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Frequently Asked Questions in CML
Questions about CML
Questions about Glivec® (imantinib) in CML
- How does Glivec work in CML?
- What are the side effects?
- How does Glivec interact with other drugs?
- What if I’m pregnant?
- How do I take Glivec? What’s the dosage for CML?
- What if I take more Glivec than I should?
- What are my responsibilities?
- What if I have additional questions?
Questions about CML
What is CML?
Leukaemia is a type of cancer of the blood and the bone marrow (the inner part of bones where blood cells are made). With leukaemia, 2 things happen. First, certain blood cells become abnormal. Second, the body keeps producing large numbers of these abnormal cells.
CML is one type of leukaemia. “Chronic” means that it is a slow-acting cancer that may take years to progress. “Myeloid” means that the type of abnormal blood cell being overproduced is a type of white blood cell called a myeloid cell. So, chronic myeloid leukaemia is a slow-acting cancer that makes the body produce an excess of cancerous myeloid white blood cells.
There are 3 phases of CML: the chronic phase, the accelerated phase, and the blast crisis phase. As patients move through these phases, their disease progresses, and they experience more physical symptoms.
When a person is healthy, signals in the body tell it to grow new blood cells. These signals reach the source of blood cells, which are called stem cells. The signals turn stem cells on and off as necessary to produce the number of blood cells the body needs. When a person has CML, a change takes place place in their DNA and makes this signal stay on constantly. Because this signal stays on, the body produces more and more leukaemia cells.
CML is either treated with drug therapy or with a bone marrow transplant (BMT)
BMT
BMT is also known as a stem cell transplant (SCT). This type of therapy involves 2 steps. First, a very high dose of a drug is given to the patient to kill most of the cells in the bone marrow (cancer cells and healthy cells). The second step is to replace all of the stem cells that were destroyed with only healthy cells. These replacement cells are usually taken from someone else (this is known as an allogeneic transplant), and are occasionally taken from the patient (this is known as an autologous transplant). Very few patients are actually candidates for BMT.
Glivec
Glivec is an oral therapy that targets the specific cause of CML. Unlike prior drug therapies used in the treatment of CML, Glivec has been shown to extend survival of patients in all phases of CML in clinical trials1-3.
Questions about Glivec in CML
Glivec is a unique therapy that specifically targets the cause of CML. As mentioned earlier, with CML there is a constant signal that tells the body to keep producing abnormal white blood cells. Glivec works by blocking, or turning off, that signal so the extra white blood cells are not made.
This is the first time a therapy has targeted the cause of CML. This is a very important difference from other types of therapy. BMT destroys most of the cells in a patient’s bone marrow (cancer cells and healthy cells). Side effects can be severe. Chemotherapy enters the bloodstream and destroys as many cells as possible—again, cancer cells and healthy cells. Patients receiving certain types of chemotherapy also have many side effects and are sometimes forced to stop their treatment.
Glivec, on the other hand, targets the signal that produces leukaemic cells, so most healthy cells are left unharmed. Most patients receiving Glivec do not have major problems with side effects.
In clinical studies, most patients experienced mild or moderate side effects with Glivec therapy. Most patients are not bothered enough by side effects to discontinue Glivec therapy. The most common side effects include nausea, vomiting, diarrhoea, abdominal pain, fatigue, myalgia, muscle cramps, skin rash, and fluid retention.
Some patients experienced bleeding from the GI tract or the tumour while on Glivec therapy (GI bleeds are more common in GIST than CML). While bleeding may have been caused by the tumour-not Glivec-you should notify your physician immediately if you observe any blood in your stools, have pain in your abdomen, feel weak or dizzy, or look pale.
If you experience any of these symptoms during Glivec therapy, contact your physician, particularly if they are severe:
- nausea
- vomiting
- diarrhoea
- abdominal pain
- fatigue
- myalgia
- muscle cramps
- skin rash
- fluid retention
How does Glivec interact with other drugs?
Like many medications, Glivec can affect, or be affected by, other products you may be taking. When this happens, Glivec or the other drugs may lose their effectiveness or produce more severe side effects. Some drugs that can cause interactions are commonly used over-the-counter medications, such as paracetamol (acetaminophen) or herbal products such as St. John’s Wort. Also, birth control pills (oral contraceptives), blood thinners (especially warfarin), and anticonvulsants might interact with Glivec. In addition, Glivec should not be taken with grapefruit juice. Therefore, it is very important to talk to your physician about all medications and supplements you are currently taking or are planning to take in the future.
If Glivec is used during pregnancy, or if the patient becomes pregnant while receiving Glivec, the patient should be apprised of the potential hazard to the fetus. Women of child-bearing potential are encouraged to use effective contraception during treatment. Please discuss these issues with your physician or nurse before beginning therapy with Glivec.
How do I take Glivec? What’s the dosage for CML?
Glivec is a convenient therapy for patients to take. Unlike many drugs that must be administered in the hospital, Glivec is available in tablet form and is taken by mouth once a day. It is recommended that patients take Glivec with a meal and a large glass of water to avoid gastrointestinal upset.
Your physician or nurse will discuss with you the dose that you should be taking. Generally, dosing of Glivec depends on your stage of CML, your age, and your response to therapy.
Adult patients with CML in the chronic phase normally take 400 mg/d. Adult patients with CML in the accelerated or blast crisis phase normally take 600 mg/d.
Dosing for children with CML is based on body surface area. Glivec is supplied as 100 mg and 400 mg tablets, so you may need more than one tablet for each dose. Your physician will specify which dose you should take and how many of each tablet. Talk to your doctor or nurse about how and when to take the correct dose each day.
Depending on your response to treatment, your physician may decide to change the dose of Glivec that you are taking. If your daily dose is changed, be sure to follow your physician's recommendations.
What if I take more Glivec than I should?
If you think you may have taken more Glivec than you should have, talk to your doctor immediately. You may require medical attention
If vomiting occurs, do not take another dose. Contact your physician.
Because Glivec is an oral therapy, you have the important responsibility of ensuring that you take the correct dose every day.
If you experience side effects, you should talk with your physician.
It is very important for you to continue taking Glivec unless your physician has told you to stop. Contact your physician before stopping your therapy. Following your prescribed dosage is crucial in achieving optimal results. If you are feeling discouraged, talk to your physician, your nurse, or a friend or family member about the way you feel. Getting emotional support during your treatment is just as important as getting medical support.
What if I have additional questions?
If you have additional questions or would like more information, please contact your physician.
You may also choose to access patient support groups, which will allow you to share your experiences with others. Ask your physician for advice on getting additional information.
Find out about efficacy, dosage, and safety in Prescribing Glivec.