SillaJen, Inc. (KOSDAQ: 215600) develops and commercializes oncolytic virus immunotherapeutics and related anti-cancer therapies targeting solid tumors. The company offers Pexa-Vec (JX-594), a first-in-class oncolytic immunotherapy in Phase 3 clinical trials for advanced liver cancer (hepatocellular carcinoma) and under evaluation in combinations with checkpoint inhibitors such as cemiplimab for renal cell carcinoma and nivolumab for liver cancer; BAL0891, a dual TTK/PLK mitotic checkpoint inhibitor; SJ-600 (GEEV platform), a next-generation CD55-expressing vaccinia virus enabling intravenous delivery, evasion of neutralizing antibodies and complement system for repeated administration in various solid tumors; JX-900 (VVDD), an enhanced oncolytic vaccinia platform; and JX-970 for tumor tissue treatment, all developed using the proprietary SOLVE (Selective Oncolytic Vaccinia Engineering) platform. SillaJen operates primarily in the immuno-oncology segment, serving patients with advanced cancers through clinical-stage pipelines; it maintains research and development facilities in Busan and Yangsan, finance and management in Seoul, South Korea, and a U.S. affiliate, SillaJen Biotherapeutics, Inc., in San Francisco, California, for clinical operations, regulatory affairs and manufacturing. Founded in 2006 and headquartered in Seoul, South Korea, the company acquired Jennerex Biotherapeutics in 2014, listed on KOSDAQ in 2016, and maintains partnerships including clinical collaborations with Regeneron Pharmaceuticals and the U.S. National Cancer Institute. Recent developments include a January 2025 Master Service Agreement with ReiThera Srl for GMP manufacturing and clinical development of the SJ-600 series; an April 2024 memorandum of understanding with OSR Holdings to collaborate on immuno-oncology technologies and U.S. market expansion; and ongoing Phase 3 PHOCUS trial enrollment in China with Lee's Pharmaceutical for Pexa-Vec in liver cancer.