cytosine deaminase vector

Cytosine deaminase (CD) vector refers to a gene therapy platform that utilizes viral vectors (typically retroviral or adenoviral) to deliver the CD gene into cancer cells. This approach is a form of gene-directed enzyme prodrug therapy (GDEPT), where the expressed CD enzyme converts the non-toxic prodrug 5-fluorocytosine (5-FC) into the cytotoxic metabolite 5-fluorouracil (5-FU) directly within the tumor. This localized conversion aims to achieve high intratumoral concentrations of chemotherapy while reducing systemic side effects. The most clinically advanced version was Toca 511 (vocimagene amiretrorepvec), a retroviral replicating vector developed by Tocagen for recurrent high-grade glioma, though it failed to meet primary endpoints in Phase 3 trials. Various other vectors using different viral platforms and sources of the CD gene (e.g., *E. coli* or yeast) have been investigated for colorectal and other cancers.

Other names

CD vectorcytosine deaminase gene therapyCD-GDEPT