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Larotrectinib Dosage

Medically reviewed by Drugs.com. Last updated on Dec 29, 2020.

Applies to the following strengths: 25 mg; 100 mg; 20 mg/mL

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Solid Tumors

Body surface area least 1 m2:
100 mg 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 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

Renal Dose Adjustments

No adjustment recommended.

Liver Dose Adjustments

-Mild hepatic impairment (Child-Pugh A): No adjustment recommended.
-Moderate (Child-Pugh B) to severe (Child-Pugh C) hepatic impairment: Reduce the initial dose by 50%.

Dose Adjustments

Recommended Dose Modifications for Adverse Reactions:
FIRST DOSE REDUCTION:
-Adult and pediatric patients with body surface area (BSA) of at least 1 m2: Reduce dose to 75 mg orally 2 times a day.
-Pediatric patients with BSA less than 1 m2: Reduce dose to 75 mg/m2 orally 2 times a day.
SECOND DOSE REDUCTION:
-Adult and pediatric patients with BSA of at least 1 m2: Reduce dose to 50 mg orally 2 times a day.
-Pediatric patients with BSA less than 1 m2: Reduce dose to 50 mg/m2 orally 2 times a day.
THIRD DOSE REDUCTION:
-Adult and pediatric patients with BSA of at least 1 m2: Reduce dose to 100 mg orally once a day.
-Pediatric patients with BSA less than 1 m2: Reduce dose to 25 mg/m2 orally 2 times a day.

Permanently discontinue therapy in patients who are unable to tolerate this drug after 3 dose modifications.

Dose Modifications for Coadministration with Strong CYP450 3A4 Inhibitors:
-Avoid coadministration of strong CYP450 3A4 inhibitors with this drug
-If coadministration cannot be avoided, reduce the dose of this drug by 50%
-After the inhibitor has been discontinued for 3 to 5 elimination half-lives, resume the dose of this drug taken prior to initiating the CYP450 3A4 inhibitor.

Dose Modifications for Coadministration with Strong CYP450 3A4 Inducers:
-Avoid coadministration of strong CYP450 3A4 inducers with this drug.
-If coadministration cannot be avoided, double the dose of this drug.
-After the inducer has been discontinued for 3 to 5 elimination half-lives, resume the dose of this drug taken prior to initiating the CYP450 3A4 inducer.

Dosage Modifications for Adverse Reactions:
FOR GRADE 3 OR 4 ADVERSE REACTIONS:
-Withhold therapy until adverse reaction resolves or improves to baseline or Grade 1.
-Resume at the next dosage modification if resolution occurs within 4 weeks.
-Permanently discontinue therapy if an adverse reaction does not resolve within 4 weeks.

Precautions

CONTRAINDICATIONS:
-None

Safety and efficacy have not been established in patients less than 28 days old.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:
-This drug may be taken with or without food.
-The capsule or oral solution may be used interchangeably.
-Do not make up a missed dose within 6 hours of the next scheduled dose.
-If vomiting occurs after taking a dose, take the next dose at the scheduled time.
-Swallow capsules whole with water. Do not chew or crush.
-Discard any unused oral solution remaining after 90 days of first opening the bottle.
-Prior to preparing an oral dose for administration, refer to the instructions for use.

Storage requirements:
-Store capsules at room temperature 20C to 25C (68F to 77F); temperature excursions between 15C and 30C (59F to 86F) are permitted.
-Store the oral solution in the refrigerator at 2C to 8C (36F to 46F); do not freeze.

Monitoring:
-Liver function tests.

Patient advice:
-Read the approved patient labeling.
-Notify your healthcare provider if you experience new or worsening
neurotoxicity.
-Do not drive or operate hazardous machinery if you are experiencing neurologic adverse reactions.
-This drug can harm a developing fetus.
-Males and females of reproductive potential should use effective contraception during therapy with this drug and for at least 1 week after.
-Inform your healthcare provider of a known or suspected pregnancy.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Frequently Asked Questions