FDA Approves First-in-Class Rusfertide to Reduce Phlebotomy Burden in Adult Patients With Polycythemia Vera

Clinical Summary:

• Based on results from the phase 3 VERIFY trial, the FDA has approved rusfertide for the treatment of erythrocytosis in adults with polycythemia vera. VERIFY evaluated rusfertide plus standard of care vs placebo plus standard of care in patients with uncontrolled hematocrit who remained phlebotomy dependent despite existing treatment.
• During weeks 20 to 32, 76.9% of patients receiving rusfertide achieved a clinical response, defined as the absence of phlebotomy eligibility, compared with 32.9% of patients receiving placebo. Rusfertide also improved hematocrit control, reduced phlebotomy requirements, and improved fatigue.
• As the first FDA-approved hepcidin mimetic for polycythemia vera, rusfertide provides a new strategy for directly controlling erythrocytosis and maintaining hematocrit below 45%, potentially reducing dependence on repeated phlebotomy while improving disease-related fatigue. 

Based on results from the phase 3 VERIFY trial, the US Food and Drug Administration (FDA) has approved rusfertide (Mimrylo; Takeda Pharmaceuticals) for the treatment of erythrocytosis in adult patients with polycythemia vera, introducing the first approved hepcidin mimetic for the disease.

In this ongoing trial, researchers enrolled 293 adult patients with polycythemia vera who had uncontrolled hematocrit and remained phlebotomy dependent despite ongoing standard-of-care therapy with phlebotomy, hydroxyurea, interferon, and/or ruxolitinib. Patients were randomized 1:1 to receive either 19 mg of subcutaneous rusfertide (titrated to maintain hematocrit below 45%) plus standard of care or placebo plus standard of care for 32 weeks. 

The primary end point was the proportion of patients achieving a clinical response during weeks 20 and 32, defined as the absence of phlebotomy eligibility. Patients met criteria for phlebotomy if they had a confirmed hematocrit of at least 45% that was at least 3% higher than their baseline hematocrit or a hematocrit of at least 48%.

During weeks 20 to 32, 76.9% of patients receiving rusfertide achieved a clinical response compared with 32.9% of patients receiving placebo. Rusfertide also improved hematocrit control and reduced the need for phlebotomy compared with placebo plus standard-of-care therapy.

Treatment with rusfertide also improved fatigue as measured by the PROMIS Fatigue Short Form 8a. Other key secondary end points evaluated at week 32 included the mean number of phlebotomies, the proportion of patients maintaining hematocrit below 45%, and total symptom burden.

Rusfertide was generally well tolerated through 52 weeks of treatment in VERIFY. The most common adverse reactions were injection-site reactions occurring in 56% of patients and anemia, occurring in 16% of patients. 

Warnings and precautions include new or worsening thrombocytosis, injection-site reactions, and embryo-fetal toxicity. Rusfertide may increase platelet counts in patients with polycythemia vera, with platelet counts generally plateauing by week 8. Complete blood counts should be monitored every 2 to 4 weeks after treatment initiation and during dose modifications, or as clinically indicated.

The randomized, placebo-controlled portion of VERIFY has been completed, and patients are now participating in the open-label portions of the study. The study is evaluating rusfertide over a 156-week period, with an extension available for patients continuing to derive treatment benefit.

“For patients living with [polycythemia vera], uncontrolled hematocrit can have serious consequences, including an elevated risk of life-threatening thrombotic events,” stated lead investigator Andrew Kuykendall, MD, Moffitt Cancer Center, Tampa, Florida. This approval “offers clinicians and patients a novel, first-in-class therapy that targets erythrocytosis, which drives excess red blood cell production in [polycythemia vera].”

Source:

US Food and Drug Administration. FDA approves first drug of its kind for polycythemia vera, a rare blood disorder. Published online: August 28, 2026. Accessed on: August 31, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-its-kind-polycythemia-vera-rare-blood-disorder

Takeda. Takeda receives US FDA approval of mimrylo (rusfertide), marking a potential shift in the treatment paradigm for polycythemia vera. Published online: August 28, 2026. Accessed on: August 31, 2026. https://www.takeda.com/newsroom/newsreleases/2026/fda-approval-mimrylo/