A Study to Test the Safety of the Investigational Drug Selitrectinib in Children and Adults That May Treat Cancer

Inclusion Criteria

• •Advanced solid tumor for which, in the opinion of the investigator, no other standard therapy offers greater benefit.
• •A solid tumor diagnosis in the setting of:
• •* a) a documented NTRK fusion and a clinical history of relapse following a response to a prior TRK inhibitor
• •* b) a documented NTRK fusion unresponsive to a prior TRK inhibitor
• •* c) a documented NTRK fusion and a clinical history of intolerance to a prior TRK inhibitor
• •NTRK gene fusions will be identified in a CLIA-certified (or equivalently-accredited diagnostic) laboratory. If such a report cannot be provided, other available certifications/accreditations are required and need to be documented. Patients with infantile fibrosarcoma (IFS) or congenital mesoblastic nephroma (CMN) may be enrolled based on an ETV6+ FISH test without identifying NTRK3.
• •Performance Status: Eastern Cooperative Oncology Group (ECOG) score ≤ 2 in adults or Karnofsky Performance Status (KPS) Score≥50% (age ≥ 16 years) or Lansky Performance Score (LPS) ≥ 40% (age \< 16 years).
• •Life expectancy of at least 3 months.
• •Adequate hematologic, hepatic and renal function.
• •Ability to receive study drug orally or by enteral administration