Acute Lymphocytic Leukemia - Treatment to Achieve Remission

Treatment to Achieve Remission

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 administer 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 done about a week later to confirm the first results.
• A bone marrow transplant is considered for patients who do not respond at all to induction treatment.

Drugs Used for Induction Chemotherapy

Drugs Used for Standard or Low-Risk Patients. A three-drug regimen is typically used for standard or low-risk patients. (A fourth drug, such as cyclophosphamide, may be added for adult patients.) Examples of drugs used in regimens for children include:

• Vincristine
• Corticosteroids (prednisone or dexamethasone) -- a 2003 study reported better survival rates with dexamethasone compared to prednisone.
• Asparaginase -- several forms are available, including L-asparaginase (Elspar) and pegaspargase (Oncaspar). In 2006, the FDA approved the use of pegaspargase in place of L-asparaginase for treating newly diagnosed ALL in children and adults. (Pegaspargase had previously been approved only for patients who were allergic to L-asparaginase.) With pegaspargase, patients will need to receive only 3 injections over a 20-week period instead of the 21 injections required for L-asparaginase.

When this regimen is used together with CNS prophylaxis, remission rates of greater than 95% have been achieved in children. In a 2001 study, researchers reported that the most effective regimen for many children uses dexamethasone after the first month with a longer duration for asparaginase (30 rather than the standard 20 weeks.