Summary of clinical trials in imatinib
Phase I	36 patients with 19/36 (53%) with PR and 6/36 (17%) with minor response. MTD was established as 400 mg twice daily.
Phase II	147 patients randomized to 400 mg or 600 mg IM daily and noted 67% PR and 17% with minor response and SD. No difference in outcomes between the two dose levels. In EORTC study, 27 GIST patients on 800 mg daily and noted to have 4% CR, 67% PR, and 18% minor response and SD.
Phase III	EORTC study randomized 946 patients to 400 mg or 800 mg daily IM and noted 5% CR, 45% PR, and 32% with minor response and SD. US study randomized 746 patients to 400 mg or 800 mg IM and noted 2% CR, 46% PR, and 26% with minor response and SD. Both trials allowed crossover to higher dose at progression. No difference in RR or OS in any of the arms. PFS slightly longer in the higher dose EORTC study.