A Study of the Efficacy and Safety of Imatinib Mesylate in Patients With Unresectable or Metastatic Gastrointestinal Stromal Tumors Expressing C-kit Gene

Participants were randomized 1:1 to receive imatinib mesylate 400 mg/day or 600 mg/day. Upon unsatisfactory treatment effect on the starting dose of 400 mg/day or 600 mg/day imatinib mesylate, in the opinion of the treating physician, a dose increase up to 600 mg/day or 800 mg/day, was allowed provided that the participant continued to benefit from the treatment and in the absence of safety concerns.