Retevmo is a prescription medicine that is used to treat certain cancers caused by abnormal RET genes.

Retevmo is used in adults with locally advanced non-small cell lung cancer (NSCLC) or NSCLC that has spread.

Retevmo is used in adults and children 12 years of age and older with advanced medullary thyroid cancer (MTC) or MTC that has spread, who require a medicine by mouth or injection (systemic therapy).

Retevmo is used in adults and children 12 years of age and older with advanced thyroid cancer or thyroid cancer that has spread who require a medicine by mouth or injection (systemic therapy), and who have received radioactive iodine and it did not work or is no longer working.

Retevmo is also used in adults with locally advanced solid tumors (cancers) or solid tumors that have spread, and have gotten worse (progressed) on or after other treatment or there are no satisfactory treatment options.

Your healthcare provider will perform a test to make sure that Retevmo is right for you.

It is not known if Retevmo is safe and effective when used:

• in children younger than 12 years of age for the treatment of MTC who require systemic therapy, and advanced thyroid cancer who require systemic therapy and who have received radioactive iodine and it did not work or is no longer working, or
• in children for the treatment of any other cancers.

• Take Retevmo exactly as your healthcare provider tells you.
• Your healthcare provider may stop treatment or change your dose if you have side effects. Do not change your dose or stop treatment unless your healthcare provider tells you.
• Retevmo is taken by mouth, usually 2 times a day (about 12 hours apart) with or without food.
• If you take a proton-pump inhibitor (PPIs such as dexlansoprazole, esomeprazole, lansoprazole, omeprazole, pantoprazole sodium, and rabeprazole), take Retevmo with food.
• If you take an antacid that contains aluminum, magnesium, calcium, simethicone, or buffered medicines, take Retevmo 2 hours before or 2 hours after taking the antacid.
• If you take an H2 blocker (such as famotidine, nizatidine, and cimetidine), take Retevmo 2 hours before or 10 hours after taking the H2 blocker.
• Swallow Retevmo capsules whole. Do not chew or crush the capsules.
• If you vomit after taking a dose, do not take an extra dose. Take the next dose at your scheduled time.
• Do not take a missed dose unless it is more than 6 hours until your next scheduled dose.
• If you take too much Retevmo, call your healthcare provider or go to the nearest hospital emergency room right away.

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)

Usual Adult Dose for Solid Tumors:

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 advanced or metastatic RET-mutant solid tumors who have progressed on or following prior systemic treatment or who have no satisfactory alternative treatment options.
This indication is approved under accelerated approval based on overall response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s). 

Before you start treatment, tell your healthcare provider about all your medical conditions, including if you:

• have liver problems
• have high blood pressure
• have heart problems including a condition called QT prolongation
• have bleeding problems
• plan to have surgery. You should stop taking Retevmo at least 7 days before your planned surgery. See Retevmo side effects.
• are pregnant or plan to become pregnant. Retevmo can harm your unborn baby. You should not become pregnant during treatment.
  • If you are able to become pregnant, your healthcare provider will do a pregnancy test before you start treatment.
  • Females who are able to become pregnant should use effective birth control (contraception) during treatment and for at least 1 week after the final dose. Talk to your healthcare provider about birth control methods that may be right for you.
  • Tell your healthcare provider right away if you become pregnant or think you might be pregnant during treatment.
  • Males with female partners who are able to become pregnant should use effective birth control during treatment, and for at least 1 week after the final dose.
• are breastfeeding or plan to breastfeed. It is not known if Retevmo passes into your breast milk. Do not breastfeed during treatment, and for 1 week after the last dose.

Retevmo may cause serious side effects, including:

• Liver problems. Liver problems (increased liver enzymes) are common with Retevmo and may sometimes be serious. Your healthcare provider will do blood tests before and during treatment to check for liver problems. Tell your healthcare provider right away if you get any of the following symptoms of liver problems during treatment:
  • yellowing of your skin or the white part of your eyes (jaundice)
  • dark "tea-colored" urine
  • sleepiness
  • bleeding or bruising
  • loss of appetite
  • nausea or vomiting
  • pain on the upper right side of your stomach area
• Lung problems. Retevmo may cause severe or life-threatening inflammation of the lungs during treatment, that can lead to death. Tell your healthcare provider right away if you have any new or worsening lung symptoms, including:
  • shortness of breath
  • cough
  • fever
• High blood pressure (hypertension). High blood pressure is common with Retevmo and may sometimes be serious. You should check your blood pressure regularly during treatment. Tell your healthcare provider if you get any of the following symptoms:
  • confusion
  • headaches
  • shortness of breath
  • dizziness
  • chest pain
• Heart rhythm changes (QT prolongation) can occur and may be serious. Retevmo may cause very slow, very fast or irregular heartbeats. Tell your healthcare provider right away if you get any of the following symptoms:
  • loss of consciousness
  • fainting
  • dizziness
  • a change in the way your heart beats (heart palpitations)
• Bleeding problems. Retevmo can cause bleeding which can be serious and may lead to death. Tell your healthcare provider if you have any signs of bleeding during treatment, including:
  • vomiting blood or if your vomit looks like coffee-grounds
  • pink or brown urine
  • red or black (looks like tar) stools
  • coughing up blood or blood clots
  • unusual bleeding or bruising of your skin
  • menstrual bleeding that is heavier than normal
  • unusual vaginal bleeding
  • nose bleeds that happen often
  • drowsiness or difficulty being awakened
  • confusion
  • headache
  • change in speech
• Allergic reactions. Retevmo can cause a fever, rash, muscle or joint pain, especially in the first month of treatment. Tell your healthcare provider if you get any of these symptoms.
• Tumor lysis syndrome (TLS). TLS is caused by a fast breakdown of cancer cells. TLS can cause kidney failure, the need for dialysis treatment, and an abnormal heartbeat. TLS can lead to hospitalization. Your healthcare provider may do blood tests to check you for TLS. You should stay well hydrated during treatment with Retevmo. Call your healthcare provider or get emergency medical help right away if you develop any of these symptoms during treatment with Retevmo:
  • nausea
  • shortness of breath
  • vomiting
  • muscle cramps
  • weakness
  • seizures
  • swelling
• Risk of wound healing problems. Wounds may not heal properly during treatment with Retevmo. Tell your healthcare provider if you plan to have any surgery before or during treatment with Retevmo.
  • You should stop taking Retevmo at least 7 days before planned surgery.
  • Your healthcare provider should tell you when you may start taking Retevmo again after surgery.

The most common side effects include:

• swelling of your arms, legs, hands, and feet (edema)
• diarrhea
• tiredness
• dry mouth
• high blood pressure
• stomach-area (abdominal) pain
• constipation
• rash
• nausea
• headache

The most common severe abnormal laboratory test results with Retevmo include decreased white blood cell count, decreased levels of sodium in the blood, and decreased levels of calcium in the blood.

Retevmo may affect fertility in females and males, which may affect your ability to have children. Talk to your healthcare provider if this is a concern for you.

These are not all the possible side effects.

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

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Certain other medicines may affect how Retevmo works.

You should avoid taking the following medicines during treatment with Retevmo:

• St. John’s wort
• proton pump inhibitors (PPIs such as dexlansoprazole, esomeprazole, lansoprazole, omeprazole, pantoprazole sodium, rabeprazole)
• H2 blockers (such as famotidine, nizatidine, and cimetidine), and
• antacids that contain aluminum, magnesium, calcium, simethicone, or buffered medicines.

If you cannot avoid taking PPIs, H2 blockers, or antacids, see How should I take Retevmo? for more information on how to take Retevmo with these medicines.

Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.