Gossamer Bio, Inc., a clinical-stage biopharmaceutical company, focuses on discovering, acquiring, developing, and commercializing therapeutics in the disease areas of immunology, inflammation, and oncology in the United States. The company is developing GB002, an inhaled, small molecule, platelet-derived growth factor receptor, or PDGFR, colonystimulating factor 1 receptor, or CSF1R, and c-KIT inhibitor for the treatment of pulmonary arterial hypertension; GB004, a gut-targeted, oral small molecule for the treatment of inflammatory bowel disease; GB5121, an oral, irreversible, covalent, small molecule inhibitor of Bruton's Tyrosine Kinase for the treatment of primary central nervous system lymphoma; and GB7208, an oral, small molecule, BTK inhibitor for the treatment of multiple sclerosis. It has license agreements with Pulmokine, Inc. to develop and commercialize GB002 and related backup compounds; and Aerpio Pharmaceuticals, Inc. to develop and commercialize GB004 and related compounds. The company was formerly known as FSG, Bio, Inc. and changed its name to Gossamer Bio, Inc. in 2017. Gossamer Bio, Inc. was incorporated in 2015 and is headquartered in San Diego, California.