Real-World Retrospective Report on the Efficacy, Tolerability, and Molecular Responses to Ropeginterferon-α2b in Patients with Myeloproliferative Neoplasms

<b>Background:</b> Ropeginterferon alfa-2b (Ropeg-IFNa) is increasingly used in myeloproliferative neoplasms (MPN), particularly polycythemia vera, but real-world data across subtypes are limited. We evaluated clinical and molecular responses to Ropeg-IFNa in routine practice. <b>Methods:</b> We retrospectively analyzed 20 JAK2^V617F-positive MPN patients treated at a tertiary center. Baseline features, dosing, treatment line, hematologic responses, adverse events, and serial JAK2^V617F variant allele frequency (VAF) were extracted from records. <b>Results:</b> Median age at initiation was 53 years; 55% were ELN high-risk. Ropeg-IFNa was started first-line or after peginterferon alfa-2a, hydroxyurea, or a tapered JAK2 inhibitor. Mean treatment duration was 14 ± 11 months at 195 ± 143 µg Q2W. Hematologic control increased from 45% at the start to 60% at the last follow-up. Among patients with serial molecular monitoring (n = 11), median JAK2^V617F VAF declined from 21.2 to 12.7%. Ropeg-IFNa was generally well tolerated; adverse effects were mostly manageable, although 3/20 (15%) discontinued due to side effects, including mood disturbances, while others continued with supportive care and dose adjustments. <b>Conclusions:</b> In this single-center cohort, Ropeg-IFNa was tolerable and associated with improved hematologic control and modest VAF reductions, supporting its use in multi-subtype MPN cohorts. These findings underscore the value of longitudinal driver-mutation monitoring during therapy.