Treatment
Treatment of ALL is divided into three phases: induction, consolidation, and maintenance. It is important to start treatment immediately after diagnosis because ALL progresses very rapidly.
- Induction - Induction is the first phase of treatment for ALL, in which your doctor will aim to put the cancer into remission. Your doctor will use chemotherapy to destroy the blasts in your blood and reduce the blasts in your bone marrow down to normal levels.
- Consolidation - Consolidation is the second phase of treatment for ALL. After your cancer is in remission, your doctor will try to kill any small amount of cells left in your body that may eventually cause a relapse.
- Maintenance - Maintenance is the third phase of treatment for ALL. It is recommended in most subtypes of ALL. The maintenance phase consists of lower doses of chemotherapy given for longer periods of time to ensure that there are no leukemic cells left in the body.
- CNS prophylaxis (intra thecal chemotherapy)
Your doctor may recommend any of the following procedures during these three phases of treatment:
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Chemotherapy
Chemotherapy is the use of drugs to treat rapidly growing cancer cells in an effort to destroy them. These medicines can be given by mouth or through injections. Doctors usually give a combination of different chemotherapy drugs to treat ALL in the induction phase. In the consolidation phase, you may receive a different combination of chemotherapy drugs or high doses of chemotherapy combined with stem-cell transplantation. Since most chemotherapy does not reach the fluid around your brain and spinal cord and ALL can grow in this sanctuary, your doctor will also recommend central nervous system (CNS) sanctuary therapy (CNS prophylaxis) using intrathecal chemotherapy. Your doctor will inject chemotherapy drugs into the fluid chamber that surrounds your brain in order to prevent the cancer from spreading to your brain or spinal cord, typically during a spinal tap (lumbar puncture). During maintenance, you will receive some drugs by injection and others by mouth.
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Allogeneic Stem-cell transplantation
In this procedure, stem cells from a healthy donor are transferred to the patient after high intensity chemotherapy or radiation. These stem cells grow into normal bone marrow and blood cells such as white blood cells, red blood cells, and platelets. The donor immune cells will also recognize and destroy any residual leukemia cell. Donors may be family members or unrelated volunteers.
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Targeted Therapy
In ALL, chromosome changes may cause your leukemia cells to use substances called tyrosine kinases to signal the cell to grow uncontrollably. Tyrosine kinase inhibitors are a form of targeted therapy that prevents this process from occurring by “shutting off” the overactive tyrosine kinases.
Some ALL cases express proteins that may not be found frequently on normal cells or are overexpressed compared to normal cells. These proteins can be targeted by monoclonal antibodies.
CAR-T Immunotherapy
One approach to immunotherapy currently being studied in clinical trials involves engineering a patient’s own immune cells to recognize and attack their tumors. T-cells are a type of immune cell collected from the patient’s own blood. After collection, the T-cells are genetically engineered to produce special receptors on their surface called chimeric antigen receptors (CARs). These genetically engineered cells are then re-infused into the patient’s bloodstream. After re-infusion, the T-cells multiply in the patient’s body and with guidance from their engineered receptor, are able to recognize and kill cancer cells.
CAR-NK Immunotherapy
Recently, a new type of immunotherapy called CAR NK therapy is being tested in clinical trials. This type of treatment enhances the cancer-fighting power of NK cells, called Natural-Killer cells. NK cells are part of our immune system and they patrol our bodies for abnormal cells like cancer and kill them. The NK cells are taken from the blood of an umbilical cord donated by the parents after their baby’s birth and added to a CAR, (chimeric antigen receptor). The new CAR NK cells recognize a target on the surface of invisible cancer cells and attack.
Immunotherapy
First: naked antibody (rituzimab CD20) antibody drug conjugate (Inotuzumab ozogamicin CD22 Ab)
Second BiTe blinatumomab: bi-specific CD3-CD19 antibody construct
Third: Chimeric antigen receptor T-cell therapy (CAR T-cell) is being used as a form of immunotherapy. The aim of this therapy is to harness the patient's immune system in order to attack the B-cell leukemia. T-cells are activated and express a receptor that binds to CD19 expressed on B-cells causing the killing of B-cells. Preliminary results are encouraging.
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Radiation Therapy
Radiation therapy uses waves of high energy rays to destroy cancer cells. Radiation therapy is not commonly used as a primary treatment for ALL, but may be used to treat enlarged internal organs and areas of bone weakened by invasion of ALL cells. Your doctor may also recommend undergoing low-dose radiation treatment to your entire body before a stem-cell transplantation.
Clinical Trials
Clinical trials allow patients to try a new treatment before it is available to the general public. In some cases, this may be a new drug that has not been used in humans before, or it may be a drug or drug combination that is not currently used for that specific type of cancer. Early phase clinical trials are often used to test side effects of a drug or drug combination, while later phase clinical trials are used to see how effective a new treatment might be for a certain type of cancer. Clinical trials allow doctors and researchers to improve the treatment of cancers with possibly more effective therapies. A clinical trial may be a new, groundbreaking drug or it may have no effect. It is important to talk with your doctor about the pros and cons of clinical trials for your particular situation.
