The study evaluates the efficacy and tolerability of an intensified induction and consolidation therapy in combination with rituximab in CD20 positive standard risk patients. Thereafter patients receive additional consolidation and reinduction cycles combined with rituximab. In parallel minimal residual disease is evaluated. After six months and one year the decision on intensification or discontinuation of therapy is made based on results of MRD evaluation

Inclusion Criteria:

• B-precursor ALL (common / pre B-ALL)
• Standard risk
• CD20 expression >20%
• Ph/BCR-ABL negative
• Age 15-65 years (55-65 if biologically younger)
• Written informed consent

Exclusion Criteria:

• Severe complications due to leukemia or secondary illnesses
• Late relapse of childhood ALL
• Cytostatic pretreatment
• Pregnancy
• Severe psychiatric illness or other circumstances which may compromise cooperation of the patient or informed consent
• Known severe allergy to foreign proteins