Larotrectinib is primarily used in the treatment of cancers that are caused by specific genetic mutations, particularly those involving the NTRK gene fusion. It is effective in targeting and inhibiting the activity of TRK proteins, which are often overactive in these types of cancers. This medication is applicable across a wide range of tumor types, regardless of where the cancer originates in the body, making it a versatile option for patients with NTRK fusion-positive solid tumors. It is especially valuable in cases where traditional treatments have been ineffective, offering a targeted approach that can lead to significant tumor shrinkage and improved patient outcomes. Larotrectinib is administered orally, providing a convenient treatment option for patients.