EGFR Program for NSCLC

We are currently investigating the use of our pan-variant tyrosine kinase inhibitors to help people with lung cancer.

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer, accounting for approximately 85 percent of the estimated 2.2 million cases of lung cancer diagnosed in 2020. Up to half of NSCLC patients have tumors that are driven by activating mutations in the epidermal growth factor receptor (EGFR) and up to 90 percent of those mutations are found in exons 19 and 21. Most patients’ tumors, in response to treatment, develop one or more additional EGFR mutations, causing resistance and rendering current therapies ineffective.

The most common resistance mutations that NSCLC tumors develop in response to treatment with osimertinib, the current standard of care and a third-generation inhibitor, are C797S and T790M.

We have developed a series of potent, selective, single molecule, fourth-generation EGFR inhibitors designed to inhibit all major classes of EGFR cancer-causing and resistance mutations in patients failed by current approved therapies.

About Our Fourth-generation EGFR Inhibitor
To address this problem of treatment resistance in NSCLC due to EGFR mutations, Theseus is developing a fourth-generation selective EGFR inhibitor. The compound is designed to inhibit the full range of single-, double-, and triple-mutant EGFR variants found in the tumors of patients with EGFR-mutant NSCLC who have developed resistance to first- or later-line osimertinib, including the C797S and T790M mutations, with central nervous system (CNS) activity as disease will ultimately relapse in the brain.

Theseus has demonstrated preclinically that pan-variant inhibition of all major single-, double-, and triple-mutant EGFR variants, including those with the T790M and C797S mutations, with selectivity over wild-type EGFR and CNS activity, can be achieved with a single molecule. Theseus intends to nominate a development candidate from our EGFR inhibitor program in the third quarter of 2022 and submit an IND for this program in 2023.

Learn more about our EGFR program for NSCLC.