RP2 + RP3

**RP2 + RP3** refers to a combination of two related investigational oncolytic immunotherapies developed by Replimune. Both RP2 and RP3 are genetically modified herpes simplex virus type 1 (HSV-1) vectors designed for intratumoral administration. - **RP2** expresses the fusogenic gibbon ape leukemia virus glycoprotein (GALV-GP-R–), granulocyte-macrophage colony-stimulating factor (GM-CSF), and an anti–CTLA-4 antibody-like molecule. - **RP3** expresses GALV-GP-R–, activating ligands for 4-1BB and CD40, but does not express GM-CSF. Both RP2 and RP3 are designed to: - Directly lyse tumor cells (oncolytic activity) - Stimulate local and systemic antitumor immunity through expression of immune modulatory agents - Remodel the tumor microenvironment and enhance immune infiltration The combination is being investigated primarily in advanced solid tumors—specifically metastatic colorectal cancer (MSS/pMMR CRC) and hepatocellular carcinoma (HCC)—often in combination with the checkpoint inhibitor atezolizumab and the VEGF inhibitor bevacizumab. Administration method is direct intratumoral or image-guided tumor injection[1][2][4][5][7].