04:02 AM EDT, 06/02/2025 (MT Newswires) -- Protagonist Therapeutics ( PTGX ) and Takeda (TAK) said Sunday their investigational drug rusfertide as a potential treatment for patients with polycythemia vera met primary and key secondary endpoints in a randomized, placebo-controlled phase 3 study.

The companies, which are co-developing the drug, said 76.9% of patients in the 156-week, 293-patient study receiving once-weekly rusfertide as an add-on to current standard of care treatment achieved a clinical response compared with 32.9% receiving a placebo plus standard of care.

They added that 62.6% of patients treated with rusfertide plus standard of care maintained levels of hematocrit below 45%, versus 14.4% treated with placebo plus standard of care.

Rusfertide has received US Food and Drug Administration fast-track and orphan drug designations, the companies said.

Polycythemia vera is characterized by the overproduction of red blood cells, which can increase blood thickness and result in life-threatening cardiac events.