Chemotherapy

Because of acute lymphoblastic leukemia's (ALL's) rapid growth, most patients need to start chemotherapy soon after diagnosis.

Chemotherapy drugs kill fast-growing cells throughout the body including cancer cells and normal, healthy cells. The damage to normal, healthy cells can cause side effects. Yet, not everyone experiences side effects the same way. 

ALL treatment consists of:

Induction Therapy

The first phase of treatment is induction therapy. The goal of induction therapy is to destroy as many cancer cells as possible in order to achieve (induce) a remission. Typically, initial therapy requires a hospital stay of 4 to 6 weeks.

Induction regimens for ALL generally use a combination of drugs that include

  • Vincristine (Oncovin®)
  • Anthracyclines (daunorubicin [Cerubidine®], doxorubicin [Adriamycin®])
  • Corticosteroids (prednisone, dexamethasone)
  • With or without pegaspargase (PEG-L asparaginase, Oncaspar®) and/or cyclophosphamide (Cytoxan®)

At the end of induction therapy, doctors will check to see whether the patient has achieved a complete remission. A complete remission is achieved when

  • No more than 5 percent of cells in the bone marrow are blast cells
  • No blasts are found in the blood 
  • Blood cell counts are back to normal 
  • All signs and symptoms of ALL are gone.

To see a list of standard drugs and drugs under clinical study to treat ALL, order or download The Leukemia & Lymphoma Society's free booklet Acute Lymphoblastic Leukemia (ALL) in Adults

For information about the drugs listed on this page, visit Drug Listings.

 

Minimal Residual Disease (MRD)

Even when a complete remission is achieved, some leukemia cells that cannot be seen with a microscope may still remain in the body. The presence of these cells is referred to as “minimal residual disease (MRD).” Patients who have achieved remission after initial treatment for this type of ALL, but have MRD are at increased risk of disease relapse.

It is important to get tested for MRD after achieving remission. The tests used most often to detect MRD are flow cytometry, polymerase chain reaction (PCR), and next-generation sequencing. These three tests typically use samples of bone marrow cells, but in some cases blood samples can be used. The tests are much more sensitive than standard tests that examine cell samples with a microscope. It is often recommended that MRD testing be done after the completion of induction therapy. Recommendations for additional MRD testing depend on the treatment regimen used.

For patients in remission but who test positive for MRD, blinatumomab (Blincyto®) may be prescribed. 



 

Postremission Therapy

“Postremission therapy” refers to ALL treatments given to patients after their disease is in a complete remission. Residual leukemia cells remain after remission, so the optimal treatment for ALL patients requires additional intensive postremission therapy. Individual factors that may influence the treatment approach include:

  • Age
  • Ability to tolerate intensive treatment,
  • Cytogenetic findings
  • Availability of a stem cell donor.

Post-remission therapy consists of two phases:

  • Consolidation therapy (given in cycles over 4 to 6 months)
  • Maintenance therapy (given for about 2 years for adults and 2-3 years for children).

Consolidation Therapy. The second phase of chemotherapy is called “consolidation” therapy or "intensification" therapy. During this phase, the chemotherapy drugs are given in higher doses than those given during the induction phase. The combination of drugs and the duration of therapy for consolidation regimens vary but can consist of combinations of drugs similar to those drugs used during the induction phase. Generally, several chemotherapy drugs are combined to help prevent the leukemia cells from developing drug resistance.

Some of the drugs used in the consolidation treatment phase include

  • High-dose methotrexate
  • Cytarabine
  • Vincristine
  • 6-mercaptopurine (6-MP)
  • Cyclophosphamide
  • Pegaspargase
  • Corticosteroids (prednisone, dexamethasone)

Maintenance Therapy. The third phase of ALL treatment is called “maintenance.” The goal of maintenance therapy is to prevent disease relapse after induction and consolidation therapy. Most maintenance drugs are given orally and, typically, patients are treated in an outpatient setting. They receive lower doses of chemotherapy drugs and, as a result, tend to have less severe side effects. In some cases, postremission chemotherapy also includes drugs that were not used during induction treatment.

Most maintenance regimens include

  • 6-mercaptopurine (administered daily)
  • Methotrexate (administered weekly)
  • Periodic doses of vincristine and corticosteroids

Central Nervous System Prophylaxis

Although the presence of leukemia cells in the cerebrospinal fluid at diagnosis is not common (found in only 3 to 7 percent of cases), a large percentage of patients (50 percent or more) eventually develop CNS leukemia without the routine administration of CNS-targeted therapy, also called “central nervous system prophylaxis.” CNS prophylaxis is administered to prevent leukemia cells from spreading to the area around the brain and the spinal cord and is typically given to all patients throughout the entire course of ALL treatment—during the induction phase, the consolidation phase and the maintenance phase.

Central nervous system-directed therapy may include

  • Intrathecal chemotherapy. In this treatment, anticancer drugs are injected into the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord. These drugs may include methotrexate, cytarabine and corticosteroids (prednisone, dexamethasone). 
  • Systemic chemotherapy. In this treatment, anticancer drugs travel through the blood to cells all over the body. These drugs may include high-dose methotrexate, intermediate-/high-dose cytarabine and pegaspargase.
  • Cranial irradiation. Radiation therapy to the brain.

 

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