Ropeg superior to phlebotomy alone in maintaining hematocrit control in polycythemia vera

The researchers compared ropeginterferon alfa-2b (100 μg every two weeks) with phlebotomy only concerning the maintenance of a median hematocrit level of ≤45% over 12 months in the absence of progressive disease (primary endpoint). If the primary endpoint was not met, crossover to the alternative treatment group was allowed in the follow-up.

The researchers reported the following findings:

• 127 patients were enrolled (ropeg: n=64; standard group: n=63). The primary endpoint was met in 81% and 51% of the ropeg and standard groups, respectively.
• Responders continued the assigned treatment until month 24 and maintained 83% and 59% responses, respectively.
• Ropeg responders less frequently experienced moderate/severe symptoms (33% versus 67% in the standard group) and palpable splenomegaly (14% versus 37%) and showed normalization of ferritin levels and blood counts.
• Nonresponders at 12 months crossed over to the standard (n=9) or ropeg (n=23) group; in patients switched to ropeg only, 7 of 23 met the response criteria in 12 months, and phlebotomy need was high (4.7 per patient per year).
• Discontinuation because of adverse events occurred in seven patients treated with ropeg.

"Our findings showed ropeg superior to phlebotomy alone in maintaining hematocrit on target," the researchers wrote. "No dose-limiting side effects or toxicities were seen; 9.2% of patients on ropeg and no patients on standard treatment developed neutropenia."

Reference:

The study "Ropeginterferon versus Standard Therapy for Low-Risk Patients with Polycythemia Vera" was published in NEJM Evidence. DOI: 10.1056/EVIDoa2200335