ASH 2018: 5-Year Analysis of Imatinib vs. Dasatinib in Newly Diagnosed Chronic Phase CML
Posted: Thursday, December 20, 2018
Imatinib remains a highly effective first-line therapy for newly diagnosed patients with chronic phase chronic myeloid leukemia (CML), according to 5-year analysis of the SPIRIT2 trial, which was presented at the 2018 American Society of Hematology (ASH) Annual Meeting & Exposition (Abstract 457) in San Diego. The results of this large phase III prospective randomized open-label trial, comparing imatinib and dasatinib in patients with CML, found no significant difference in event-free or overall survival between the two treatments. However, a higher molecular and cytogenetic response rate as well as a higher rate of pleural effusion was observed with dasatinib.
“Subgroup analyses are planned to explore whether dasatinib may have advantages in particular clinical scenarios,” concluded Stephen O’Brien, MBBS, BSc, PhD, of Newcastle University, United Kingdom, and colleagues.
A total of 812 patients were randomly assigned to receive 400 mg of imatinib (406) or 100 mg of dasatinib daily (406). Ultimately, 424 patients completed the 5-year study while still taking first-line medication. At 5 years, the probably of treatment failure–free survival was higher with dasatinib (60.9%) than imatinib (52.9%), but the investigators found no significant difference in event-free survival (91% vs. 89%, respectively) or overall survival (91.9% vs. 91.2%, respectively). Of the patients who discontinued first-line therapy, more patients who received imatinib switched because of suboptimal polymerase chain reaction response than who received dasatinib (71 patients vs. 7 patients, respectively). More patients who received dasatinib than imatinib discontinued treatment because of intolerance (123 vs. 68, respectively). Regarding pleural effusion, the overall rate over 5 years in the dasatinib arm was 36%, and older patients seemed to have a higher incidence.