Weinberg, Olga K.

ABSTRACT The World Health Organization (WHO) 5th Edition and International Consensus Classification (ICC) have continued to delineate more genetically defined acute leukemias. Both recognize genetic aberrations associated with myelodysplastic syndromes/neoplasms (MDS) as defining MDS‐related AML (AML‐MR). Mutations in RUNX1 are included in this category in the ICC, but not WHO. The current classifications are unclear on how acute leukemias with ambiguous lineage (ALAL), including those of mixed lineage (MPAL) and those without a defined lineage (AUL), should be categorized in the presence of such mutations. Our multi‐institutional study aims to determine the significance of RUNX1 mutation in ALAL compared to de novo AML. Newly diagnosed MPAL, AUL, and AML with RUNX1 mutations were collected. ALAL with MDS‐related cytogenetics, BCR::ABL1 , KMT2A rearrangements, or ZNF384 or BCL11b abnormalities were excluded. We analyzed 17 cases of ALAL and 71 cases of AML that met inclusion criteria. ALAL‐ RUNX1 and AML‐ RUNX1 showed overlapping mutational landscapes with frequent comutations in MDS‐associated genes. No ALAL‐ RUNX1 or AML‐ RUNX1 cases showed concomitant TP53 mutation. ALAL‐ RUNX1 had more bone marrow blasts and more karyotypic abnormalities; however, neither impacted survival, nor did RUNX1 variant allele frequency (VAF). Survival analysis revealed similarly poor outcomes between them. AML‐directed therapies and allogeneic hematopoietic stem cell transplant trended toward improved survival in ALAL‐ RUNX1; however, it did not reach significance. Our results suggest ALAL‐ RUNX1 is associated with younger age, higher blasts, and more karyotypic abnormalities, but has similar clinical and genetic features and outcomes to AML‐ RUNX1 . Our findings suggest, like other MR mutations, RUNX1 ‐mutated ALALs should be included within AML‐MR.

Abstract Objective The successful diagnosis and classification of lymphoid neoplasms in blood and bone marrow is the responsibility of the practicing pathologist. This guide provides a general “roadmap” for this process, from initial case recognition to final classification. Methods The integration of hematologic, morphologic, immunophenotypic, and genetic features for the full spectrum of precursor and mature B-cell, T-cell, and natural killer–cell neoplasms that typically manifest in blood and bone marrow is included. Results Classification systems for lymphoid neoplasms provide criteria for pathologists to render a diagnosis that is optimal for patient care, treatment, and outcome prediction. Conclusions This guide provides diagnostic strategies for lymphoid neoplasms encountered in blood and bone marrow specimens using both the International Consensus Classification and the World Health Organization fifth edition classification systems. Key tips are provided for each entity along with testing requirements, differential diagnosis, nonneoplastic mimics, and other unique features based on the experience of the Bone Marrow Pathology Group members.

Background: Clonal cytopenia of undetermined significance (CCUS) is characterized by the presence of a clone with somatic mutations in genes associated with myeloid neoplasms (MN) or abnormal cytogenetics, along with unexplained and persistent cytopenias in the absence of significant marrow dysplasia. CCUS is considered a premalignant state with a risk of progression to MN. The clinical outcomes of patients (pts) with high risk CCUS (Weeks et al, NEJM Evidence 2023) may be similar that of some patients with myelodysplastic syndromes (MDS). This study aims to predict the outcomes of CCUS patients using the molecular international prognostic scoring system (IPSS-M) developed for MDS. Methods: A retrospective analysis was conducted in patients diagnosed with CCUS between 2015 and 2023, we included patients harboring pathogenic mutations (MUT) identified through next-generation sequencing (NGS) testing at two institutions: Mayo Clinic and the University of Texas Southwestern Medical Center, Dallas, TX, USA were included. Progression was considered present if patients with CCUS progressed into myeloid neoplasm at follow up. Statistical analysis was performed using JMP® 17.1.0 Software. IPSS-M risk scores were calculated via the IPSS-M Risk Calculator (mds-risk-model.com). Results: A total of 103 patients were included in the study. The median age was 72 years, the majority were male patients (73%), and the median bone marrow blast % at the time of NGS was 1%. Forty-five % had an isolated mutation in a single gene, and 55% had co-mutations in ≥1 gene. The median number of mutations was 2 (range 1 - 5), occurring across 43 different genes. The most common mutations were in TET2 (N=28; 27%), ASXL1 (N=21; 20%), SRSF2 (N=21; 20%), U2AF1 (N=18; 17%), DNMT3A (N=16; 16%), and TP53 (N=12; 12%). Additionally, 25% of patients had an abnormal karyotype. Hematologic and genetic characteristics are summarized in (Table 1A). The median IPSS-M score was -0.9 (-3 to +2.34) and the median IPSS- Revised (R) score was 2 (0 - 6). The majority of patients had low (L) IPSS-M risk category (53%), followed by moderate low (ML) (19%) and very low (VL) (17%). Per IPSS-R, the majority had low-risk category (47%), followed by VL (38%) and intermediate (14%). Overall, 26 (25%) pt died after a median follow-up of 34 months and 21% progressed to MN (MDS 14 & CMML 8), and 1 patient with MDS and 1 with CMML progressed to secondary AML (2%). The median overall survival (mOS) was not reached, with a 2-year estimated (YE) OS and leukemia-free survival (LFS) of 80%. Predictive Power: When utilizing the IPSS-M risk category ( L, M, H) * by combining the risk categories into L *(L+VL), M * (ML+MH), and H *(H+VH) to overcome the low sample size limitation, it significantly predicted OS (p < .0001) ( Figure 1A) and median MN-free survival (FS) (p < .0001) ( Figure 1B). The 2YE-OS rates by IPSS-M risk category were as follows: VL - 93%, L - 87%, ML - 75%, high (H) - 25%, very high (VH) - 0% and the 2YE-OS rates by IPSS-M ( L, M, H) are summarized in Table 1B. IPSS-M hazard ratio (HR) for OS was 1.6 for ( M*) compared to 25 for ( H *) risk category (p < .0001). The ( L *) category, being the largest, was used as the reference level. Conclusion: This study provides the first real-world experience of using the IPSS-M and a modified version of the IPSS-M ( L, M, H) * risk category model to predict survival and progression into MN in CCUS (MUT) pt. The IPSS-M risk category was found to be a significant predictor of OS and MN-free survival. We propose that larger cohorts are needed to validate our findings.

Abstract The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.

Background:PRM‐151, a recombinant human pentraxin‐2 molecule, prevents and reverses fibrosis in animal models of myelofibrosis (MF) in part by targeting differentiation of fibrocytes from monocytes. In the first stage of a two‐stage trial, treatment of patients (pts) with primary (PMF), post‐essential thrombocythemia/polycythemia vera (post‐ET/PV) MF with PRM‐151 ± ruxolitinib (Rux) was associated with decreases in bone marrow fibrosis (BMF), improvements in hemoglobin (Hgb) and platelets (PLT), reductions in transfusions and symptoms, and modest reductions in splenomegaly.Aims:Here, we report efficacy and safety data from a stage 2 randomized, double‐blind evaluation of single agent PRM‐151.Methods:Pts with DIPPS Int‐1, Int‐2, and high risk PMF or post‐ET/PV MF who were ineligible for, intolerant of, or had an inadequate response to Rux were randomized between 0.3, 3, and 10 mg/kg of PRM‐151 as a sole agent. PRM‐151 was to be administered by IV infusion at one of the three assigned doses on Days 1, 3, and 5 of Cycle 1 and on Day 1 of each subsequent 28‐day cycle for at least 9 cycles. Randomization was stratified according to baseline (BL) Hgb <100 g/L receiving transfusions and/or PLT <50 x 109/L. Bone marrow biopsies and imaging for spleen volume were obtained at BL, C4D1, C7D1, and C9D29. BMF score was evaluated centrally by three independent, blinded hematopathologists. The primary objective of the study was to determine the effect size of three different doses of PRM‐151 on reduction in BMF by ≥ 1 grade at any time during the study.Results:Of the 98 randomized patients, 97 were treated with 0.3 mg/kg (n = 33), 3 mg/kg (n = 32), or 10 mg/kg (n = 32). BL characteristics are provided in Table 1. Forty‐six pts discontinued treatment prior to Cycle 9. Decrease in BMF grade at any time was observed in 10 of 33 pts (30%) at 0.3 mg/kg, 9 of 31 pts (28%) at 3 mg/kg, and 8 of 32 pts (25%) at 10 mg/kg. Decrease in BM collagen grade was observed in 31–37% of pts. In pts who were RBC transfusion dependent or with Hgb <100 g/L and transfusion independent at BL, 16–29% of pts had ≥50% reduction in RBC transfusions or Hgb increases ≥10 g/L for ≥12 consecutive weeks. In pts who were PLT transfusion dependent or with PLT<25 or PLT25‐<50 x 109/L and transfusion independent at BL, 31–40% of pts had ≥50% reduction in PLT transfusions, PLT ≥25 x 109/L or PLT ≥50 x 109/L or doubling of PLT count, without transfusions for ≥12 consecutive weeks. Improvement from BL in MPN‐SAF TSS of ≥25% for ≥12 consecutive weeks was observed in 10–26% of pts. Reduction in spleen volume was observed with a maximum reduction of 34% in one pt. Response rates for BM collagen, Hgb, PLT, MPN‐SAF, and spleen were generally similar across the three dose levels. The most common treatment emergent adverse events (AEs) were fatigue, cough, thrombocytopenia, and abnormal weight loss. A majority of the AEs were Grade 2 or lower in severity and consistent with disease progression. Grade 3 and 4 related AEs were reported in 12% and 6% of pts, respectively.Summary/Conclusion:The study enrolled a large proportion of MF pts with advanced disease (Int‐2 or high risk, BMF grade 3, anemic/transfusion dependent, and PLT <50 x 109/L). Decrease in BMF and collagen grade were observed across all dose levels. Increases in Hgb and PLT count or reduction in transfusion requirements were also reported across all dose levels. Improvements in MPN‐SAF TSS and spleen volume were observed in a proportion of pts. PRM‐151 treatment for up to 9 cycles was well tolerated. These data warrant confirmation in a larger controlled study.image

Abstract Objectives Given the increased complexity of molecular and cytogenetic testing (MOL-CG), the Society for Hematopathology Education Committee (SH-EC) was interested in determining what the current expectations are for MOL-CG education in hematopathology (HP) fellowship training. Methods The SH-EC sent a questionnaire to HP fellowship program directors (HP-PDs) covering MOL-CG training curricula, test menus, faculty background, teaching, and sign-out roles. These findings were explored via a panel-based discussion at the 2018 SH-EC meeting for HP-PDs. Results HP fellows are expected to understand basic principles, nomenclature, and indications for and limitations of testing. Interpretation of common assays is within that scope, but not necessarily proficiency in technical troubleshooting of testing or analysis of complex raw data. Conclusions The consensus was that HP fellows should understand the components of MOL-CG testing necessary to incorporate those results into an accurate, clinically relevant, and integrated HP report.