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Sometimes a CML medication doesn’t fit.

Medications may work well for many patients with chronic myeloid leukemia (CML). But over time, some people may find that their medication no longer fits—whether it’s because they do not respond to treatment or they experience intolerable side effects.

How CML medications work

Most people with CML are treated with a type of targeted therapy that is thought to inhibit the BCR-ABL protein that leads to uncontrolled growth of leukemic cells.

Some people have a different experience

As your doctor continues to treat CML, one goal is to see the number of leukemic cells in your blood go down. For some people, that may not happen. These patients may experience any of the following:

  • Lack of response (primary drug resistance): The body does not respond to treatment
  • Secondary drug resistance: The body loses its response to a medication over time
  • Drug intolerance: Side effects of a medication become so bothersome that a patient can no longer tolerate it

If your doctor determines that you are not responding to treatment or you cannot tolerate the side effects of a medication, your doctor may decide if it’s appropriate to adjust your dose or consider another medication. That’s why it’s important to have an open conversation with your doctor about the results of your blood work and any side effects you may experience.

Don’t keep your concerns to yourself

Some patients try to tough out the side effects of their CML medication. But if the side effects are becoming unmanageable, it’s important to talk with your doctor. Don’t try to manage side effects on your own.

Be sure to discuss any side effects with your doctor and explain how they are affecting you. To help guide your conversation, take this quiz or click the button below for a Doctor Discussion Guide.

Drug resistance

Some patients with CML find that over time, the number of leukemic cells in their blood starts going up instead of staying stable or going down. This may be due to drug resistance, which happens when cancer cells no longer respond to a medication.

In CML, one of the causes of resistance is a mutation in the BCR-ABL1 gene. A mutation is a change in a cell’s DNA.

The role of mutation testing

To determine if you have a mutation, your doctor may order a gene mutation test. It looks for mutations in the BCR-ABL1 gene that may cause certain medications to stop working.

Your doctor may decide to test for a mutation if you are:

  • Not responding or no longer responding to medication
  • Unable to reach a treatment milestone
  • Progressing to the accelerated phase or blast phase

Talk with your doctor

If your CML medication doesn’t seem to fit—whether it’s because you’re not responding to treatment or you’re experiencing unmanageable side effects—talk with your doctor. To help you get the conversation started, take this quiz or use this Doctor Discussion Guide.  

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11/21 170520