Gleevec (imatinib) is a brand-name oral tablet prescribed for certain types of blood cancer. It works to treat these conditions by targeting specific proteins in cancer cells.

Gleevec contains the drug imatinib, which belongs to a class of drugs called tyrosine kinase inhibitors (TKIs). Medications in the TKI drug class are targeted therapies. They affect specific proteins in cancer cells.

Gleevec is approved to treat several different conditions. Here we’ll explore how Gleevec works to treat two of them.

For Ph+ CML

In Philadelphia-positive (Ph+) chronic myeloid leukemia (CML), the cells that create white blood cells have a mutation in their genetic makeup. This genetic mutation is found on a DNA strand called the Philadelphia chromosome.

The Philadelphia chromosome contains an abnormal gene (BCR-ABL1) that causes too many white blood cells to form. These white blood cells don’t mature and die as they should. Immature white blood cells called “blasts” crowd out other types of blood cells that your blood needs to work correctly.

Gleevec works by attaching to a protein called tyrosine kinase in cells made by BCR-ABL1. When Gleevec binds to this protein, the drug prevents the cell from sending signals that tell the cell to grow. Without these growth signals, the cancerous blood cells die. This helps restore the number of blast cells to a healthier level.


Gleevec also helps treat gastrointestinal stromal tumors (GIST). In many GIST tumor cells, there are a higher number of certain proteins, called Kit and platelet-derived growth factor (PDGF), than in normal cells. These proteins help cancer cells grow and divide.

Gleevec targets these proteins and prevents them from working. This slows the growth of cancer. It also causes cancer cells to die.

It depends. The timing of when Gleevec starts to work is different for each person.

Clinical trials looked at people with CML who received Gleevec treatment. In one month, the number of cancerous cells in the blood was reduced in about half of the people in the blast crisis stage (advanced stage of CML). In clinical trials of people with GIST who took Gleevec, the tumors stopped growing or reduced in size within 3 months.

Your doctor will monitor your blood levels to determine whether Gleevec is working for you.

If you’d like to learn more about Gleevec, talk with your doctor or pharmacist. They can help answer any questions you have about how the drug works in your body.

If you’d like to learn about other aspects of Gleevec, you can explore these articles:

  • More information about Gleevec. For details about other aspects of Gleevec, refer to this article.
  • Side effects. To learn about side effects of Gleevec, see this article. You can also look at the Gleevec prescribing information.
  • Cost. If you’d like to learn about Gleevec and cost, see this article.
  • Drug comparison. To learn how Gleevec compares with Tasigna, read this article.
  • Dosage. For information about the dosage of Gleevec, view this article.
  • A look at cancer. For details about cancer, see our cancer hub.

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