Outcomes for children with recurrent supratentorial brain tumors are extremely poor. Novel innovative treatments are greatly needed. One promising new approach is the use of a genetically engineered, conditionally replicating herpes simplex virus (HSV) that has shown tumor specific tropism and potential efficacy in the treatment of malignant brain tumors.
Primary: To assess the safety and tolerability of G207 administered intratumorally via stereotactic infusion alone or followed by a single dose of radiation within 24 hours of G207 administration in children with recurrent or progressive malignant supratentorial brain tumors. To establish a maximum tolerated dose (MTD) or maximal planned dose if no dose-limiting toxicity is observed.
Secondary: To obtain preliminary information concerning the potential efficacy of and biological response to G207 alone or combined with a single dose of radiation in pediatric patients with recurrent or progressive malignant brain tumors by assessing radiographic response, performance scale, progression-free and overall survival, immune response, and presence of G207 in blood, saliva, and conjunctiva.
Investigational Drug: G207 is a genetically altered HSV that has been demonstrated to be aneurovirulent secondary to deletions of both copies of the γ134.5 gene. After stereotactic biopsy to confirm tumor recurrence, up to 4 silastic catheters will be passed to predefined coordinates of enhancing tumor. Subsequently, patients will be inoculated with 2.4 ml of G207 at one of two doses over 6 hours alone or followed by a single 5 Gy fraction of radiation within 24 hours of virus inoculation.