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How Treatment May Help

GLEEVEC

Get information about the conditions that GLEEVEC® (imatinib mesylate) is approved to treat. Please select either KIT+ GIST or Ph+ CML to learn more.

Get information about the conditions that GLEEVEC® (imatinib mesylate) is approved to treat. Please select either KIT+ GIST or Ph+ CML to learn more.

Get information about the conditions that GLEEVEC® (imatinib mesylate) is approved to treat. Please select either KIT+ GIST or Ph+ CML to learn more.

See The Difference GLEEVEC After Surgery Can Make

KIT+ GIST can occur nearly anywhere food passes through the body, from the esophagus down to the rectum. Most GIST tumors tend to occur in the stomach or intestines. 

For GIST tumors that can be operated on, the first form of therapy is surgical removal. For some patients, their GIST may return after surgery.

Tests done in a laboratory environment (in vitro) have shown that GLEEVEC® (imatinib mesylate) therapy inhibits the overproduction of cells that can form these tumors.

See the difference longer GLEEVEC therapy can make See the difference longer GLEEVEC therapy can make

More about the study

This study compared 2 groups of people (397 in total) after surgery for KIT+ GIST:

  • 198 people took GLEEVEC for 3 years
  • 199 people took GLEEVEC for 1 year

All people in the study had 1 of the following tumor conditions:

  • Tumor size >5 cm with a growth rate >5 per 50 high-power fields*
  • Tumor size >10 cm with any rate of growth
  • Any tumor size with a growth rate >10 per 50 high-power fields
  • A tumor that has ruptured

*High-power fields (or HPFs) are a unit of measure for the visible area under a microscope during maximum magnification.

Tumor size reference Tumor size reference

Even with no sign of KIT+ GIST after surgery, staying on treatment as prescribed may help decrease the chance of your KIT+ GIST returning.

Speak to an oncologist experienced in KIT+ GIST about your next steps after surgery. See if GLEEVEC therapy may be right for you.

What You Need to Know After Surgery for Advanced KIT+ GIST

Surgery is not always a cure. It’s important for you to speak to an oncologist about your next steps after surgery.

Know that after tumors of any size are removed, KIT+ GIST can return or spread to other parts of the body (metastasize) years later.

Even if the surgeon believes the entire tumor has been removed, risk assessment tools can help an oncologist determine your risk of the cancer returning. Currently, several risk assessment tools are in use, but no one tool has been universally adopted. Regardless of which tool is used, it's important to speak to an oncologist about your appropriate care after surgery.

The Following Factors May Play a Role in Your Risk of Recurrence:

  • Mitotic rate (a measure of the growth rate within the tumor)
  • Tumor size
  • Tumor location
  • If the tumor ruptures
  • Patient characteristics, such as age

Risk assessment tools cannot be used as a substitute for medical advice, diagnosis, or treatment of any health condition or problem. Ask an oncologist to explain your risk and possible ways to lower it.

How Does GLEEVEC Work to Treat Ph+ CML?

The abnormal Bcr-Abl protein that drives blast growth in Ph+ CML is a type of protein called a tyrosine kinase. As a tyrosine kinase inhibitor (TKI), GLEEVEC® (imatinib mesylate) works by seeking out the leukemic cells with the BCR-ABL mutation. GLEEVEC then fits into the "folds" of the Bcr-Abl protein that causes abnormal cell replication, blocking the signal for growth. Without growth instructions, the abnormal cells stop reproducing. This process reduces the number of abnormal cells in your body.

While therapies like GLEEVEC are designed to target leukemic cells, there are known side effects. If you believe you are experiencing side effects as a result of your medication, you should talk to your doctor immediately.

How Will I Know If GLEEVEC Is Working?

The only way to tell if your treatment is working is through monitoring and a specific set of tests that measure the amount of leukemic cells in your body. As this amount decreases as a result of treatment, more sensitive tests are used to evaluate treatment thereafter. Even if your blood count returns to normal, you may still have an undetectable level of abnormal cells in your body. Therefore, additional tests and examinations may be necessary, including the examination of your white blood cells under a microscope. This examination may show a pattern of white blood cells that is characteristic of Ph+ CML: a small proportion of immature cells, called leukemic blasts and promyelocytes, and a larger proportion of fully matured white blood cells, called myelocytes and neutrophils. Blast cells, promyelocytes, and myelocytes are not present in healthy blood. Talk to your doctor if you have questions about the testing you may need.