Researchers are now studying the causes, diagnosis, and treatment of leukemia at many medical centers, university hospitals, and other institutions.
As noted in the section “Do we know what causes childhood leukemia?” scientists are making progress in understanding how changes in the DNA inside bone marrow stem cells can cause them to develop into leukemia cells. Understanding these gene changes (such as translocations or extra chromosomes) can help explain why these cells may grow out of control, and why they don’t develop into normal, mature cells. Doctors are now looking to use these changes to help them determine a child’s outlook and whether they should receive more or less intensive treatment.
This progress has already led to vastly improved and very sensitive tests for detecting leukemia cells in blood or bone marrow samples. The polymerase chain reaction (PCR) test, for example, can identify very small numbers of leukemia cells based on their chromosome translocations or other rearrangements. This test is useful in determining how completely the leukemia has been destroyed by treatment, and whether a relapse will occur if further treatment is not given.
Most children with leukemia are treated at major medical centers, where treatment often means taking part in clinical trials to get the most up-to-date care. Several important questions are now being studied in clinical trials. Among them are:
- Why do some children with acute lymphocytic leukemia (ALL) relapse after treatment, and how can this be prevented?
- Are there other prognostic factors that will help identify which children need more or less intensive treatment?
- Can chemotherapy drug resistance in acute myelogenous leukemia (AML) be reversed?
- Are there better drugs or combinations of drugs for treating the different types of childhood leukemia?
- When exactly should a stem cell transplant be used to treat leukemia?
- How effective are stem cell transplants in children who don’t have a brother or sister who is a good tissue type match?
- Can a second stem cell transplant help children who relapse after a first stem cell transplant?
- What are the best treatment approaches for children with less common forms of leukemia, such as juvenile myelomonocytic leukemia (JMML) and chronic myeloid leukemia (CML)?
Immunotherapy to treat childhood leukemia
Immunotherapies are treatments that boost a child’s own immune system to help fight leukemia. Some types of immunotherapy have shown a lot of promise in treating ALL, even when other treatments are no longer working.
Chimeric antigen receptor (CAR) T-cell therapy
In this treatment, immune cells called T cells are removed from the child’s blood and genetically altered in the lab to have specific receptors (called chimeric antigen receptors, or CARs) on their surface. These receptors can attach to proteins on the surface of leukemia cells. The T cells are then multiplied in the lab and given back into the child’s blood, where they can seek out the leukemia cells and launch a precise immune attack against them.
This technique has shown very encouraging results in early clinical trials against some advanced, hard-to-treat cases of ALL. In many children the leukemia could no longer be detected after treatment, although it’s not yet clear if these children have been cured.
Some children have had serious side effects from this treatment, including very high fevers and dangerously low blood pressure in the days after it’s given. Doctors are learning how to manage these side effects.
Doctors are still improving how they make the T cells and are learning the best ways to use them. CAR T-cell therapy is only available in clinical trials at a handful of major medical centers at this time.
Monoclonal antibody therapy
Antibodies are proteins made by the body’s immune system to help fight infections. Man-made versions, called monoclonal antibodies, can be designed to attack a specific target, such as a protein on the surface of leukemia cells.
An example is blinatumomab (Blincyto), a special kind of monoclonal antibody that can attach to 2 different proteins at the same time. One part of blinatumomab attaches to a protein found on B cells (the cells that become leukemia cells in most cases of ALL). Another part of the antibody attaches to a protein on immune cells called T cells. By binding to both of these proteins, this drug brings the leukemia cells and immune cells together, which is thought to cause the immune system to attack the cancer cells. Early results with this drug against B-cell ALL have been promising, although so far it has been studied more in adults than in children.
Last Revised: 02/03/2016