Feasibility of the trial was proven to be absent.

The study investigates valproic acid added to radiation and temozolomide therapy (standard of care) for progressive or recurrent pediatric brain tumors.

Patients with progressive or recurrent pediatric brain tumors are administered valproic acid, an HDAC inhibitor, along with standard of care therapy (radiation and temozolomide) for induction therapy. Thereafter, patients will be able to continue on valproic acid and temozolomide therapy as long as the combination is well tolerated and the tumor is not progressing.

Inclusion Criteria:

• Subject, parent, or guardian willing and able to give informed consent
• Recurrent or progressive pediatric brain tumor, with MRI evidence of disease
• Age at first diagnosis of brain tumor 1-21 years old
• Lansky or Karnofsky performance score of at least 50 at diagnosis

Exclusion Criteria:

• Pregnancy
• Prior intolerance to valproic acid
• History of use of temozolomide
• Use of enzyme inducing anticonvulsant medications (see appendix B)
• Known urea cycle disorder (e.g. ornithine transcarbamylase deficiency)