Proposed treatment monitoring strategy. Allo HSCT indicates allogeneic hematopoietic stem cell transplantation. *Failure and warning signs (or suboptimal response) are defined in Table 3. **Choice will be influenced by the type of warning sign. For example, no change may be appropriate for a patient with CCyR and declining BCR-ABL1 transcript level but no MMR at 18 months, whereas the absence of CCyR at 12 months may warrant consideration for switching to an alternative TKI (after assessing for ABL tyrosine kinase domain point mutations). The presence of a resistance-conferring mutation warrants a change in treatment strategy. †For CP patients who develop a T315I mutation on first-line therapy but who have no evidence of additional cytogenetic aberrations or other features of progression, I typically first switch to ponatinib and follow closely to determine the need to proceed to allogeneic transplantation. ‡Monitoring on second-line therapy (nilotinib, dasatinib, bosutinib, or ponatinib) is similar to monitoring on first-line therapy. Figure modified with permission from Coveler and Oehler.⁴⁷