Individualized Dosing of Ropeginterferon Alfa-2b Improves Response Rates in Patients with Low-Risk Polycythemia Vera

Individualized, response-driven dosing of ropeginterferon alfa-2b produced high long-term response rates in patients with low-risk polycythemia vera (PV), according to results presented at the 65th American Society of Hematology Annual Meeting and Exposition by Heinz Gisslinger, MD, of the Medical University of Vienna, and colleagues.

The researchers analyzed low-risk PV patients allocated to the ropeginterferon alfa-2b arm of the PROUD-PV/CONTINUATION-PV studies, who received ropeginterferon alfa-2b for a total of ≥6 years. Ropeginterferon alfa-2b was started at a dose of 100 µg/2 weeks (50 µg if transitioning from hydroxyurea) and escalated by 50 µg/2 weeks until blood counts normalized to a maximum of 500 µg/2 weeks.

The researchers assessed complete hematologic response defined by modified European LeukemiaNet criteria (without the spleen criterion) and safety data at 12, 24, and 72 months in order to examine the impact of baseline characteristics and individually optimized dose levels.

The results showed that high long-term response rates (80.4% at 24 months and 73.2% at 72 months) were achieved with ropeginterferon alfa-2b treatment in the low-risk PV population when the dose was optimized on an individual basis based on response.

In the second year, the median four weekly doses were 997 µg for nonresponders versus 690 µg for responders (P=.2024), indicating that non-responders received and tolerated the maximum dose (500 µg/2 weeks).

The researchers were unable to identify any specific baseline characteristics among low-risk PV patients that were associated with long-term response to ropeginterferon alfa-2b.

“The PROUD-PV/CONTINUATION-PV studies show that … some low-risk patients require and can tolerate high doses and that the optimal dose of ropeginterferon alfa-2b varies substantially between patients,” the researchers stated.

Reference

Gisslinger H, Klade C, Georgiev P, et al. Individualized dosing of ropeginterferon alfa-2b ensures optimal response in patients with low-risk polycythemia vera (PV). Abstract #4563. Presented at the 65th American Society of Hematology Annual Meeting and Exposition; December 9-12, 2023; San Diego, California.