Protagonist Therapeutics, Inc. is a biopharmaceutical company. The Company uses its peptide-based chemical entities rusfertide and JNJ-2113 in different stages of development, all derived from its proprietary discovery technology platform. Its clinical programs fall into two categories of diseases: hematology and blood disorders, and inflammatory and immunomodulatory diseases. Its lead clinical asset, rusfertide (PTG-300), is an injectable hepcidin mimetic in development for the treatment of erythrocytosis, iron overload and other blood disorders. The Company's Interleukin-23 receptor (IL-23R) antagonist compound JNJ-2113 is an orally delivered investigational drug that is designed to block biological pathways targeted by marketed injectable antibody drugs. Its PN-943 is a wholly owned, investigational, orally delivered, gut-restricted alpha 4 beta 7 (?4?7) specific integrin antagonist for inflammatory bowel disease (IBD).