F4L-deleted vaccinia virus

**F4L-deleted vaccinia virus** is a genetically engineered oncolytic virus derived from vaccinia virus with a targeted deletion of the *F4L* gene, which encodes the virus homolog of the small subunit of ribonucleotide reductase (RRM2). This deletion markedly attenuates replication in normal cells while permitting selective replication and cytotoxic activity in cancer cells that typically overexpress RRM2. As a result, the virus demonstrates tumor-selective oncolytic activity, robust tumor regression, and the ability to induce anti-tumor immune responses as shown in preclinical bladder cancer models. Its enhanced safety profile makes it a promising candidate for treatment of cancers, especially those refractory to existing therapies such as BCG, or in immunocompromised patients[1][2][3][6][7].

Other names

F4L-deleted VACVF-4L-deleted VACVF 4L-deleted VACVΔF4L VACV