Pronounce: er-da-FI-ti-nib
Classification: Tyrosine Kinase Inhibitor
Erdafitinib is a type of targeted therapy called a tyrosine kinase inhibitor. A kinase is an enzyme that promotes cell growth. There are many types of kinases, which control different phases of cell growth. By blocking a particular enzyme from working, this medication can slow the growth of cancer cells.
Erdafitinib is a tyrosine kinase inhibitor that blocks an enzyme called a fibroblast growth factor receptor (FGFR). It works by targeting receptors present on the cancer cells. By blocking these targets on cancer cells, tumor growth and angiogenesis (the development of a blood supply to the tumor) are blocked, causing cell death. This medication specifically targets FGFR2 or FGFR3 genetic mutations. Your oncology team will test your tumor for this genetic alteration, which must be present in order to receive the medication.
Erdafitinib comes as a tablet to take by mouth. It can be taken with or without food. Swallow the tablets whole; do not crush, break, or chew. If you vomit after taking erdafitinib, the next dose should be taken the next day. If you miss a dose, take the missed as soon as possible. Resume the regular daily dose schedule for erdafitinib the next day. Extra tablets should not be taken to make up for the missed dose.
The blood levels of this medication can be affected by certain foods and medications, so you should discuss your current medication list (including prescription medicines, over-the-counter drugs, and herbal products) and your diet with your provider before starting erdafitinib. Grapefruit, pomegranate and star fruit (and their juices) can interfere with erdafitinib and should be avoided. Certain medications can interfere with erdafitinib, so make sure your provider is aware of all the medications, vitamins and supplements you are taking, including but not limited to: carbamazepine, phenytoin, rifampin, azole antifungals, clarithromycin, sevelemar, and lanthanum.
Store your medication in the original, labeled container at room temperature and in a dry location (unless otherwise directed by your healthcare provider or pharmacist).
If a caregiver prepares your dose for you, they should consider wearing gloves or pour the pills directly from their container into the cap, a small cup, or directly into your hand. They should avoid touching the pills. They should always wash their hands before and after giving you the medication. Pregnant or nursing women should not prepare the dose for you. Ask your oncology team where to return any unused medication for disposal. Do not flush down the toilet or throw in the trash.
Erdafitinib is available through select specialty pharmacies. Your oncology team will work with your prescription drug plan to identify an in-network specialty pharmacy for distribution of this medication and shipment directly to your home.
This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage. Co-pay cards, which reduce the patient co-pay responsibility for eligible commercially (non-government sponsored) insured patients, may also be available. Your care team can help you find these resources, if they are available.
There are a number of things you can do to manage the side effects of erdafitinib. Talk to your care team about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:
This medication can affect the normal levels of electrolytes (potassium, sodium, magnesium, calcium, phosphorous, etc.) in your body. In particular, erdafitinib can make levels of phosphorous in your body increase to unsafe levels. Your levels will be monitored using blood tests before and during treatment. If your levels become too high, your care team may prescribe specific medications, called phosphate binders, to decrease the levels of phosphorous in your body. If these levels become dangerously high, your provider may have you stop taking erdafitinib.
You should keep your phosphorous intake at 600-800 mg daily. Avoid large portions of foods that can make your phosphorous level increase, including:
Contact your provider right away if you have painful skin lesions, muscle cramps, or numbness and tingling around your mouth. Do not take any supplements without first consulting with your care team.
While receiving erdafitinib, some patients may develop dry or inflamed eyes, irritation or damage to the cornea (clear covering of the eyeball), or disorders of the retina (thin layer of tissue that lines the back of the eye on the inside). Notify your healthcare team if you develop any eye pain or dryness, swelling, redness or any vision changes, including blurriness and sensitivity to light. You should use artificial tear substitutes, hydrating or lubricating eye gels or ointments at least every 2 hours during waking hours to help prevent dry eyes. During treatment with erdafitinib, your healthcare provider will send you to see an eye specialist.
Certain cancer treatments can cause sores or soreness in your mouth and/or throat. Notify your oncology care team if your mouth, tongue, inside of your cheek or throat becomes white, ulcerated or painful. Performing regular mouth care can help prevent or manage mouth sores. If mouth sores become painful, your doctor or nurse can recommend a pain reliever.
Avoid smoking and chewing tobacco, drinking alcoholic beverages and citrus juices.
Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your healthcare team for helpful tips on dealing with this side effect.
This medication can cause kidney problems, including an increased creatinine level, which your oncology care team may monitor through blood tests. Notify your healthcare provider if you notice decreased urine output, blood in the urine, swelling in the ankles, or loss of appetite.
Your oncology care team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals and seeds. Soluble fiber is found in some foods and absorbs fluid, which can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange sections, boiled potatoes, white rice, products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses of non-alcoholic, un-caffeinated fluid a day to prevent dehydration.
This medication can cause xerostomia, also known as dry mouth. Xerostomia can be uncomfortable and can affect your speech, swallowing and dental health. Ways to manage this side effect include:
Speak to your provider if this side effect continues to be a problem.
Erdafitinib has some unique nail and skin side effects that you may experience. Nails may develop "ridges" in them or fall off. This may appear several months after starting treatment, but can last for many months after treatment stops.
Erdafitinib can also cause dry skin. Tips for managing your skin include:
If you develop peeling or blistering of the skin, notify your healthcare team right away.
This medication can cause liver toxicity, which your oncology care team may monitor for using blood tests called liver function tests. Notify your healthcare provider if you notice yellowing of the skin or eyes, your urine appears dark or brown, or you have pain in your abdomen, as these can be signs of liver toxicity.
Nutrition is an important part of your care. Cancer treatment can affect your appetite and, in some cases, the side effects of treatment can alter your taste and make eating difficult. Ask your oncology care team about nutritional counseling services at your treatment center to help with food choices.
Your red blood cells are responsible for carrying oxygen to the tissues in your body. When the red cell count is low, you may feel tired or weak. You should let your oncology care team know if you experience any shortness of breath, difficulty breathing or pain in your chest. If the count gets too low, you may receive a blood transfusion.
There are several things you can do to prevent or relieve constipation. Include fiber in your diet (fruits and vegetables), drink 8-10 glasses of non-alcoholic fluids a day, and keep active. A stool softener once or twice a day may prevent constipation. If you do not have a bowel movement for 2-3 days, you should contact your healthcare team for suggestions to relieve the constipation.
Hand foot syndrome (HFS) is a skin reaction that appears on the palms of the hands and/or the soles of the feet, as a result of certain chemotherapy agents being absorbed by the skin cells. HFS can begin as a mild tingling, numbness, pins-and-needles feeling, redness or pain or swelling of the hands and/or feet. This can then progress to painful swelling, blistering or peeling skin that can interfere with your ability to do normal activities. Be sure to let your oncology team know right away if you notice these symptoms, as they may need to adjust the chemotherapy dose or take a break to allow the skin to heal. Some tips to help prevent HFS include:
Your hair may become thin, brittle, or may fall out. This typically begins two to three weeks after treatment starts. This hair loss can be all body hair, including pubic, underarm, legs/arms, eyelashes, and nose hairs. The use of scarves, wigs, hats and hairpieces may help. Hair generally starts to regrow soon after treatment is completed. Remember your hair helps keep you warm in cold weather, so a hat is particularly important in cold weather or to protect you from the sun.
Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms.
Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.
Your healthcare provider can recommend medications and other strategies to help relieve pain.
Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment and for at least 1 month after treatment. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. Women should not breastfeed during treatment and for 1 month after the final erdafitnib dose. Erdafitinib may impair fertility in females of reproductive potential. Talk with your provider concerning these risks.
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