Firstline treatment with ruxolitinib versus best available therapy in patients with polycythemia vera: results from the randomized RuxoBEAT trial.

Ruxolitinib (RUX) is approved as second-line treatment for HU-intolerant/-resistant patients with polycythemia vera (PV). Here, we assessed RUX vs. best available therapy (BAT) as first-line treatment in PV in the randomized multicenter RuxoBEAT clinical trial (NCT02577926). Crossover from BAT to RUX was possible after 6 months. Baseline characteristics in the RUX (n = 44) and BAT (n = 34) arms were comparable. The primary endpoint, the clinico-hematologic complete response (CR) rate at month 6, was not met (2.3% vs. 2.9%, p = 1.000). Analyses of secondary and exploratory endpoints showed that RUX was significantly more effective than BAT in improving hematocrit, splenomegaly, and patient-reported pruritus and fatigue, but less effective in reducing platelet counts. Compared to baseline, JAK2V617F variant allele frequency decreased significantly in both RUX and BAT groups at 6 months. The time on treatment (p < 0.001) and duration of treatment (p = 0.022) were significantly superior for RUX vs. BAT during the 24-month study period. There were no new safety signals. These findings demonstrate that RUX did not lead to higher CR rates than BAT and suggest that RUX may induce clinically meaningful additional disease improvements in first-line therapy of PV patients.