Prognostic impact of SF3B1 mutation and multilineage dysplasia in myelodysplastic syndromes with ring sideroblasts: a Mayo Clinic study of 170 informative cases.

The revised 4th edition of the World Health Organization (WHO4R) classification lists myelodysplastic syndromes with ring sideroblasts (MDS-RS) as a separate entity with single lineage (MDS-RS-SLD) or multilineage (MDS-RS-MLD) dysplasia. The more recent International Consensus Classification (ICC) distinguishes between MDS with SF3B1 mutation (MDS-SF3B1) and MDS-RS without SF3B1 mutation; the latter is instead included under the category of MDS not otherwise specified. The current study includes 170 Mayo Clinic patients with WHO4R-defined MDS-RS, including MDS-RS-SLD (N=83) and MDS-RS-MLD (N=87); a subset of 145 patients were also evaluable for the presence of SF3B1 and other mutations, including 126 with (87%) and 19 (13%) without SF3B1 mutation. Median overall survival for all 170 patients was 6.6 years with 5- and 10-year survival rates of 59% and 25%, respectively. A significant difference in overall survival was apparent between MDS-RS-MLD and MDS-RS-SLD (p<0.01) but not between MDS-RS with and without SF3B1 mutation (p=0.36). Multivariable analysis confirmed the independent prognostic contribution of MLD (HR 1.8, 95% CI 1.1-2.8; p=0.01) and also identified age (p<0.01), transfusion need at diagnosis (p<0.01), and abnormal karyotype (p<0.01), as additional risk factors; the impact from SF3B1 or other mutations was not significant. Leukemia-free survival was independently affected by abnormal karyotype (p<0.01), RUNX1 (0.02) and IDH1 (p=0.01) mutations, but not by MLD or SF3B1 mutation. Exclusion of patients not meeting ICC-criteria for MDSSF3B1 did not change the observations on overall survival. MLD-based, as opposed to SF3B1 mutationbased, disease classification for MDS-RS might be prognostically more relevant.

One thousand patients with essential thrombocythemia: the Mayo Clinic experience.

We describe 1000 patients with essential thrombocythemia seen at the Mayo Clinic between 1967 and 2023: median age 58 years (18-90), females 63%, JAK2/CALR/MPL-mutated 62%/27%/3%, triple-negative (TN) 8%, extreme thrombocytosis (ExT; platelets ≥1000 × 109/L) 26%, leukocytosis (leukocyte count >11 × 109/L) 20%, and abnormal karyotype 6%. JAK2-mutated patients were older (median 71 years), and CALR mutated (52 years), and TN (50 years) younger (p < 0.01). Female gender clustered with TN (73%) and JAK2 (69%) vs. CALR/MPL (49%/47%) mutations (p < 0.01). ExT clustered with CALR (type-2 more than type-1) and TN and leukocytosis with JAK2 mutation (p < 0.01). In multivariable analysis, risk factors for overall survival were older age (p < 0.01), male gender (HR 1.8), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.6), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.5), hypertension (HR 1.7), and arterial thrombosis history (HR 1.7); for leukemia-free survival, ExT (HR 2.3) and abnormal karyotype (HR 3.1); for myelofibrosis-free survival, ANC ≥ 8 × 109/L (HR 2.3) and MPL mutation (HR 3.9); for arterial thrombosis-free survival, age ≥60 years (HR 1.9), male gender (HR 1.6), arterial thrombosis history (HR 1.7), hypertension (HR 1.7), and JAK2 mutation (HR 1.8); for venous thrombosis-free survival, male gender (HR 1.8) and venous thrombosis history (HR 3.0). Associations between ExT and leukemic transformation and between ANC and fibrotic progression were limited to JAK2-mutated cases. Aspirin therapy appeared to mitigate both arterial (HR 0.4) and venous (HR 0.4) thrombosis risk. HR-based risk models delineated patients with median survivals ranging from 10 years to not reached and 20-year leukemia/myelofibrosis incidences from 3%/21% to 12.8%/49%. The current study provides both novel and confirmatory observations of essential thrombocythemia.

Reappraisal of mast cell leukemia based on a single institution review of 16 cases: Mast cell morphology determines clinical outcome.

Cytologic abnormalities of atypical mast cells in mastocytosis. The mature mast cells have oval-shaped nuclei, cytoplasmic hypogranulation and spindle-shaped cytology. or well-differentiated displaying a round nucleus with condensed chromatin, and abundant dense cytoplasmic granulations. Immature mast cells include promastocytes and metachromatic blast-like forms.

Venetoclax duration (14 vs. 21 vs. 28 days) in combination with hypomethylating agent in newly diagnosed acute myeloid leukemia: Comparative analysis of response, toxicity, and survival.

Overall survival and response rates of 270 patients with newly diagnosed acute myeloid leukemia receiving venetoclax (Ven) plus hypomethylating agent, stratified by Ven dosing schedule (Cycle 1 Ven 14 vs. 21 vs. 28 days).

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

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

Therapy-related clonal cytopenia as a precursor to therapy-related myeloid neoplasms.

Therapy-related myeloid neoplasms (t-MN) are aggressive leukemia that develops as a complication of prior exposure to DNA-damaging agents. Clonal cytopenia of undetermined significance (CCUS) is a precursor of de novo myeloid neoplasms. Characteristics of CCUS that develop following cytotoxic therapies (therapy-related clonal cytopenia, t-CC) and outcomes following t-CC have not been described. We identified 33 patients with t-CC and compared to a cohort of the WHO-defined t-MN (n = 309). t-CC had a distinct genetic and cytogenetic profile: pathogenic variants (PV) in TET2 and SRSF2 were enriched in t-CC, whereas TP53 PV was more common in t-MN. Ten (30%) t-CC patients developed a subsequent t-MN, with a cumulative incidence of 13%, 23%, and 50% at 6 months, 1, and 5 years, respectively. At t-MN progression, 44% of evaluable patients had identifiable clonal evolution. The median survival following t-CC was significantly superior compared all t-MN phenotype including t-MDS with <5% bone marrow blasts (124.5 vs. 16.3 months, P < 0.001) respectively. The presence of cytogenetic abnormality and the absence of variants in DNMT3A, TET2, or ASXL1 (DTA-genes) were associated with a higher likelihood of developing a subsequent t-MN and an inferior survival. We describe a putative precursor entity of t-MN with distinct features and outcomes.

A dynamic 3-factor survival model for acute myeloid leukemia that accounts for response to induction chemotherapy.

The current study was approached with the assumption that response to induction chemotherapy, in acute myeloid leukemia (AML), overshadows pre-treatment risk variables in predicting survival and therefore be used as an anchor for a simplified risk model. We considered 759 intensively-treated patients with AML, not promyelocytic: median age 60 years; primary 66%, secondary 25%, and therapy-related 9%; European LeukemiaNet cytogenetic risk category favorable 8%, intermediate 61%, and adverse 31%. Complete remission with (CR) or without (CRi) count recovery was achieved in 608 (80%) patients. After a median follow-up of 22 months, 503 deaths, 272 relapses, and 257 allogeneic hematopoietic stem cell transplants (AHSCTs) were recorded. Multivariable analysis identified failure to achieve CR/CRi (HR 3.8, 95% CI 3.1-4.8), adverse karyotype (2.2, 1.8-2.8), and age >55 years (2.1, 1.6-2.7) as main risk factors for survival. HR-weighted scoring resulted in four-tiered risk stratification: low (0 points; N = 183), intermediate-1 (1 point; N = 331), intermediate-2 (2 points; N = 117), and high (≥3 points; N = 128), with respective median survival (5-year rate) not reached (68%), 34 (37%), 13 (20%), and 5 (5%) months (p < .001). FLT3-ITD mutation was associated with inferior survival in intermediate-1 (p = .004) and TP53 in intermediate-2 (p = .06) and high (p = .02) risk disease; the latter was fully accounted for by the close association between TP53 mutation and complex/monosomal karyotype while the observations regarding FLT3-ITD were not affected by treatment with midostaurin. AHSCT had a favorable impact on survival, most apparent in intermediate-1 (p < .001), intermediate-2 (p = .03), and high (p = .01) risk disease. The proposed 3-factor survival model offers a novel prototype that is amenable to further enhancement by molecular information and was validated in an external cohort of 1032 intensively-treated AML patients.

Chronic neutrophilic leukemia: 2022 update on diagnosis, genomic landscape, prognosis, and management.

DISEASE OVERVIEW: Chronic neutrophilic leukemia (CNL) is a rare, often aggressive myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis, bone marrow granulocyte hyperplasia, and frequent hepatosplenomegaly. The 2013 seminal discovery of oncogenic driver mutations in colony-stimulating factor 3 receptor (CSF3R) in the majority of patients with CNL not only established its molecular pathogenesis but provided a diagnostic biomarker and rationale for pharmacological targeting. DIAGNOSIS: In 2016, the World Health Organization (WHO) recognized activating CSF3R mutations as a central diagnostic feature of CNL. Other criteria include leukocytosis of ≥25 × 109 /L comprising >80% neutrophils with <10% circulating precursors and rare blasts, and absence of dysplasia or monocytosis, while not fulfilling criteria for other MPN. MANAGEMENT: There is currently no standard of care for management of CNL, due in large part to the rarity of disease and dearth of formal clinical trials. Most commonly used therapeutic agents include conventional oral chemotherapy (e.g., hydroxyurea), interferon, and Janus kinase (JAK) inhibitors, while hematopoietic stem cell transplant remains the only potentially curative modality. DISEASE UPDATES: Increasingly comprehensive genetic profiling in CNL, including new data on clonal evolution, has disclosed a complex genomic landscape with additional mutations and combinations thereof driving disease progression and drug resistance. Although accurate prognostic stratification and therapeutic decision-making remain challenging in CNL, emerging data on molecular biomarkers and the addition of newer agents, such as JAK inhibitors, to the therapeutic arsenal, are paving the way toward greater standardization and improvement of patient care.