A Study of Pimitespib in Combination With Imatinib in Patients With GIST (CHAPTER-GIST-101)

This study consists of Dose escalation part and Expansion part. In Dose Escalation Part, the maximum tolerated dose of combination of pimitespib and imatinib in patients with gastrointestinal stromal tumors (GIST) who are judged to be refractory to imatinib, estimate the recommended dose, evaluate safety and pharmacokinetics, and observe the antitumor effect. Expansion part consists of 3 arms. In Arm A, the efficacy and safety will be evaluated, which of the combination of pimitespib and imatinib in patients with GIST who have failed imatinib at doses below the MTD determined in Dose Escalation Part. In Arm B, the efficacy and safety of pimitespib monotherapy will be evaluated and the therapeutic effect of imatinib administration after pimitespib will be evaluated in an exploratory manner. In Arm C, the efficacy and safety of sunitinib monotherapy will be evaluated as reference data.

NCT Number	NCT05245968
Lead Sponsor	Taiho Pharmaceutical Co., Ltd.
Conditions	Gastrointestinal Stromal Tumors
Enrollment	78 participants
Start Date	2021-12-01
Primary Completion	2026-12 (estimated)
Study Completion	2026-12 (estimated)
Updated on ClinicalTrials.gov	2026-01-20