SillaJen, Inc. announced the first patient has been enrolled in Part 2 of JX594-REN026, a Phase 1b clinical trial of Pexa-Vec (pexastimogene devacirepvec) in combination with Libtayo®(cemiplimab-rwlc), for the treatment of renal cell cancer (RCC). Enrollment of Part 1 (dose-escalation phase) of the trial was completed in March 2019 without significant safety concerns, and the first seven patients in Part 2 were enrolled in South Korea, with expansion to sites in the United States and Australia anticipated over the coming weeks. SillaJen is collaborating with Regeneron to evaluate Pexa-Vec, SillaJen's lead clinical candidate, in combination with Regeneron's Libtayo®, an anti-PD1 monoclonal antibody Regeneron is developing in collaboration with Sanofi. The aim of the trial is to assess the safety and efficacy of the combination in patients with unresectable or metastatic renal cell carcinoma. The study will also investigate the immune modulating potential of Pexa-Vec given concurrently with checkpoint inhibitor therapy by evaluating multiple blood and tissue biomarkers.