The safety of VITRAKVI was evaluated in 176 patients, irrespective of NTRK* gene fusion status, in 1 of 3 clinical trials.1

Adverse Reactions Occurring in 10% of Patients Treated With VITRAKVI1

*NTRK, neurotrophic receptor tyrosine kinase. aNational Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) v4.03. bOne Grade 4 adverse reaction of pyrexia.


Laboratory Abnormalities Occurring in 5% of Patients Treated With VITRAKVI

aDenominator for each laboratory parameter is based on number of patients with a baseline and post-treatment laboratory value available, which ranged from 170 to 174 patients. bNCI-CTCAE v4.03.

Incidence of treatment-related discontinuations1

  • Permanent discontinuation of VITRAKVI for an AE* occurred in 13% of patients
    • The most common adverse reactions (1%-2% each) resulting in discontinuation were brain edema, intestinal perforation, pericardial effusion, pleural effusion, small intestinal obstruction, dehydration, fatigue, increased ALT, increased AST, enterocutaneous fistula, increased amylase, increased lipase, muscular weakness, abdominal pain, asthenia, decreased appetite, dyspnea, hyponatremia, jaundice, syncope, vomiting, acute myeloid leukemia, and nausea
  • Adverse reactions leading to dose interruption or reduction occurred in 37% of patients
    • The most common adverse reactions (≥3%) resulting in dose modification (interruption or reduction) were increased ALT (6%), increased AST (6%), and dizziness (3%)
    • Most (82%) adverse reactions leading to dose modification occurred during the first 3 months of exposure
*AE, adverse event; ALT, alanine transaminase; AST, aspartate transaminase.
See the Interactive PI


VITRAKVI is indicated for the treatment of adult and 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, and
  • have no satisfactory alternative treatments or that have progressed following treatment.

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 trials.

Important Safety Information

Neurotoxicity: Among the 176 patients who received VITRAKVI, neurologic adverse reactions of any grade occurred in 53% of patients, including Grade 3 and Grade 4 neurologic adverse reactions in 6% and 0.6% of patients, respectively. The majority (65%) of neurological adverse reactions occurred within the first three months of treatment (range 1 day to 2.2 years). Grade 3 neurologic adverse reactions included delirium (2%), dysarthria (1%), dizziness (1%), gait disturbance (1%), and paresthesia (1%). Grade 4 encephalopathy (0.6%) occurred in a single patient. Neurologic adverse reactions leading to dose modification included dizziness (3%), gait disturbance (1%), delirium (1%), memory impairment (1%), and tremor (1%).

Advise patients and caretakers of these risks with VITRAKVI. Advise patients not to drive or operate hazardous machinery if they are experiencing neurologic adverse reactions. Withhold or permanently discontinue VITRAKVI based on the severity. If withheld, modify the VITRAKVI dose when resumed.

Hepatotoxicity: Among the 176 patients who received VITRAKVI, increased transaminases of any grade occurred in 45%, including Grade 3 increased AST or ALT in 6% of patients. One patient (0.6%) experienced Grade 4 increased ALT. The median time to onset of increased AST was 2 months (range: 1 month to 2.6 years). The median time to onset of increased ALT was 2 months (range: 1 month to 1.1 years). Increased AST and ALT leading to dose modifications occurred in 4% and 6% of patients, respectively. Increased AST or ALT led to permanent discontinuation in 2% of patients.

Monitor liver tests, including ALT and AST, every 2 weeks during the first month of treatment, then monthly thereafter, and as clinically indicated. Withhold or permanently discontinue VITRAKVI based on the severity. If withheld, modify the VITRAKVI dosage when resumed.

Embryo-Fetal Toxicity: VITRAKVI can cause fetal harm when administered to a pregnant woman. Larotrectinib resulted in malformations in rats and rabbits at maternal exposures that were approximately 11- and 0.7-times, respectively, those observed at the clinical dose of 100 mg twice daily.

Advise women of the potential risk to a fetus. Advise females of reproductive potential to use an effective method of contraception during treatment and for 1 week after the final dose of VITRAKVI.

Most Common Adverse Reactions (≥20%): The most common adverse reactions (≥20%) were: increased ALT (45%), increased AST (45%), anemia (42%), fatigue (37%), nausea (29%), dizziness (28%), cough (26%), vomiting (26%), constipation (23%), and diarrhea (22%).

Drug Interactions: Avoid coadministration of VITRAKVI with strong CYP3A4 inhibitors (including grapefruit or grapefruit juice), strong CYP3A4 inducers (including St. John’s wort), or sensitive CYP3A4 substrates. If coadministration of strong CYP3A4 inhibitors or inducers cannot be avoided, modify the VITRAKVI dose as recommended. If coadministration of sensitive CYP3A4 substrates cannot be avoided, monitor patients for increased adverse reactions of these drugs.

Lactation: Advise women not to breastfeed during treatment with VITRAKVI and for 1 week after the final dose.

For important risk and use information about VITRAKVI, please see the full Prescribing Information.

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  • 1. VITRAKVI [package insert]. Stamford, CT: Loxo Oncology, Inc.; November 2018.