SARC044: A Phase II Trial of Bezuclastinib in Combination With Sunitinib in Patients With GIST

This is an open label, single arm, phase 2 trial investigating bezuclastinib plus sunitinib in patients with GIST who have previously progressed on sunitinib. After washout, patients will begin bezuclastinib and add sunitinib 2 weeks later. Patients will continue on treatment until progression, unacceptable toxicity, or withdrawal of consent. Patients may stay on treatment beyond progression if there is clinical benefit in the opinion of the investigator. Imaging response assessments will be performed every 8 weeks until the participant reaches 15 months on study. After 15 months, response assessments may be performed every 3 months. Circulating tumor DNA (ctDNA) will be collected at baseline, with sequential initiation of bezuclastinib and sunitinib, at the first response assessment, and at the time of progression. In a subset of 20 patients, PET/CT will be performed at baseline and with sequential initiation of bezuclastinib and sunitinib, and tumor biopsies will be performed on cycle 2 day 1 for correlative studies. EORTC QLQ-C30 will be administered during the study to assess patient-reported quality of life.