A-C) Athymic nude mice bearing intracranial patient derived primary GBM12 tumors were treated with control IgG or OS2966 (5mg/kg) intra-tumorally twice a week for 1 month. oHSV were injected by IT injection on day 10 after tumor implantation and mice were then monitored for survival. (A) T1-weighted MRI images of coronal sections of tumor-bearing mice 3 days post oHSV treatment (13 days post tumor implantation). (B) The volume of tumor measured on MRI. (C) Data shown are Kaplan-Meier survival curves of animals in each group (n=8 for IgG, OS2966, and oHSV+IgG, and oHSV+OS2966). Mice were euthanized when they showed symptoms of hunched posture, rough coat, thin body, or limb paralysis.