Most of the exciting current research in treating cancer revolves around immunotherapy. Although the PD-1, CTLA-4, and PD-L1 inhibitors have made a large impact in a subset of patients, the reality is that only approximately 20% of patients benefit from these checkpoint inhibitors.
Oncolytic viruses (OV) are interesting but, as a single agent, had not been successful because macrophages recognize infected cells and kill them together with their viruses. OV therapy, as a single agent, had not been successful because macrophages recognize infected cells and kill them together with their viruses.
Recent studies use new designs of OV that can stimulate cytotoxic T cells to kill cancer cells before the viral population is significantly depleted by the macrophages. Some of these studies introduce enhancement of the T cells by blocking their checkpoints. Mice experiments demonstrated that both CTLA-4 and PD-L1 checkpoints blockade enhance the OV treatment.
Although patients typically will enter a clinical trial to get a combination of oncolytic virus with checkpoint inhibitors, we have the ability to compassionately use these on patients, outside of a clinical trial.
Rigvir is a genetically unaltered oncolytic virus with approval in a few European countries. The efficacy data is extremely scarce and only for melanoma, but perhaps combined with checkpoint inhibition, its efficacy would improve. For those of you interested in treating patients with this combination, I will make myself available.
healthyliving May 14th, 2019
Posted In: cancer care, Cancer Prevention
cancer, cancer care, immunotherapy, oncolytic virus, OV, OV therapy, rigvir