Shuttle Pharmaceuticals Holdings, Inc., through its subsidiary, Shuttle Pharmaceuticals, Inc., focuses on the discovery, development, and commercialization of drugs for sensitizing cancers to radiation therapy. Its products in clinical stage include Ropidoxuridine, an oral halogenated pyrimidine to treat patients with brain tumors and soft tissue sarcomas; and Doranidazole, an injectable hypoxic cell radiation sensitizer for treatment of pancreatic, lung, and liver cancers. The company was founded in 2012 and is based in Rockville, Maryland.