Ropeginterferon alfa-2b: Real-world outcomes in patients with Ph− MPN

Real-world data from a retrospective cohort study investigating the outcomes and safety of ropeginterferon alfa-2b (ropegIFN) in 64 patients with Philadelphia chromosome-negative (Ph−) myeloproliferative neoplasms (MPN) were recently published by Chang et al. in Clinical Lymphoma, Myeloma and Leukemia. The cohort included patients with polycythemia vera (PV; n = 15), essential thrombocythemia (ET; n = 16), prefibrotic myelofibrosis (preMF; n = 5), and overt myelofibrosis (MF; n = 28).

Key data: After a median follow-up of 5.3 years, 36-month hematological response (HR) rates were 87% in PV, 75% in ET, 80% in preMF, and 47% in MF (p = 0.026). Best molecular response (MR) rates were 80% in PV, 60% in ET, 75% in preMF, and 42% in overt MF (p = 0.11). Median JAK2 variant allele frequency (VAF) declined significantly from 67.9% at baseline to 18.7% during follow-up (p < 0.001). Patients with MF harboring high-molecular-risk (HMR) mutations showed no HR (24 months; 0% vs 72%, p = 0.002) nor MR (24 months; 0% vs 18%, p = 0.4), alongside significantly worse median overall survival (OS; 5.3 months vs not reached; p < 0.001) and a significantly higher cumulative incidence of adverse events (AEs; 48% vs 7%, p < 0.001).

Key learning: RopegIFN demonstrated hematological and molecular efficacy across Ph− MPN subtypes, with a manageable safety profile; however, its effectiveness appears limited in patients with MF, particularly those with HMR mutations.