This is an assessment of efficacy and safety of three different doses of pegylated recombinant asparaginase (PEG-rASNase) in comparison to Oncaspar® during treatment of adults with de novo acute lymphoblastic leukaemia (ALL). This study will provide first data for determining specific asparaginase doses to yield various durations of L-asparagine (ASN) depletion which are required within different treatment phases of ALL therapy.

Inclusion Criteria:

• Previously untreated acute lymphoblastic leukaemia (pro-B, common, pre-B, early T, thymic T, mature T)
• Age 18 years - 55 years
• Treatment according to German Multicenter Trials for adult Acute Lymphoblastic Leukaemia (GMALL) 07/2003 protocol or subsequent GMALL protocols for patients with de novo ALL
• Written informed consent
• Women of child-bearing potential or partner of men with child-bearing potential must use a highly effective method of contraception
• Negative pregnancy test for women of child-bearing potential

Exclusion Criteria:

• Patients with Philadelphia chromosome (BCR-ABL) positive ALL
• Severe comorbidity or leukaemia-associated complications
• Known hypersensitivity to asparaginase
• History of severe pancreatitis
• History of thrombosis or pulmonary embolism
• Pre-existing clinically relevant coagulopathy
• Liver dysfunction (e.g. acute or current hepatitis, alcohol or drug abuse) or history of clinically relevant liver disease
• Bilirubin > 1.5 x Upper Limit Norm (ULN)
• Other current malignancies
• Severe psychiatric illness or other circumstances which may compromise the cooperation of the patient or the ability to give informed consent
• Body mass index > 30 kg/m²
• Known pregnancy, breast feeding