Correlation of distinct circulating cytokine/chemokine profiles with clinical benefits of Pexa-Vec (thymidine kinase-deactivated vaccinia virus plus GM-CSF) and cemiplimab (REGN2810; anti-PD-1) in metastatic or unresectable renal cell carcinoma (mRCC).

e14539 Background: This study explores the transformation of 'cold' tumour microenvironments into 'hot' ones in mRCC, focusing on the potential of Oncolytic Viruses (OVs) for personalized immunotherapy. Recognizing the variability in patient responses, the research underscores the necessity for reliable biomarkers. The objective is to examine the correlation between plasma cytokine/chemokine levels and the efficacy of Pexa-Vec and cemiplimab, proposing that these biomarkers could predict treatment outcomes and contribute to more personalized cancer treatment protocols. Methods: In this study, mRCC patients from the REN026 trial were categorized into three treatment groups: Pexa-Vec (Intratumoral and intravenous) and cemiplimab combination therapy (N=65), intravenous Pexa-Vec and cemiplimab combination therapy (N=54), and cemiplimab monotherapy (N=14). Blood samples were collected at baseline, during treatment, and at end of treatment (EOT) for analysis. Subsequently, the plasma samples underwent analysis using the Human Cytokine 96-Plex Discovery Assay through the Luminex 200 system. The statistical approach included the Mann–Whitney U-test or Wilcoxon signed-rank test, along with a Cox proportional hazards model. The False Discovery Rate (FDR) method was employed to control type I error. Results: During the follow-up period from June 2018 to February 2023, key outcomes were observed as follows (Table): In the Pexa-Vec and cemiplimab cohort, a lower baseline of MCP-3 or an increased rate of change in post-treatment levels of IFNβ, Eotaxin, IL-1α, and sFasL were associated with improved Progression-Free Survival (PFS). Specifically, a low baseline of MCP-3 or an increased level of Eotaxin and sFasL post-treatment correlated with enhanced Overall Survival (OS). In the intravenous Pexa-Vec and cemiplimab group, a rise in post-treatment levels of IFNβ, Eotaxin, IL-17F, and sFasL were indicative of better PFS, with elevated Eotaxin also suggesting improved OS. Within the cemiplimab monotherapy group, an increase in post-treatment IP-10 was linked to favourable PFS. Conclusions: Our findings suggest the potential utility of plasma cytokine and chemokine profiles in clinical benefits of mRCC patient to the combination of Pexa-Vec and cemiplimab, thereby aiding in future personalized treatment approaches.