Gleevec® (imatinib) may be used to treat certain forms of advanced melanoma with c-KIT mutations. It may be used when the melanoma:1
- Cannot be removed with surgery (unresectable) or
- Has spread to distant parts of the body (metastasized)
The US Food and Drug Administration approves drugs for certain uses. They make these decisions based on the results of large clinical trials. Gleevec is approved for certain types of cancer, such as certain forms of blood cancer and blood cell disorders, soft tissue cancer (sarcoma), and gastrointestinal stromal tumors.2
Gleevec is not approved for melanoma. However, it has been studied for certain types of advanced melanoma.3 National cancer guidelines suggest it as one option when other treatments are not working.1 Generic forms of imatinib are available.
How does Gleevec work?
Gleevec is a type of medication called a kinase inhibitor. It works by blocking a receptor called c-KIT.
The c-KIT receptor is in the cell membrane (wall) of many different cells.4 In normal cells, a signaling molecule called “Stem Cell Factor” binds (connects) to c-KIT.4 This action sets a chain of events in motion. These events allow cells to grow and survive. Stem Cell Factor acts like a switch. It turns on the chain of events only when it is needed. This mechanism helps to keep cell processes under control.
Mutations cause c-KIT to act abnormally. C-KIT may start the chain of events without Stem Cell Factor. This leads to uncontrolled cell growth, which is when cancer develops. C-KIT mutations are found in approximately 6% of melanoma cases. 5
Gleevec blocks (inhibits) c-KIT.2 Using Gleevec to treat melanoma cells with a c-KIT mutation slows cell growth and increases cell death.3 Gleevec is called a targeted therapy because it targets one feature that makes cancer cells different from normal cells.
Cancer cells can also have too many copies of the c-KIT genes (instructions). Having too many copies is called “amplification.” Gleevec may not work as well in cancer cells with c-KIT amplification.3
Before taking Gleevec, read the Medication Guide that comes in the package. Follow your doctor’s instructions for taking Gleevec.
Gleevec comes as tablets. Your doctor will tell you how often to take the medication.2 Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their imatinib regimen.
For approved uses (indications), Gleevec is typically taken until the cancer progresses or the side effects are unacceptable.2 Ask your doctor how long you should take Gleevec. Talk with your doctor before stopping any medication.
What are the side effects of Gleevec?
Nearly everyone experiences side effects with Gleevec. The most common side effects of Gleevec in patients with melanoma include:3
- Nausea and vomiting
- Low red blood cell count (anemia)
- High blood sugar (hyperglycemia)
Other common side effects include:6
- Swelling and fluid retention (may be serious)
- Muscle cramps or pain
- Bone pain
- Abdominal pain
- Loss of appetite
- Abnormal bleeding (may be severe)
Less common but serious possible side effects include:6
- Low blood cell counts
- Congestive heart failure
- Severe liver problems
- Low levels of thyroid hormone
- Electrolyte disturbance
This is not an exhaustive list of all potential side effects of imatinib. Talk to your healthcare provider or pharmacist for further information.
Who should not take Gleevec?
If you are pregnant, plan to become pregnant, or are breastfeeding or plan to breastfeed, talk with your doctor. Imatinib can cause harm to a developing fetus and should not be taken by women who are pregnant.2 While taking imatinib, females who can become pregnant should use contraceptives during treatment and for a period of time after completing treatment (patients should discuss appropriate birth control methods, and how long they need to use them, with their doctor). Females should not breastfeed during imatinib treatment and for a period of time following the final dose (patients should discuss breastfeeding considerations with their doctor).
Tell your doctor about any medical conditions you have, especially: 6
- Heart disease
- Current or past kidney failure
- Thyroid problems
- Eye problems
- Liver problems
- Muscle problems
Tell your doctor about all the prescription and non-prescription medications and supplements that you take. The coating for Gleevec contains iron. Tell your doctor if you take or are planning to take a supplement with iron.
What precautions are needed when taking Gleevec?
Use caution when driving a car or operating machinery. Possible side effects of Gleevec include dizziness, blurred vision, or drowsiness. Patients have reported motor vehicle accidents while using Gleevec.6
Avoid grapefruit juice and other foods that affect the way Gleevec works. You can speak with your pharmacist about what foods may interact with your medications.2