There are several other treatment methods that may be used to manage symptoms and prevent progression of chronic myeloid leukemia (CML), such as tyrosine kinase inhibitors, myelosuppressive therapy, splenectomy, and interferon alfa-2b treatment. It can also be cured with a bone marrow or allogeneic stem cell transplant.
The aim of treatment is to achieve:
- Hematologic remission: complete blood count and physical examination
- Cytogenetic remission: Philadelphia chromosome positive cells
- Molecular remission: polymerase chain reaction
The treatment decision will depend on the individual case and the specific factors, such as age, prognosis, and the stage of the disease.
Chronic Phase Management
In the chronic phase, Bcr-Abl tyrosine-kinase inhibitor drugs are usually used to manage the condition CML and prevent progression into more advanced stages of the disease.
Previously, anti-metabolites, alkylating agents, interferon, and steroid medications were used, but Bcr-Abl tyrosine-kinase inhibitor drugs are now favored, as they target the Philadelphia chromosomal translocation, which is responsible for the disease.
Hydroxyurea continues to be used in some cases to reduce the elevation of white blood cells, which is associated with some tyrosine-kinase inhibitor medications.
If the leukemia does not respond well to treatment and the patient’s condition shows signs of worsening, there are several techniques that may increase efficacy. These include:
- Increasing dose of tyrosine kinase inhibitor
- Using an alternative tyrosine kinase inhibitor
- Administering interferon or chemotherapy
- Performing a stem cell transplant from a donor with matching tissue type
Bcr-AblTyrosine Kinase Inhibitors
Bcr-Abl tyrosine kinase inhibitors are a new class of drugs with the first medication, imatinibmesylate (Glivec) to be introduced to the market in the United States in 2001. It was found to inhibit the progression of the disease in most patients (7 in 10 patients) and assist in normal stem cell regrowth in the bone marrow. However, as some leukemic cells remain, the treatment needs to be continued on a continuous basis.
Examples of Bcr-Abl tyrosine kinase inhibitors include:
It is useful to have access to several types of tyrosine kinase inhibitors, particularly in the event of resistance to one of these drugs.
There are also several other pharmaceutical agents that may be used in the management of chronic myeloid leukemia. Myelosuppressive or leukapheresis therapy is often indicated to counteract leukocytosis during early treatment. For some patients, a splenectomy, interferon alpha-2b, or chemotherapy may be useful.
There are two treatments that have the potential to cure chronic myeloid leukemia: a bone marrow transplant or an allogeneic stem cell transplant. The likelihood of success and the survival rate is more positive when they are performed with the administration of tyrosine kinase inhibitor drugs.
In some cases, patients are able to cease the tyrosine kinase inhibitor after some time and reach remission. However, it is not known for how long this period of remission is likely to last.
The introduction of tyrosine kinase inhibitors in the treatment of CML has helped to improve the prognosis of patients significantly. Previously, the median survival time was approximately 3-5 years after diagnosis but treatment with imatinib has led to a survival rate of almost 9 in 10 patients at five years after diagnosis. The long-term effects of the drug remain to be seen, but the life expectancy may be similar to that of other individuals with treatment.
Reviewed by Susha Cheriyedath, MSc