This open label phase II study of Dasatinib will enroll adult de novo Ph+ ALL patients. A minimum of 48 cases will be required to complete the study. Accrual is expected to be completed in 18 months. The study will be considered completed for patients in HCR after completion of a total of 12 weeks of treatment. After completion patients will go off study and will be treated according to the best treatment option for Ph+ ALL patients in 1st HCR. The enrollment in the post-remissional phase of the current GIMEMA LAL protocol will be suggested.