1. Randomized question: what is the best way to administer pegaspargase? A cohort of children and adolescents with standard or medium risk ALL will be randomized to receive during induction either one infusion of ONCASPAR® 2500 IU/m2 at D12 or two infusions of ONCASPAR® at 1250 IU/m2 each at D12 and D26. Patients will then receive 2500 IU/m2 or 1250 IU/m2 per dose during consolidation and delayed intensification according to the initial arm of randomization.