The last 5 years have seen unprecedented developments in cancer immunotherapy. It has been know for many years that the immune system is able to recognize and eliminate cancer cells. Unfortunately, cancers have an wide array of escape mechanisms. The advent of checkpoint inhibitors targeting the CTLA-4 and PD-1 pathways has heralded a new era in immunotherapy giving long remissions in significant numbers of patients. There is hope that 20% long term survival rate seen with ipilimumab will be significantly increased with the PD-1 inhibitors alone or in combination. The promise seen in melanoma is being extended to a range of other cancers.
There is however significant room for improvement. Our better understanding of the mechanisms of immune activation and regulation have identified several therapeutic avenues. The next generation of dendritic cell vaccines using naturally occurring DCs are already being developed and vaccine approaches that specifically target dendritic cell antigen presentation, have shown promise in the clinic. Novel approaches targeting immune suppression in the tumour microenviroment such as IDO and myeloid derived suppressor cells are being actively pursued. Personalised vaccine strategies have been developed that harness the ability to gene sequence an individual’s tumour to identify in particular mutations that can be targeted by the immune response.