What does TRK fusion-positive cancer mean?
TRK fusion-positive cancer occurs when there's a specific genetic abnormality in the TRK gene, which codes for a protein involved in cell growth and survival. This abnormality can lead to the development of various cancers, including non-small cell lung cancer, colorectal cancer, breast cancer, and others [1].
How does Vitrakvi work?
Vitrakvi (larotrectinib) is an oral medication that targets the TRK protein. It's a tyrosine kinase inhibitor, which means it blocks the activity of the TRK protein, thereby inhibiting cancer cell growth and proliferation [2]. Vitrakvi is designed to treat cancers that have a TRK fusion, such as the ones mentioned earlier.
Clinical trials and approvals
Vitrakvi has been evaluated in numerous clinical trials, including the Phase 1/2 and Phase 2 trials. These trials demonstrated promising results, with objective responses observed in patients with TRK fusion-positive cancer [3]. Based on these findings, Vitrakvi was granted accelerated approval by the FDA in 2018 for the treatment of adult and pediatric patients with TRK fusion-positive solid tumors [4].
How is Vitrakvi administered?
Vitrakvi is available as a tablet and should be taken orally once daily, with or without food. The recommended dose range is 100-200 mg once daily, and the maximum dosage is 200 mg once daily [5].
What side effects are associated with Vitrakvi?
Common side effects of Vitrakvi include dizziness, fatigue, nausea, and vomiting. Less common but more serious side effects may include increased liver enzymes, abnormal heartbeats, and anaphylaxis [6]. Patients with a history of QT prolongation may also be at risk of developing this condition while on Vitrakvi.
What's next for Vitrakvi?
Vitrakvi is currently being further evaluated in clinical trials for other types of cancer, including bladder cancer, endometrial cancer, and others. The long-term efficacy and safety of Vitrakvi are also being explored in ongoing trials.
Sources:
[1] National Cancer Institute. (2022). NCI Dictionary of Cancer Terms. TRK fusion-positive cancer.
[2] National Cancer Institute. (2022). NCI Dictionary of Cancer Terms. Tyrosine kinase inhibitor.
[3] Drilon, A. et al. (2018). Efficacy of Larotrectinib in TRK Fusion-Positive Sarcomas and Other Cancers. New England Journal of Medicine, 378(9), 731-739.
[4] FDA News Release. (2018). FDA approved Larotrectinib for the treatment of adult and pediatric patients with TRK fusion-positive solid tumors.
[5] Merck & Co., Inc. (2022). Vitrakvi Tablets.
[6] FDA Package Insert. (2022). Vitrakvi Tablets.