Selpercatinib is used to treat a certain type of non-small cell lung cancer in adults.

Selpercatinib is also used to treat certain types of thyroid cancer in adults and children at least 12 years old.

selpercatinib is used when the cancer has spread to other parts of the body (metastatic).

Selpercatinib is used only if your cancer has a specific genetic marker (an abnormal "RET" gene). Your doctor will test you for this gene.

Selpercatinib was approved by the US Food and Drug Administration (FDA) on an "accelerated" basis. In clinical studies, some people responded to this medicine, but further studies are needed.

Selpercatinib may also be used for purposes not listed in this medication guide.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Selpercatinib is usually taken every 12 hours.

Take selpercatinib with food if you also use a "proton pump inhibitor" stomach acid medicine such as esomeprazole, lansoprazole, omeprazole, Prevacid, Prilosec, Nexium, and others.

Follow your doctor's dosing instructions very carefully.

If you vomit shortly after taking selpercatinib, do not take another dose. Wait until your next scheduled dose time to take the medicine again.

Selpercatinib doses are based on weight (especially in children and teenagers). Your dose needs may change if you gain or lose weight.

You may be given steroid medicine if you have an allergic reaction. Keep using this medicine for as long as your doctor has prescribed.

Your blood pressure will need to be checked often.

If you need surgery, tell your surgeon you currently use selpercatinib. You may need to stop for at least 7 days before a planned surgery.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Non-Small Cell Lung Cancer:

Less than 50 kg: 120 mg orally 2 times daily (approximately every 12 hours) until disease progression or unacceptable toxicity

50 kg or greater: 160 mg orally 2 times daily (approximately every 12 hours) until disease progression or unacceptable toxicity

Use: For the treatment of adult patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC)

Usual Adult Dose for Thyroid Cancer:

Less than 50 kg: 120 mg orally 2 times daily (approximately every 12 hours) until disease progression or unacceptable toxicity

50 kg or greater: 160 mg orally 2 times daily (approximately every 12 hours) until disease progression or unacceptable toxicity

Uses:
-For the treatment of adult patients with advanced or metastatic RET-mutant medullary thyroid cancer (MTC) who require systemic therapy.
-For the treatment of adult patients with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine-refractory (if radioactive iodine is appropriate)

Usual Pediatric Dose for Thyroid Cancer:

12 years and older:
Less than 50 kg: 120 mg orally 2 times daily (approximately every 12 hours) until disease progression or unacceptable toxicity

12 years and older:
50 kg or greater: 160 mg orally 2 times daily (approximately every 12 hours) until disease progression or unacceptable toxicity

Uses:
-For the treatment of pediatric patients 12 years and older with advanced or metastatic RET-mutant medullary thyroid cancer (MTC) who require systemic therapy
-For the treatment of pediatric patients 12 years and older with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine-refractory (if radioactive iodine is appropriate)

You should not use selpercatinib if you have untreated or uncontrolled hypertension (high blood pressure).

Tell your doctor if you have ever had:

• liver disease; or

• long QT syndrome (in you or a family member).

Both men and women using selpercatinib should use effective birth control to prevent pregnancy. Selpercatinib can harm an unborn baby if the mother or father is using this medicine. Keep using birth control for at least 1 week after your last dose.

Tell your doctor right away if a pregnancy occurs while either the mother or the father is using selpercatinib.

This medicine may affect fertility (ability to have children) in both men and women. However, it is important to use birth control to prevent pregnancy because selpercatinib can harm an unborn baby.

Do not breastfeed while using this medicine, and for at least 1 week after your last dose.

Take the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 6 hours. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

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.

Talk to your doctor about eating grapefruit or drinking grapefruit juice while taking this medication.

Ask your doctor before using any medicine to reduce stomach acid, including an antacid.

Avoid taking an herbal supplement containing St. John's wort.

Get emergency medical help if you have signs of an allergic reaction: hives, rash; fever, joint or muscle pain; difficult breathing; swelling of your face, lips, tongue, or throat.

Selpercatinib may cause serious side effects. Call your doctor at once if you have:

• easy bruising or bleeding (nosebleeds, bleeding gums);

• coughing up blood or vomit that looks like coffee grounds;

• any wound that will not heal;

• fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);

• fever, chills, cough with mucus, chest pain, feeling short of breath; or

• liver problems--loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes).

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of selpercatinib may include:

• abnormal blood tests;

• high blood pressure;

• tiredness;

• dry mouth;

• diarrhea;

• swelling;

• rash; or

• constipation.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Selpercatinib can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Some medicines can make selpercatinib much less effective when taken at the same time. If you take any of the following medicines, take them separately from your dose of selpercatinib:

• an antacid--take selpercatinib 2 hours before or 2 hours after taking the antacid; or

• stomach acid medicines (such as cimetidine, famotidine, Axid, Pepcid, Tagamet, and others)--take selpercatinib dose 2 hours before or 10 hours after you take the other medicine.

Other drugs may affect selpercatinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Keep all appointments with your doctor and the laboratory. Your doctor will order a lab test before you begin your treatment to see whether your cancer can be treated with selpercatinib. Your doctor will 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.