Consolidation treatments for acute lymphoblastic leukemia

Consolidation, or intensification, treatment for acute lymphoblastic leukemia (ALL) is given to prevent leukemia cells from coming back. The consolidation treatment phase begins once you go into remission after induction treatment.

Consolidation treatment is needed because you may have minimal residual disease (MRD) after induction therapy. MRD means that there are leukemia cells in the bone marrow, but they can only be seen using sensitive tests, such as flow cytometry or polymerase chain reaction (PCR). The leukemia cells can't be seen with standard tests, such as looking at the cells under a microscope. But even if you do not have MRD, consolidation treatment reduces the risk of ALL coming back in the future.

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

Chemotherapy is the primary consolidation treatment for ALL. The chemotherapy is quite intense because the drugs are usually given in higher doses. Many of the same drugs that you receive during induction are often given for consolidation treatment, such as vincristine, doxorubicin, pegaspargase (Oncaspar) or crisantaspase recombinant (Rylaze) and steroids like prednisone or dexamethasone. Other drugs may be used too, such as nelarabine (Atriance).

During consolidation treatment, you may also receive other chemotherapy regimens, including a combination called hyper-CVAD. Hyper-CVAD is a hyperfractioned chemotherapy, which means that your daily dose of chemotherapy is divided into smaller doses and given to you multiple times throughout the day. The hyper-CVAD combination includes:

• cyclophosphamide
• vincristine
• doxorubicin
• dexamethasone

Hyper-CVAD is alternated with high-dose cytarabine and high-dose methotrexate in cycles of 3 to 4 weeks.

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.

During the consolidation phase of your treatment, you will continue to receive targeted therapy 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.

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

Find out 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. CNS prophylaxis or treatment to destroy leukemia cells that have already spread to the CNS begins during the induction phase and may continue during consolidation with 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.

A stem cell transplant replaces stem cells, which are found in bone marrow, blood and umbilical cords. They are basic cells that develop into different types of cells that have different jobs. For example, all our blood cells develop from blood stem cells. A stem cell transplant is also called a bone marrow transplant.

A stem cell transplant may be offered to people whose ALL goes into remission, but there is still a high risk it will relapse (come back). There is a high risk of relapse with certain subtypes of ALL or other poor prognostic factors.

The preferred type of stem cell transplant is an allogeneic transplant, which takes stem cells from one person (the donor) and gives them to another person (the recipient). The donor may or may not be related to the recipient. If a donor is not available, an autologous stem cell transplant may be an option for some people. This means that the transplant uses stem cells from your own body.

A stem cell transplant is a complex treatment with many risks. It must be done in a special transplant centre or hospital. Your healthcare team can help you consider the risks and benefits of this treatment and recommend if a transplant is right for you.

Find out more about a stem cell transplant for ALL.

Radiation therapy uses high-energy rays or particles to destroy cancer cells. External radiation therapy is the type of radiation therapy used to treat ALL.

During consolidation treatment, you may continue to receive radiation to the brain as part of CNS prophylaxis or to treat leukemia cells that have already spread to the CNS. Radiation to the brain may be called cranial irradiation.

Radiation therapy may also be given as part of the conditioning treatment before a stem cell transplant.

Find out more about radiation therapy for ALL.

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

Supportive therapies given during consolidation 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
• blood thinners (also called anticoagulants) to prevent blood clots, especially if consolidation treatment includes pegaspargase

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.