The aim of this phase is to lower the initial leukemia load, for which it is necessary to eradicate over 99% of the leukemia cells and reestablish normal hematopoiesis.

The most commonly used drugs for this phase are:

• vincristine
• daunorubicin
• L-asparaginase
• Cyclophosphamide
• Prednisone and dexamethasone
• L-asparaginase

Rituximab (anti-CD20 monoclonal antibody) can be used in 40% of B-cell ALL that express CD 22, and the anti-CD22 antibody.