Rusfertide (MIMRYLO), a hepcidin mimetic designed to regulate iron distribution and red blood cell overproduction, received US Food and Drug Administration approval for the treatment of erythrocytosis in adults with polycythemia vera, according to a press release from Takeda.

Polycythemia vera is a chronic blood cancer characterized by erythrocytosis, which leads to elevated hematocrit that can increase blood viscosity and result in thrombotic events, including stroke, deep vein thrombosis, and pulmonary embolism. Maintaining hematocrit below 45% is a primary treatment goal.

Rusfertide is a hepcidin mimetic designed to regulate iron distribution and red blood cell overproduction to control hematocrit. The treatment is administered once weekly by subcutaneous injection.

The approval was supported by results from the phase 3 VERIFY trial, an ongoing global, randomized, placebo-controlled study of 293 patients with polycythemia vera. The trial enrolled patients with uncontrolled hematocrit who were dependent on phlebotomy despite standard-of-care treatment, which could include phlebotomy, hydroxyurea, interferon, and/or ruxolitinib.

During the randomized, placebo-controlled portion, patients received rusfertide plus standard of care or placebo plus standard of care. The primary endpoint was the proportion of patients who achieved a response during weeks 20 to 32, defined as not meeting eligibility criteria for phlebotomy. Takeda reported that 77% of patients receiving rusfertide plus standard of care achieved a clinical response during weeks 20 to 32. The company reported that patients receiving rusfertide plus standard of care had a higher response rate compared with those receiving placebo plus standard of care, along with hematocrit control, reduced need for phlebotomy, and improvement in fatigue.

“For patients living with PV [polycythemia vera], uncontrolled hematocrit can have serious consequences, including an elevated risk of life-threatening thrombotic events,” said VERIFY lead investigator Andrew T. Kuykendall, MD, an associate member of the Department of Hematology at  Moffitt Cancer Center. “The approval of MIMRYLO [rusfertide] offers clinicians and patients a novel, first-in-class therapy that targets erythrocytosis.”

Rusfertide was generally well tolerated through 52 weeks of treatment in VERIFY, according to Takeda. The most common adverse reactions were injection-site reactions, reported in 56% of patients, and anemia, reported in 16%. Warnings and precautions include new or worsening thrombocytosis, injection-site reactions, and embryo-fetal toxicity.

All patients have completed the randomized, placebo-controlled portion of VERIFY and are now in the open-label portions of the study.

Source: Takeda