Sébastien Perreault, MD, FRCPC, Centre Hospitalier Universitaire Sainte-Justine, Montreal, Canada, outlines efficacy and safety data of larotrectinib, a first-in-class, highly selective TRK inhibitor in adult and pediatric patients with tropomyosin receptor kinase (TRK) fusion-positive primary central nervous system (CNS) tumors. In patients with TRK fusion-positive CNS tumors, larotrectinib demonstrated rapid and durable responses, high disease control rate, and a favorable safety profile. This interview took place at the American Society of Clinical Oncology (ASCO) 2021 Virtual Meeting.