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 is positioned to enhance the tumor killing ability of the virus and increases immunogenic cell death. Initial data shows RP1 can destroy 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.

Replimune believes that other therapeutics (antibody-based infusions) targeting these pathways may be sub-optimal both in terms of efficacy and/or toxicity. Replimune believes its 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.