Pemigatinib (Pemazyre®)

Author: Karen Arnold-Korzeniowski, MSN RN
Last Reviewed: April 6, 2026

Pronounce: PEM-i-GA-ti-nib

Classification: Kinase inhibitor

About Pemigatinib (Pemazyre®)

Pemigatinib is a kinase inhibitor. A kinase is an enzyme that promotes cell growth. There are many types of kinases that control different phases of cell growth. By blocking a particular enzyme from working, this medication can slow the growth of cancer cells. This medication works in patients whose tumors have tested positive for an FGFR2 fusion or rearrangement.

How to Take This Medication

This medication comes in a tablet form to be taken by mouth. You should swallow the tablet whole, with or without food, around the same time every day. You should not crush, break, or chew the tablet. If you miss a dose by 4 or more hours or if you vomit after taking your dose, do not take your next dose until its scheduled time. Do not take extra tablets to make up for a missed or vomited dose.

The blood levels of this medication can be affected by certain foods and medications, so they should be avoided. These include: grapefruit, grapefruit juice, itraconazole, esomeprazole, and other proton pump inhibitors, carbamazepine, phenobarbital, verapamil, ketoconazole, rifampin, phenytoin, St. John’s wort, and modafinil, among others. Certain medications taken at the same time may lead the provider to reduce your dose of therapy as well. Be sure to tell your healthcare provider about all medications and supplements you take.

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. You should also double-check with your provider about which days you should take this medication.

Storage and Handling

Store your medication in the original container with the label. If you want to use a pillbox, talk to your pharmacist. Keep it in a dry place at room temperature unless your provider or pharmacist tells you otherwise. 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 people should not prepare the dose for you. Ask your provider 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?

Some cancer medications are only available through specialty pharmacies. Your provider or pharmacist will start this process. Your insurance plan may also affect where you can get your medication.  Call your prescription plan provider to find out which specialty pharmacies are in-network.

Insurance Information

This medication may be covered by your prescription plan. If you qualify, you may be able to get financial help through patient assistance programs (PAP). Co-pay cards may also be available to lower your out-of-pocket cost if you have commercial (not Medicare/Medicaid/Tricare) insurance. Your pharmacist, social worker, or navigator can help find resources for financial support.

Possible Side Effects

These are some of the most common or most serious side effects of this medication. Talk with your provider about the side effects you are having and how they can be managed.

Hyperphosphatemia (High phosphate levels)

This medication can cause a high level of phosphate in your blood. You will have blood drawn to monitor the level of phosphate. Symptoms of hyperphosphatemia include muscle cramps, numbness, and tingling around the mouth. If you have any of these symptoms you should call your provider right away. A change in your treatment, diet and medical treatment may be needed to manage hyperphosphatemia.

Loss or Thinning of Scalp and Body Hair (Alopecia)

Alopecia is when your hair gets thin, brittle (breaks easily), or falls out. This may happen during the few weeks after treatment starts. Hair loss can be all of your body hair, including pubic, underarm, legs/arms, eyelashes, and nose hairs. You may want to use scarves, wigs, hats, and hairpieces. Your hair helps keep you warm in cold weather, and it can protect you from the sun, so it is important to wear a hat if you are in cold weather or in the sun. If you are going to be out in the sun, protect your scalp by using a sunscreen with SPF 30 or higher. Wash your scalp with a mild or baby shampoo. After you are done with treatment, hair often starts to grow back.

Diarrhea

Diarrhea is when you pass three or more stools in a day. Your providers can suggest medications to relieve diarrhea. Do not take any medications to manage your diarrhea without talking to your provider first, as your stool may need to be tested. To manage it, try eating foods that are low in fiber and bland, like white rice and boiled or baked chicken. Try not to eat raw fruits, vegetables, whole grain breads, cereals, and seeds. Soluble fiber is a type of fiber found in some foods that helps absorb (soak up) fluid. Foods high in soluble fiber are applesauce, bananas (ripe), canned fruit, oranges, boiled potatoes, white rice, foods made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Stay hydrated by drinking 8 to 10 glasses of non-alcoholic, non-caffeinated fluid each day.

Nail Changes

Your fingernails/toenails may become dark, brittle, split, or fall off. Keep your fingernails and toenails clean and dry. You may use nail polish, but do not wear fake nails (gels, acrylics, overlay). If any nails fall off, clean the nail bed well with soap and water and cover with a band-aid.

Fatigue

Fatigue can cause exhaustion, feeling worn out and that your body is "heavy" and hard to move, or being unable to focus. It is common when you have cancer, and it is not the same as feeling tired. You may need to adjust your schedule to manage fatigue. Plan times to rest during the day and save your energy for more important activities. Exercise can help lessen fatigue. Talk to your providers about ways to deal with this side effect.

Decrease in Appetite or Taste Changes

Nutrition is an important part of your care. Cancer treatment can affect your appetite and make it hard to eat. Ask your provider about nutrition counseling services. Some tips you can follow are:

  • Try to eat five or six small meals or snacks during the day, instead of 3 larger meals.
  • Nutritional supplements may help if you are not eating enough.
  • You may have a metallic taste or find that food has no taste. You may dislike foods or beverages that you liked before cancer treatment. These symptoms can last for 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 dressing.
  • Use seasonings like basil, oregano, or rosemary to add flavor.

Nausea and/or Vomiting

Talk to your providers if you have nausea and/or vomiting. They can prescribe medications to help you. Making changes to your diet can also help. Avoid things that make your symptoms worse, like heavy or greasy/fatty foods and spicy or acidic foods, like tomatoes, lemons, and oranges. Try saltines or ginger ale to help your symptoms.  

Call your providers if you cannot keep fluids down for more than 12 hours or if you feel lightheaded or dizzy.

Constipation

Constipation is when you have less bowel movements than usual or are having trouble passing stool. To relieve constipation, you can include fiber in your diet (fruits like prunes, apples, peaches, and pear nectars/juices), drink 8 to 10 glasses of non-alcoholic fluids a day, and stay active. Taking a stool softener once or twice a day can prevent constipation. If you do not have a bowel movement for 2 to 3 days, call your provider. 

Mouth Ulcers (Mucositis)

This medication can cause sores or soreness in your mouth and/or throat, called mucositis. Tell your providers if your mouth, tongue, inside of your cheek, or throat becomes white, has ulcers, or is painful. Medications can be used to manage pain. Regular mouth care can help prevent or manage mouth sores. Some things you can do are:

  • Brush with a soft-bristle toothbrush or cotton swab twice a day.
  • Avoid mouthwashes that contain alcohol. A baking soda and/or salt with warm water mouth rinse (2 level teaspoons of baking soda or 1 level teaspoon of salt in an eight-ounce glass of warm water) can be used a few times each day.
  • If your mouth gets dry, eat moist foods, drink plenty of fluids (6 to 8 glasses), and suck on sugarless hard candy.
  • Avoid smoking and chewing tobacco, and drinking alcoholic beverages and citrus juices.

Low White Blood Cell Count (Leukopenia or Neutropenia)

White blood cells (WBC) help your body fight infection. While you are having treatment for cancer, your WBC count can drop, putting you at a higher risk of an infection. Tell your provider right away if you have a fever (temperature greater than 100.4°F or 38°C), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.

Tips for preventing infection:

  • Hand washing: both yours and your visitors is the best way to prevent the spread of infection.
  • Avoid large crowds and people who are sick (those who have a cold, fever, or cough, or live with someone with these symptoms).
  • When working outside, wear clothes that protect you, like long pants and gloves.
  • Do not handle pet waste.
  • Keep all cuts and scratches clean.
  • Shower or bathe daily. 
  • Brush your teeth at least twice a day.
  • Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
  • Ask your providers before scheduling dental appointments or procedures.
  • Ask your providers before you or someone you live with has any vaccines

Low Platelet Count (Thrombocytopenia)

Platelets are blood cells that help your blood clot. Thrombocytopenia is when your platelet count is lower than normal, and you are at a higher risk of bleeding. Tell your providers if you have any bruising or bleeding, including nose bleeds, bleeding gums, or blood in your urine or stool. If your count gets too low, you may receive platelets from a donor. 

  • Do not use a razor (an electric razor is fine).
  • Do not do activities that can cause injury or bleeding.
  • Talk to your provider before taking any non-steroidal, anti-inflammatory medications (NSAIDs) like Motrin/Advil (ibuprofen), Aleve (naproxen), Celebrex (celecoxib), and others. These can raise the risk of bleeding. 
  • Use a soft-bristle toothbrush to brush your teeth. Ask your provider about flossing or using toothpicks. 

Low Red Blood Cell Count (Anemia)

Anemia is when your red blood cell count is lower than normal. Red blood cells carry oxygen to the tissues in your body. When your red cell count is low, you may feel tired or weak. Tell your providers if you have shortness of breath, trouble breathing, or pain in your chest. If your count gets too low, you may receive a blood transfusion.

Muscle or Joint Pain/Aches and Headache

You may have joint or muscle pain/aches and headaches while taking this medication. Your provider can recommend medications and other ways to help relieve your pain.

Hypophosphatemia (Low phosphate levels)

In some cases, this medication can cause a low level of phosphate in the blood. Symptoms include weakness, trouble breathing, and loss of appetite. You should notify your provider if you are having any of these symptoms.

Dry Skin or Rash

You may have dry skin or a rash while taking this medication. Use moisturizing soaps and warm (not hot) water when bathing. Use a fragrance-free moisturizer to hydrate your skin. In cold weather, protect your skin by using gloves, scarf, and hat. Also, make sure you are staying hydrated by drinking enough non-caffeinated fluids each day.

Eye Concerns

This medication can cause dry eyes, inflammation of the cornea (the front part of the eye), increased tear production, and a disorder of the retina. You will need to see an eye specialist before you begin treatment, then every 2 months for the first 6 months of treatment, and then every 3 months until you are done treatment. You can use artificial tears to moisturize your eyes. Your provider may prescribe one. In rare cases, this medication can cause retinal pigment epithelial detachment. If you have any symptoms of eye issues such as blurred vision, flashes of light, or see black spots you need to call your provider right away.

Reproductive Concerns

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 one week after treatment for both male and female patients. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should not breastfeed while receiving this medication or for one week after your last dose.