Larotrectinib – A Novel Age and Tumor Agnostic Therapy for TRK Fusion-Positive Cancers

Tumor genomic profiling enables the identification of specific genomic alterations and thereby can provide personalized treatment options with targeted therapies that are specific for those molecular targets. Next-Generation Sequencing (NGS) platforms or second-generation sequencing perform massively parallel sequencing, which allows sequencing of millions of fragments of DNA from a single sample. Recently reported genomic profiling studies performed in patients with advanced cancer suggest that actionable mutations are found in 20-40% of patients’ tumors.
Larotrectinib is a potent and highly selective small molecule inhibitor of three TRK proteins, Tropomyosin Receptor Kinase genes NTRK1, NTRK2, and NTRK3. In a phase I-II study involving children, adolescents and adults with 17 unique cancer diagnoses, the Overall Response Rate was 75% and at 1 year, 71% of the responses were ongoing and 55% of the patients remained progression-free. It was concluded from this study that TRK fusions defined a unique molecular subgroup of advanced solid tumors in children and adults and Larotrectinib had marked and durable antitumor activity in patients with TRK fusion-positive cancer, regardless of the age of the patient or tumor type.