RPx therapies are engineered using a proprietary HSV-1 strain and immune activating transgenes to maximize T cell stimulation and systemic immune activation.   

• RP1 is designed to treat more immune responsive tumor types. The encoded GALV-GP R- protein enhances the tumor killing ability of the virus and increases immunogenic cell death. Initial data shows RP1 destroys tumors both locally and systemically, including in patients who have progressed on prior treatment with anti-PD1.
• RP2, which additionally encodes an anti-CTLA-4 antibody, has been optimally designed to treat more immunologically silent tumors.
• RP3, additionally expresses a pair of immune costimulatory pathway activating ligands, CD40L and 4-1BBL, to further increase the potency of the immune responses to treat immunologically ‘cold’ tumors.

RP2 and RP3 target clinically validated pathways with the transgenes incorporated. Replimune believes that other therapeutics (antibody-based infusions) targeting these pathways may be sub-optimal both in terms of efficacy and/or toxicity. Replimune’s approach delivers the therapy at both the time and place needed for immune activation which we expect will enhance activation of these pathways, thus stimulating a powerful immune response while also reducing the side effects resulting from systemic dosing.