Chronic Myeloid Leukemia (CML): Targeted Therapy  

What is targeted therapy?

Targeted therapy is the use of medicines that act on parts of cancer cells that make them different from normal cells. They can damage the cancer cells without affecting most normal, healthy cells. These medicines are different from standard chemotherapy medicines. They often have less severe side effects.

Types of targeted therapy for CML

The types of targeted medicines used to treat chronic myeloid leukemia (CML) are called tyrosine kinase inhibitors (TKIs). These medicines block a substance called kinase protein inside the CML cells. This protein is made as a result of the cells having the abnormal BCR-ABL gene. It helps the leukemia cells grow.

Some of the TKIs used to treat CML include:

  • Imatinib

  • Dasatinib

  • Nilotinib

  • Bosutinib

  • Ponatinib

When is targeted therapy used to treat CML?

In most cases, TKIs are the first treatment used for CML. These medicines often work well at keeping the CML under control for long periods of time. It’s not yet clear if they can cure the leukemia. Your healthcare provider will monitor your CML with blood tests or other tests during treatment. If one of these medicines doesn't work or stops working over time, the dose might be increased. Or another TKI may be used.

How targeted therapy is done

These medicines are taken as pills or capsules, once or twice a day. Take them exactly as your healthcare team tells you. Taking these medicines every day gives them the best chance to treat your leukemia. It's likely you'll need to take these pills for a very long time to keep the CML under control.

Tell your healthcare provider about all other medicines you take. This includes over-the-counter medicines and supplements such as herbs and vitamins. Some medicines and supplements can change the way targeted therapy medicines work.

During treatment, blood tests will be done. This is to check for a decrease in your white or red blood cells or platelet levels. Blood tests will be done more often at the start of treatment. 

Possible side effects of targeted therapy

Side effects of TKIs depend on the medicine used, and may include:

  • Bloating or swelling from fluid retention

  • Diarrhea

  • Itchy skin rashes

  • Muscle pain

  • Nausea

  • Severe tiredness (fatigue)

  • Belly (abdominal) pain 

  • Lower blood cell counts, which can increase your risk of infections, bleeding, and bruising

Side effects from these medicines tend to be mild. But in some cases they can cause more severe side effects such as:

  • Fluid buildup around the heart or lungs, which can cause trouble breathing

  • Changes in heart rhythm

  • High blood pressure

  • Liver damage

Ponatinib can also cause serious blood clots. This newer medicine may be used only if none of the other TKIs are working, or if the leukemia cells have a certain gene change (mutation).

Working with your healthcare provider

It's important to know which medicines you're taking. Write down the names of your medicines. Ask your healthcare team how they work, how to take them, and what side effects they might have.

Talk with your healthcare providers about what side effects to watch out for, and when you should call your healthcare team. Make sure you know what number to call with problems or questions, even on evenings and weekends.

It may be helpful to keep a diary of your side effects. Write down any physical, thinking, and emotional changes. A written list will make it easier for you to remember your questions when you go to your appointments. It will also make it easier for you to work with your medical team to make a plan to manage your side effects. 

Online Medical Reviewer: Kimberly Stump-Sutliff RN MSN AOCNS
Online Medical Reviewer: Louise Cunningham RN BSN
Online Medical Reviewer: Todd Gersten MD
Date Last Reviewed: 2/1/2021
© 2021 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare provider's instructions.