MPN-540 Disease Progression and Leukemic Transformation in Patients With Lower-Risk Myelofibrosis: An Analysis From the Myelofibrosis and Essential Thrombocythemia Observational Study (MOST)

• Published in: Clinical lymphoma, myeloma and leukemia Vol. 23; p. S400
• Main Authors: Komrokji, Rami, Grunwald, Michael R., Braunstein, Evan, Hamer-Maansson, J.E., Kalafut, Tricia, Mascarenhas, John
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2023
• Subjects: leukemic transformation; myelofibrosis; progressive disease; leukemic transformation; myelofibrosis; progressive disease
• ISSN: 2152-2650; 2152-2669
• DOI: 10.1016/S2152-2650(23)01252-1

Progressive disease (PD) in myelofibrosis is associated with increased bone marrow fibrosis, worsening anemia, and increased circulating blasts, and can result in leukemic transformation (LT). Real-world data regarding PD and LT in lower-risk myelofibrosis are limited. An analysis of MOST (NCT02953704) describing PD/LT incidence in lower-risk patients and comparing characteristics of patients with vs without physician-reported PD. Longitudinal, noninterventional, prospective study. Adults with DIPSS low/intermediate-1–risk myelofibrosis (age >65 years alone). Of 232 patients enrolled, 204 were analyzed (cutoff: 09/30/2022; with PD, n=59; without PD, n=134; unknown, n=11; median [range] time from diagnosis to enrollment, 1.8 [0-38] years; median [range] enrollment duration, 4.4 [3.5-5.6] years). Versus non-PD patients, PD patients were older (median [range], 70.0 [35-88] vs 66.5 [35-88] years), more were Black (10.2% vs 5.2%), fewer were employed (20.3% vs 44.4%); and more were unable to work (16.9% vs 2.3%). Among PD patients, PD indicators were reported (per physician) as changes in hematologic parameters (45.8%), spleen size (32.2%), myelofibrosis symptoms (27.1%), and blasts (13.6%); 25.4% had LT; 20.3% died from PD. More low-risk patients had changes in blasts (20.0% vs 10.3%); fewer had LT (20.0% vs 28.2%); fewer died from PD (10.0% vs 25.6%) vs intermediate-1 risk. Symptomology of patients with vs without PD at enrollment was not significantly different. At enrollment, 117/204 patients (57.4%) received myelofibrosis-directed monotherapy (hydroxyurea, 44.4%; ruxolitinib, 41.9%). Of patients receiving monotherapy, more with PD received ruxolitinib (62.9% vs 32.4%) and fewer received hydroxyurea (25.7% vs 51.4%), vs without PD. However, more patients receiving ruxolitinib vs hydroxyurea at enrollment had intermediate-1–risk myelofibrosis (65.3% vs 48.1%), palpable spleen (50.0% vs 28.2%), and a longer median myelofibrosis duration from diagnosis to enrollment (2.6 vs 1.1 years) and from diagnosis to PD (4.3 vs 3.0 years). In this real-world analysis of MOST, approximately one-third of patients had physician-reported PD; these patients were older, less likely employed/able to work, more likely Black, and more likely receiving ruxolitinib vs hydroxyurea at enrollment. Patients receiving ruxolitinib more likely had signs of progression at enrollment, suggesting greater ruxolitinib use in higher PD-risk myelofibrosis.