RUX-MF real-world study subanalysis: Prognostic impact of cytopenia in MF treated with ruxolitinib.

Results from a subanalysis of the real-world, multicenter RUX‑MF study (NCT06516406), evaluating the prognostic impact of persistent and treatment-emergent cytopenia in 879 patients with myelofibrosis (MF) treated with ruxolitinib for ≥6 months, were published in Cancer by Palandri et al. The objectives of this analysis were to assess the prognostic impact of cytopenia during the first 6 months of therapy, to compare clinical outcomes between treatment-emergent anemia and thrombocytopenia, to evaluate the prognostic significance of hemoglobin improvement in patients with isolated baseline anemia, and to assess the impact of changes in cytopenia status on symptom burden. Study participants were categorized into four groups: never cytopenic (n = 317), treatment-emergent cytopenia (n = 273), persistent cytopenia (n = 235), and improved anemia (n = 54). 

Key data: In the overall cohort, cytopenia prevalence increased from 40.6% at baseline to 57.8% after 6 months. Median overall survival (OS) was longest in patients who were never cytopenic (8.07 years; 95% confidence interval [CI], 7.04–9.29) and lowest in patients with persistent cytopenia (3.68 years; 95% CI, 3.08–4.41; p < 0.001). Among patients with treatment-emergent cytopenias, those who developed anemia alone had a median OS of 6.15 years, while those with isolated thrombocytopenia had a median OS of 4.33 years (p = 0.008). Patients who were never cytopenic or had improved cytopenia demonstrated the greatest decrease in Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN‑SAF TSS). 

Key learning: Results demonstrate that cytopenia trajectory monitoring during the first 6 months of ruxolitinib therapy may be a clinically actionable prognostic tool in MF. Future prospective studies with molecular, cytogenetic, and supportive care data are warranted to expand the understanding of cytopenia dynamics in MF.