Highlights from

ASH 2020

62nd Annual Meeting & Exposition of the American Society of Hematology

Virtual 5 - 8 December 2020

Updates from the Myelofibrosis and Essential Thrombocythemia Observational (MOST) Study: Essential Thrombocythemia

Current treatment guidelines may not adequately address symptomatology in patients with low-risk essential thrombocythemia. Despite treatment, patients meeting European LeukaemiaNet (ELN) criteria for low-risk essential thrombocythemia have a greater symptom burden than high-risk patients.

The Myelofibrosis and Essential Thrombocythemia Observational Study (MOST) (NCT02953704) describes the clinical characteristics, treatments, and disease burden experienced by patients with myelofibrosis or essential thrombocythemia (ET). The study began in 2016, and Dr Mark Grunwald (Levine Cancer Institute, North Carolina, USA) shared interim real-world data about 1,210 patients with ET enrolled in MOST [1].

For inclusion in the ET cohort of this study, patients must be ≥60 years old or have a history of thromboembolic events, or currently be undergoing ET-directed therapy. Patients are categorised as having either high-risk or low-risk ET in accordance with ELN criteria. High-risk patients are defined as those ≥60 years of age, with or without a history of thromboembolic events; patients are defined as low-risk if they are receiving ET-directed therapy (not including aspirin only). In this present analysis of 1,210 patients, 159 (13.1%) were classified as low-risk and treated, 887 (73.3%) were classified as high-risk and treated, and 164 (13.6%) were classified as high-risk and untreated.

Participants in MOST report their symptoms using two measures: the myeloproliferative neoplasm (MPN) symptom assessment form, and the Total Symptom Score (TSS), which is the patient’s grading of symptom severity using a scale of 0 (absent) to 100 (worst imaginable). The combination of these scores constitutes the patient’s symptom burden. At the time of this analysis, objective findings of splenomegaly and elevated platelet count were higher in the high-risk, untreated cohort. The presence of comorbidities was generally similar across cohorts. Significantly, mean TSS was highest in the low-risk cohort, and was similar in both of the high-risk cohorts. Several individual symptom scores such as abdominal discomfort, concentration, numbness/tingling, night sweats, itching, bone pain, and weight loss were also significantly higher in the low-risk cohort. These findings reveal that there is a need for effective and more well-tolerated second-line therapies for the treatment of high-risk ET.

  1. Grunwald M, et al. Clinical Characteristics and Treatment Patterns By Risk Stratification in Patients with Essential Thrombocythemia: An Analysis of the MOST Study. 62nd ASH Annual Meeting, 5-8 December 2020. Abstract 1258.

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