In this study, cytogenetic response rate after timely switching to a second-generation tyrosine kinase inhibitor (TKI) was evaluated among patients with CML-CP, after failure to achieve CCyR 1 year after imatinib initiation.Patients and Methods:
An online physician-administered medical chart review was used to retrospectively collect information from 108 US-based hematologists and oncologists on CML-CP patients who initiated imatinib as first-line therapy and failed to achieve CCyR at 12 months after imatinib initiation. Patients who switched to a second-generation TKI within 3 months after the CCyR failure were defined as timely switchers, and those who continued taking imatinib for at least 3 months after the CCyR failure were defined as nonswitchers. CCyR achievement was compared between timely switchers and nonswitchers using multivariate Cox proportional hazard models.Results:
Physicians provided information on 593 patients, with 306 defined as timely switchers and 287 defined as nonswitchers. Among the nonswitchers, 78 switched to a second-generation TKI at a later date. After adjusting for potential confounding factors, timely switchers had statistically significantly greater likelihood of achieving CCyR (hazard ratio, 1.80; P = .002) compared with nonswitchers.Conclusion:
Timely switching from imatinib to a second-generation TKI after CCyR failure 1 year after imatinib initiation was associated with a greater likelihood of achieving CCyR compared with delaying the switch or not switching to a second-generation TKI.