Health Canada has approved ropeginterferon alfa-2b (Besremi) for the treatment of adult patients with polycythemia vera.1
In the phase 1/2 PEGINVERA trial (NCT01193699), patients with polycythemia vera treated with ropeginterferon alfa-2b (n = 51) achieved a complete hematological response (CHR) rate of 61% (95% CI, 46%-74%); CHR was defined as a hematocrit level of less than 45%, no phlebotomy within 2 months, a platelet count no more than 400 x 109/L, a leukocyte count of no more than 10 x 109/L, normal spleen size, and absence of thromboembolic events.2 The median duration of response was 14.3 months (95% CI, 5.5-30.1).
“Polycythemia vera is a chronic myeloproliferative neoplasm that requires long-term management to reduce the risk of complications and control symptoms. The approval of [ropeginterferon alfa-2b] in Canada is an important and welcome development for patients living with polycythemia vera and for the physicians who care for them,” Shireen Sirhan, MD, president of the Canadian Myeloproliferative Neoplasms (MPN) Group, vice-president of research at the Quebec Research Group for Chronic Myeloid Leukemia and Myeloproliferative Neoplasms, and a hematologist at Jewish General Hospital of McGill University Montreal, stated in a news release.1 “The availability of an interferon therapy specifically approved for polycythemia vera has been long anticipated within the Canadian MPN community and represents a meaningful expansion of the treatment options available to patients. This approval reflects continued progress in the field and supports a more individualized approach to the management of polycythemia vera."
In November 2021, the FDA approved ropeginterferon alfa-2b-njft for use as a treatment in patients with polycythemia vera.3 In June 2026, the FDA also approved a prefilled pen device for the administration of ropeginterferon alfa-2b in adult patients with polycythemia vera.4
How was the PEGINVERA trial designed?
Ropeginterferon Alfa-2b Wins Canadian Approval for Polycythemia Vera.
- Health Canada approved ropeginterferon alfa-2b for the treatment of adult patients with polycythemia vera.
- In the phase 1/2 PEGINVERA trial, ropeginterferon alfa-2b generated a CHR rate of 61% (95% CI, 46%-74%).
- Ropeginterferon alfa-2b was approved by the FDA for patients with polycythemia vera in 2021, and the regulatory agency also approved a prefilled pen for administration of the agent in June 2026.
The open-label, prospective, multicenter, dose-escalation study enrolled patients 18 to 90 years of age with confirmed polycythemia vera per WHO 2008 criteria or Polycythemia Vera Study Group criteria.5 Patients could be treatment naive, pretreated, or receiving ongoing cytoreductive therapy. An ECOG performance status of 2 or less was required.
In part 1, a 3+3 design was used to determine the maximum tolerated dose of ropeginterferon alfa-2b, which was established at 540 µg.2,5 In part 2, patients began dose escalation at 150 µg, or 100 µg if they were titrating from hydroxyurea. Ropeginterferon alfa-2b was given every 2 weeks at doses of 225 µg, 300 µg, 400 µg, and 450 µg, and dose escalation was stopped as hematological parameters were stabilized.2 Hydroxyurea was tapered off over the first 12 weeks for patients receiving it. After 1 year of treatment, some patients were allowed to transition to dosing once every 4 weeks.
What is the safety profile of ropeginterferon alfa-2b?
The prescribing information for ropeginterferon alfa-2b shows that the most common adverse effects (AEs) reported in at least 40% of patients included influenza-like illness (58%), arthralgia (47%), fatigue (47%), pruritus (45%), nasopharyngitis (43%), and musculoskeletal pain (41%).
AEs that led to permanent treatment discontinuation in more than 2% of patients included depression (8%), arthralgia (4%), fatigue (4%), and general physical health deterioration (4%).
References
- PharmaEssentia announces Health Canada approval of Besremi (ropeginterferon alfa-2b) for polycythemia vera (PV). News release. PharmaEssentia. https://us.pharmaessentia.com/pharmaessentia-announces-health-canada-approval-of-besremi-ropeginterferon-alfa-2b-for-polycythemia-vera-pv/
- Besremi. Prescribing information. PharmaEssentia. Updated June 2026. Accessed July 6, 2026. https://us.pharmaessentia.com/downloads/Besremi_USPI_ENG.pdf
- US FDA approves Besremi (ropeginterferon alfa-2b-njft) as the only interferon for adults with polycythemia vera. News release. PharmaEssentia. November 12, 2021. Accessed July 6, 2026. https://bwnews.pr/3nbXCYO
- PharmaEssentia announces FDA approval and U.S. launch of BESREMi Pen (ropeginterferon alfa-2b-njft) for polycythemia vera. News release. PharmaEssentia. June 26, 2026. Accessed July 6, 2026. https://us.pharmaessentia.com/pharmaessentia-announces-fda-approval-and-u-s-launch-of-besremi-pen-ropeginterferon-alfa-2b-njft-for-polycythemia-vera/
- Safety study of pegylated interferon alpha 2b to treat polycythemia vera (PEGINVERA). ClinicalTrials.gov. Updated January 30, 2018. Accessed July 6, 2026. https://clinicaltrials.gov/study/NCT01193699