Real world experience with ropeginterferon alpha-2b (Besremi) in essential thrombocythaemia and polycythaemia vera following exposure to pegylated interferon alfa-2a (Pegasys).

Despite widespread use of Pegylated forms of Inteferon in the management of Myeloproliferative Neoplasms (MPN), most clinicians have experience predominantly with peginterferon alfa-2a (Pegasys). Third generation pegylated IFNα, ropeginterferon alfa-2b (ropegIFN; Besremi), was recommended by the European Medicine Authority (EMA) for treatment of Polycythaemia Vera (PV) following a Phase III trial (PROUD-PV / CONTINUATION-PV). FDA approval for PV, regardless of treatment history, was subsequently granted in November 2021. We hereby demonstrate the safety and tolerability of ropegIFN in a series of MPN patients at variable doses. It corroborates reports of efficacy of ropegIFN in patients with PV and use in pregnancy.