Takeda bolsters blood cancer portfolio with FDA nod for Mimrylo in polycythemia vera
The FDA approved the hepcidin-mimetic peptide rusfertide for erythrocytosis in adults with polycythemia vera.
TL;DR
- On August 28, 2026, the FDA approved Takeda's Mimrylo (rusfertide), a first-in-class hepcidin-mimetic peptide, for erythrocytosis in adults with polycythemia vera.
- In the Phase 3 VERIFY trial of 293 patients, 76.9% of those on Mimrylo met the response definition in weeks 20 to 32, compared with 32.9% on placebo.
- The most common adverse reactions above 15% in the company labeling summary were injection-site reactions and anemia. The open-label extension is still underway.
The FDA approved Takeda's Mimrylo (rusfertide) on August 28, 2026, for erythrocytosis in adults with polycythemia vera. Takeda describes Mimrylo as a first-in-class hepcidin mimetic, given once weekly under the skin, that limits iron available for excess red-cell production. Fierce Pharma reported the decision the same day. [1, 2] [1] [2]
The approval rests on the randomized Phase 3 VERIFY study, which enrolled 293 patients with uncontrolled hematocrit. Takeda said 76.9% of patients on Mimrylo achieved a clinical response during weeks 20 to 32. Fierce Pharma reported the corresponding placebo figure as 32.9%, using the trial's definition of no longer being eligible for phlebotomy. Takeda also reported less need for phlebotomy and an improvement in fatigue on the PROMIS Fatigue Short Form 8a. [1, 2] [1] [2]
Takeda's release lists injection-site reactions in 56% of treated patients and anemia in 16% as the most common adverse reactions above 15%. The label summary also warns of new or worsening thrombocytosis and of possible fetal harm. Fierce Pharma quoted Tanya Wroblewski of the FDA's Center for Drug Evaluation and Research, who called the approval a first-in-class option that could reduce the burden of frequent blood draws. The open-label portion of VERIFY is continuing. [1, 2] [1] [2]
Takeda says polycythemia vera affects about 90,000 people in the United States and that about 78% of patients do not keep hematocrit controlled on current care. Protagonist Therapeutics discovered the peptide and led it through Phase 3. Fierce Pharma reported that Takeda paid $300 million upfront in 2024 and later bought out its partner, and that Takeda now commercializes the drug globally while Protagonist remains eligible for sales royalties. [1, 2] [1] [2]
Why it matters
Rusfertide is a peptide drug, not a supplement, and its approval adds a new mechanism in a blood cancer that has relied on phlebotomy, hydroxyurea, interferons, and a JAK inhibitor. The commercial question is whether hematologists change practice; the clinical question still open is how the benefit holds up in the ongoing open-label extension and outside the United States.
Editor's note
Manual catch-up of the August 28, 2026 approval, which was not in an earlier edition. Company figures are attributed to Takeda. No treatment recommendation.