JAK 2V617F molecular response and event-free survival in an early polycythemia vera population

During the European Hematology Association Hybrid Congress 2024, Jean-Jacques Kiladjian delivered a presentation on the correlation between JAK2^V617F molecular response (MR) and event-free survival (EFS) in early polycythemia vera (PV).¹ The final data from the phase III PROUD-PV and CONTINUATION-PV trials were used to assess this correlation, as well as the impact of ropeginterferon (ropeg) alfa-2b on EFS.¹

The probability of EFS during the study periods was significantly higher in patients who experienced a MR at a hazard ratio (HR) of 0.24 (95% confidence interval [CI], 0.07–0.83; p = 0.02).

Time spent in MR was higher in patients treated with ropeg alfa-2b compared with hydroxyurea or best available therapy (BAT) at 66.7% vs 8.4%, respectively (p = 0.01).

A higher JAK2^V617F allele burden was associated with an increased risk of events at an HR of 1.042 (95% CI, 1.023–1.062; p = 0.0001), equating to 4.2% increased risk of events per 1% increase in variant allele frequencies.

These data suggest that a 10% decrease in allele burden could correspond with a 34% decreased risk of events. 

Treatment with ropeg alfa-2b was associated with higher rates of <1% JAK2^V617F allele burden, achieved in 20.7% of patients compared with 1.4% in the control arm (p = 0.0001).