Avapritinib (a-va-PRI-ti-nib)

Treats gastrointestinal stromal tumor (GIST). Also treats a rare disorder called advanced systemic mastocytosis (AdvSM) and indolent systemic mastocytosis (ISM).

Brand Name(s):

Ayvakit

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet

• Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
• It is best to take this medicine on an empty stomach. Take this medicine at least 1 hour before or 2 hours after a meal.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose:
  • If you miss a dose and it is less than 8 hours until your next dose, skip the missed dose and go back to your regular dosing schedule. If you miss a dose and it is more than 8 hours until your next dose, take it as soon as possible, and then go back to your regular dosing schedule.
  • If you vomit after taking a dose, take the next dose at the regular time.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how avapritinib works. Tell your doctor if you are using efavirenz, fluconazole, itraconazole, or rifampin.

Warnings While Using This Medicine:

• This medicine may cause birth defects if either partner is using it during conception or pregnancy. Tell your doctor right away if you or your partner becomes pregnant. If you are a woman who can get pregnant, your doctor may do tests to make sure you are not pregnant before starting treatment. Use an effective form of birth control during treatment with this medicine and for 6 weeks after the last dose. Male patients with female partners should use an effective form of birth control during treatment and for 6 weeks after the last dose.
• Do not breastfeed during treatment with this medicine and for at least 2 weeks after the last dose.
• Tell your doctor if you have kidney disease or liver disease.
• This medicine may cause bleeding in the brain (intracranial hemorrhage).
• This medicine may cause changes in mood or behavior, trouble sleeping, or hallucinations (seeing, hearing, or feeling things that are not there). It may also make you drowsy, dizzy, confused, or less alert than you are normally. Do not drive or do anything else that could be dangerous until you know this medicine affects you.
• Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
• This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.
• This medicine could cause infertility. Talk with your doctor before using this medicine if you plan to have children.
• Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Confusion, dizziness, drowsiness, agitation, changes in mood or behavior, problems in learning
• Headache, sudden and severe weakness, nausea, vomiting
• Rapid weight gain, swelling in your hands, ankles, or feet
• Seeing, hearing, or feeling things that are not there
• Trouble sleeping

If you notice these less serious side effects, talk with your doctor:

• Decreased appetite and weight, stomach pain
• Diarrhea, constipation
• Increased tears, swelling of the eye
• Thinning or loss of hair, changes in hair color
• Unusual tiredness or weakness
• Warmth or redness in your face, neck, arms, or upper chest

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088