Selpercatinib is used to treat a certain type of non-small cell lung cancer (NSCLC) in adults that has spread to other parts of the body in adults. It is also used to treat a certain type of thyroid cancer in adults and children 12 years of age and older that has spread to other parts of the body. Selpercatinib is also used to treat another type of thyroid cancer that has spread to other parts of the body in adults and children 12 years of age and older who have been treated unsuccessfully with radioactive iodine. Selpercatinib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps slow or stop the spread of cancer cells.

Selpercatinib comes as a capsule to take by mouth. It is usually taken twice daily (every 12 hours) with or without food. Take selpercatinib at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take selpercatinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the capsules whole; do not open, chew, or crush them.

If you vomit after taking selpercatinib, do not take another dose. Continue your regular dosing schedule.

Your doctor may decrease your dose, or interrupt or discontinue your treatment. This depends on how well the medication works for you and the side effects you experience. Talk to your doctor about how you are feeling during your treatment. Continue to take selpercatinib even if you feel well. Do not stop taking selpercatinib without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking selpercatinib,

• Tell your doctor and pharmacist if you are allergic to selpercatinib, any other medications, or any of the ingredients in selpercatinib capsules. Ask your pharmacist for a list of the ingredients.
• Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antifungals such as fluconazole (Diflucan), itraconazole (Onmel, Sporanox), ketoconazole, and voriconazole (Vfend); aprepitant (Emend); carbamazepine (Carbatrol, Tegretol, Equetro, others); clarithromycin (Biaxin, in Prevpac); diltiazem (Cardizem, Cartia, Tiazac, others); erythromycin (E.E.S., E-Mycin, Erythrocin); certain medications for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) including efavirenz (Sustiva), indinavir (Crixivan), nelfinavir (Viracept), nevirapine (Viramune), ritonavir (Norvir, in Kaletra), and saquinavir (Invirase); nefazodone; phenobarbital; phenytoin (Dilantin, Phenytek); pioglitazone (Actos); quinidine (in Nuedexta); repaglinide (Prandin); rifabutin (Mycobutin); rifampin (Rifadin, Rimactane, in Rifamate, in Rifater); and verapamil (Calan, Verelan, others). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with selpercatinib, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• If you are taking an H₂ blocker medication for indigestion, heartburn, or ulcers such as cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), or ranitidine (Zantac), take selpercatinib at least 2 hours before or 10 hours after taking one of these medications.
• If you are taking an antacid that contains aluminum, magnesium, calcium, or simethicone; or buffered medications such as buffered aspirin, take selpercatinib at least 2 hours before or at least 2 hours after you take one of these medications.
• If you are taking a proton-pump inhibitor such as esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix), and rabeprazole (AcipHex), take each dose of selpercatinib along with food.
• Tell your doctor what herbal products you are taking, especially St. John’s wort.
• Tell your doctor if you have or have ever had a slow, fast, or irregular heartbeat; a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death); high blood pressure; bleeding problems; or kidney or liver disease.
• Tell your doctor if you are pregnant, plan to become pregnant, or if you plan on fathering a child. You should not become pregnant while you are taking selpercatinib. If you are female, you will need to take a pregnancy test before you start treatment and use birth control to prevent pregnancy during your treatment with selpercatinib and for 1 week after your final dose. If you are male, you and your female partner should use birth control during your treatment with selpercatinib and for 1 week after your final dose. If you or your partner become pregnant while taking selpercatinib, call your doctor immediately. Selpercatinib can cause fetal harm.
• Tell your doctor if you are breastfeeding. You should not breastfeed while you are taking selpercatinib and for 1 week after your final dose.
• You should know that this medication may decrease fertility in men and women. Talk to your doctor about the risks of taking selpercatinib.
• If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking selpercatinib. Your doctor may tell you not to take selpercatinib 7 days before your surgery or procedure and will tell you when you should start taking the medication again.

Do not eat grapefruit or drink grapefruit juice while taking this medication.

Take the missed dose as soon as you remember it. However, if it is within 6 hours of your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Selpercatinib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• Dry mouth
• Diarrhea
• Constipation
• Nausea
• Vomiting
• Stomach pain
• Headache
• Tiredness
• Cough
• Shortness of breath
• Swelling of your arms, legs, hands, and feet

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

• Pain in the right upper part of the stomach; unusual bruising or bleeding; dark urine; or yellowing of the skin and eye
• Heart palpitations
• Dizziness or lightheadedness
• Fainting
• Coughing up or vomiting blood or material that looks like coffee grounds; unusual bleeding or bruising, pink; red, or dark brown urine; or red or tarry black bowel movements
• Nausea; vomiting; shortness of breath; muscle cramps; weakness; seizures; or swelling of arms and legs
• Fever, rash, or joint or muscle pain

Selpercatinib may cause the bones to stop growing too soon in teenagers who are still growing. Talk to your child’s doctor about the risks of giving this medication to your child.

Selpercatinib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your doctor will check your blood pressure regularly and order certain lab tests before and during your treatment to check your body’s response to selpercatinib.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.