This medication is used to treat desmoid tumors. Nirogacestat works by slowing or stopping the growth of tumor cells.

Read the Patient Information Leaflet if available from your pharmacist before you start taking nirogacestat and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually twice daily. Swallow the medication whole. Do not break, crush, or chew the tablets. The dosage is based on your medical condition and response to treatment.

If you vomit after taking a dose, do not take another dose at that time. Take your next dose at the regular time.

Antacids can decrease the absorption of nirogacestat. If you are taking an antacid, take nirogacestat 2 hours before or 2 hours after taking antacids.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Also avoid eating Seville oranges (often found in marmalade) and star fruit. Grapefruit, Seville oranges, and star fruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of serious side effects will increase.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Nausea, headache, tiredness, hair loss, cold symptoms (stuffy/runny nose, cough), abdominal pain, or diarrhea may occur. Your doctor may prescribe other medications to control the diarrhea, or may stop/lower the dose of nirogacestat. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Pain or sores in the mouth and throat may occur. Brush your teeth carefully/gently, avoid using mouthwash that contains alcohol, and rinse your mouth often with cool water mixed with baking soda or salt. It may also be best to eat soft, moist foods.

People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

This medication may cause mineral imbalance (low potassium/phosphate). Your doctor may prescribe supplement(s) to replace these minerals. Tell your doctor right away if you have any symptoms of low potassium or phosphate blood levels, including muscle cramps or irregular heartbeat.

Tell your doctor right away if you have any serious side effects, including:

• irregular periods
• hot flashes
• night sweats
• shortness of breath

This medication may rarely cause new skin cancers. Your doctor should do regular skin exams before and during treatment. Tell your doctor right away if you notice any unusual skin changes (such as change in appearance/size of moles).

Nirogacestat can commonly cause a mild rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe allergic reaction. Get medical help right away if you develop any rash.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking nirogacestat, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver disease
• low blood mineral levels (potassium, phosphate)

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using nirogacestat. Nirogacestat may harm an unborn baby. Your doctor should order a pregnancy test before you start this medication. Women should ask about the use of reliable forms of birth control (such as condoms, birth control pills) during treatment and for 1 week after the last dose. Men should ask about the use of reliable forms of birth control during treatment and for 1 week after the last dose. If you or your partner becomes pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this medication passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this medication and for 1 week after the last dose. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are:

• certain drugs that reduce stomach acid (including H2 blockers such as famotidine, proton pump inhibitors such as omeprazole)

Other medications can affect the removal of nirogacestat from your body, which may affect how nirogacestat works. Examples include azole antifungals (such as fluconazole, itraconazole, ketoconazole), diltiazem, efavirenz, fluvoxamine, macrolide antibiotics (such as clarithromycin, erythromycin), rifamycins (such as rifampin), drugs used to treat seizures (such as carbamazepine, phenytoin), verapamil, among others.

This medication can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include bosutinib, dordaviprone, elacestrant, ensartinib, lemborexant, lomitapide, midazolam, rilzabrutinib, taletrectinib, tolvaptan, among others.

This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use reliable backup birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as liver function, blood mineral levels, skin exams) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.