The initial goal in treating people with chronic phase CML is to restore blood counts to normal levels. This is followed by a more profound reduction or elimination of CML cells altogether, while keeping an acceptable quality of life.
- Usually returns the blood cell counts to normal values within one month and maintains them either at or close to normal levels (slightly lower levels in blood cell counts are not uncommon)
- Reduces the size of the spleen quickly until it approaches its normal size
- Helps prevent infections and abnormal bleeding
- Allows patients to resume their previous levels of day-to-day activities.
Patients will need to receive periodic health checks, including blood cell counts and other tests to determine the extent and stability of cytogenetic and molecular remission. Periodic bone marrow examinations may be necessary early in treatment but can often be done less frequently over time; periodic blood-based monitoring of treatment response by PCR continues indefinitely. Individuals also need to have their tolerance to drugs assessed from time to time and may need dosage adjustments.
Tyrosine Kinase Inhibitor Therapy
Tyrosine kinase inhibitors (TKIs) are drugs that target the abnormal BCR-ABL protein that causes the uncontrolled CML cell growth. This protein, made by the BCR-ABL gene, is located on or near the surface of cells and is called a “tyrosine kinase.” TKIs inhibit (block) the BCR-ABL protein from sending the signals that cause the growth of abnormal cells. Three TKI drugs are approved as initial therapy (first-line treatment) for chronic phase CML and all three are good options for newly diagnosed patients. These drugs are
- Imatinib mesylate (Gleevec®)
- Dasatinib (Sprycel®)
- Nilotinib (Tasigna®)
Other CML Drug Therapies
Before the FDA approved Gleevec, Sprycel and Tasigna, other drugs such as interferon were the initial treatment for CML. If you're unable to tolerate or are resistant to TKIs, your doctor may suggest one of the following drugs instead; however, their side effects may be severe:
- Interferon alpha (Roferon®-A and Intron® A)
- Pegylated interferon alpha
- Hydroxyurea (Hydrea®)
- Cytarabine (Cytosar-U®)
- Busulfan (Myleran®)
These drugs, or new treatment approaches, such as ponatinib (Iclusig®), or options in clinical trials, may be used to treat CML patients with a specific mutation (change) called T315I. This mutation changes the BCR-ABL gene to make current TKIs ineffective.
If Initial Therapy Doesn't Work
“Initial” treatment is the first therapy given for a disease. Depending on the drug you take as a newly diagnosed patient - Gleevec, Sprycel or Tasigna - if you have strong side effects (called drug intolerance), your drug does not control your CML (called drug resistance) or the drug no longer works for you (called a loss of response), your doctor may prescribe:
- Another TKI
- Bosutinib (Bosulif®)
- Omacetaxine mepesuccinate (Synribo®)
- Ponatinib (Iclusig®)
See Relapsed and Refractory CML for more information.
For information about the drugs mentioned on this page, visit Drug Listings.
Measuring Your Treatment Response
TKI drug therapy doesn't cure chronic phase CML, but it brings about a stable remission (no signs or symptoms of the disease). Most patients being treated for CML can go about their day-to-day activities. Treatment usually returns blood cell levels to normal and the spleen to its normal size. Studies show that patients who've been treated with Gleevec since the drug has been on the market (2001) have been able to keep their chronic phase CML under control.
During your treatment, which can be indefinite, your doctor will continue to carefully check you for any signs that CML is returning (called a relapse). You'll need regular health checkups, including blood tests. From time to time, you'll need a bone marrow test.
Treatment in Older Adults
The first treatment choice for older adults who have chronic myeloid leukemia (CML) is the standard of care for all CML patients: targeted drug therapy with Gleevec, Tasigna or Sprycel. Because of their relatively mild side effects, these drugs are usually well tolerated by older adults. However, if you're not responding well to drug therapy, your doctor may suggest a clinical trial or that you undergo a stem cell transplantation.
- Measuring Treatment Response
- Download lists of suggested questions to ask your doctor
- Download or order The Leukemia & Lymphoma Society's free booklet Understanding Side Effects of Drug Therapy