Disease Focus

Our development programs are designed to address the critical challenge of cancer mutations that become resistant to treatment.

Theseus is developing pan-variant tyrosine kinase inhibitors (TKIs) for clinically validated cancer targets with clear unmet medical need. Existing TKIs are limited by constantly mutating cancers, and data demonstrate that these TKIs are unable to overcome a broad array of resistance mutations to inhibit their targets successfully.
We are developing pan-variant tyrosine kinase inhibitors for clinically validated targets in cancers with clear unmet medical need.
Our lead candidate is THE-349, a potential best-in-class, fourth-generation, selective epidermal growth factor receptor (EGFR) inhibitor in development for non-small cell lung cancer (NSCLC) that has become resistant to previous lines of targeted treatment.

Our discovery programs include a pan-variant BCR-ABL inhibitor for the treatment of relapsed/refractory chronic myeloid leukemia (CML) and newly diagnosed Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL), and a next-generation, highly selective, pan-variant KIT inhibitor for the treatment of early-line GIST.