Phase 2 Trial of G207 + 5 Gy Radiation for Children With High-Grade Gliomas

Inclusion Criteria: Exclusion Criteria: Pregnancy Pregnant women are excluded from this study. Female patients of childbearing potential must have a negative serum or urine pregnancy test. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. Pregnant women are excluded from this study because G207 is an agent with the potential for teratogenic or abortifacient effects. Lactation Status Lactating females are not eligible unless they have agreed not to breastfeed their infants Because there is an unknown potential risk for adverse events in nursing infants secondary to treatment of the mother with G207, breastfeeding should be discontinued if the mother is treated with G207. Disease-Related Exclusion Criteria Patients with a prior or concurrent malignancy whose natural history or treatment has the potential to interfere with the safety or efficacy assessment of the investigational regimen for this trial. Patients with primary tumor involving the cerebellum, brainstem or spinal cord, or that would require surgical access through a ventricle to deliver the prescribed protocol treatment. Metastatic disease or diffuse, widespread, abnormal tumor pattern involving 3 or more lobes of the brain. Tumor with evidence of clinically significant uncal herniation or midline shift, or evidence of ventricular obstruction from tumor or tonsillar herniation. Concurrent Illness Patients with any clinically significant unrelated systemic illness (serious infections or significant cardiac, pulmonary, hepatic or other organ dysfunction), that in the opinion of the investigator would compromise the patient's ability to undergo surgery and/or tolerate protocol therapy, put them at additional risk for toxicity or would interfere with the study procedures or results. Known HIV seropositivity. Diagnosis of encephalitis or CNS infection \< 12 weeks prior, or receiving ongoing treatment for encephalitis, CNS infection or multiple sclerosis. Concurrent Medications Patients who are receiving any other anti-cancer or investigational drug therapy are ineligible. Patients who are receiving ≥ 2 mg of dexamethasone (or ≥ 10 mg of prednisone) daily * Patient requires an escalation in ongoing systemic corticosteroid therapy within 7 days prior to G207 inoculation * For this study, 'systemic corticosteroids' include oral, intravenous, or intramuscular formulations. A single, non-consecutive dose does not constitute exclusion. Physiologic corticosteroid replacement therapy (e.g., hydrocortisone for adrenal insufficiency), intermittent use of bronchodilators and topical steroids, is not considered immunosuppressive and does not constitute exclusion. Concurrent therapy with any drug active against HSV (acyclovir, valacyclovir, penciclovir, famciclovir, ganciclovir, foscarnet, cidofovir). Inability to Participate Patients who in the opinion of the investigator are unwilling or unable to return for required followup visits or obtain follow-up studies required to assess toxicity to therapy or to adhere to the drug administration plan, other study procedures, and study restrictions.