Optimizing oncolytic virus therapy for glioblastoma

ABSTRACT The overarching goal of this project is to identify a new lead oncolytic virus for the treatment of adult glioblastoma (GBM). Oncolytic viral (OV) therapy is a promising biological therapy that preferentially targets tumor cells for lytic destruction [1, 2]. Oncolytic HSV-1 (oHSV) derived virus that encodes for GM-CSF (IMLYGIC®) has been recently approved for non-ressectable metastatic melanoma [3, 4]. In our past endeavors, we have created and tested the therapeutic efficacy of oHSV armed with therapeutic transgenes. These viruses have been created in rHSVQ1 (HSVQ): an HSV virus backbone that is deleted for both copies of the viral neuro- virulence gene ICP34.5 and it contains a gene disrupting insertion in viral ICP6. This backbone has attenuations identical to G207, a virus that has been tested and found to be safe in patients with GBM after intracranial inoculation into the tumor or when given into the post resection tumor cavity [5, 7-10]. Here we will create a novel dually armed oncolytic virus (that encode for therapeutic transgenes: Vstat120, PTENα or both) and then compare the dually armed and single transgene armed viruses to identify an optimal vector for future IND guided studies.