The dosage of ropeginterferon in polycythaemia vera: Balancing efficacy, safety and pharmacoeconomics across risk categories

The doses of ropeginterferon alpha- 2b (Ropeg) used in the initial phase of treatment in this study were significantly higher than in the PROUD/CONTINUATION- PV trial,2 which led to the drug's approval by the EMA (2019) and FDA (2021). In PROUD- PV, a stepwise dose escalation strategy was used, starting patients at 100 μg or 50 μg for those pretreated with hydroxyurea (HU), with 50 μg increments every 2 weeks up to a maximum dose of 500 μg depending on haematological response. This approach demonstrated a significantly higher rate of complete haematological response (CHR) in the Ropeg arm compared to HU at 24 months (70.5% vs. 49.3%). Additionally, patients on Ropeg showed a steady reduction in mean absolute JAK2 V617F variant allele frequency (VAF) to less than half of baseline by month 36 (from 42.8% to 19.7%), while the reduction in the HU arm was transient and lost by month 36. After 5 years of treatment, the majority of patients achieved a JAK2 V617F VAF of <10%, with a subset being potential candidates for treatment discontinuation.3 These results underscore the potential disease- modifying capabilities of Ropeg. This stepwise dosing strategy is now considered the standard of care for polycythaemia vera (PV) patients, regardless of thrombotic risk.