MG18L

MG18L is an experimental oncolytic herpes simplex virus type 1 (oHSV-1) candidate being investigated for the treatment of glioblastoma (GBM). It is genetically engineered with two primary modifications: the deletion of the *Us3* gene and the inactivation of the *ICP6* gene (which encodes the large subunit of ribonucleotide reductase). The *Us3* deletion is intended to enhance the pro-apoptotic activity of the virus and improve safety, while the *ICP6* inactivation restricts viral replication to rapidly dividing neoplastic cells that express high levels of cellular ribonucleotide reductase. MG18L has demonstrated potent anti-tumor activity in preclinical models of glioblastoma stem-like cells (GSCs) and shows significant synergy when combined with DNA-dependent protein kinase catalytic subunit (DNA-PKcs) inhibitors, such as peposertib (M3814).