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What Is Ph+ CML?

Philadelphia chromosome–positive chronic myeloid leukemia (Ph+ CML)

Understanding the disease

Over the years, there has been great progress in treating leukemia—a type of cancer of the blood. That's especially true for chronic myeloid leukemia, or CML. For more than 15 years, medications for CML have been transforming this disease from one that is life-threatening to a condition that is manageable for many people.


What is chronic myeloid leukemia (CML)?

CML is 1 of 4 major types of leukemia. It is called chronic because the disease progresses slowly. The term myeloid has to do with, or is related to, bone marrow.


When you have CML, the bone marrow makes too many white blood cells. These extra cells are abnormal and do not become healthy. They can build up in the blood, the bone marrow, or both. This leaves less room for healthy white blood cells, red blood cells, and platelets. It can lead to problems such as infection, anemia, or easy bleeding.


What is Ph+ CML?

Ph+ CML stands for Philadelphia chromosome–positive chronic myeloid leukemia. You're not born with this disease. It's also not handed down from one generation to the next. Below is more background that you may find helpful about Ph+ CML.


What causes Ph+ CML?

The cause of Ph+ CML has to do with a change in chromosomes in your body. As your cells wear out, they make copies of themselves. Each cell copies everything inside it, including its chromosomes. The cell then splits in 2—creating 2 identical cells.


But sometimes a mistake happens when the cell is copying itself. For example, a piece of 1 chromosome in a cell may break off and attach to another chromosome. Or 2 chromosomes may swap places. These mistakes can create an abnormal gene.


When you have Ph+ CML, a cell triggers the creation of an abnormal gene called BCR-ABL. This, in turn, produces an abnormal protein, also called BCR-ABL.


What happens in Ph+ CML?

Think of the BCR-ABL protein like a light switch. It "turns on" the bone marrow—a sponge-like tissue found in the center of most bones—to make too many immature white blood cells. These immature white blood cells grow abnormally. Your doctor may refer to them as leukemic cells.


Here's what happens inside your body when you have Ph+ CML:

  • The leukemic cells start to grow and divide
  • They build up in the bone marrow, move into the bloodstream, and travel throughout the body
  • Over time, excess leukemic cells crowd out healthy red blood cells and platelets
  • This can cause problems such as anemia, bruising easily, bleeding that takes longer to stop, and a greater chance of infections


Today, there are treatment options for Ph+ CML that can play an important role in helping stop the growth of leukemic cells. Talk to your doctor to see if prescription TASIGNA® (nilotinib) capsules may be right for you.



A recap of helpful terms

As you explore the TASIGNA website and come across new terms, you can visit the Glossary. Below are some definitions that apply to some of the terms used on this page.


BCR-ABL: An abnormal gene that creates a damaged protein by the same name. It causes the bone marrow to create leukemic cells. The BCR-ABL gene is formed when 2 specific chromosomes combine. The gene then creates the BCR-ABL protein—the underlying cause of Ph+ CML.


Bone marrow: A sponge-like tissue found in the center of most bones.


Chromosome: The DNA found in a cell. Human cells normally have 23 pairs of chromosomes.


Leukemic cells: Diseased white blood cells that grow abnormally.


Platelets: Very small cells in the bone marrow that form blood clots and control bleeding.


Red blood cells: Move oxygen from the lungs to the body.


White blood cells: Help your body fight infection and disease.