How it is administered

Imatinib is taken by mouth, usually as a tablet or oral solution. Tablets are available in 100 mg and 400 mg strengths. The oral solution contains 80 mg of imatinib per mL. All doses should be taken with a meal and a large glass of water to help reduce stomach upset. For patients who have difficulty swallowing tablets, the tablets can be dissolved in water or apple juice. The oral solution should be measured with an accurate dosing syringe, not a household spoon.

How it works

Imatinib is a type of medication called a tyrosine kinase inhibitor. In certain blood cancers, such as chronic eosinophilic leukemia (CEL) and hypereosinophilic syndrome (HES), abnormal proteins called tyrosine kinases drive the growth of cancer cells. Imatinib works by blocking the activity of these abnormal proteins, including BCR-ABL, PDGFR, and c-Kit. By inhibiting these proteins, imatinib stops the cancer cells from growing and causes them to die off (apoptosis). This targeted approach helps control the disease and can lead to remission in many patients.

Imatinib is especially effective in CEL and HES patients who have a specific genetic change called the FIP1L1-PDGFRα fusion kinase, but it can also be used in patients without this genetic marker. Its action is more selective than traditional chemotherapy, which means it generally causes fewer side effects related to damage of normal cells.

Who Should take it

Imatinib is indicated for adults with chronic eosinophilic leukemia (CEL) and/or hypereosinophilic syndrome (HES), especially those who have the FIP1L1-PDGFRα fusion kinase. It can also be used in patients with CEL/HES who do not have this genetic marker or whose status is unknown. Imatinib is also used for other blood cancers, such as chronic myeloid leukemia (CML), and for certain solid tumors, but for CEL and HES, it is a first-line treatment when the disease is aggressive, symptomatic, or not responding to other therapies.

Your doctor may recommend imatinib if you have a confirmed diagnosis of CEL or HES, especially if genetic testing shows the presence of the FIP1L1-PDGFRα fusion. It is also used in other blood cancers and conditions as specified by your healthcare provider.

Who should not take it

There are no absolute contraindications listed for imatinib, but certain people should use caution or avoid it. If you have a known allergy to imatinib or any of its ingredients, you should not take this medication. Pregnant women should avoid imatinib, as it can cause harm to the developing fetus. Women of reproductive potential should use effective contraception during treatment and for 14 days after stopping imatinib.

People with severe liver or kidney problems may need dose adjustments or may not be able to tolerate imatinib. Always tell your doctor about all your health conditions, including heart, liver, or kidney disease, and any other medications you are taking, as imatinib can interact with many other drugs.

Commonly used with

Imatinib is often used alone for chronic eosinophilic leukemia, but in other blood cancers, it may be combined with chemotherapy or other targeted therapies. For pediatric acute lymphoblastic leukemia (ALL), imatinib is used in combination with chemotherapy. In some cases, supportive medications such as anti-nausea drugs, diuretics for fluid retention, or medications to manage low blood counts may be used alongside imatinib.

Commonly tested with

Imatinib is commonly tested in combination with chemotherapy agents in pediatric and adult acute lymphoblastic leukemia. In clinical trials for CEL and HES, it has been studied as a single agent. In other blood cancers, it may be tested with other targeted therapies or supportive medications. Your doctor may also order regular blood tests to monitor your response to treatment and check for side effects while you are taking imatinib.