Gossamer Bio Inc. Gossamer Bio Inc is a clinical-stage biopharmaceutical company. It focuses on discovering, acquiring, developing, and commercializing therapeutics in the disease areas of immunology, inflammation, and oncology. The company pipeline products include Seralutinib, which address the cellular overgrowth, fibrosis, and vascular remodeling which underlie PAH (pulmonary arterial hypertension); GB004, for the treatment of inflammatory bowel disease, including ulcerative colitis and Crohn's disease; GB1275, for the treatment of oncology indications; and GB001, for the treatment of moderate-to-severe eosinophilic asthma.