*3.5. C134*

C134 is a chimeric oHSV that was altered by deletion of the neurovirulence factor γ*34.5* and expression of the human cytomegalovirus gene IRS1, with the latter preserving late viral protein synthesis, which is disabled by deletion of γ*34.5* [56]. Preclinical studies proved that C134, compared to γ*34.5* deleted HSV-1 variants, had a higher replication potential in glioblastoma in in vivo models and was able to increase survival in glioma and neuroblastoma-bearing mice in contrast to γ*34.5* deleted controls [57]. Safety and tolerability of C134 for treatment of advanced or progressive gliomas is currently investigated in a phase I clinical trial (NCT03657576).
