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.