Eliciting a systemic antitumor immune response, in a patient who presents with or who is at risk of developing multiple metastatic tumors of a given
cell type, entails, in one embodiment, inoculating a tumor in the patient with a pharmaceutical composition consisting essentially of (A) a
herpes simplex virus (HSV) that infects
tumor cells but that does not spread in normal cells and (B) a pharmaceutically acceptable vehicle for the
virus, such that an immune response is induced that is specific for the tumor
cell type and that kills cells of the inoculated tumor and of a non-inoculated tumor. In another embodiment, the pharmaceutical composition also comprises a defective HSV vector which contains an expressible
nucleotide sequence encoding at least one
immune modulator. In another embodiment, the pharmaceutical composition contains a second HSV that infects
tumor cells but that does not spread in normal cells. According to the latter approach, both the first HSV and the second HSV may have genomes that comprise, respectively, an expressible
nucleotide sequence coding for at least one
immune modulator. In another embodiment, the pharmaceutical composition comprises, in addition to a
herpes simplex virus (HSV) that infects
tumor cells but that does not spread in normal cells, a
viral vector comprising at least one expressible
nucleotide sequence coding for at least one
immune modulator.