264 Correlation of virus-specific CD8+ T cells to clinical response following treatment with Pexa-Vec and Cemiplimab in patients with advanced renal cell carcinoma by Gavin Thurston, Israel Lowy, Vladimir Jankovic, Myles Dillon, Lianjie Li, Jeongsook Bang, Nicholas Gaspar, Jessica Kuhnert, Nathalie Fiaschi, Glenn Kroog, Kyoung Soo Ha, Raquel Deering