Disease Focus

Our development programs are designed to address a critical challenge of cancer treatment — drug resistance mutations.

Theseus is developing pan-variant inhibitors for clinically validated targets with clear unmet medical need. Existing tyrosine kinase inhibitors (TKIs) are limited by constantly mutating cancers, and data demonstrate their inability to compensate for a broad array of driver oncogene variants.

At Theseus, we believe truly transformative, targeted therapeutics must inhibit all clinically relevant variants. We are focused on conquering cancer resistance by predicting how a cancer will mutate, before it happens, to improve potential treatment outcomes.

We are developing pan-variant inhibitors for clinically validated targets with clear unmet medical need.
Our lead program, THE-630, is a pan-variant KIT inhibitor for gastrointestinal stromal tumors (GIST), and is the most common sarcoma of the gastrointestinal tract with 4,000-6,000 new cases diagnosed in the U.S. each year.

Our second program is a fourth-generation, selective epidermal growth factor receptor (EGFR) inhibitor designed to overcome C797S-mediated resistance in EGFR mutant non-small cell lung cancer (NSCLC).