FDA Approves Ropeginterferon Alpha-2b for Polycythemia Vera

Adult patients with polycythemia vera may now be treated with ropeginterferon alpha-2b, the only interferon available for this population.

The FDA granted approval to the monopegylated, long-acting interferon ropeginterferon a-2b-njft (Besremi) for the treatment of patients with polycythemia vera, according to the drug maker PharmaEssentia Corporation.1

The decision was based on safety data from the phase 1/2 PEGINVERA trial (NCT01193699) and the phase 3 CONTINUATION-PV and PROUD-PV trials, as well as efficacy data from PEGINVERA in patients with polycythemia vera.2

“The FDA approval of Besremi for people with polycythemia vera represents the next step in advancing patient care as it provides a critical addition to managing not only symptom burden and near-term complications, but also treating the cancer early, which may help reduce the risk of disease progression over time,” Srdan Verstovsek, MD, PhD, director of the Hanns A. Pielenz Clinical Research Center for Myeloproliferative Neoplasms in the Department of Leukemia at the University of Texas MD Anderson Cancer Center, said in a statement. “With the availability of an FDA-approved, next-generation interferon for this indication, it’s time that we focus on preserving the long-term health of patients with polycythemia vera.”

With 7.5 years of treatment, ropeginterferon a-2b was able to induce complete hematologic responses in 61% of patients with polycythemia vera treated on PEGINVERA. Response in this trial was defined as hematocrit below 45% without phlebotomy for at least 2 months since the last phlebotomy, platelets of 400 x 109/L or less, leukocytes at or below 10 x 109/L, and a normal spleen size. Additionally, 80% of patients achieved at least some hematologic response on therapy.

The most common adverse reactions occurring in at least 40% of patients who were assessed in the pooled safety analysis included influenza-like illness, arthralgia, fatigue, pruritus, nasopharyngitis, and musculoskeletal pain.

“We are incredibly proud to deliver on our goal of bringing treatments like Besremi to the polycythemia vera community where there is clear unmet need for more effective, tolerable and durable treatments to preserve patients’ health and well-being,” Ko-Chung Lin, PhD, co-founder and chief executive officer for PharmaEssentia and inventor of ropeginterferon a-2b, said in a statement. “As we begin working closely with the community to integrate this important treatment into clinical practice, we also continue to expand our scientific efforts to unlock the full potential of our pioneering molecule.”


  1. U.S. FDA approves BESREMi (ropeginterferon alfa-2b-njft) as the only interferon for adults with polycythemia vera. News release. PharmaEssentia Corporation. November 12, 2021. November 13, 2021. https://bwnews.pr/2YHruCT
  2. Gisslinger H, Klade C, Georgiev P, et al. Ropeginterferon alfa-2b versus standard therapy for polycythaemia vera (PROUD-PV and CONTINUATION-PV): a randomised, non-inferiority, phase 3 trial and its extension study. Lancet Haematol. 2020;7(3):e196-e208. doi:10.1016/S2352-3026(19)30236-4