Ph+ CML—Understanding the Basics
Understanding Ph+ CML
Philadelphia chromosome–positive chronic myeloid leukemia, or Ph+ CML, is a slow-growing type of cancer of the blood and bone marrow. The bone marrow is the inner part of your bones where blood cells are made. When you have CML, your body makes too many abnormal white blood cells (cells that normally fight infection). These abnormal cells eventually crowd out healthy red blood cells, causing an unhealthy imbalance.
Cause of Ph+ CML
Inside each cell in your body are chromosomes. Chromosomes are used in the creation of new cells. Ph+ CML begins when a young white blood cell accidentally makes an abnormal chromosome when sections of chromosome 22 and chromosome 9 break off and switch with each other. This phenomenon is known as a translocation. This new, shortened chromosome is called the Philadelphia (Ph) chromosome. Cells containing this chromosome are called Ph-positive (Ph+) cells.
The Ph chromosome causes problems because it makes a protein called Bcr-Abl. This abnormal protein sends signals to white blood cells to grow and reproduce rapidly. Over time, these Ph+ cells begin to crowd out normal healthy blood cells. The resulting imbalance of cancerous cells to healthy cells can cause serious problems in the body and, ultimately, death.
Ph+ CML has 3 phases
| Phase | Characteristics | Possible Symptoms |
|---|---|---|
Chronic phase |
More white blood cells than usual in bone marrow and blood; abnormal white blood cells make up less than 15% of total |
Mild fatigue or weakness; Many new patients have no symptoms |
Accelerated phase |
Increasing number of white blood cells in bone marrow and blood; abnormal white blood cells make up ≥15% of total |
Fatigue, fever, poor appetite, weight loss |
Blast crisis |
Abnormal white blood cells make up ≥30% of total white blood cells in bone marrow and blood |
Fatigue, fever, poor appetite, weight loss; |
Ph+ CML usually progresses from chronic phase to blast crisis in 3 to 5 years if untreated. The overall goal of treatment is to keep patients in the chronic phase. In an ongoing clinical trial, GLEEVEC® has helped reduce disease progression in newly diagnosed patients in the chronic phase.
Other treatment options are available for newly diagnosed patients with Ph+ CML and for patients who are no longer responding or intolerant to GLEEVEC. Click here to learn more about another option that may work better for you.





