Acute Lymphocytic Leukemia - Treatment During Remission

Treatment During Remission

Consolidation and maintenance therapies follow induction and first remission. The goal of consolidation and maintenance therapies is to prevent a relapse. The specific treatment choices and degree of aggressiveness after induction therapy depend on a number of factors, particularly the risk factors for relapse.

Consolidation (or Intensification) Therapy

Consolidation therapy is additional treatment that is administered after induction therapy and before maintenance therapy. This is an intense regimen that is designed to prevent the high relapse rates that occur with induction therapy alone. (The benefits of this therapy are clearer in children than in older adults, who may just be given maintenance.)

Consolidation therapy usually continues for approximately 6 months and uses 1 - 6 courses of chemotherapy, depending on risk factors for relapse.

Examples of consolidation regimens for children at standard risk:

• A limited number of courses of intermediate- or high-dose methotrexate, one of the oldest drugs used for leukemia.
• An anthracycline drug, such as daunorubicin (Cerubidine), used for reinduction followed by cyclophosphamide (Cytoxan, Neosar) 3 months after remission. These are very powerful drugs, but when used in this way toxicity is limited.

More intense regimens are used for children at high-risk for relapse.

Maintenance

The last phase of treatment is maintenance, or continuation therapy:

• Maintenance therapy typically uses weekly administration of methotrexate (usually in oral form) and daily doses of mercaptopurine. (Mercaptopurine should be given in the evening.)
• Treatment continues for between 2 - 3 years for most children with ALL (with the exception of those with mature B-cell leukemia). It is not yet clear if prolonged maintenance therapy benefits adults with ALL.
• If children were not given CNS prophylaxis before, it may be given now.

A maintenance regimen is usually less toxic and easier to tolerate than induction and consolidation. Some studies, however, indicate that overall survival could further be improved with more-aggressive maintenance therapies, including: