Fludarabine (phosphate)

Fludarabine (phosphate) is an analogue of adenosine and deoxyadenosine, which is able to compete with dATP for incorporation into DNA and inhibit DNA synthesis. In Vitro: Fludarabine phosphate significantly reduces the cell viability in a dose-dependent manner. Fludarabine phosphate exhibits no effect in all tested concentrations when combined with either PBS or control vector, ACE-GFP. Fludarabine phosphate causes a significant decrease in cell viability for 24 h after exposure to ACE-PNP when compared to PBS and ACE-GFP at concentrations of 2.5, 5 and 10 μg/mL^[2]. In Vivo: F-araAMP (100 mg/kg given 15 times, 167 mg/kg given 9 times, or 250 mg/kg given 3 times, i.p.) leads to complete regressions of all tumors and cures of all mice. Parental D54 tumors (i.e. without E. coli PNP) are not sensitive to treatment with F-araAMP. Intratumoral injection of Ad/PNP followed by IT F-araAMP can elicit a substantial regressive effect on otherwise refractory solid tumors in a fashion substantially superior to viral PNP transduction followed by systemic prodrug administration^[1]. The comparison of ACE-GFP/fludarabine phosphate with ACE-GFP/PBS demonstrats that fludarabine phosphate alone has no growth inhibitory activity on KU-19-19 tumors^[2].