Theseus Pharmaceuticals is a biotechnology company focused on oncology. The company specializes in the research and development of therapies designed to anticipate and inhibit treatment-resistant cancer mutations. The drug lead candidate the company develops, THE-630, is a pan-variant KIT inhibitor in development for the treatment of refractory GIST. It also develops a selective EGFR inhibitor to overcome C797S-mediated resistance to first- or later-line osimertinib treatment for patients with non-small cell lung cancer.