The administration of ropeginterferon alfa-2b yielded high hematologic and molecular response rates among patients with low-risk polycythemia vera (PV) compared with hydroxyurea and other available treatments, according to findings from a phase 3 study.

At the 2022 ASH Annual Meeting and Exposition in New Orleans, LA, Jean-Jacques Kiladjian, MD, Université Paris Cité, Paris, France, presented data from the study. 

According to Dr. Kiladjian and co-authors, low-risk PV is managed far too “conservatively despite higher risk of vascular events and impaired quality of life.” Recent treatment guidelines (European LeukemiaNet [ELN] 2021) denote that cytoreductive treatment should be implemented among low-risk PV patients meeting specific criteria and in high-risk patients. 

The results of the phase-3 PROUD-PV trial reported the long-term efficacy and safety of ropeginterferon alfa-2b in low-risk and high-risk PV patients. This CONTINUATION-PV trial assessed the differences between low-risk and high-risk patients.

46 patients with low-risk PV (mean age: 50.7 years; median duration of 1.9 months since PV diagnosis) and 49 patients with high-risk PV (mean age: 63.7 years; median duration of 1.5 months since PV diagnosis) were enrolled in the ropeginterferon alfa-2b arm. This subgroup was stratified by risk stratum and assessed for complete hematologic response (CHemR), molecular response rates, and safety analyses. 

The results showed that low-risk patients who received ropeginterferon alfa-2b achieved a significantly higher CHemR rate than high-risk patients during long-term treatment (Month 72: 73.2% vs 38.3% in LR and HR respectively [RR: 2.41; 95% confidence interval (CI), 1.50 to 3.90; p=0.0003]). Low-risk patients achieved molecular response more rapidly than high-risk patients (median time to first response: 12 months [95% CI, 12 to 18] vs 18 months [95% CI, 12 to 24]; Log-rank test p=0.03), and at a higher rate (LOCF at month 72: 84.4% vs 49.0% respectively, RR: 2.15 [95% CI, 1.37 to 3.37]; p=0.0009). 

Adverse drug reactions to ropeginterferon alfa-2b led to withdrawal of treatment in only 1 low-risk patient vs 13 high-risk patients. Low-risk patients were less likely than high-risk patients to experience adverse reactions of grade≥3 severity (5.4% vs 23.9%).

Dr. Kiladijan et al concluded, “LR patients may have a greater potential benefit: higher hematologic and molecular response rates can be safely achieved, and the patients are more likely to remain on long-term treatment,” adding, “these data provide further evidence for an early treatment start as recently outlined by the updated ELN guidelines.”

Source: 

Kiladjian JJ, Klade C, Georgiev P, et al. Efficacy and safety of long-term ropeginterferon alfa-2b treatment in patients with low-risk and high-risk polycythemia vera (PV). Presented at ASH Annual Meeting and Exposition; December 10-13, 2022; New Orleans, LA. Abstract 4345.