This study involves taking a study drug called ALRN-6924. ALRN-6924 is an investigational cancer treatment that activates p53, which suppresses the growth of tumors by blocking proteins in the cell called MDM2 and MDMX that inhibit p53 from doing its job. The overall goals of this study are to evaluate the side effects and benefits of ALRN-6924 in patients with relapsed or treatment refractory solid tumor or brain tumor, and to determine the best dose of ALRN-6924 for children and adolescents. This study will also look at how the body breaks down ALRN-6924 by measuring the amount of ALRN-6924 in the blood over time after a dose.

This study aims to explore a new type of magnetic resonance imaging (MRI) called Chemical Exchange Saturation Transfer (CEST) in children aged 6-18 years with brain tumors. An MRI is a machine that takes detailed pictures of the brain. The CEST MRI used in this study is still being tested and has not been approved by the FDA yet. The study wants to find out if this new type of MRI can help doctors evaluate brain tumors. CEST MRI creates images using water molecules and protons in the brain. Early research shows that CEST could be helpful in understanding brain tumor changes.

This study will enroll 5 participants.

The purpose of this research study is to determine if certain markers in your blood are increased over the duration of your chemotherapy, especially as you get sicker, such as developing a severe infection (sepsis) or severe respiratory failure (acute respiratory distress syndrome).

This study involves taking a study drug called CUDC-907. CUDC-907 is an oral drug that blocks certain proteins in tumor cells; these proteins may be important in the growth of some cancers. The overall goals of this study are to evaluate the side effects and benefits of CUDC-907 in patients with relapsed or treatment refractory solid tumor, brain tumor, or lymphoma, and to determine the best dose of CUDC-907 for children and adolescents. This study will also look at the levels of CUDC-907 in the blood over time after a dose.

This study has two parts. Part A enrolls patients who have been diagnosed with a solid tumor, lymphoma or desmoid tumor that has either come back ("relapsed") or does not respond to therapy ("is refractory"). Part B enrolls patients with a relapsed or refractory Ewing sarcoma, desmoid tumor, osteosarcoma, liver tumor, Wilms tumor, or tumors with changes in a gene family known as the Wnt pathway. This study involves taking a study drug called tegavivint. The study will be testing different doses of the study drug to find the safest dose.