Ambrx Biopharma Inc., a clinical stage biopharmaceutical company, focuses on discovering and developing antibody drug conjugates (ADCs) and other engineered therapies to modulate the immune system. It focuses on portfolio of clinical and preclinical programs designed to optimize efficacy and safety in multiple cancer indications, including ARX517, its proprietary antibody-drug conjugate (ADC) targeting the prostate-specific membrane antigen (PSMA) and ARX788, its proprietary ADC targeting HER2. The company also has preclinical and clinical collaborations with multiple partners on drug candidates using Ambrx technology. The company was incorporated in 2003 and is headquartered in La Jolla, California. As of March 7, 2024, Ambrx Biopharma Inc. operates as a subsidiary of Johnson & Johnson.