Efficacy and Safety of Recombinant Asparaginase in Infants With Previously Untreated Acute Lymphoid Leukemia (ALL)

Inclusion Criteria: * Previously untreated T-lineage or precursor B-lineage ALL or biphenotypic leukaemia according to EGIL criteria. * Morphological verification of the diagnosis, confirmed with cyto¬chemistry and immunophenotyping. * Age \< 1 year at diagnosis. * Written informed consent of the parents or other legally authorised guardian of the patient. * Treatment according to protocol INTERFANT 06 Exclusion Criteria: * Mature B-lineage ALL, defined by the immunophenotypical presence of surface immunoglobulins or t(8;14) and breakpoint as in B-ALL. * The presence of the t(9;22)(q34;q11) or bcr-abl fusion in the leukaemic cells. * Systemic use of corticosteroids less than 4 weeks before diagnosis. Patients who received corticosteroids by aerosol are eligible. * Known allergy to any ASNase preparation. * Pre-existing known coagulopathy (e.g. haemophilia). * Pre-existing pancreatitis. * Liver insufficiency (bilirubin \> 50 µmol/L; SGOT/SGPT \> 10 x the upper limit of normal).