On Aug. 28, 2026, the US Food and Drug Administration (FDA) approved Takeda Pharmaceuticals’ Mimrylo™ (rusfertide) for the treatment of erythrocytosis in adults who have polycythemia vera (PV). Mimrylo is a first-in-class hepcidin mimetic that regulates iron availability to limit excessive red blood cell production and help maintain hematocrit control. This provides a new therapeutic approach for patients with PV who have not achieved adequate disease control with existing therapies. The recommended starting dose is 19mg administered by subcutaneous (SC) injection once weekly, with dosage adjustments based on efficacy and safety to a maximum of 108mg weekly. Warnings and precautions include new or worsening thrombocytosis, injection-site reactions, and embryo-fetal toxicity. Patients should undergo regular monitoring of the complete blood count, particularly during treatment initiation and dose adjustments. Launch is expected within 48 hours of approval, and each vial will cost about $4,200. Here is the prescribing information.
At a Glance
- Brand Drug: Mimrylo™(rusfertide)
- Manufacturer: Takeda Pharmaceuticals
- Date Approved: Aug. 28, 2026
- Indication: For the treatment of erythrocytosis in adults with polycythemia vera (PV)
- Dosage Forms Available: 9.5mg, 19mg, 28mg, 41mg, and 54mg as a lyophilized powder in single-dose vials for reconstitution
- Launch Date: Soon after approval.
- Estimated Annual Cost: $218,000
- FDA Designation: Orphan Drug. Breakthrough Therapy. Fast Track. Priority Review.
- PV is a chronic blood cancer characterized by excessive red blood cell production (erythrocytosis), which increases hematocrit and blood viscosity and may increase the risk of thrombotic events, including stroke, deep vein thrombosis and pulmonary embolism.
- Current treatment options for PV include therapeutic phlebotomy, low-dose aspirin and cytoreductive therapies such as hydroxyurea, interferon-based regimens and ruxolitinib.
- Maintaining hematocrit below 45% is associated with lower thrombotic risk and improved symptom control, while uncontrolled hematocrit has been linked to a fourfold higher risk of cardiovascular death or major cardiovascular events.
- Approximately 90,000 people in the US are affected, yet an estimated 78% of patients continue to experience uncontrolled hematocrit despite available treatment options.
- Mimrylo is the first FDA-approved hepcidin mimetic for polycythemia vera and offers a novel mechanism of action that addresses iron regulation and red blood cell production.
- Approval was based on the phase III VERIFY trial in which 76.9% of patients treated with Mimrylo did not meet criteria for phlebotomy during the primary evaluation period, compared with 32.9% of patients receiving placebo, supporting its ability to reduce phlebotomy requirements and maintain hematocrit control.
- The most common adverse reactions reported in the trial were injection-site reactions (56%) and anemia (16%).