A Phase I Gene Therapy Study of FP253/Fludarabine for Prostate Cancer

The primary objective of this study is to determine the safety and tolerability of a gene-directed enzyme prodrug therapy for prostate cancer. FP253 contains an ovine atadenovirus that expresses the E. coli enzyme purine nucleoside phosphorylase (PNP) under the control of a prostate-directed promoter. PNP converts systemically administered fludarabine (the prodrug) into 2-fluoroadenine (the active agent) at the site where FP253 has been administered (the prostate). This localized conversion is expected to provide organ-targeted chemotherapy that should reduce the systemic side effects associated with classical chemotherapy and also reduce the risk of debilitating damage to tissues surrounding the prostate.