Description Callisto Pharmaceuticals is working on a constellation of medical therapies. Its drug candidates include treatments for gastrointestinal diseases, inflammatory conditions, and a variety of cancers. The company is developing certain candidates through licensing and development agreements with other drug and research organizations, such as Genzyme and the M.D. Anderson Cancer Center. Callisto conducts research and development operations through its subsidiaries, Synergy Pharmaceuticals and Callisto Research Labs.