Induction treatments for acute lymphoblastic leukemia

Induction treatment is also called remission induction therapy. The goal of induction treatment for acute lymphoblastic leukemia (ALL) is to rapidly clear the blood and bone marrow of leukemia cells and bring about a complete remission (complete response). This means that the numbers of blood cells (red blood cells, white blood cells and platelets) have returned to normal levels and less than 5% of cells in the bone marrow are leukemia cells (also called blast cells or blasts). With a complete remission, there are no general signs or symptoms of ALL and no signs or symptoms that ALL has spread to the brain and spinal cord (called the central nervous system, or CNS) or anywhere else in the body.

The induction phase of treatment usually lasts about a month. People with ALL must start induction treatment right away. Since treatment is so urgent, most people with ALL begin induction within days of a diagnosis.

You may be offered the following induction treatments for ALL. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.

Chemotherapy is the primary induction treatment for ALL. It uses drugs to destroy cancer cells.

The goal of chemotherapy is to destroy as many leukemia cells as quickly as possible and get blood cell counts back to normal. Your healthcare team will use what they know about the cancer and about your health to plan the drugs, doses and schedules. The most common chemotherapy drug combination used for induction therapy includes:

• vincristine
• daunorubicin (Cerubidine), doxorubicin or a similar anthracycline drug
• steroids such as prednisone or dexamethasone

You may be offered other drugs as part of the induction phase, including:

• cyclophosphamide (Procytox)
• pegaspargase (Oncaspar) or crisantaspase recombinant (Rylaze)
• high-dose methotrexate or high-dose cytarabine

Find out more about chemotherapy for ALL.

Targeted therapy uses drugs to target specific molecules (such as proteins) on cancer cells or inside them to stop the growth and spread of cancer.

Targeted therapy is a standard treatment if the leukemia cells have the Philadelphia chromosome (called Ph-positive ALL or Ph+ ALL). This happens when genetic material swaps between chromosomes 9 and 22, resulting in an abnormal chromosome and creating a new gene. The new gene is called BCR-ABL.

A targeted therapy drug called a tyrosine kinase inhibitor (TKI) is usually added to the chemotherapy regimen for people with Ph+ ALL. The most common targeted therapy used to treat Ph+ ALL is a TKI called imatinib (Gleevec). If this doesn't work, you may be offered the drug dasatinib (Sprycel) or another TKI.

Learn more about targeted therapy for ALL.

With ALL, leukemia cells can spread to the brain and spinal cord (called the central nervous system, or CNS). Treatment given to prevent leukemia cells from spreading to the CNS is called CNS prophylaxis. During the induction phase of treatment, you typically receive CNS prophylaxis or treatment to destroy leukemia cells that have already spread to the CNS.

CNS prophylaxis or treatment may include one or more of the following:

• intrathecal chemotherapy with methotrexate, cytarabine or a steroid such as prednisone
• high-dose methotrexate given intravenously (through an IV)
• radiation therapy to the brain and spinal cord

Intrathecal chemotherapy gives chemotherapy drugs directly into the cerebrospinal fluid (CSF), which is fluid around the brain and spinal cord. This type of chemotherapy is given through a lumbar puncture (also called a spinal tap) or an Ommaya reservoir.

Radiation therapy uses high-energy rays or particles to destroy cancer cells. During induction treatment for ALL, external radiation therapy may be used as part of CNS prophylaxis or treatment.

You may be offered radiation to the brain, which is also called cranial irradiation.

Find out more about radiation therapy for ALL.

Supportive therapy is important during every phase of treatment for ALL. It is used to treat the complications that can happen with treatments for ALL and complications from the leukemia itself.

Supportive therapies given during induction treatment may include:

• antibiotics, antivirals or antifungals to prevent or fight infections
• growth factors to help the bone marrow recover from chemotherapy and make more blood cells (chemotherapy can lower the white blood cell count, which increases your risk for infection)
• transfusions of red blood cells, platelets, fresh frozen plasma and cryoprecipitate (a product that replaces clotting factors) as needed
• drugs to bring down high levels of some substances in the blood that increase when many cancer cells die at the beginning of treatment (called tumour lysis syndrome)
• leukapheresis to remove large numbers of white blood cells from the blood

Find out more about supportive therapy for ALL.

Talk to your doctor about clinical trials open to people with ALL in Canada. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.