Larotrectinib (1 brand name, 1 dosage form, 0 routes)
Available dosage forms: CAPSULE.
Brand Names
- LAROTRECTINIB
Indications and Usage
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. Select patients for therapy based on an FDA-approved test [see Dosage and Administration (2.1)].
Contraindications
None.
Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling: Central Nervous System Effects [see Warnings and Precautions (5.1)] Skeletal Fractures [see Warnings and Precautions (5.2)] Hepatotoxicity [see Warnings and Precautions (5.3)]
Mechanism of Action
Larotrectinib is an inhibitor of the tropomyosin receptor kinases (TRK), TRKA, TRKB, and TRKC. In a broad panel of purified enzyme assays, larotrectinib inhibited TRKA, TRKB, and TRKC with IC50 values between 5-11 nM. One other kinase TNK2 was inhibited at approximately 100-fold higher concentration. TRKA, B, and C are encoded by the genes NTRK1, NTRK2, and NTRK3. Chromosomal rearrangements involving in-frame fusions of these genes with various partners can result in constitutively-activated chimeric TRK fusion proteins that can act as an oncogenic driver, promoting cell proliferation and survival in tumor cell lines. In in vitro and in vivo tumor models, larotrectinib demonstrated anti-tumor activity in cells with constitutive activation of TRK proteins resulting from gene fusions, deletion of a protein regulatory domain, or in cells with TRK protein overexpression. Larotrectinib had minimal activity in cell lines with point mutations in the TRKA kinase domain, including the clinically identified acquired resistance mutation, G595R. Point mutations in the TRKC kinase domain with clinically identified acquired resistance to larotrectinib include G623R, G696A, and F617L.