• Feasibility and safety of the addition of IMATINIB to conventional chemotherapy schedule. [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
• Long-term clinical outcome (EFS, survival), [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• Pattern of molecular response (MRD) [ Time Frame: 5 time points between S4 and S22 ] [ Designated as safety issue: No ]
• Conversion rate to CR in patients resistant to the first part of the induction phase of chemotherapy included in the Poor-risk group. [ Time Frame: 2 years ] [ Designated as safety issue: No ]

• - To Determine the safety and feasibility of Imatinib added to chemotherapy,
• - To Evaluate the long-term clinical outcome (EFS, survival) in both groups,
• - To Assess the antileukemic potential of Imatinib by analyzing the pattern by arm of the molecular response on the basis of 5 measurements of minimal residual disease (MRD) taken at 5 time points between S4 and S22,
• - To evaluate the role of molecular response as surrogate for DFS.

The purpose of this study is to determine whether Imatinib is safe and effective in association with intensive treatment of Ph+ALL in children. Patients will be randomized to receive or not Imatinib in addition to chemotherapy.

Recent advances in treatment have increased the cure of childhood ALL to 75% or better. However, attempts to improve results for resistant subtypes of ALL, such as Ph+ ALL, have been largely unsuccessful. Imatinib, an inhibitor of protein-tyrosine kinases, is currently being tested in several phase I, II and III trials covering most Chronic Myeloid Leukemia patient populations and patients with overtly relapsed or refractory Ph+ALL. Pediatric patients with Ph+ALL will be stratified as Good-risk and Poor-risk, according to their initial prednisone and chemotherapy responses and the achievement of the complete remission at day 28. The Good-risk patients will be randomized to receive or not Imatinib whereas all Poor-risk patients will receive Imatinib, added to intensive, post-induction BFM-type chemotherapy. The endpoint will be the evaluation on the long-term clinical outcome, in particular on the Disease Free Survival (DFS).

• Acute Lymphoblastic Leukemia
• Philadelphia Chromosome

• Drug: Standard chemotherapy + Imatinib
• Drug: Standard chemotherapy

Inclusion Criteria:

• Children and adolescents aged 1 to 17 years at diagnostic
• Documented Ph+ ALL
• Eligibility for the current local prospective therapeutic study of childhood ALL
• Informed consent given by the parents or by legal guardian

Exclusion Criteria:

• Abnormal hepatic functions
• Abnormal renal functions
• Active systemic bacterial, fungal or viral infection

• Ministry of Health, France
• Novartis