This study is a multicenter trial of treatment for young ALL patients. All ALL patients will receive the same steroid pre-phase in order to evaluate sensitivity or resistance. Then, patients will be included into 3 specific trials according to biological features (immunophenotype, cytogenetics, and molecular biology).

Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL) 2005:

• T ALL or B ALL non Ph (N=810 patients planned).
• GRAALL 2005 R: B ALL non Ph CD20+ (N=220 patients planned).
• GRAAPH 2005: ALL Ph+ (N=270 patients planned)

GRAALL 2005: T ALL or B ALL non Ph

Randomization between standard versus intensified cyclophosphamide administration during a 4-drug, 4 week chemotherapy and late intensification.

(N=810 patients planned)

GRAALL 2005 R: B ALL non Ph CD20+

Randomization between standard versus intensified cyclophosphamide administration during a 4-drug, 4 week chemotherapy and late intensification.

Randomization between Mabthera (rituximab) or no Mabthera during all induction and consolidation courses.(N=220 patients planned)

Allogenic transplantation will be performed depending on unfavourable risk factors.

GRAAPH 2005: ALL Ph

Randomization between an imatinib-based induction and a chemotherapy + imatinib induction. (N=270 patients planned)

Allogenic transplantation will be systematically performed in the presence of related or unrelated donors.

Autologous transplantation could be performed in the absence of a donor in case of Molecular Residual Disease (MRD) ≤ 10-4.

Consolidation therapy will be performed in the absence of a donor in case of MRD > 10-4.

Inclusion Criteria:

• 18-59 years
• ALL newly diagnosed (blast < 20%)
• Central Nervous System (CNS) positive or negative
• Signed written informed consent
• For GRAAPH trial only: t(9;22) or BCR- ABL positive

Exclusion Criteria:

• Lymphoblastic lymphoma
• ALL 3
• Chronic myeloid leukemia
• Severe organ condition