Protagonist Therapeutics, Inc., a clinical-stage biopharmaceutical company, discovers and develops peptide-based therapeutic drugs to address unmet medical needs. It is developing PTG-300, an injectable hepcidin mimetic that is in Phase II clinical trial for the treatment of patients with polycythemia vera and hereditary hemochromatosis, as well as for the treatment of other blood disorders; PTG-200, an oral, interleukin-23 receptor specific antagonist peptide, which is in phase II clinical trial for the treatment of moderate-to-severe Crohn's disease; and PN-943, an oral, alpha-4-beta-7 specific integrin antagonist that is in Phase II clinical trial for treating inflammatory bowel disease (IBD). The company has a license and collaboration agreement with Janssen Biotech, Inc. for the development, manufacture, and commercialization of PTG-200 for the treatment of Crohn's disease and ulcerative colitis; and PN-235 and PN-232 oral interleukin-23 receptor antagonist candidates for IBD and non-IBD indications. Protagonist Therapeutics, Inc. was incorporated in 2006 and is headquartered in Newark, California.