What's New in Chronic Myeloid Leukemia Research?

Chronic myeloid leukemia (CML) is being studied in labs and in clinical trials around the world.

Genetics of chronic myeloid leukemia

Scientists are making great progress in understanding how changes in a person's DNA can cause normal bone marrow cells to develop into CML cells. Learning about changes in the genes (regions of the DNA) involved in CML is providing insight into why these cells grow too quickly, live too long, and fail to develop into normal blood cells. The explosion of knowledge in recent years is being used to develop many new drugs.

Researchers are looking closely at how specific gene changes could be used to determine treatment, predict disease progression, and develop other drugs to treat CML.

Treatment

Choosing the best targeted drug

Imatinib, dasatinib, nilotinib, and other tyrosine kinase inhibitor (TKI) drugs that target the BCR-ABL protein have proven to work very well, but by themselves these drugs don't help everyone. Studies are now looking at the effects of using higher doses of TKIs, and to see if combining these drugs with other treatments, such as chemotherapy or interferon might be better than either one alone.

Because TKIs have drastically changed the treatment and outcomes of CML, an exciting area of research is looking at whether TKI treatment can be stopped. Clinical trials are being done to see if this is possible and what should be done if the CML comes back. This has also led scientists to look for better ways to define molecular remission in an effort to help make decisions about stopping treatment.

New drugs for CML

Because researchers know a main cause of CML is the BCR-ABL gene and its protein, they've been able to develop many new drugs that might work against it. Still, these drugs don't always work, and CML can become resistant to TKIs over time. Scientists continue to look for new drugs to treat CML, especially CML that no longer responds to TKIs.

In some people, CML cells develop a change in the BCR-ABL oncogene known as a T315I mutation, which makes them resistant to many of the TKI drugs used today. Ponatinib is the only TKI that can work against T315I mutant cells. More drugs aimed at this mutation are now being tested.

Many other kinds of drugs are also being tested in clinical trials, such as immunotherapy drugs. These are given along with TKIs in hopes of getting a better response than is seen with TKIs alone.

Cancer vaccines

Cancer cells are different from normal cells, so it's sometimes possible to get the body's immune system to react against them. One way to do this is to use a cancer vaccine -- a substance injected into the body that boosts the immune system and causes it to attack certain cells. Several vaccines are now being studied for use against CML, but more research is needed.