FP253

FP253 is a gene therapy investigational drug designed for the treatment of prostate cancer. It consists of an ovine atadenovirus vector engineered to express the E. coli enzyme purine nucleoside phosphorylase (PNP) under the control of a prostate-specific promoter. When administered intraprostatically, this vector leads to localized expression of PNP in prostate tissue. Systemically administered fludarabine phosphate acts as a prodrug; once it reaches the site where FP253 has been delivered, PNP converts fludarabine into 2-fluoroadenine, a cytotoxic agent that induces cell death in tumor cells. This approach aims to provide organ-targeted chemotherapy with reduced systemic toxicity and minimized damage to surrounding tissues compared to conventional chemotherapy.