Larotrectinib for the Treatment of NTRK Amplification Positive, Locally Advanced or Metastatic Solid Tumors

Inclusion Criteria: * At least 16 years of age * Locally-advanced or metastatic malignancy with an NTRK1, NTRK2, or NTRK3 gene amplification identified through molecular assays (such as IHC and any next-generation sequencing \[NGS\] platform, reference lab NGS, or in house NGS platform) as routinely performed at The University of Texas MD Anderson Cancer Center or other similarly-certified laboratories. The minimum level of amplification is 7 copies. This rationale of amplification level is based on data from MOCLIA at The University of Texas MD Anderson Cancer Center * Must have received prior standard therapy appropriate for tumor type and stage of disease, or, in the opinion of the investigator, is unlikely to tolerate or derive clinically meaningful benefit from appropriate standard of care therapy * Must have at least one measurable lesion as defined by RECIST v1.1. Subjects with primary CNS tumors should meet the following criteria: * Must have received prior treatment including radiation and/or chemotherapy, with radiation completed \> 12 weeks prior to cycle 1 day 1 (C1D1) of therapy, as recommended or appropriate for the tumor type * Must have \>= 1 site of bi-dimensionally measurable disease (confirmed by magnetic resonance imaging \[MRI\] and evaluable by RANO), with the size of at least one of the measurable lesions \>= 1 cm in each dimension * Must have imaging study within 28 days before enrollment. If on steroid therapy, the dose must be stable for at l…