Pexa-Vec + TG6006

**Pexa-Vec + TG6006** is a combination of two oncolytic viruses, Pexa-Vec (pexastimogene devacirepvec, also known as JX-594), a thymidine kinase-deleted vaccinia virus engineered to express granulocyte-macrophage colony-stimulating factor (GM-CSF) and β-galactosidase, and TG6006, an oncolytic vaccinia virus. Pexa-Vec selectively replicates in cancer cells, causing direct lysis, disrupting tumor vasculature, and stimulating systemic anti-tumor immunity via GM-CSF-mediated dendritic cell activation and tumor antigen release. Developed collaboratively by companies including Transgene and SillJen (formerly Jennerex Biotherapeutics), it has been primarily investigated for advanced hepatocellular carcinoma (HCC) and other solid tumors, often in combination with immune checkpoint inhibitors like nivolumab or durvalumab/tremelimumab, showing dose-dependent survival benefits in phase 2 trials but facing development challenges post-phase 3 futility analysis.[2][4][7][9]