BACKGROUND: The use of imatinib combined with chemotherapy has demonstrated 
improved outcome in adults with Philadelphia chromosome-positive acute 
lymphoblastic leukemia (Ph-positive ALL). However, a substantial proportion of 
patients continue to die as a result of disease progression.
PATIENTS AND METHODS: We assessed the minimal residual disease (MRD)-based 
effect and long-term outcome of first-line incorporation of dasatinib (100 mg 
once daily) into chemotherapy alternatively for adults with Ph-positive ALL. The 
primary end point was the major molecular response (MMR) rate by the end of the 
second dasatinib cycle. Patients with a donor proceeded to allogeneic stem cell 
transplantation (SCT) as early as possible. MRD monitoring was centrally 
evaluated by real-time quantitative polymerase chain reaction (4.5-log 
sensitivity) using bone marrow samples.
RESULTS: Fifty-one patients (median age, 46 years) were enrolled and treated 
with this strategy. After the first dasatinib cycle, 50 patients (98.0%) 
achieved complete remission (CR). By the end of the second dasatinib cycle, 46 
(93.9%) of 49 assessable patients had persistent CR, and 38 (77.6%) had MMR 
(32.7%) or undetectable MRD (44.9%). On the basis of the MRD kinetics by this 
time point, the numbers of early-stable, late, and poor molecular responders 
were 23 (46.9%), 15 (30.7%), and 11 (22.4%), respectively. Thirty-nine patients 
(76.5%) underwent allogeneic SCT in CR1. After a median follow-up of 54 months, 
the 4-year cumulative incidence of relapse and disease-free survival (DFS) rate 
for all patients were 30.0% and 52.0%, respectively, and the corresponding 
outcomes among those receiving allogeneic SCT in CR1 were 20.5% and 64.1%, 
respectively. Poor molecular responders had a higher risk of relapse and DFS 
than those of early-stable molecular responders.
CONCLUSION: This dasatinib-based protocol was effective for achieving a good 
quality molecular response and durable DFS in adults with Ph-positive ALL.
TRIAL REGISTRATION: clinicaltrials.gov, NCT01004497.