KIT Program for GIST

We are developing a highly selective, pan-variant targeted therapy for gastrointestinal stromal tumors (GIST) that is designed to address treatment resistance.

About GIST
GIST is the most common sarcoma of the gastrointestinal tract with an estimated 4,000 to 6,000 new cases diagnosed in the United States each year. Approximately 80% of GIST cases are driven by mutations in KIT, and the disease remains KIT-dependent through successive lines of therapy. Most patients who receive first-line imatinib as a treatment for GIST later experience disease progression due to the emergence of other KIT resistance mutations rendering subsequent lines of targeted therapy significantly less effective.

About KIT Program
A high selective, pan-variant KIT inhibitor could confer substantial clinical benefit in GIST, particularly when administered in early-line settings, given the heterogeneity of the disease.

Theseus is developing a next-generation, highly selective, pan-variant KIT inhibitor for the treatment of early-line GIST. We expect to nominate a development candidate for this program in the first half of 2024.