Background: Dasatinib, a highly potent BCR-ABL inhibitor, is an effective treatment for patients with chronic myeloid leukemia in chronic phase (CML CP) after resistance, suboptimal response, or intolerance to prior imatinib. In a phase 3 dose optimization trial in patients with CML CP (CA180-034), the occurrence of pleural effusion was significantly minimized with dasatinib 100 mg once daily (QD) compared with other treatment arms (70 mg twice daily [twice daily], 140 mg QD, or 50 mg twice daily).
Methods: To investigate the occurrence and management of pleural effusion during dasatinib treatment, and efficacy in patients with or without pleural effusion, data from CA180-034 were analyzed.
Results: With 24-month minimum follow-up, 14% of patients treated with dasatinib 100 mg QD incurred pleural effusion (grade 3: 2%; grade 4: 0%) compared with 23% to 26% in other study arms. The pleural effusion rate showed only a minimal increment from 12 to 24 months. In the 100 mg QD study arm, median time to pleural effusion (any grade) was 315 days, and after pleural effusion, 52% of patients had a transient dose interruption, 35% had a dose reduction, 57% received a diuretic, and 26% received a corticosteroid. Three patients in the 100 mg QD study arm discontinued treatment after pleural effusion. Across all study arms, patients with or without pleural effusion demonstrated similar progression-free and overall survival, and cytogenetic response rates were higher in patients with a pleural effusion.
Conclusions: Pleural effusion is minimized with dasatinib 100 mg QD dosing and its occurrence does not affect short- or long-term efficacy.