[[G47Δ]] is a genetically engineered [[Herpes simplex virus type 1]] (HSV-1) with triple [[mutation]]s that realized augmented viral replication in tumor cells, strong induction of antitumor immunity and enhanced safety in normal tissues. 

A clinical trial of G47Δ in patients with [[recurrent glioblastoma]] started in 2009. One of the advantages of HSV-1 is its capacity to incorporate large and/or multiple transgenes within the viral genome. In preclinical studies, "arming" of an oncolytic HSV-1 with transgenes encoding immunomodulatory molecules, such as [[interleukin 12]], has been shown to greatly augment the efficacy of oncolytic HSV-1 therapy. [[Oncolytic virus]] therapy using HSV-1 may be a useful treatment for glioma that can also function as an efficient in situ tumor vaccination
((Todo T. Active immunotherapy: oncolytic virus therapy using HSV-1. Adv Exp Med
Biol. 2012;746:178-86. doi: 10.1007/978-1-4614-3146-6_14. Review. PubMed PMID:
22639168.
)).