Larotrectinib

Larotrectinib is used to treat certain tumors caused by an abnormal "NTRK" gene. Larotrectinib is used when the cancer has spread to other parts of the body or cannot be removed with surgery or other cancer treatments.

Larotrectinib is sometimes given after other cancer treatments did not work or have stopped working.

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

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

Your doctor will perform a test to make sure larotrectinib is the right treatment for your type of tumor.

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.

Take this medicine with a full glass of water.

You may take larotrectinib with or without food.

Swallow the capsule whole and do not crush, chew, break, or open it.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

You will need frequent medical tests to check your liver function.

Your doctor will determine how long to treat you with larotrectinib.

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

Store the capsules at room temperature, away from moisture and heat.

Store the liquid medicine in the refrigerator, do not freeze. Throw away any unused liquid after 90 days.

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.

Tell your doctor if you have ever had:

• liver disease; or
• nerve problems.

You may need to have a negative pregnancy test before starting this treatment.

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

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

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

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Larotrectinib may cause serious side effects. Call your doctor right away if you have:

• severe or ongoing stomach pain, vomiting, or diarrhea;
• confusion, memory problems, severe dizziness;
• problems with speech or coordination;
• numbness, tingling, or burning pain in your hands or feet;
• fever, flu symptoms, sore throat, cough;
• sores or ulcers in your mouth or on your skin;
• unusual tiredness, feeling light-headed or short of breath;
• pale skin, cold hands and feet;
• pain, warmth, redness, or swelling under your skin; or
• liver problems—loss of appetite, stomach pain (upper right side), nausea, vomiting, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

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

Common side effects of larotrectinib may include:

• nausea, vomiting, diarrhea, constipation;
• cough;
• dizziness;
• tiredness; or
• abnormal liver function tests.

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

Usual Adult Dose for Solid Tumors:

Body surface area least 1 m2:100 mg orally 2 times a day until disease progression or unacceptable toxicityComments:-Select patients for treatment with this drug based on the presence of a NTRK gene fusion in tumor specimens. Use: For the treatment of adult patients with solid tumors that:-Have a neurotrophic receptor tyrosine kinase (NTRK) gene fusion without a known acquired resistance mutation-Are metastatic or where surgical resection is likely to result in severe morbidity -Have no satisfactory alternative treatments or that have progressed following treatment

Usual Pediatric Dose for Solid Tumors:

28 days and older:-Body surface area at least 1 m2: 100 mg orally 2 times a day until disease progression or unacceptable toxicity-Body surface area less than 1 m2: 100 mg/m2 orally 2 times a day until disease progression or unacceptable toxicity.Comments:-Select patients for treatment with this drug based on the presence of a NTRK gene fusion in tumor specimens. Use: For the treatment of pediatric patients with solid tumors that:-Have a neurotrophic receptor tyrosine kinase (NTRK) gene fusion without a known acquired resistance mutation-Are metastatic or where surgical resection is likely to result in severe morbidity-Have no satisfactory alternative treatments or that have progressed following treatment

Use 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 use two doses at one time.

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

Avoid driving or doing dangerous activities until you know how larotrectinib will affect you. Your reactions could be impaired.

Grapefruit may interact with larotrectinib and lead to unwanted side effects. Avoid the use of grapefruit products.

Avoid taking an herbal supplement that contains St. John's wort.

Sometimes it is not safe to use certain medications together. Some drugs can change the levels of other drugs in your blood, which may increase side effects or make the medications less effective.

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