TK99UN

TK99UN is a recombinant, replication-deficient adenoviral vector (serotype 5) engineered to deliver the herpes simplex virus thymidine kinase (HSV-tk) gene, primarily developed for the treatment of hepatocellular carcinoma (HCC). Developed by the Clínica Universidad de Navarra and its commercialization partner Digna Biotech, the drug functions as a suicide gene therapy, or gene-directed enzyme prodrug therapy (GDEPT). Following intratumoral injection, the vector transduces tumor cells to express the HSV-tk enzyme, which subsequently converts systemically administered prodrugs such as ganciclovir or valganciclovir into a cytotoxic triphosphate metabolite. This metabolite acts as a DNA chain terminator, inhibiting DNA polymerase and inducing apoptosis in infected cells and adjacent tumor cells via the bystander effect. While Phase I trials established its safety and feasibility in Spain, clinical development of this specific construct appears to have stabilized in early stages.

Other names

rAd-TKAd-TKrAd-HSV-tkAd5-HSV-tkAd-5-HSV-tkAd 5-HSV-tk