 48.8%, respectively; HR, .96; CI, .64 to 1.44; P = .85). Subset analysis defined by clinical disease and cytogenetic risk with the propensity risk score applied suggest that in patients with high clinical disease risk and nonadverse cytogenetics, the higher dose busulfan RIC regimen may be of marginal benefit (2-year progression-free survival: HR, .54; CI, .29 to 1.03; P = .062). For the majority of patients with MDS or AML undergoing busulfan and fludarabine RIC peripheral blood stem cell transplantation, however, the dose of busulfan (3.2 mg/kg versus 6.4 mg/kg) is not associated with significant differences in overall outcomes., (Copyright © 2013 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Acute intestinal GVHD remains a major source of morbidity after allogeneic hematopoietic cell transplantation (HCT). α4β7 integrin is a cell surface molecule that mediates lymphocyte trafficking to intestinal tissue. In this analysis, peripheral blood was collected at the time of presentation of symptoms of acute GVHD and before any treatment. In all, 45 samples were collected and divided into three groups on the basis of subsequent evaluation: intestinal GVHD (n=15), skin GVHD (n=20) and no GVHD (n=10). Two patients developed intestinal GVHD after DLI. The no-GVHD group comprised 10 patients who presented with suspicious symptoms, but evaluation yielded other etiologies. Analysis by flow cytometry showed that intestinal GVHD patients had a significantly higher percentage of α4β7 integrin-expressing memory CD8(+) T cells (median 7.69%; lower and upper quartiles, 1.06% and 11.64%, respectively) compared with patients with skin GVHD (1.26%; 0.57% and 2.49%) and no GVHD (0.96%; 0.44% and 1.85%), P=0.03. No differences were found in α4β7 expression in any CD4(+) T-cell subsets or naive CD8(+) T cells. This study adds to the evidence that α4β7 integrin is involved in lymphocyte trafficking in acute intestinal GVHD.

Purpose: The purpose of this study was to determine remission induction frequency when bortezomib was combined with daunorubicin and cytarabine in previously untreated older adults with acute myeloid leukemia (AML) and safety of bortezomib in combination with consolidation chemotherapy consisting of intermediate-dose cytarabine (Int-DAC)., Patients and Methods: Ninety-five adults (age 60 to 75 years; median, 67 years) with previously untreated AML (including therapy-related and previous myelodysplastic syndrome) received bortezomib 1.3 mg/m(2) intravenously (IV) on days 1, 4, 8, and 11 with daunorubicin 60 mg/m(2) on days 1 through 3 and cytarabine 100 mg/m(2) by continuous IV infusion on days 1 through 7. Patients who achieved complete remission (CR) received up to two courses of consolidation chemotherapy with cytarabine 2 gm/m(2) on days 1 through 5 with bortezomib. Three cohorts with escalating dose levels of bortezomib were tested (0.7, 1.0, and 1.3 mg/m(2)). Dose-limiting toxicities were assessed during the first cycle of consolidation. The relationship between cell surface expression of CD74 and clinical outcome was assessed., Results: Frequency of CR was 65% (62 of 95), and 4% of patients (four of 95) achieved CR with incomplete platelet recovery (CRp). Eleven patients developed grade 3 sensory neuropathy. Bortezomib plus Int-DAC proved tolerable at the highest dose tested. Lower CD74 expression was associated with CR/CRp (P = .04) but not with disease-free or overall survival., Conclusion: The addition of bortezomib to standard 3 + 7 daunorubicin and cytarabine induction chemotherapy for AML resulted in an encouraging remission rate. The maximum tested dose of bortezomib administered in combination with Int-DAC for remission consolidation was 1.3 mg/m(2) and proved tolerable. Further testing of this regimen is planned.

Mutations of genes encoding isocitrate dehydrogenase (IDH1 and IDH2) have been recently described in acute myeloid leukemia (AML). Serum and myeloblast samples from patients with IDH-mutant AML contain high levels of the metabolite 2-hydroxyglutarate (2-HG), a product of the altered IDH protein. In this prospective study, we sought to determine whether 2-HG can potentially serve as a noninvasive biomarker of disease burden through serial measurements in patients receiving conventional therapy for newly diagnosed AML. Our data demonstrate that serum, urine, marrow aspirate, and myeloblast 2-HG levels are significantly higher in IDH-mutant patients, with a correlation between baseline serum and urine 2-HG levels. Serum and urine 2-HG, along with IDH1/2-mutant allele burden in marrow, decreased with response to treatment. 2-HG decrease was more rapid with induction chemotherapy compared with DNA-methyltransferase inhibitor therapy. Our data suggest that serum or urine 2-HG may serve as noninvasive biomarkers of disease activity for IDH-mutant AML.

Purpose: Therapy-related myeloid neoplasms (t-MN) represent a unique clinical syndrome occurring in patients treated with chemotherapy and/or external-beam radiation (XRT) and are characterized by poorer prognosis compared with de novo disease. XRT techniques have evolved in recent years and are associated with significantly reduced bone marrow exposure. The characteristics of post-XRT t-MN in the current era have not been studied., Patients and Methods: We analyzed patients who developed acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) after XRT alone (47 patients) or cytotoxic chemotherapy/combined-modality therapy (C/CMT, 181 patients) and compared them with patients with de novo MDS or AML (222 patients). We estimated bone marrow exposure to radiation and compared the clinical, pathologic, and cytogenetic features and outcome of the XRT patients with the C/CMT patients and with patients with de novo MDS and AML., Results: Patients with t-MN after XRT alone had superior overall survival (P = .006) and lower incidence of high-risk karyotypes (P = .01 for AML and < .001 for MDS) compared with patients in the C/CMT group. In contrast, there were no significant differences in survival or frequency of high-risk karyotypes between the XRT and de novo groups., Conclusion: AML and MDS diagnosed in the past decade in patients after receiving XRT alone differ from t-MN occurring after C/CMT and share genetic features and clinical behavior with de novo AML/MDS. Our results suggest that post-XRT MDS/AML may not represent a direct consequence of radiation toxicity and warrant a therapeutic approach similar to de novo disease.

Leaving the safety of home exposes our vulnerabilities. In this issue of Blood, Uy and coauthors explore the clinical benefit of interrupting the protective niches in which leukemia cells live in an effort to enhance the benefit of chemotherapy in treating patients with acute myeloid leukemia (AML).

AML patients under the age of 60 whose blasts harbor a FLT3 internal tandem duplication (ITD) mutation have a higher relapse rate and inferior survival compared to those without this mutation. To determine if FLT3ITD also carries a negative prognostic impact in older adults receiving therapies commonly used in this age group, we retrospectively analyzed outcomes of patients ≥60 years with CN-AML according to FLT3 mutation status. We identified 91 newly diagnosed CN-AML patients, 55 with wild-type FLT3 and 36 with FLT3ITD. Of the 91 patients, 36 received supportive care and/or experimental therapies while the remaining 55 received induction chemotherapy, followed by allogeneic SCT in 17 of these patients. Based on univariate analysis, advanced age at diagnosis was significantly associated with shorter overall survival (OS) (p<.0001) while intensive therapies were associated with improved OS (p<.0001). In a multivariate analysis that accounted for type of treatment, patient age, gender, and WBC count, FLT3ITD was significantly associated with shorter OS compared to wtFLT3 [p=.001; hazard ratio (HR)=2.23; 95% CI: 1.35-3.70]. Our data support the negative prognostic impact of FLT3ITD in older adults with CN-AML., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

AKT activation is associated with many malignancies, where AKT acts, in part, by inhibiting FOXO tumor suppressors. We show a converse role for AKT/FOXOs in acute myeloid leukemia (AML). Rather than decreased FOXO activity, we observed that FOXOs are active in ∼40% of AML patient samples regardless of genetic subtype. We also observe this activity in human MLL-AF9 leukemia allele-induced AML in mice, where either activation of Akt or compound deletion of FoxO1/3/4 reduced leukemic cell growth, with the latter markedly diminishing leukemia-initiating cell (LIC) function in vivo and improving animal survival. FOXO inhibition resulted in myeloid maturation and subsequent AML cell death. FOXO activation inversely correlated with JNK/c-JUN signaling, and leukemic cells resistant to FOXO inhibition responded to JNK inhibition. These data reveal a molecular role for AKT/FOXO and JNK/c-JUN in maintaining a differentiation blockade that can be targeted to inhibit leukemias with a range of genetic lesions., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Purpose: Chronic lymphocytic leukemia (CLL) cells treated with dasatinib in vitro undergo apoptosis via inhibition of Lyn kinase. Thus, in this study we tested the activity of dasatinib in patients with relapsed CLL., Experimental Design: Patients were eligible for this phase II trial if they had documented CLL/SLL and had failed at least 1 prior therapy with a fludarabine-containing regimen and if they required therapy according to NCI-WG criteria. The starting dose of dasatinib was 140 mg daily., Results: Fifteen patients were enrolled, with a median age of 59 and a median of 3 prior regimens. All patients had received fludarabine, and 5 were fludarabine-refractory. Eleven of the 15 (73%) had high risk del(11q) or del(17p) cytogenetics. The primary toxicity was myelosuppression, with grade 3 or 4 neutropenia and thrombocytopenia in 10 and 6 patients, respectively. Partial responses by NCI-WG criteria were achieved in 3 of the 15 patients (20%; 90% CI: 6-44). Among the remaining 12 patients, 5 had nodal responses by physical exam, and 1 patient had a nodal and lymphocyte response but with severe myelosuppression. Pharmacodynamic studies indicated apoptosis in peripheral blood CLL cells within 3 to 6 hours after dasatinib administration, associated with downregulation of Syk (spleen tyrosine kinase) mRNA., Conclusions: Dasatinib as a single agent has activity in relapsed and refractory CLL., (©2011 AACR.)

Double umbilical cord blood transplantation (UCBT) with a reduced-intensity conditioning regimen is an effective strategy for adult patients without a matched donor. The risk of second malignancies in these patients has not yet been established, however. In the present study, 98 adults with a hematologic malignancy underwent double UCBT. Seventy patients received a reduced-intensity conditioning regimen of fludarabine 30 mg/m(2)/day for 6 days, melphalan 100 mg/m(2)/day for 1 day, and rabbit antithymocyte globulin 1.5 mg/kg/day for 4 days, and 28 patients received a myeloablative total body radiation-containing conditioning regimen. Sixty-three patients received sirolimus-based graft-versus-host disease (GVHD) prophylaxis, and 35 patients received non-sirolimus-based GVHD prophylaxis. The median patient age was 48 years (range, 19-67 years). Eighteen patients developed a second malignancy at a median of 134 days after transplantation. Sixteen patients had lymphoma, and 2 patients had myelodysplasic syndrome/myeloproliferative disorder (MDS/MPD). Sixteen of these second malignancies (both cases of MDS/MPD and 14 of the lymphomas) were donor-derived; the origins of the others were not determined. GVHD prophylaxis, HLA matching, primary disease, age, total nucleated cell dose, and CD34(+) cell dose were not associated with a higher rate of second malignancy. Second myelogenous malignancies of donor origin occur after double UCBT, suggesting that a search for donor origin should be performed in all patients with suspected relapse.

The BCR-ABL inhibitor imatinib revolutionized the treatment of chronic myeloid leukemia (CML). However, resistance and intolerance to imatinib have emerged as substantial clinical issues. The mechanisms underlying resistance are multifactorial and may include mutations in the kinase domain of BCR-ABL, increased production of BCR-ABL, or activation of BCR-ABL-independent pathways. Two second-line BCR-ABL inhibitors are now approved for treatment of patients with resistance or intolerance to imatinib. Dasatinib is a dual BCR-ABL/Src-family kinase (SFK) inhibitor approved for patients with imatinib-resistant and -intolerant CML in any phase and Ph+ ALL. Nilotinib, an analogue of imatinib, is approved for the treatment of imatinib-resistant or -intolerant patients with chronic or accelerated phase CML. Both agents have shown significant clinical activity in patients with imatinib-resistant or -intolerant CML, and their approval represents a major advancement in the treatment options available. Choosing the most appropriate treatment after imatinib failure may be critical in attaining the best possible long-term prognosis. The presence of certain disease characteristics (e.g. specific BCR-ABL mutations) or patient comorbidities may facilitate more effective treatment. In this review, we discuss mechanisms of imatinib resistance and preclinical and clinical data with dasatinib and nilotinib which may have potential use for guiding second-line treatment decisions.