Peak Bio, Inc. is engaged in the research and development of therapeutics, including small molecules and antibody-drug conjugates, for the treatment of cancer and rare diseases. The company develops small molecule inhibitors and antibody-drug conjugates for therapeutic use, with its lead product candidate, PHP-303, being an oral, once-daily small molecule inhibitor of neutrophil elastase for alpha-1 antitrypsin deficiency and COVID-19-related acute respiratory distress syndrome. It advances a proprietary toxin platform, including PH-1, a spliceosome modulator used to generate ADC product candidates targeting cancer, such as an ADC targeting the Trop2 antigen in solid tumors. The company conducts preclinical research activities and pharmacology studies, collaborating with contract research organizations and contract development and manufacturing organizations. It receives pre-clinical grants to support research and development efforts, with a pipeline focused on therapies for inflammatory, rare, and specialty diseases, as well as cancer. The company serves clients in the biotechnology, pharmaceutical, and medical device industries, organizations involved in oncology and rare disease research, research institutions, and government agencies. The company is based in Pleasanton, California.