This study is testing a new medicine called CX-4945 (also known as silmitasertib sodium) for kids with a type of brain tumor called medulloblastoma. Medulloblastoma is a cancer that starts in the brain and can come back after treatment. The study will determine the best dose and check the safety of the medicine. There are two parts of the study: Phase I and Phase II.

In Phase I, the medicine’s dose will start low and gradually increase to find the safest amount for children who haven’t finished growing yet. In Phase II, the study will look at how safe it is for older teens and adults. Some patients may need surgery to remove the tumor, and the study will also explore if the medicine helps during surgery.

• The study lasts up to 2 years, with medicine given twice daily.
• Participants may need to have surgery as part of the study.
• There are eligibility criteria, such as age limits and previous treatments.

It’s important for families to consider the potential risks and benefits before joining the study. Participants must have a recurrent medulloblastoma diagnosis and meet specific health requirements.