It is known that cancer cells are often defective in anti-viral pathways and are thus susceptible to virus infection. SV5, also known as PIV5, is not associated with symptoms or diseases in humans. This study will test the hypothesis that SV5 mutant viruses can selectively kill advanced tumors.  

SV5 viruses with mutation in SH or V proteins induce apoptosis in many cell types. Initial results have been promising with late-stage solid tumors, and in preliminary studies, mutant SV5 viruses killed human metastatic breast cancer cells, as well as Lewis lung carcinoma cells. Using cytolytic viruses as anti-tumor agent provides a viable alternative to surgery and chemotherapy.