PD-1 inhibitor plus oncolytic vaccinia virus is a safe and effective treatment option for metastatic renal cell carcinoma

• Published in: Cancer cell international 2024-01, Vol.24 (1), p.50-11, Article 50
• Main Authors: Park, Jee Soo, Lee, Myung Eun, Kim, Jongchan, Oh, Keunhee, Lee, Namhee, Jung, Minsun, Jang, Won Sik, Ham, Won Sik
• Format: Article
• Language: English
• Subjects: Animal models; Apoptosis; Ascites; Cancer therapies; Cell death; Cloning; CTLA-4 protein; Cytotoxicity; Hepatitis; Immune checkpoint inhibitors; Immune-related adverse events; Immunofluorescence; Immunotherapy; Kidney cancer; Laboratory animals; Lung nodules; Lymphocytes; Lymphocytes T; Metastases; Metastasis; Microenvironments; Normal distribution; Oncolysis; Oncolytic viruses; PD-1 protein; Peritoneum; Renal cell carcinoma; Tumors
• ISSN: 1475-2867; 1475-2867
• DOI: 10.1186/s12935-024-03238-z

Although a combination of immune checkpoint inhibitors (ICIs) is recommended as the first line treatment option for metastatic renal cell carcinoma (mRCC), several immune-related adverse events (irAEs) occur, especially hepatitis. We explored the therapeutic benefits and safety profile of combining oncolytic vaccinia virus, JX-594, with a programmed cell death protein-1 (PD-1) inhibitor. We used early-stage and advanced-stage orthotopic murine mRCC models developed by our group. PD-1 inhibitor monotherapy or a PD-1 inhibitor combined with either JX-594 or a cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitor were systemically injected through the peritoneum. An immunofluorescence analysis was performed to analyze the tumor immune microenvironment (TIME). irAEs were assessed in terms of hepatitis. In the early-stage mRCC model mice, the combination of JX-594 and a PD-1 inhibitor significantly decreased the primary tumor size and number of lung nodules, compared with the ICI combination, but the JX-594 and PD-1 inhibitor combination and ICI combination did not differ significantly in the advanced-stage mRCC model mice. The JX-594 and PD-1 inhibitor combination induced tumor-suppressing TIME changes in both the early- and advanced-stage mRCC models. Furthermore, mice treated with the ICI combination had significantly greater hepatic injuries than those treated with the JX-594 and PD-1 inhibitor combination which was evaluated in early-stage mRCC model. The JX-594 and PD-1 inhibitor combination effectively reduced primary tumors and the metastatic burden, similar to ICI combination therapy, through dynamic remodeling of the TIME. Furthermore, hepatitis was significantly decreased in the JX-594 and PD-1 inhibitor combination group, suggesting the potential benefit of that combination for reducing ICI-induced toxicity.