Phase 1 study of azacitidine in combination with quizartinib in patients with FLT3 or CBL mutated MDS and MDS/MPN.

We conducted a phase 1 study evaluating 3 dose levels of quizartinib (30 mg, 40 mg or 60 mg) in combination with azacitidine for HMA-naïve or relapsed/refractory MDS or MDS/MPN with FLT3 or CBL mutations. Overall, 12 patients (HMA naïve: n=9, HMA failure: n=3) were enrolled; 7 (58 %) patients had FLT3 mutations and 5 (42 %) had CBL mutations. The maximum tolerated dose was not reached. Most common grade 3-4 treatment-emergent adverse events were thrombocytopenia (n=5, 42 %), anemia (n=4, 33 %), lung infection (n=2, 17 %), skin infection (n=2, 17 %), hyponatremia (n=2, 17 %) and sepsis (n=2, 17 %). The overall response rate was 83 % with median relapse-free and overall survivals of 15.1 months (95 % CI 0.0-38.4 months) and 17.5 months (95 % CI NC-NC), respectively. FLT3 mutation clearance was observed in 57 % (n=4) patients. These data suggest quizartinib is safe and shows encouraging activity in FLT3-mutated MDS and MDS/MPN. This study is registered at Clinicaltrials.gov as NCT04493138.

Ponatinib-review of historical development, current status, and future research.

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

Outcomes and genetic dynamics of acute myeloid leukemia at first relapse.

Patients with relapsed acute myeloid leukemia (rAML) experience dismal outcomes. We performed a comprehensive analysis of patients with rAML to determine the genetic dynamics and survival predictive factors. We analyzed 875 patients with newly diagnosed AML who received intensive treatment (IT) or low-intensity treatment (LIT). Of these patients, 197 experienced subsequent rAML. Data was available for 164 patients, with a median time from CR/CRi to relapse of 6.5 months. Thirty-five of the 164 patients (21%) experienced relapse after allogeneic hematopoietic stem cell transplantation (alloSCT). At relapse mutations in genes involved in pathway signaling tended to disappear, whereas clonal hematopoiesis-related mutations or TP53 tended to persist. Patients with normal karyotypes tended to acquire cytogenetic abnormalities at relapse. Patients treated with IT had a higher emergence rate of TP53 mutations (16%), compared to patients treated with LIT (1%, P = 0.009). The overall response rates were 38% and 35% for patients treated with salvage IT or LIT, respectively. Seventeen patients (10%) underwent alloSCT after salvage therapy. The median overall survival (OS) duration after relapse was 5.3 months, with a 1-year OS rate of 17.6%. Complex karyotype (hazard ratio [HR] = 2.14, P < 0.001), a KMT2A rearrangement (HR = 3.52, P = 0.011), time in remission < 12 months (HR = 1.71, P = 0.011), and an elevated white blood cell count at relapse (HR = 2.38, P = 0.005) were independent risk factors for OS duration. More effective frontline and maintenance therapies are warranted to prevent rAML.

Diagnostic utility of immunohistochemistry in detection of NPM1 mutations in acute myeloid leukemia with a patchy distribution.

Nucleophosmin 1 (NPM1) mutations occur in approximately one-third cases of adult de novo acute myeloid leukemia (AML). Identification of NPM1 mutations is important for classification, risk stratification, tailored therapy, and monitoring minimal residual disease. Mutational analysis is widely used for detecting NPM1 mutations. Immunochemistry assessing abnormal cytoplasmic localization of NPM1 protein has been used as a surrogate marker for NPM1 mutations. We present a case of AML with mutated NPM1 that was missed by sequencing analysis but detected by immunohistochemistry. This case highlights the value of immunohistochemistry in identifying NPM1 mutations in a subset of AML cases.

Characteristics and outcomes of acute myeloid leukaemia patients with baseline CD7 expression.

Targeted therapy development for acute myeloid leukaemia (AML) requires an understanding of specific expression profiles. We collected flow cytometry data on 901 AML patients and recorded aberrant CD7 expression on leukaemic blasts. 263 (29.2%) had blasts positive for CD7. CD7+ AML was more likely to be adverse risk (64.6% vs. 55.6%, p = 0.0074) and less likely to be favourable risk (15.2% vs. 24.1%, p = 0.0074) by European LeukemiaNet 2022 criteria. Overall survival was inferior (11.9 [95% CI, 9.7-15.9] vs. 19.0 months [95% CI, 16.1-23.0], p = 0.0174). At relapse, 30.4% lost and 19.0% gained CD7, suggesting moderate instability over time.

BRG1/BRM inhibitor targets AML stem cells and exerts superior preclinical efficacy combined with BET or Menin inhibitor.

BRG1 (SMARCA4) and BRM (SMARCA2) are the mutually exclusive core ATPases of the chromatin remodeling BAF (BRG1/BRM-associated factor) complexes. They enable transcription factors/co-factors to access enhancers/promoter and modulate gene-expressions responsible for cell growth and differentiation of AML stem/progenitor cells. In AML with MLL1r (MLL1 rearrangement) or mutant (mt) NPM1, although Menin inhibitor (MI) treatment induces clinical remissions, most patients either fail to respond or relapse, some harboring Menin mutations. FHD-286 is an orally bioavailable, selective inhibitor of BRG1/BRM under clinical development in AML. Present studies show that FHD-286 induces differentiation and lethality in AML cells with MLL1r or mtNPM1, concomitantly causing perturbed chromatin accessibility and repression of c-Myc, PU.1 and CDK4/6. Co-treatment with FHD-286 and decitabine, BET inhibitor (BETi) or MI, or venetoclax synergistically induced in vitro lethality in AML cells with MLL1r or mtNPM1. In patient-derived xenograft (PDX) models of AML with MLL1r or mtNPM1, FHD-286 treatment reduced AML burden, improved survival, and attenuated AML-initiating potential of stem-progenitor cells. Compared to each drug, co-treatment with FHD-286 and BETi, MI, decitabine or venetoclax significantly reduced AML burden and improved survival, without inducing significant toxicity. These findings highlight the FHD-286-based combinations as promising therapy of AML with MLL1r or mtNPM1.

Hematopoietic stem cells with granulo-monocytic differentiation state overcome venetoclax sensitivity in patients with myelodysplastic syndromes.

The molecular mechanisms of venetoclax-based therapy failure in patients with acute myeloid leukemia were recently clarified, but the mechanisms by which patients with myelodysplastic syndromes (MDS) acquire secondary resistance to venetoclax after an initial response remain to be elucidated. Here, we show an expansion of MDS hematopoietic stem cells (HSCs) with a granulo-monocytic-biased transcriptional differentiation state in MDS patients who initially responded to venetoclax but eventually relapsed. While MDS HSCs in an undifferentiated cellular state are sensitive to venetoclax treatment, differentiation towards a granulo-monocytic-biased transcriptional state, through the acquisition or expansion of clones with STAG2 or RUNX1 mutations, affects HSCs' survival dependence from BCL2-mediated anti-apoptotic pathways to TNFα-induced pro-survival NF-κB signaling and drives resistance to venetoclax-mediated cytotoxicity. Our findings reveal how hematopoietic stem and progenitor cell (HSPC) can eventually overcome therapy-induced depletion and underscore the importance of using close molecular monitoring to prevent HSPC hierarchical change in MDS patients enrolled in clinical trials of venetoclax.

Outcome of Patients With Relapsed Acute Promyelocytic Leukemia.

BACKGROUND: The outcome of patients with acute promyelocytic leukemia (APL) has improved significantly since the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) as APL therapies. The optimal therapy for APL relapse is believed to require autologous or allogeneic stem cell transplantation (SCT) based on historical experience. STUDY AIMS: To evaluate the outcome of patients with relapsed APL before and after the era of ATRA-ATO. PATIENTS AND METHODS: We reviewed 61 patients with relapsed APL treated from November 1991 to June 2023; 31 patients (51%) received modern therapy with the combination of ATRA and ATO with and without idarubicin and gemtuzumab ozogamicin (GO). RESULTS: Overall, 56 patients (92%) achieved CR after the first salvage therapy; 20 patients received SCT (10 autologous SCT;10 allogeneic SCT). With a median follow-up time of 138 months, the median survival durations were 32 months and 164 months with historical therapy vs. modern (ATRA-ATO) therapy (P = .035); the 5-year survival rates were 44% vs. 71%. With a 10-month landmark analysis, the median survival durations were 102 months vs. not reached, and the 5-year survival rates were 57% and 70% without SCT vs. with SCT (P = .193). The survival benefit with SCT was more prominent in the historical therapy era. However, patients who received the modern combination therapy of ATRA-ATO with and without idarubicin and GO had similar outcomes without vs. with SCT (P = .848). CONCLUSION: The combination of ATRA-ATO (+/- GO and idarubicin) is a highly effective salvage therapy in relapsed APL. The use of SCT may not be needed after first relapse-second remission but may be considered in subsequent relapses.

Fifth Edition of the World Health Organization Classification of Tumors of the Hematopoietic and Lymphoid Tissues: Acute Lymphoblastic Leukemias, Mixed-Phenotype Acute Leukemias, Myeloid/Lymphoid Neoplasms With Eosinophilia, Dendritic/Histiocytic Neoplasms, and Genetic Tumor Syndromes.

This manuscript represents a review of lymphoblastic leukemia/lymphoma (acute lymphoblastic leukemia/lymphoblastic lymphoma), acute leukemias of ambiguous lineage, mixed-phenotype acute leukemias, myeloid/lymphoid neoplasms with eosinophilia and defining gene rearrangements, histiocytic and dendritic neoplasms, and genetic tumor syndromes of the 5th edition of the World Health Organization Classification of Tumors of the Hematopoietic and Lymphoid Tissues. The diagnostic, clinicopathologic, cytogenetic, and molecular genetic features are discussed. The differences in comparison to the 4th revised edition of the World Health Organization classification of hematolymphoid neoplasms are highlighted.

SOHO State of the Art Updates and Next Questions | Diagnosis, Outcomes, and Management of Prefibrotic Myelofibrosis.

Prefibrotic primary myelofibrosis (prefibrotic PMF) is a myeloproliferative neoplasm with distinct characteristics comprising histopathological and clinico-biological parameters. It is classified as a subtype of primary myelofibrosis. In clinical practice, it is essential to correctly distinguish prefibrotic PMF from essential thrombocythemia especially but also overt PMF besides other myeloid neoplasms. Risk stratification and survival outcomes for prefibrotic PMF are worse than that of ET but better than that of overt PMF. Rates of progression to overt PMF and blast phase disease are also higher for prefibrotic PMF than ET. In this review we first discuss the historical context to the evolution of prefibrotic PMF as an entity, its presenting features and diagnostic criteria. We emphasize the differences between prefibrotic PMF, ET, and overt PMF with regards to presenting features and disease outcomes including thrombohemorrhagic events and progression to fibrotic and blast phase disease. Next, we discuss the risk stratification models and contextualize these in the setting of clinical management. We share our view of personalizing treatment to address unique patient needs in the context of currently available management options. Lastly, we discuss areas of critical need in clinical research and speculate on the possibility of future disease course modifying therapies in prefibrotic PMF.

Targetable genetic abnormalities in patients with acute myeloblastic leukemia across age groups.

Incidence of potential targetable genetic abnormalities by age in AML.

Efficacy of novel agents against cellular models of familial platelet disorder with myeloid malignancy (FPD-MM).

Germline, mono-allelic mutations in RUNX1 cause familial platelet disorder (RUNX1-FPD) that evolves into myeloid malignancy (FPD-MM): MDS or AML. FPD-MM commonly harbors co-mutations in the second RUNX1 allele and/or other epigenetic regulators. Here we utilized patient-derived (PD) FPD-MM cells and established the first FPD-MM AML cell line (GMR-AML1). GMR-AML1 cells exhibited active super-enhancers of MYB, MYC, BCL2 and CDK6, augmented expressions of c-Myc, c-Myb, EVI1 and PLK1 and surface markers of AML stem cells. In longitudinally studied bone marrow cells from a patient at FPD-MM vs RUNX1-FPD state, we confirmed increased chromatin accessibility and mRNA expressions of MYB, MECOM and BCL2 in FPD-MM cells. GMR-AML1 and PD FPD-MM cells were sensitive to homoharringtonine (HHT or omacetaxine) or mebendazole-induced lethality, associated with repression of c-Myc, EVI1, PLK1, CDK6 and MCL1. Co-treatment with MB and the PLK1 inhibitor volasertib exerted synergistic in vitro lethality in GMR-AML1 cells. In luciferase-expressing GMR-AML1 xenograft model, MB, omacetaxine or volasertib monotherapy, or co-treatment with MB and volasertib, significantly reduced AML burden and improved survival in the immune-depleted mice. These findings highlight the molecular features of FPD-MM progression and demonstrate HHT, MB and/or volasertib as effective agents against cellular models of FPD-MM.

Optical genomic mapping is a helpful tool for detecting CCND1 rearrangements in CD5-negative small B-cell lymphoma: Two cases of leukemic non-nodal mantle cell lymphoma.

Optical genome mapping (OGM) is a new DNA-based technology which provides comprehensive examination of the entire genome. We report two patients who presented with splenomegaly and leukocytosis with lymphocytosis including villous lymphocytes. Neither patient had lymphadenopathy. Bone marrow evaluation showed involvement by small B-cell lymphoma in a sinusoidal and interstitial distribution, and immunophenotypic analysis showed that the neoplastic cells were positive for B-cell markers and cyclin D1 but were negative for SOX11 and CD5. Initially, the clinicopathologic features in both patients were thought to be suspicious for hairy cell leukemia variant or splenic marginal zone lymphoma. However, OGM detected CCND1 rearrangement: t(2;11)/IGK::CCND1 in one case and t(11;14)/IGH::CCND1 in the other case. These cases illustrate the valuable role OGM can play in establishing the diagnosis of MCL. Case 1 also contributes to the paucity of literature on the rare occurrence of IGK::CCND1 in MCL.

Practical considerations in clinical application of WHO 5th and ICC classification schemes for acute myeloid leukemia.

The updated WHO 5th edition and ICC 2022 classification systems for AML aim to refine our diagnostic criteria and definitions of AML with deeper incorporation of cytogenetic and molecular aberrations. The two classification systems diverge, however, in numerous AML defining criteria and subclassifications, including the incorporation of blast enumeration and the integration of specific genomic mutations. These differences often create challenges for clinicians in not only establishing a diagnosis of AML, but also in determining the best treatment plan for patients. In this review, we highlight the literature surrounding the contrasting areas between the WHO and ICC guidelines and offer guidance in the clinical application of these guidelines in the management of patients with AML.

Phase 1/2 study of CPX-351 for patients with Int-2 or high risk International Prognostic Scoring System myelodysplastic syndromes and chronic myelomonocytic leukaemia after failure to hypomethylating agents.

Failure after hypomethylating agents (HMAs) is associated with dismal outcomes in higher risk myelodysplastic syndromes (HR-MDS) or chronic myelomonocytic leukaemia (CMML). We aimed to evaluate the safety and preliminary activity of lower doses of CPX-351, a liposomal encapsulation of cytarabine and daunorubicin, in a single-centre, phase 1/2 study for patients with HR-MDS or CMML after HMA failure. Four doses of CPX-351 (10, 25, 50 and 75 units/m2 ) administered on Days 1, 3 and 5 of induction and Days 1 and 3 of consolidation were evaluated. Between June 2019 and June 2023, 25 patients were enrolled (phase 1: n = 15; phase 2: n = 10) including 19 (76%) with HR-MDS and 6 (24%) with CMML. Most common grade 3-4 non-haematological treatment-emergent adverse events were febrile neutropenia (n = 12, 48%) and lung infection (n = 5, 20%). Three patients (age >75) experienced cardiac toxicity at the 75 units/m2 dose. Further enrolment continued at 50 units/m2 . Four- and 8-week mortality were 0% and 8% respectively. The overall response rate was 56% with median relapse-free and overall survivals of 9.2 (95% CI 3.2-15.1 months) and 8.7 months (95% CI 1.8-15.6 months) respectively. These data suggest that lower doses of CPX-351 are safe. Further studies are needed to evaluate its activity.

Current State and Future Prospects of Diagnosis and Management of TP53-Mutated Myeloid Neoplasms.

TP53-mutated myeloid neoplasms including acute myeloid leukemia (AML) and myelodysplastic neoplasms (MDS) are notoriously treatment resistant with uniformly poor outcomes. TP53 status is an important prognostic indicator and early knowledge of the TP53 mutation/allelic state may assist in appropriate management including clinical trial enrollment for eligible patients. Thus far, no therapy has shown to demonstrate durable response or incremental survival benefit in TP53-mutated AML or MDS. Therefore, there is an urgent need for innovative therapies to improve the outcomes in this notoriously recalcitrant genomic subset. In this review, we dissect the biology, classification, prognosis, current treatment landscape, and the early phase evaluation of investigational agents in TP53-mutated AML and MDS.