Classification: Targeted Therapy, IDH2 Inhibitor
About: Enasidenib (Idhifa®)
This medication is a type of targeted therapy called an isocitrate dehydrogenase-2 (IDH2) inhibitor. Enasidenib works by targeting and blocking IDH 1 enzyme. In some cancers, this receptor is overactive, causing cells to grow and divide too fast. By inhibiting these, this medication can slow or stop tumor growth. Your oncology team will test your tumor for this abnormality, which must be present in order to receive the medication.
How to Take Enasidenib
Enasidenib comes in tablet form to be taken once a day, with or without food. Take the tablets whole with a glass of water; do not break, crush or chew the tablets. You should take your dose around the same time each day. If you miss a dose or vomit after taking it, take another dose as soon as possible on the same day. Return to your normal schedule the next day. Do not take 2 doses to make up for a missed dose. If you are having trouble swallowing your tablets, contact your pharmacist or provider.
It is important to make sure you are taking the correct amount of medication every time. Before every dose, check that what you are taking matches what you have been prescribed. Be sure to let your medical team know about all medications, including prescription and over-the-counter, vitamins and supplements you are taking, to check for any interactions.
Storage and Handling
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). This medication should not be stored in a pillbox. Keep containers out of reach of children and pets.
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.
Where do I get this medication?
Enasidenib 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 depending upon 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.
Possible Side Effects
There are a number of things you can do to manage the side effects of enasidenib. 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 some of the electrolyte levels in your blood. Most often it causes elevated bilirubin. It can also cause decreased calcium, decreased potassium, and decreased phosphorus. Elevated bilirubin can cause jaundice, or a yellowing of your skin and the whites of your eyes. You should notify your care provider if you develop any of these symptoms. Your lab values will be monitored with blood tests and treated as needed.
Nausea and/or Vomiting
Talk to your oncology care team 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 saltines, or ginger ale to lessen symptoms.
Call your oncology care team if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.
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 on non-alcoholic, un-caffeinated fluid a day to prevent dehydration.
Decrease in Appetite or Taste Changes
Nutrition is an important part of your care. Cancer treatment can affect your appetite and, in some cases, the side effects of treatment can make eating difficult. Ask your oncology care team about nutritional counseling services at your treatment center to help with food choices.
- Try to eat five or six small meals or snacks throughout the day, instead of 3 larger meals.
- If you are not eating enough, nutritional supplements may help.
- You may experience a metallic taste or find that food has no taste at all. You may dislike foods or beverages that you liked before receiving cancer treatment. These symptoms can last for several months or longer after treatment ends.
- Avoid any food that you think smells or tastes bad. If red meat is a problem, eat chicken, turkey, eggs, dairy products and fish without a strong smell. Sometimes cold food has less of an odor.
- Add extra flavor to meat or fish by marinating it in sweet juices, sweet and sour sauce or dressings. Use seasonings like basil, oregano or rosemary to add flavor. Bacon, ham and onion can add flavor to vegetables.
Less common, but important side effects can include:
- Differentiation Syndrome: This medication can cause very rapid maturing of myeloid cells, which can lead to this serious side effect. This can occur at any point while taking this medication. Call your care provider immediately if you develop any of the following: fever, shortness of breath, cough, chest pain, rapid weight gain (10 pounds or more in 1 week), swelling in your arms, legs, neck, groin, or underarms, or bone pain. This side effect may be treated with steroids.
- Leukocytosis: This is a rapid increase in the number of white blood cells. You will be monitored for this with frequent blood tests.
- Tumor Lysis Syndrome: If there are a large amount of tumor cells in your body prior to treatment, you are at risk for tumor lysis syndrome. This happens when the tumor cells die too quickly and their waste overwhelms the body. If you experience nausea, vomiting, diarrhea or become lethargic (drowsy, sluggish), notify your oncology team right away. TLS can affect your kidney function. Drink plenty of fluids. Your provider will monitor your kidney function with blood work. Notify your provider if you have little or no urine output.
Sexual & Reproductive Concerns
This medication may affect your reproductive system, resulting in the menstrual cycle or sperm production becoming irregular or stopping permanently. Women may experience menopausal effects including hot flashes and vaginal dryness. In addition, the desire for sex may decrease during treatment. You may want to consider sperm banking or egg harvesting if you may wish to have a child in the future. Discuss these options with your oncology team.
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. This medication may affect the blood level of hormonal contraception. Speak to your care team about the best choice for contraception. You should consult with your healthcare team before breastfeeding while receiving this medication.