Retevmo contains the active ingredient selpercatinib, which is a kinase inhibitor. It is available in capsules with doses of 40 mg or 80 mg, and as tablets with doses of 40 mg, 80 mg, 120 mg, or 160 mg, all intended for oral use. Key inactive ingredients include microcrystalline cellulose and, in tablets, also croscarmellose sodium and hydroxypropyl cellulose. Retevmo is designed to block proteins that help cancer cells grow and multiply, potentially slowing the spread of cancer.

How should I use this medication?

Take this medication by mouth. Take it as directed on the prescription label at the same time every day. Do not cut, crush, or chew this medication. Swallow the capsules and tablets whole. You can take it with or without food. If it upsets your stomach, take it with food. Keep taking it unless your care team tells you to stop.

Do not take this medication with grapefruit juice.

Talk to your care team about the use of this medication in children. While it may be prescribed for children as young as 2 years for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can unless it is more than 18 hours late. If it is more than 18 hours late, skip the missed dose. Take the next dose at the normal time.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

• Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
• If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, take the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

• Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• Bleeding—bloody or black, tar-like stools, vomiting blood or brown material that looks like coffee grounds, red or dark brown urine, small red or purple spots on skin, unusual bruising or bleeding
• Dry cough, shortness of breath or trouble breathing
• Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
• Increase in blood pressure
• Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
• Low thyroid levels (hypothyroidism)—unusual weakness or fatigue, increased sensitivity to cold, constipation, hair loss, dry skin, weight gain, feelings of depression
• Tumor lysis syndrome (TLS)—nausea, vomiting, diarrhea, decrease in the amount of urine, dark urine, unusual weakness or fatigue, confusion, muscle pain or cramps, fast or irregular heartbeat, joint pain

Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):

• Constipation
• Diarrhea
• Dry mouth
• Nausea
• Rash
• Swelling of the ankles, hands, or feet

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

• Bleeding disorder
• Having surgery or recent surgery
• High blood pressure
• Irregular heartbeat or rhythm
• Liver disease
• Lung disease
• An unusual or allergic reaction to selpercatinib, other medications, foods, dyes or preservatives
• Pregnant or trying to get pregnant
• Breast-feeding

What may interact with this medication?

Do not take this medication with any of the following:

• Cisapride
• Dronedarone
• Ketoconazole
• Levoketoconazole
• Pimozide
• Thioridazine

This medication may also interact with the following:

• Calcium channel blockers, such as diltiazem or verapamil
• Certain antivirals for HIV or hepatitis
• Certain medications for fungal infections like itraconazole, posaconazole
• Grapefruit juice
• Other medicines that cause heart rhythm changes
• Repaglinide
• Rifampin
• St. John's Wort
• Stomach acid blockers like cimetidine, famotidine, ranitidine, lansoprazole, omeprazole, pantoprazole

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

This medication may make you feel generally unwell. This is not uncommon as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your care team tells you to stop.

You may need bloodwork while you are taking this medication.

Before having surgery, talk to your care team to make sure it is ok. This medication can increase the risk of poor healing of your surgical site or wound. You will need to stop this medication at least 7 days before surgery. After surgery, wait at least 2 weeks before restarting this medication. Make sure the surgical site or wound is healed enough before restarting this medication. Talk to your care team if you have questions.

Talk to your care team if you wish to become pregnant or think you might be pregnant. This medication can cause serious birth defects if taken during pregnancy. A negative pregnancy test is required before starting this medication. A reliable form of contraception is recommended while taking this medication and for 1 week after stopping it. Do not breast-feed while taking this medication and for 1 week after stopping it.

Males who get this medication must use a condom during sex with females who can get pregnant. If you get a woman pregnant, there is potential for serious harm to an unborn child. You will need to continue wearing a condom for 1 week after stopping the medication. Tell your care team right away if you think your partner might be pregnant.

This medication may cause infertility. Talk to your care team if you are concerned about your fertility.

Your mouth may get dry. Chewing sugarless gum or sucking hard candy and drinking plenty of water may help. Contact your care team if the problem does not go away or is severe.

Check your blood pressure as directed. Know what your blood pressure should be and when to contact your care team.

Do not treat yourself for coughs, colds, or pain while you are using this medication without asking your care team for advice. Some medications may increase your blood pressure.

This medication may increase your risk to bruise or bleed. Call your care team if you notice any unusual bleeding.