Figure 1.
Schematic showing the engineering of Talimogene laherparepvec (T-VEC). The backbone is the JS17 strain of herpes Simplex virus, type 1 in which the two viral ICP34.5 genes have been deleted and replaced with copies of the human GM-CSF genes under control of a CMV promoter. In addition, the viral ICP47 gene is deleted transitioning the viral US11 gene to an immediate-early promoter. The implications of these genetic modifications are listed in the box. Abbreviations: CMV, cytomegalovirus; hGM-CSF, human granulocyte-macrophage colony-stimulating factor; ICP, infected cell protein; IRL, long inverted repeat region; pA, polyadenylation tail; TRL, long terminal repeat; TRS, short terminal repeat; UL, unique long region; US, unique short region; US11, unique short sequence 11.