Imatinib has improved outcomes in patients with Philadelphia chromosome-positive 
(Ph+) acute lymphoblastic leukemia (all). Minimal residual disease (mrd) is a 
useful tool for predicting leukemia relapse. However, there is no consensus on 
how to treat children with elevation of BCR-ABL transcripts but no evidence of 
hematologic relapse during chemotherapy combined with imatinib. Here, we report 
the case of a child with Ph+ all who had persistent elevation of mrd, but no 
evidence of hematologic relapse while receiving imatinib plus intensive 
chemotherapy. Dasatinib was substituted for imatinib because no suitable donor 
for allogeneic hematopoietic stem-cell transplantation (hsct) was available. 
Less-intensive chemotherapy with methotrexate and 6-mercaptopurine was 
administered concomitantly. No serious adverse events were encountered. With 
continuous dasatinib combined with chemotherapy, but no allogeneic hsct, our 
patient reached complete molecular remission and has been in complete molecular 
remission for more than 13 months. This report is the first about the long-term 
use of dasatinib in patients with Ph+ all and mrd elevation but hematologic 
remission during imatinib chemotherapy. In a similar situation, chemotherapy 
combined with dasatinib instead of allogeneic hsct could be considered to avoid 
hsct-related mortality and morbidity. Clinical trials are needed.