Protagonist Therapeutics is a clinical-stage biopharmaceutical company focused on discovering and developing peptide-based therapeutics for hematological disorders and inflammatory diseases. Their lead candidate, rusfertide, is a synthetic mimetic of the hormone hepcidin, currently in Phase 3 clinical trials for the treatment of polycythemia vera, a rare blood disorder. In 2024, the company entered into an agreement with Takeda Pharmaceutical, receiving an upfront payment of $300 million for global commercialization rights to rusfertide outside the U.S.