Acute Lymphocytic Leukemia - Treatment

Treatment to Achieve Remission (Induction Therapy)

The aim of induction therapy, the first treatment phase, is to reduce the number of leukemia cells to undetectable levels. The general guidelines for induction therapy are as follows:

• Patients are given intensive chemotherapy that uses powerful multi-drug regimens. (Infants require special regimens not discussed here.)
• For both children and adults, some of these therapies are administered orally, others intravenously.
• Hospitalization is usually necessary at some point to help prevent infection and to give transfusions of blood, platelets, and other blood products. However, much of this therapy can be given on an outpatient basis.
• After the first cycle of induction, bone marrow tests are done to determine if the patient is in remission.
• Another bone marrow test is sometimes performed about a week later to confirm the first results.
• A bone marrow transplant is considered for select patients who do not respond to induction treatment.

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Drugs Used for Induction Chemotherapy

Both children and adults typically start with a 3-drug regimen. Imatinib (Gleevec) or dasatanib (Sprycel) may be added for patients with Philadelphia chromosome-positive ALL.

For children, the standard drugs are:

• Vincristine (Oncovin), a vinca alkaloid drug
• Prednisone or dexamethasone. These drugs are corticosteroids.
• Asparaginase. Generally provided as pegaspargase (Oncaspar) in place of L-asparaginase (Elspar) for treating newly diagnosed ALL in children.

For adults, the standard drugs are:

• Vincristine
• Prednisone
• Anthracycline drug, such as such as doxorubicin, daunorubicin, or epirubicin. Some adult chemotherapy regimens also add on an asparaginase drug or cyclophosphamide (Cytoxan).

Preventing Central Nervous System Disease (CNS Prophylaxis)

As mentioned, chemotherapy given intravenously or orally does not penetrate the blood-brain barrier sufficiently to destroy leukemic cells in the brain. Since the brain is one of the first sites for relapsing leukemia, preventive treatment is administered to the brain, spine, and testes (called sanctuary disease sites). This is called CNS prophylaxis.

For children, CNS prophylaxis uses intrathecal chemotherapy, in which a drug is injected directly into the spinal fluid. Intrathecal chemotherapy is given with methotrexate alone or a combination of methotrexate (MTX), cytarabine, and hydrocortisone.