Inclusion Criteria:

- According to the investigator opinion, patient must able to carry out with all the
clinical trial requirements

- Patient or Legal Representative must volunteer sign the inform consent before any
study specific test, that is not part of the common patient attention, is performed.

- Age 16 to 30

- Patient diagnosed with standard risk ALL no previously treated. Standard risk ALL is
defined by the following criteria:

- Leukocyte count < 25x109/L

- Absence of poor prognosis cytogenetic abnormalities:

t(9;22) or demonstration of BCR-ABL rearrangements. 11q23 alterations or
demonstration of ALL1-AF4 rearrangements.

- Childbearing women must have a negative pregnancy test and must accept to use an
effective contraception method.

Exclusion Criteria:

- CNS involvement at diagnosis, defined as presence of blasts in a centrifugated sample
of craneospinal fluid with a cellular count of more than 5 cels/L, in the absence of
traumatic puncture (more than 10 red blood cels/ml), or as neurological symptoms that
suggest of neuromeningeal involvement and imaging tests compatible, in the absence of
blasts in craneospinal fluid.

- B mature cell phenotype (sIg+) or with the Burkitt ALL cytogenetic abnormalities
(t[8;14], t[2;8], t[8;22])

- ALL with t(9;22) or BCR-ABL rearrangements.

- Acute biphenotypic and bilineal leukemias

- Acute undifferentiated leukemia

- History of coronary or valvular disease or hypertensive cardiopathy

- Chronic hepatopathy

- Chronic respiratory insufficiency

- Chronic renal insufficiency not due to ALL

- Serious neurological disorders not due to ALL

- Abnormal ECOG (WHO scale grade 3 and 4) not done by ALL

- Pregnant or currently breast feeding women

- Patients participating in other clinical trial or receiving any other investigational
agent within 30 days previous to the study inclusion