Low-PV trial: Long-term outcomes with low-dose ropeginterferon alpha-2b in patients with low-risk PV

In the Low-PV trial (NCT03003325), 81% of patients with low-risk polycythemia vera treated with ropeginterferon alpha-2b (ropeg) 100 µg every 2 weeks achieved the primary endpoint at 12 months compared with 51% of patients who received phlebotomy only. Responses were maintained at 24 months in 67% of patients treated with ropeg vs 30% who received phlebotomy only. At trial completion, 36 patients who achieved a complete hematological response and had received ropeg for 24 months entered an observational study, results of which were presented by Tiziano Barbui during the European Hematology Association (EHA) 2025 Congress, June 12–15, 2025, Milan, IT.¹

Key learnings

Among the 36 responders, 61% had continued on ropeg, while 17% had switched to alternative treatments, including conventional peginterferon alfa-2a. Treatment responses were maintained in all of these patients (n = 28) with HCT ≤45% and no thrombotic events.

Based on ELN criteria, 51.9% of patients achieved MiMR (JAK2 VAF ≥1% and reduction in VAF 20–49%) or PMR (JAK2 VAF ≥1% and reduction in VAF 50%) with ropeg, while 18.2% of patients achieved MMR (JAK2 VAF <1%).

The trend of JAK2 suppression was maintained over time in patients who switched to peginterferon alfa-2a.

The sustained hematologic control and durable molecular responses seen here with low-dose ropeg support the potential of low-dose regimens to effectively suppress JAK2 mutations while maintaining efficacy and safety.