Induction therapy is administered. Patients experiencing slow response (> 10 % blasts in the 15th mo of treatment) were included in the LAL -AR -03 protocol, on the arm of intensified induction. Those who do not reach the RC will be excluded from the study and will be treated according to the protocol LAL-AR/03 , which will be incorporated receiving blocks consolidation. All patients in CR consolidation treatment (1 and 2 ) followed reinducciones maintenance (maintenance -1 ) to complete the first year of treatment and maintenance without reinducciones (maintenance -2 ) to complete two years from the RC will be administered . If after union persistent high levels of ER ( > 0.05 %) and this reappears later during maintenance therapy the patient will be excluded from the study and will be treated according to the protocol of high risk ( PETHEMA LAL-AR/03 ) . In case of persistent high levels of ER patients after consolidation will consolidate blocks PETHEMA LAL-AR/03 protocol followed by allogeneic HSCT . If the ER reappears during maintenance treatment the patient will receive an allogeneic HSCT , Standby thereof, may be administered one or two blocks consolidation of LAL -AR -03 protocol.