Theseus Pharmaceuticals ^{Priced, Nasdaq: THRX}

We are a biopharmaceutical company focused on improving the lives of cancer patients through the discovery, development and commercialization of transformative targeted therapies. Our initial focus is on developing the next generation of tyrosine kinase inhibitors, or TKIs, and is rooted in the critical role that tyrosine kinases play in the development of cancer. Our goal is to develop “pan-variant” kinase inhibitors -- inhibitors that target all major cancer causing and drug resistance mutations in clinically significant protein kinases. Our lead product candidate, THE-630, is a pan-variant inhibitor of all major classes of activating and resistance mutations of the KIT kinase, or a pan-KIT inhibitor, for the treatment of gastrointestinal stromal tumors, or GIST, a type of cancer characterized by oncogenic activation of KIT. THE-630 is derived from intellectual property exclusively licensed to us by ARIAD Pharmaceuticals, Inc., or ARIAD. We plan to submit an Investigational New Drug, or IND, application to the U.S. Food and Drug Administration, or FDA, in the fourth quarter of 2021 for the evaluation of THE-630 in patients with advanced GIST whose disease has developed resistance to prior KIT-targeting therapies, and, if accepted, initiate a phase 1/2 dose escalation and expansion clinical trial.