FDA Approves Takeda/Protagonist's MIMRYLO (Rusfertide), First Hepcidin Mimetic Peptide, for Polycythemia Vera

The FDA approved MIMRYLO (rusfertide), a subcutaneously self-administered first-in-class hepcidin mimetic peptide, for the treatment of erythrocytosis in adults with polycythemia vera (PV) — a chronic myeloproliferative blood cancer. Discovered by Protagonist Therapeutics and developed through Phase 3 before Takeda took over NDA submission and commercialization, MIMRYLO is the first and only approved hepcidin mimetic therapy for PV. In the Phase 3 VERIFY trial (293 patients), 76.9% of patients achieved clinical response during weeks 20-32 versus placebo, with sustained hematocrit control, reduced therapeutic phlebotomy burden, and improved fatigue scores. The most common adverse reaction was injection site reactions (56%). Approval triggered $275 million in milestone payments to Protagonist, with up to $875 million more in potential milestones and tiered royalties of 14-29% on worldwide sales.