Phase 2 clinical trials of imatinib for CML. The results of the phase 2 studies are shown in chronic phase patients who previously received interferon therapy, and accelerated phase and blast crisis patients. Results shown are with a median follow-up of up to 30 months and the rate of disease progression is at 24 months.^46-48  Complete response (CR) and partial response (PR) for cytogenetic responses include patients with Ph chromosome–positive metaphases of less than or equal to 35%. Illustration by A. Y. Chen.