Correlation of CCyR rates and the in vitro mutation sensitivity rankings for CP patients treated with dasatinib. The CCyR rates of patients with various imatinib-resistant mutations treated in trials of dasatinib³⁷  were plotted according to the in vitro sensitivity classification of (A) Redaelli et al³⁹  (n = 286 patients) and (B) O'Hare et al³⁸  (n = 335 patients). The mutations are ranked in order of in vitro sensitivity (highest to lowest from the left). The number of patients with each mutation at dasatinib start ranged from 5 for L387M to 60 for G250E. The cumulative CCyR rate for all patients with mutations in the study was 43%. CCyR rates between 30% and 40% were achieved for patients with sensitivity classifications of (A) resistant (orange), moderately resistant (yellow), and sensitive (green), and (B) intermediate sensitivity (yellow) and sensitive (green). Only patients with T315I or F317L, which are classed as SGI clinically relevant, had CCyR rates less than 10%. This suggests that the in vitro sensitivity was only partially predictive of the clinical response to dasatinib.