Takeda has won US market approval for Mimrylo (rusfertide), a first-in-class hepcidin analogue licenced from Protagonist Therapeutics, for adults with polycythaemia vera (PV), a myeloproliferative neoplasm where excess red-cell production drives haematocrit above safe thresholds and raises thrombotic risk fourfold.

The decision rests on the Phase III VERIFY trial (n=293) showing rusfertide, dosed weekly subcutaneously, achieved response (no phlebotomy needed) in 77% of patients versus 33% on placebo across weeks 20 to 32, cut average phlebotomy events from 1.8 to 0.5 per patient over 32 weeks, and carried a manageable safety profile dominated by injection-site reactions and anaemia, with Takeda holding global development and commercialisation rights.

Roughly 90,000 patients live with PV in the US alone, and up to 78% experience haematocrit escape under standard phlebotomy or cytoreductive care, leaving a clear unmet need for iron-distribution modulation that complements, rather than replaces, interferon or ruxolitinib. Rusfertide's hepcidin-pathway mechanism offers a differentiated lever versus JAK inhibitors and aspirin-phlebotomy maintenance, while the weekly subcutaneous cadence positions it for long-term adherence in a chronic indication.

The approval triggers milestone and royalty cash flows for Protagonist.