Chronic Myeloid Leukemia (CML) Treatment

There are several different treatment options for chronic myeloid leukemia. This condition is also called chronic myelogenous leukemia or CML. The type of treatments recommended is based on several factors, including:¹

• The phase of CML
• Age of the person with CML
• Their general health

The phases of CML are:¹

• Chronic phase – This is when most people are diagnosed. It is defined by the peripheral blood and/or bone marrow containing less than 10 percent blasts (immature white blood cells).
• Accelerated phase – This is also considered an advanced phase of CML. It is usually defined by one of the following:
  • An increase in blasts of more than 15 percent but less than 30 percent in the blood
  • Peripheral blasts plus myelocytes at least 30 percent in the blood
  • Basophils at least 20 percent in the blood
  • Platelet count less than 100,000 unrelated to therapy
  • New genetic changes in the CML cells that have the Philadelphia chromosome
• Blast phase – This is also called blast crisis. It is also considered an advanced phase of CML. This phase occurs when the bone marrow or blood has at least 20 percent blasts or there is spread of CML cells outside the blood or bone marrow (extramedullary disease). At this phase, CML tends to behave more like an aggressive leukemia.

Types of treatment for chronic myeloid leukemia

Several types of treatment may be used for CML, including:²

• Targeted therapy
• Chemotherapy
• Stem cell transplant
• Immunotherapy
• Surgery
• Donor lymphocyte infusion

Targeted therapy

Targeted therapies are cancer treatments that block or slow the growth and spread of cancer. They do this by interfering with specific areas of cancer cells involved in the growth of the cells or by focusing on specific features that are unique to cancer cells.^2,3

While chemotherapy drugs often kill cancer cells, targeted therapy usually blocks the growth of cancer cells. Targeted therapies used to treat CML are known as tyrosine kinase inhibitors (TKIs). TKIs target a specific protein that is found in CML cancer cells.^2,3

TKIs are the standard treatment for CML in the chronic phase. However, they may also be used to treat other phases of CML. While TKIs may be a lifelong treatment for most, select patients may eventually be able to stop treatment following a discussion with their oncologist.^2,3

Chemotherapy

Chemotherapy is the use of drugs to stop cancer cells. Chemotherapy works by targeting fast-growing cells, such as cancer cells. However, there are other fast-growing cells in the body that can also be affected, such as those in the gastrointestinal tract and hair.^2,4

Chemotherapy drugs may be used together with other drugs or alone. They may be taken by mouth or injected into a vein or muscle.^2,4

Stem cell transplants

Stem cell transplants are used along with high doses of chemotherapy. The high doses destroy cancer cells. However, they can also damage healthy blood cells. The transplant of stem cells (immature cells that can become new blood cells) is given to restore the bone marrow. The stem cells may be gathered from the person before chemotherapy. They may be given by a donor, which is called an allogeneic transplant.^2,5

Allogeneic stem cell transplants are more common in CML treatment, and they are the only known cure for CML. Not everyone is a candidate for stem cell transplants. Since the high doses of chemotherapy can be very taxing on a person's body, stem cell transplants may not be tolerated by older adults or those with other health problems.^2,5

Immunotherapy

Immunotherapy is a type of cancer treatment that helps boost the body's immune system to fight cancer cells. For CML, the most common type of immunotherapy is interferon-alpha.^2,6

Surgery

In some cases, a person with CML may have surgery to remove an enlarged spleen. This surgery is called a splenectomy. While this surgery does not cure CML, it can relieve some of the symptoms, such as when an enlarged spleen presses on other organs like the stomach.^2,7

Donor lymphocyte infusion

Donor lymphocyte infusions may be used in people with CML after relapsed disease after a transplant. Lymphocytes, white blood cells that play a key role in the immune system, are gathered from the donor who provided stem cells. These donated lymphocytes are given to the person with CML, with the goal that the lymphocytes will attack and kill any remaining cancer cells.²

Clinical trials

Clinical trials are a type of research where new treatments are studied. Clinical trials are an important part of the scientific process to find and prove the safety and effectiveness of new treatments. They offer people a chance to receive the latest treatments and be closely monitored by doctors. You can learn more about clinical trials by talking to your doctor or visiting the ClinicalTrials.gov website. Your doctor can help you decide if a clinical trial may be right for you.^2,8