Treats large injected & uninjected tumors

RP2 and RP3 are follow-on versions of RP1 that express additional proteins. RP2 expresses the anti-CTLA-4 molecule and RP3 expresses the anti-CTLA-4 and optimized immune co-stimulatory pathway ligands. These therapeutics provide targeted delivery of proteins to the sites of immune response initiation in the tumor and draining lymph nodes which should focus the efficacy and limit off target toxicities, in comparison to the results of the systemic exposure which occurs with traditional systemic antibody-based approaches.