Dynamics of long-term imatinib mesylate treatment response. The figure displays the kinetics of the leukemic cell burden in patients treated with imatinib mesylate for 10 years after diagnosis in early chronic phase. (A-D) The panels show the percentage of cancer cells (BCR-ABL1/BCR as measured by RQ-PCR) of 4 individual patients with CML (circles) and the fitted biphasic exponential model (red curves, starting from month 6 of treatment). Converted data points are shown in green (see “Methods” and supplemental Information). This fitted model shows that there is a biphasic exponential depletion of leukemic cells, starting from 6 months after the initiation of therapy. (E) The panel displays the median (orange circles) and quartiles of the long-term imatinib mesylate response data together with the fitted biphasic exponential model (red curve). See supplemental Figure 2 for all patient plots and model fitting.