LuciLaro (Larotrectinib): Uses, Dosing, and Practical Guidance for NTRK Fusion–Positive Cancers

Uses of LuciLaro

LuciLaro is used to treat solid tumors of any origin that have a confirmed NTRK gene fusion. This means the location of the cancer does not matter—what matters is the presence of this specific genetic change.

Cancers that may be treated with LuciLaro include:

• Lung cancer
• Thyroid cancer
• Colon or colorectal cancer
• Breast cancer
• Salivary gland cancer
• Soft tissue sarcoma
• Brain tumors
• Pediatric cancers

The main purpose of LuciLaro is to target the genetic driver of the cancer. By blocking the abnormal signal caused by an NTRK gene fusion, LuciLaro can slow or stop tumor growth regardless of where the cancer began.

Tablet Details

• Drug Name: LuciLaro
• Active Ingredient: Larotrectinib
• Strength: 100 mg
• Dosage Form: Hard gelatin capsule
• Appearance: White capsule, debossed with “Lucius” on one side
• Packaging: Bottle of 30 capsules

Dosage and Administration

Adults

• 100 mg taken orally twice daily, about 12 hours apart

Pediatric Patients

• 100 mg/m² taken orally twice daily
• Maximum dose: 100 mg twice daily
• Dose is calculated based on body surface area (BSA)

Treatment is continued until the disease progresses or side effects become unacceptable.

Dose Adjustments

Hepatic (Liver) Impairment

• In moderate to severe liver impairment, reduce the dose by 50%
• Liver function tests should be done before starting treatment and monitored regularly

Adverse Reactions Requiring Adjustment
Dose interruption, reduction, or discontinuation may be necessary if patients develop:

• Elevated liver enzymes
• Severe neurological side effects
• Other significant toxicities

How to Take Larotrectinib Capsules

• Take by mouth, with or without food
• Available as:
  • Capsules (for adults and older children)
  • Oral solution (for children or patients who cannot swallow capsules)
• Take doses approximately 12 hours apart

If a Dose Is Missed

• Take it as soon as remembered unless it is close to the next dose
• Do not take two doses at the same time

If Vomiting Occurs After a Dose

• Do not take an extra dose
• Continue with the next scheduled dose

Daily Tips to Maximize LuciLaro Effectiveness

1. Take it consistently
   Take your capsule at the same times each day to maintain steady drug levels.
2. Be consistent with food
   You may take it with or without food—just try to do it the same way every day.
3. Listen to your body
   Symptoms like fatigue, nausea, or dizziness should be noted and shared with your doctor.
4. Stay hydrated and well nourished
   Drink enough fluids and eat balanced meals; smaller, frequent meals may help with nausea.
5. Avoid grapefruit
   Grapefruit and grapefruit juice can interfere with how the medicine works.
6. Keep up with tests and visits
   Regular blood tests and checkups help catch problems early.
7. Care for your overall well-being
   Gentle activity, rest, and stress management can improve how you feel during treatment.

Adverse Effects (Side Effects)

Most side effects are mild to moderate and manageable with monitoring.

Common Side Effects

• Fatigue
• Dizziness
• Nausea or vomiting
• Constipation or diarrhea
• Anemia
• Weight gain
• Increased liver enzymes (ALT, AST)

Neurologic Effects (Important to Monitor)

• Dizziness
• Balance problems
• Confusion (less common)

Serious but Less Common Effects

• Liver injury (hepatotoxicity)
• Severe neurological symptoms
• Severe anemia or neutropenia (rare)

Liver function tests are usually monitored before and during treatment.

Contraindications and Precautions

• No absolute contraindications are listed
• Use caution in patients with:
  • Significant liver disease
  • Severe neurological symptoms

Dose reduction or interruption may be required if serious toxicity occurs.

Use in Specific Populations

Pediatric Patients

• Approved for both children and adults
• Shown to be effective even in very young children
• Dose based on weight or body surface area

Elderly Patients

• No routine dose adjustment required
• Close monitoring for neurological side effects is recommended

Hepatic Impairment

• Dose reduction required in moderate to severe impairment
• Close liver monitoring is essential

Renal Impairment

• No dose adjustment usually needed for mild to moderate impairment
• Limited data in severe kidney disease

Pregnancy

• Not recommended
• May cause harm to the fetus
• Effective contraception is advised during treatment

Breastfeeding

• Breastfeeding should be avoided during treatment and for at least one week after the last dose