Early Implementation of Increased Dose of Ropeginterferon Driven by Phlebotomy Need Improves Efficacy Among Patients With Low-Risk Polycythemia Vera

5-Year Drug Survival and Efficacy Findings

A phase 2 trial published in Annals of Hematology on the 5-year survival and efficacy of ropeginterferon showed that increasing the dose of ropeginterferon and implementing it earlier driven by high phlebotomy needs improved efficacy outcomes among patients with low-risk polycythemia vera (PV). 

According to Tiziano Barbui, MD, Papa Giovanni XXIII Hospital, Bergamo, Italy, and coauthors, prior studies demonstrated that “exposure to low-dose Ropeginterferon alfa-2b (Ropeg) 100 µg every 2 weeks for 2 years was more effective than the standard treatment of therapeutic phlebotomy in maintaining target hematocrit (HCT) (< 45%) with a reduction in the need for phlebotomy without disease progression” among patients with low-risk PV. 

The present study assessed the 5-year drug survival of ropeginterferon, which the authors defined as a measure of efficacy, safety, adherence, and tolerability. Within the first 2 years of treatment, ropeginterferon was stopped in 33% of the ropeginterferon arm, and phlebotomy-only was stopped in 70% of the phlebotomy-only arm, for reasons including lack of response and adverse events. 

A total of 36 patients who responded to ropeginterferon continued the drug for up to 3 years. After a median of 3.15 years, the probability of drug survival among these patients was 59%. The study authors noted that the primary composite end point was maintained in 97% of patients still taking ropeginterferon at 3 years, 94% at 4 years, and 94% at 5 years, and 60% of the cases were phlebotomy-free. 

Of the 63 patients in the phlebotomy-only arm, 37% (n = 23) did not reach the primary end point and were moved to the ropeginterferon arm. The need for over 3 bloodletting procedures within the first 6 months of treatment was the most significant determinant of this alteration in treatment. 

Based on the results, Barbui and the study authors concluded, “To improve the effectiveness of Ropeg[interferon], we suggest increasing the dose and using it earlier driven by high phlebotomy need in the first 6 months post-diagnosis.”

Source: 

Barbui T, Carobbio A, De Stefano V, et al. Ropeginterferon phase 2 randomized study in low-risk polycythemia vera: 5-year drug survival and efficacy outcomes. Ann Hematol. Published online: December 7, 2023. doi: 10.1007/s00277-023-05577-9