Long-term results from the DASISION trial suggest that dasatinib and imatinib produce similar outcomes in patients with newly diagnosed chronic phase chronic myeloid leukemia (CP-CML).
Although patients who received dasatinib experienced faster and deeper molecular responses than patients who received imatinib, the overall survival and progression-free survival rates were similar between the treatment arms.
Overall, adverse events (AEs) were similar between the arms as well.
Researchers said these results suggest that dasatinib should continue to be considered an option for patients with newly diagnosed CP-CML.
The team reported the results of this study in the Journal of Clinical Oncology. The research was sponsored by Bristol-Myers Squibb.
The trial enrolled 519 patients with newly diagnosed CP-CML. They were randomized to receive dasatinib at 100 mg once daily (n=259) or imatinib at 400 mg once daily (n=260). Baseline characteristics were well-balanced between the arms.
At 5 years of follow-up, 61% of patients in the dasatinib arm and 63% of patients in the imatinib arm remained on treatment.
Response and survival
The cumulative 5-year rate of major molecular response was 76% in the dasatinib arm and 64% in the imatinib arm (P=0.0022). The rates of MR4.5 were 42% and 33%, respectively (P=0.0251).
The estimated 5-year overall survival was 91% in the dasatinib arm and 90% in the imatinib arm (hazard ratio=1.01; 95% CI, 0.58 to 1.73).
The estimated 5-year progression-free survival was 85% and 86%, respectively (hazard ratio=1.06; 95% CI, 0.68 to 1.66).
Safety
In both treatment arms, most AEs were grade 1 or 2. Grade 3/4 AEs occurred in 15% of patients in the dasatinib arm and 11% of patients in the imatinib arm.
Rates of grade 3/4 hematologic AEs tended to be higher in the dasatinib arm than the imatinib arm.
But the rates of most drug-related, nonhematologic AEs were lower in the dasatinib arm than the imatinib arm or were comparable between the arms.
The exception was drug-related pleural effusion, which was more common with dasatinib (28%) than with imatinib (0.8%).
Drug-related AEs were largely manageable, although they led to treatment discontinuation in 16% of dasatinib-treated patients and 7% of imatinib-treated patients.
By 5 years, 26 patients (10%) in each treatment arm had died. Nine patients in the dasatinib arm died of disease progression, as did 17 patients in the imatinib arm.
