This study involves taking a study drug called BA3011. The overall goal of this study is to see if BA3011 is a possible treatment for patients with sarcoma.

This study involves taking a study drug called Lutathera. The overall goal of this study is to see if Lutathera is safe in adolescent subjects with either a gastroenteropancreatic neuroendocrine tumor (GEP-NET), or a pheochromocytoma and/or paraganglioma (PPGL). This study will also look at the levels of radioactivity after Lutathera administration.

The purpose of this study is to evaluate the effects, good or bad, of targeted therapies or immunotherapy (drugs that help the body's immune system fight cancer cells) in patients who have solid tumors with specific genetic alterations or with a high number of mutations. Patients will be assigned to cohorts (groups) based on having a specific type of genetic alteration in their tumor. The study includes cohorts for patients whose tumors have genetic alterations in the ROS1, NTRK, PIK3CA, BRAF, or RET genes or a high number of mutations in their tumor.