Last reviewed 2026-04-20 · How we verify

Besremi (ROPEGINTERFERON ALFA-2B)

Besremi works by binding to the interferon alpha/beta receptor, triggering a signaling cascade that reduces red blood cell production.

At a glance

Mechanism of action

Interferon alfa belongs to the class of type interferons, which exhibit their cellular effects in polycythemia vera in the bone marrow by binding to transmembrane receptor termed interferon alfa receptor (IFNAR). Binding to IFNAR initiates downstream signaling cascade through the activation of kinases, in particular Janus kinase (JAK1) and tyrosine kinase (TYK2) and activator of transcription (STAT) proteins. Nuclear translocation of STAT proteins controls distinct gene-expression programs and exhibits various cellular effects. The actions involved in the therapeutic effects of interferon alfa in polycythemia vera are not fully elucidated.

Approved indications

• Polycythemia vera

Boxed warnings

• These highlights do not include all the information needed to use BESREMi safely and effectively. See full prescribing information for BESREMi. BESREMi (ropeginterferon alfa-2b-njft) injection, for subcutaneous use Initial U.S. Approval: 2021 WARNING: RISK OF SERIOUS DISORDERS Risk of Serious Disorders: Interferon alfa products may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Therapy should be withdrawn in patients with persistently severe or worsening signs or symptoms of these conditions. In many, but not all cases, these disorders resolve after stopping therapy [ see Warnings and Precautions (5.1 , 5,2 , 5.3 , 5.4) and Adverse Reactions (6.1) ]. WARNING: RISK OF SERIOUS DISORDERS See full prescribing information for complete boxed warning . Risk of Serious Disorders: Interferon alfa products may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Monitor closely and withdraw therapy with persistently severe or worsening signs or symptoms of the above disorders.

Common side effects

• Liver enzyme elevations
• Leukopenia
• Thrombocytopenia
• Arthralgia
• Fatigue
• Myalgia
• Influenza-like illness
• Urinary tract infection
• Transient ischemic attack
• Depression
• Pruritis
• Nasopharyngitis

Key clinical trials

• Ropeginterferon Alfa-2b for the Treatment of Myelodysplastic Syndrome/Myeloproliferative Neoplasm Overlap Syndromes and Chronic Myelomonocytic Leukemia (PHASE2)
• Ropeginterferon Alfa-2b in Patients With Polycythemia Vera (PV) Without Symptomatic Splenomegaly
• Ropeginterferon in Patients w/Cutaneous T-Cell Lymphoma (CTCL) (PHASE1)
• LOW-PV Continuation
• Observational Study on the Use of Ropeginterferon Alfa-2b in Polycythemia Vera (ROPEG-PV)
• Phase II Study Assessing the Safety and Efficacy of Dasatinib in Combination With Ropeginterferon in Patients With Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase (PHASE2)
• Evaluation of Real-World Data on Ropeginterferon Alfa-2b in Patients With Polycythemia Vera: Insights From a Multicenter Study
• P1101 in Treating Patients With Myelofibrosis (PHASE2)

Patents

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Besremi CI brief — competitive landscape report
• Besremi updates RSS · CI watch RSS
• Pharma Essentia Corporation portfolio CI