Oral Chemo for Chronic Myelogenous Leukemia
Tyrosine Kinase Inhibitors Target Philadelphia Chromosome
Kareem Abdul Jabbar brought leukemia to the public with an announcement of his diagnosis of Philadelphia chromosome-positive chronic myelogenous leukemia (Ph+ CML). His prognosis is good due to treatment he is receiving. Patients with this type of leukemia now have the option of treatment with oral chemotherapy medication.
Ph+ Chronic Myelogenous (Myeloid) Leukemia
According to the Leukemia-Lymphoma Society, just over 5,000 people will be diagnosed with CML in the United States in 2009. CML is a bone marrow cancer where too many white blood cells are produced. This type of leukemia occurs almost exclusively in adults.
The National Cancer Institute reports patients with CML have an abnormal gene known as the Philadelphia chromosome. This causes the bone marrow to make an enzyme called tyrosine kinase that results in the production of excess white blood cells. This tyrosine kinase is a protein known as Bcr-Abl. When it appears in white blood cells, these cells reproduce too many copies of themselves, leading to an increased amount of white cells in the blood. Soon, the abnormal white cells takeover the normal white cells, leaving the body unable to adequately fight infection.
Symptoms of Ph+ CML
Patients with Ph+ CML often experience symptoms including:
- fatigue or tiring more easily
- night sweats
- unintentional weight loss
- fever or heat intolerance
- left side abdominal pain or pressure due to enlarged spleen.
Tyrosine Kinase Inhibitors for Treatment of Ph+ Chronic Myelogenous Leukemia
Oral chemotherapy medications are available to treat CML. These medications are known as tyrosine kinase inhibitors. Medications like Gleevec (imatinib), Tasigna (nilotinib) and Sprycel (dasatinib). Tyrosine kinase inhibitors block the abnormal protein caused by the Philadelphia chromosome, allowing the white blood cells to decrease.
Gleevec, made by Novartis, is usually tried first. Patients that do not tolerate Gleevec progress to one of the newer medications, Tasigna or Sprycel. Side effects of Gleevec include:
- edema (fluid retention)
- heart failure
- increased liver function tests
- abnormal bleeding
- decreased levels of thyroid hormone
- skin problems
- low blood counts
- muscle pain
- nausea, vomiting, diarrhea
- fatigue.
Response to Treatment with Gleevec
National Cancer Institute statistics indicate that patients newly-diagnosed with CML have an 80% response rate to Gleevec. After 5 years, 89% of people will survive their leukemia.
In some cases, patients may become resistant to Gleevec so that it no longer works for their leukemia. Other tyrosine kinase inhibitors may be used or patients may then undergo bone marrow transplant.
Taking Gleevec
Novartis recommends that patients take Gleevec with food to improve tolerability. Women who are pregnant or nursing should not take Gleevec.
For More Information about Gleevec
Anyone interested in Gleevec or other tyrosine kinase inhibitors should discuss these medications with their prescriber or pharmacist. Information on Ph+ CML is available through the National Cancer Institute.
Kareem Abdul Jabbar Diagnosed with CML
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