Dr. Khushalani on the Mechanism of Action of RP1 in Cancer Care

Nikhil Khushalani, MD, vise chair, Department of Cutaneous Oncology, Moffitt Cancer Center, discusses the mechanism of action vusolimogene oderparepvec (RP1) in cancer care.

RP1 is a next generation of talimogene laherparepvec (T-VEC; Imlygic), Khushalani says. RP1 is a selectively replication-specific herpes simplex virus-1 (HSV-1) for intertumoral injection, Khushalani says. What differentiates RP1 from T-VEC is the presence of a construct of HSV-1 where the neurovirulence factor gene has been deleted, allowing the virus to replicate within the tumor cells without harming normal cells through a bystander effect, Khushalani explains. Additionally, a granulocyte-macrophage colony-stimulating factor payload is encoded into RP1 to directly destroy tumors and generate an antitumor immune response, Khushalani adds.

RP1 also features an encoding codon for the glycoprotein, GALV-GP, with the deletion of the R sequence, Khushalani continues. This promotes cell-to-cell adhesion-related cytotoxicity, and tumor cells that are adjacent to one another when exposed to the agent undergo cytotoxic death, Khushalani concludes.