Efficacy and safety of 50 mg versus 100 mg daily frontline dasatinib therapy in chronic-phase chronic myeloid leukemia: a non-controlled, observational dose-comparative cohort study.

BACKGROUND: There is an increasing movement among chronic myeloid leukemia (CML) patients towards optimizing dosages and implementing personalized treatment plans. METHODS: We conducted a non-randomized, non-controlled, observational cohort analysis to evaluate the efficacy and safety of first-line dasatinib treatment for CML, and compare the differences between low-dose dasatinib (50 mg daily) and standard-dose dasatinib (100 mg daily). RESULTS: No significant baseline differences in age, sex, Sokal risk, or ELTS scores were observed. The 100 mg group had longer median treatment duration (56.1 vs. 30.3 months, P < 0.001) and lower rates of sustained first-line therapy (61.3% vs. 95.6%, P < 0.001). Both doses achieved comparable 12-month cumulative CCyR (100 mg: 83.5% vs. 50 mg: 93.2%, P = 0.25), MMR (58.3% vs. 59.1%, P = 0.94), MR4 (34.0% vs. 25.0%, P = 0.24), MR4.5 (23.3% vs.13.6%, P = 0.16), and 2-year EFS (86.3% vs. 91.1%; HR = 1.59, 95% CI = 0.69–3.64, P = 0.33). Time to response milestones (CCyR, MR4, DMR) showed no statistical difference. The 50 mg group had significantly lower pleural effusion incidence (2.2% vs. 25.2%, P < 0.001). No differences in hematologic or most non-hematologic AEs were observed. Among 37 patients who reduced from 100 mg to 50 mg, 35/37 (94.6%) maintained or deepened responses. Notably, 13 patients with MMR attained DMR post-reduction. CONCLUSION: Dasatinib 50 mg daily demonstrates non-inferior efficacy and superior safety compared to 100 mg, particularly in reducing pleural effusion risk.