Takeda And Protagonist Win Mimrylo Approval In Polycythemia Vera, Opening A Broader-Than-Expected Launch

The FDA has approved Takeda and Protagonist Therapeutics’ peptide therapeutic rusfertide for patients with polycythemia vera, a rare malignancy of the blood. Takeda said the drug will be sold as Mimrylo.

The decision gives Takeda another near-term launch after the FDA’s approval earlier this month of narcolepsy medicine Orzeyful. Jefferies wrote that the two approvals mark the first two major launches in Takeda’s next growth cycle, and the firm said Mimrylo could reach peak sales of $2 billion.

The approval case

According to Takeda, Mimrylo is the first hepcidin mimetic designed to regulate overproduction of red blood cells and the distribution of iron throughout the body to control hematocrit levels. In polycythemia vera, hematocrit is ideally kept under 45% to lower the risk of blood clots.

The FDA’s decision was supported by the Phase 3 VERIFY study. In that trial, patients treated with Mimrylo plus standard of care achieved a significantly greater response rate than placebo plus standard of care, while also lowering patients’ need for phlebotomies.

Takeda and Protagonist also appear to have secured a label with fewer restrictions than some expected. Jefferies said the approval came with a broader than expected label that does not require patients to have undergone prior treatment with medications that lower blood cell counts. That matters commercially because a less restrictive label can support earlier use and faster uptake without waiting for sequencing through another drug class.

The commercial picture

Mimrylo was originally developed by Protagonist, which struck a global co-development and co-commercialization deal with Takeda in 2024. Takeda paid $300 million upfront in that agreement.

The drug is given weekly as an under-the-skin injection. Jefferies linked the breadth of the label to its $2 billion peak sales forecast, framing the approval as more valuable than a narrower use in a rare disease setting might have implied.

The approval also fits into a larger transition story at Takeda. CEO Julie Kim said during the company’s annual shareholder meeting in June that successfully delivering three launches is a top priority and called 2026 a year of transition. Jefferies said it expects approval of zasocitinib for psoriasis to follow in the first half of the calendar year 2027, suggesting Mimrylo is part of a sequence Takeda needs to execute rather than a standalone win.