FDA Approves PharmaEssentia BESREMi (Ropeginterferon Alfa-2b-njft) for Adults With Essential Thrombocythemia; First New ET Therapy in Nearly 30 Years
PharmaEssentia announced Sunday August 30, 2026 FDA approval of BESREMi (ropeginterferon alfa-2b-njft, a monopegylated proline-modified recombinant interferon alfa-2b protein administered as biweekly subcutaneous injection) for adults with essential thrombocythemia (ET), a chronic BCR-ABL-negative myeloproliferative neoplasm characterized by excessive platelet production and increased thrombotic and hemorrhagic risk. Approval was received at the August 30 PDUFA target action date under the supplemental BLA that the FDA accepted January 2026. The approval covers adults with ET regardless of genotype or disease status (including newly-diagnosed patients naive to cytoreductive therapy) and expands the existing BESREMi commercial label (approved for polycythemia vera in November 2021). BESREMi is the first FDA-approved therapy for ET in nearly three decades — the standard-of-care landscape has been dominated by cytoreductive hydroxyurea, anagrelide, and off-label pegylated interferons plus low-dose aspirin. The ET approval follows the June 2026 Taiwan approval that marked BESREMi's first global regulatory clearance in ET.