Pharmaceutical compositions including a herpes simplex virus derived composite oncolytic vector are provided for the treatment of solid tumors in an individual. The HSV-derived composite oncolytic vector includes an HSV-derived amplicon defective viral genome carrying at least one toxic foreign gene, and an HSV-derived mutant helper virus vector that has a mutation in the vhs-1 gene. An HSV-derived mutant helper virus vector that has a mutation in the vhs-1 gene is also provided. A method for the treatment of an individual having a solid tumor is provided and includes administering an HSV-derived amplicon defective viral genome including at least one toxic foreign gene, and an HSV-derived mutant helper virus vector including a mutation in the vhs-1 gene.
