A Study Comparing the Blood Levels of Both Pegaspargase (S95014) Formulations (Liquid vs Lyophilized) in the Treatment of Paediatric Patients With Acute Lymphoblastic Leukemia (ALL)

Inclusion Criteria: * Patients aged 1 to \< 18 years * Patients with cytologically confirmed and documented newly diagnosed ALL according to National Comprehensive Cancer Network guidelines 2020 (see Appendix 2), excluding B-cell Burkitt ALL * Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2 (see Appendix 3) * Highly effective contraception method * Signed informed consent and assent, when appropriate Non-inclusion Criteria: * Unlikely to cooperate in the study * Pregnant and lactating women * Participation in another interventional study at the same time; participation in non-interventional registries or epidemiological studies is allowed * Participant already enrolled in the study (informed consent signed) * Women of childbearing potential tested positive in a serum pregnancy test within 7 days prior to the treatment period * Inadequate hepatic function (bilirubin \> 1.5 times upper limit of normal (ULN), transaminases \> 5x ULN) * Inadequate renal function defined as serum creatinine \> 1.5 x ULN * Prior treatment with chemotherapy or radiotherapy (except steroids and intrathecal therapy) * Prior surgery or bone marrow transplant related to the studied disease * Down Syndrome * Psychiatric illness/social situation that would limit compliance with study requirements * Known history of pancreatitis * Known history of significant liver disease * Known carriers of HIV antibodies * Significant laboratory abnormality likely to jeopardize the patients' safety or to interfere with the conduct of the study, in the investigator's opinion * Pre-existing known coagulopathy (e.g. haemophilia and known protein S deficiency) * History of previous or concurrent malignancy * History of sensitivity to polyethylene glycol (PEG) or PEG-based drugs * Severe or uncontrolled active acute or chronic infection * Uncontrolled intercurrent illness including life-threatening acute tumor lysis syndrome (e.g. with renal failure), symptomatic congestive heart failure, cardiac arrhythmia