Vitrakvi (larotrectinib)
An approved treatment for NTRK Fusion Cancer.
The same compound appears under different names depending on the context. Here is how to identify Larotrectinib wherever you encounter it, plus the key facts at a glance.
- Generic name
- Larotrectinib
- Brand name
- Vitrakvi
- Development codes
- LOXO-101, ARRY-470, BAY 2757556
- Drug class
- TRK inhibitor (first generation)
- Manufacturer
- Bayer
- How it's taken
- Taken by mouth twice a day, with or without food, until the cancer grows or side effects become unacceptable.
An oral TRK inhibitor approved for adults and children of any age whose solid tumor carries an NTRK gene fusion, regardless of where the cancer started. It received accelerated approval in November 2018 and full approval on April 9, 2025, based on a 60% response rate in 339 patients.
Where Larotrectinib fits
One of 3 FDA-approved TRK inhibitors and the only one approved solely for NTRK fusion cancer. It is the only one with an oral solution and no lower age limit, which makes it the usual choice for infants with infantile fibrosarcoma. Rozlytrek (entrectinib) is the alternative first-line option with stronger brain penetration data, and Augtyro (repotrectinib) is the option after a tumor becomes resistant to either.
How Larotrectinib works
In NTRK fusion cancer, a piece of an NTRK gene has joined another gene, and the result is a TRK protein that is switched on all the time and tells the cell to keep dividing. Larotrectinib fits into the part of the TRK protein that would normally use energy to send that signal and blocks it. Because it was built to hit only TRK, it has little effect on other similar proteins, which is why the side effects are mostly mild. The drug does not depend on the tumor type: the same fusion in a salivary gland tumor, a lung cancer or an infant's sarcoma responds in the same way.
Mechanism: Highly selective inhibitor of the 3 TRK proteins (TRKA, TRKB, TRKC) produced by NTRK1, NTRK2 and NTRK3 gene fusions
Side effects and safety
- Nervous system effects. Dizziness (22%), cognitive changes (11%) and mood changes (14%) at any grade; do not drive or operate machinery if affected.
- Bone fractures. Fractures occurred in 7% of patients, including children; report new bone pain or limited movement.
- Liver injury. Liver enzyme rises are common and serious drug-induced liver injury has occurred; dosing is paused or lowered for high readings.
- Harm to a fetus. Can harm an unborn baby; use contraception during treatment and for 1 week after the last dose.
- Liver tests (ALT, AST, bilirubin) before starting, every 2 weeks for 2 months, then monthly
- Pregnancy test before starting for people who can become pregnant
The most common side effects in the label (444 patients) were lab changes rather than symptoms: raised liver enzymes AST in 62% and ALT in 61%, and anemia in 45%. The most common symptoms were musculoskeletal pain (41%), fatigue (31%), vomiting (30%), cough, constipation, diarrhea and dizziness. Nervous system effects such as dizziness, confusion and mood changes occurred in 40% of patients at any grade. Bone fractures occurred in 7%. Serious liver injury has been reported, so liver tests are checked every 2 weeks for the first 2 months and then monthly. There is no boxed warning.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Larotrectinib
Taken by mouth twice a day, with or without food, until the cancer grows or side effects become unacceptable. Adults and children with a body surface area of at least 1 square meter take 100 mg twice daily; smaller children take 100 mg per square meter twice daily. It comes as 25 mg and 100 mg capsules and as a 20 mg/mL oral solution, which is how infants and young children are dosed. Strong CYP3A4 inhibitors or inducers (certain antifungals, antibiotics and seizure drugs) change the dose or should be avoided.
Availability and cost
Only available as the brand-name product.
A targeted oral cancer drug for a rare biomarker, priced at specialty oncology levels. Bayer's copay program covers commercially insured patients, and the Bayer US Patient Assistance Foundation covers free drug for eligible uninsured patients; government-insured patients are referred to independent charities.
Help paying for Vitrakvi
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
Vitrakvi $0 Co-Pay Program: eligible commercially insured patients may pay as little as $0 per month up to a program maximum. Not for patients with any government insurance or enrolled in the Bayer foundation.
For: private insurance · source - Free medicine program
Bayer US Patient Assistance Foundation supplies Bayer medicines at no cost to eligible US residents without insurance or whose plan does not cover the drug, with household income up to 300% of the federal poverty level. Call 1-866-228-7723.
For: no insurance, underinsured · source - Insurance and case manager help
Access Services by Bayer at 1-800-288-8374 checks benefits, activates the co-pay card and refers patients to the foundation; specialty pharmacies Accredo and CVS Specialty run nurse and pharmacist lines.
For: private insurance, Medicare, Medicaid, no insurance, underinsured · source
Good to know: The co-pay program site (vitrakvicopaysupport.com) states a $25,000 per year cap but its footer is dated 2021; the current patient site says only 'program maximum'. Government-insured patients are referred to independent charities.
Access and eligibility
Approved for solid tumors with an NTRK gene fusion confirmed by an FDA-approved test, without a known acquired resistance mutation, that are metastatic or where surgery would cause severe harm, and that have no satisfactory alternative or have progressed after treatment. NTRK point mutations or amplification without a fusion are not covered by the approval.
Source: Vitrakvi patient support, Bayer
Access program details are provided for informational purposes and may vary based on insurance coverage, geographic location, and individual circumstances. Confirm current eligibility directly with the manufacturer or your specialty pharmacy.
Clinical trial results
Approval rests on 3 pooled single-arm studies, LOXO-TRK-14001 (NCT02122913), SCOUT in children (NCT02637687) and NAVIGATE (NCT02576431). In the label's pooled analysis of 339 patients with NTRK fusion solid tumors, 60% responded, 24% completely, and the median response lasted 43.3 months, with 64% of responses still ongoing at 12 months[1]. Response rates by tumor type ranged from 94% in infantile fibrosarcoma (49 patients) and 84% in salivary gland cancer (25) to 27% in primary brain tumors (49). By gene, responses were 59% for NTRK1, 32% for NTRK2 and 67% for NTRK3 fusions. The first published analysis, 55 patients in the New England Journal of Medicine in 2018, reported a 75% response rate across 17 tumor types, which is the figure still widely quoted[5]. Larotrectinib is still being studied in NTRK-amplified tumors (NCT04879121), as a preparation for radioactive iodine in NTRK fusion thyroid cancer (LANTERN, NCT05783323) and in newly diagnosed pediatric high-grade glioma (NCT04655404).
Development history
Larotrectinib was discovered by Array BioPharma and developed by Loxo Oncology as LOXO-101. The FDA granted accelerated approval on November 26, 2018, which the agency described as the second tissue-agnostic cancer approval after pembrolizumab for MSI-high tumors in 2017 and the first for a targeted kinase inhibitor[2]. Eli Lilly acquired Loxo in February 2019, and Bayer, which had partnered on the drug in 2017, took exclusive global rights. On April 9, 2025 the FDA converted the accelerated approval to a traditional approval based on the 339-patient analysis, so Vitrakvi no longer carries the condition that further trials must confirm its benefit[3][4].
Explore NTRK Fusion Cancer trials
Other NTRK Fusion Cancer treatments
Common questions about Larotrectinib
▸What is Larotrectinib (Vitrakvi)?
An oral TRK inhibitor approved for adults and children of any age whose solid tumor carries an NTRK gene fusion, regardless of where the cancer started. It received accelerated approval in November 2018 and full approval on April 9, 2025, based on a 60% response rate in 339 patients.
▸How does Larotrectinib work?
In NTRK fusion cancer, a piece of an NTRK gene has joined another gene, and the result is a TRK protein that is switched on all the time and tells the cell to keep dividing. Larotrectinib fits into the part of the TRK protein that would normally use energy to send that signal and blocks it. Because it was built to hit only TRK, it has little effect on other similar proteins, which is why the side effects are mostly mild. The drug does not depend on the tumor type: the same fusion in a salivary gland tumor, a lung cancer or an infant's sarcoma responds in the same way.
▸What are the side effects of Larotrectinib?
The most common side effects in the label (444 patients) were lab changes rather than symptoms: raised liver enzymes AST in 62% and ALT in 61%, and anemia in 45%. The most common symptoms were musculoskeletal pain (41%), fatigue (31%), vomiting (30%), cough, constipation, diarrhea and dizziness. Nervous system effects such as dizziness, confusion and mood changes occurred in 40% of patients at any grade. Bone fractures occurred in 7%. Serious liver injury has been reported, so liver tests are checked every 2 weeks for the first 2 months and then monthly. There is no boxed warning.
▸How is Larotrectinib taken?
Taken by mouth twice a day, with or without food, until the cancer grows or side effects become unacceptable. Adults and children with a body surface area of at least 1 square meter take 100 mg twice daily; smaller children take 100 mg per square meter twice daily. It comes as 25 mg and 100 mg capsules and as a 20 mg/mL oral solution, which is how infants and young children are dosed. Strong CYP3A4 inhibitors or inducers (certain antifungals, antibiotics and seizure drugs) change the dose or should be avoided.
▸Is Larotrectinib FDA approved?
Yes, Larotrectinib (Vitrakvi) is FDA approved (2018) for the treatment of NTRK Fusion Cancer.
▸What is the response rate for Vitrakvi in NTRK fusion cancer?
In the FDA label's pooled analysis of 339 patients, 60% of tumors shrank enough to count as a response and 24% disappeared completely. The median response lasted 43.3 months. Rates were highest in infantile fibrosarcoma (94%) and salivary gland cancer (84%) and lowest in primary brain tumors (27%).
▸Can children take Vitrakvi?
Yes. The approval covers adults and children with no lower age limit, and the efficacy set included patients from 18 days old. Children with a body surface area under 1 square meter take 100 mg per square meter twice daily, usually as the 20 mg/mL oral solution.
▸Is Vitrakvi fully approved or still under accelerated approval?
Fully approved. The FDA granted accelerated approval on November 26, 2018 and converted it to traditional approval on April 9, 2025, so there is no longer a requirement for a confirmatory trial.
▸Does Vitrakvi work on brain metastases?
The label reports a 27% response rate in primary brain tumors, lower than in other sites. Rozlytrek (entrectinib) and Augtyro (repotrectinib) were designed to cross into the brain and report higher intracranial response rates, so doctors often weigh those for patients with brain involvement.
▸What happens if my cancer stops responding to Vitrakvi?
Most acquired resistance comes from new mutations in the NTRK gene itself, such as solvent-front mutations. Augtyro (repotrectinib) is approved for patients 12 and older whose tumors have progressed on a prior TRK inhibitor and showed a 50% response rate in that group, including 60% in people with solvent-front mutations.
▸Which side effects of Vitrakvi should I watch for?
Dizziness, confusion or mood changes, which affected 40% of patients at any grade; new bone pain, since fractures occurred in 7%; and signs of liver trouble such as yellowing of the skin or dark urine. Liver blood tests are checked every 2 weeks for the first 2 months.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. National Library of Medicine, DailyMed · 2026-05-22. Vitrakvi (larotrectinib) capsules and oral solution: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0c8ca614-58b2-4aa4-83d3-0387a8f782fd
- U.S. Food and Drug Administration · 2018-11-26. FDA approves larotrectinib for solid tumors with NTRK gene fusions. https://www.fda.gov/drugs/fda-approves-larotrectinib-solid-tumors-ntrk-gene-fusions-0
- U.S. Food and Drug Administration. Cancer Accelerated Approvals: Other. https://www.fda.gov/drugs/resources-information-approved-drugs/other-cancer-accelerated-approvals
- Bayer via Business Wire · 2025-04-09. U.S. FDA grants full approval of Vitrakvi (larotrectinib) for adult and pediatric patients with NTRK gene fusion-positive solid tumors. https://www.businesswire.com/news/home/20250409395229/en/U.S.-FDA-Grants-Full-Approval-of-VITRAKVI-larotrectinib-for-Adult-and-Pediatric-Patients-with-NTRK-Gene-Fusion-Positive-Solid-Tumors
- New England Journal of Medicine · 2018-02-22. Efficacy of larotrectinib in TRK fusion-positive cancers in adults and children. https://www.nejm.org/doi/full/10.1056/NEJMoa1714448