Theseus Pharmaceuticals is passionately committed to improving the lives of cancer patients by working to outsmart cancer resistance. Led by a team of targeted oncology pioneers with a proven track record developing and commercializing cancer therapeutics, the Company is developing next-generation tyrosine kinase inhibitors (TKIs): “pan-variant” targeted therapies that address all major drug resistant mutations. Theseus believes a pan-variant approach is the most effective way to address cancer resistance.

The Company’s lead program, THE-630, is a pan-variant KIT inhibitor for patients with advanced gastrointestinal stromal tumors (GIST), whose cancer has developed resistance to earlier lines of kinase inhibitor therapy. Theseus is also developing THE-349: a fourth-generation, selective epidermal growth factor receptor (EGFR) inhibitor to address C797X-mediated resistance to first- or later-line osimertinib treatment in patients with non-small cell lung cancer (NSCLC). Finally, Theseus is also developing a series of next-generation, pan-variant TKI molecules targeting BCR-ABL mutations for the treatment of refractory chronic myeloid leukemia (CML) and front-line Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL).