An open-label clinical trial of RP2 and RP3 oncolytic immunotherapy in combination with atezolizumab plus bevacizumab for the treatment of patients with advanced colorectal carcinoma.

• DOI: 10.1200/jco.2024.42.3_suppl.tps228
• Publication Date: 2024-01-22T21:12:58Z
• Authors: Heinz-Josef Lenz; Ashwin Somasundaram; Michael Sangmin Lee; Davendra Sohal; Rachael A Safyan; Mojun Zhu; Jeremy Clifton Jones; Aditya Bhansali; Roza Kalwar; May Cho; Axel Grothey
• Keywords: Atezolizumab

TPS228 Background: Colorectal cancer (CRC) is the third most frequently diagnosed and second leading cause of cancer-related mortality worldwide. PD-1/PD-L1 inhibition, in combination with other modalities, has demonstrated significant benefit patients (pts) microsatellite instability-high or mismatch repair–deficient CRC. However, these agents have limited, if any, clinical pts stable (MSS) repair–proficient (pMMR) RP2 an enhanced potency oncolytic herpes simplex virus type 1 which expresses fusogenic gibbon ape leukemia glycoprotein R sequence deleted (GALV-GP-R–), granulocyte-macrophage colony-stimulating factor (GM-CSF), anti–CTLA-4 antibody-like molecule; RP3 additionally 4-1BB CD40 activating ligands but does not express GM-CSF. Both preliminary safety antitumor activity solid tumors. This study will evaluate atezolizumab (Atezo) plus bevacizumab (Bev) advanced MSS/pMMR CRC (NCT05733611). Methods: Pts a histologic diagnosis unresectable and/or metastatic CRC, documented MSS pMMR status, previously treated up to 3 standard-of-care systemic regimens be enrolled + Atezo Bev treatment groups (30 per group). Further key inclusion criteria include Eastern Cooperative Oncology Group performance status 0 adequate hepatic, renal, hematologic function. RP2/RP3 injected into tumors by direct image-guided injection. receive 8 total doses 10 mL RP3, first dose concentration × 6 plaque-forming units (PFU)/mL, followed 7 PFU/mL every 2 weeks, then 4 weeks. may course injections are met. administered starting on week 1; 7. The primary endpoint objective response rate; secondary endpoints safety, overall survival, progression-free duration response, complete rate. Antitumor evaluated using Response Evaluation Criteria Solid Tumors version 1.1 as modified for this study. Safety assessed physical examination, laboratory evaluations, vital signs, monitoring adverse events (AEs; including serious AEs). Clinical trial information: NCT05733611 .