Dasatinib, a second generation tyrosine-kinase inhibitor (TKI), reduces the proliferation of BCR-ABL positive chronic myeloid leukemia (CML) cells by inhibiting the BCR-ABL pathway. Since 2006 dasatinib is approved for 2nd-line leukaemia therapy in Europe. In October 2010, the EMA granted a positive opinion for the approval of dasatinib for the 1st-line therapy of Philadelphia-chromosome positive CML in the chronic phase (Ph+CML-CP).
The pivotal DASISION trial investigates whether dasatinib 100mg orally once daily is more effective as 1st-line therapy in Ph+ CML-CP patients than the current standard of care – imatinib 400mg orally once daily.

The results of the trial indicate that dasatinib is clinically more effective than imatinib. The confirmed complete cytogenetic response, the primary endpoint, is 77% vs. 66% (p=0.007) in the dasatinib and imatinib groups, respectively. Progression to the accelerated phase or blast crisis occurred more frequent in the control group (3.5%) compared to the dasatinib group (1.9%). Whereas, haematological adverse events (AEs) occurred more frequent in the dasatinib group than in the imatinib group, the opposite is true for non-haematological AEs - except pleural effusions, these occurred only in dasatinib treated patients.

Despite these first encouraging interim results, further follow-up is essential to provide information on durability of the responses, quality-of- life and to further investigate the safety profile of dasatinib in the 1st-line therapy of CML.