Combination Intraventricular Chemotherapy Pilot Study: 5-Azacytidine (5-AZA) and Trastuzumab Infusions Into the Fourth Ventricle or Resection Cavity in Children and Adults with Recurrent or Residual Posterior Fossa Ependymoma

Patients will receive once weekly 10 mg intraventricular 5-Azacytidine infusions for six consecutive weeks followed by observation in the infusion suite for a minimum of 30 minutes and once weekly 21 mg intraventricular trastuzumab infusions for six consecutive weeks followed by observation for a minimum of 2 hour after each infusion for the first 2 infusions. During this monitoring period, temperature, blood pressure, heart rate, and oxygen saturation will be measured. Patients will also have a neurological examination performed to observe for neurological changes. All patients will undergo an MRI of the brain and total spine with and without gadolinium within 7 days after the final 5-AZA and trastuzumab infusion to determine treatment response and to assess for any signal changes in the brain or spine caused by the infusions and they will have a 30 day and a 90 day follow-up assessment by telephone or in person for assessment of outcome measures and safety