NPP-669 (NPP669) is an orally bioavailable cidofovir (CDV) analogue and prodrug, has increased lipophilicity, improved oral absorption, reduced nephrotoxicity, increased cellular uptake, and increased activity against several dsDNA viruses compared to CDV.
NPP-669 exhibits two to three orders of magnitude improved antiviral activity compared to cidofovir (CDV, Vistide).
NPP-669 is more efficacious than antiviral compounds currently in clinical use against adenovirus (AdV-5), herpesviruses (HSV-1 and HSV-2, HCMV, VZV, EBV, HHV-6, and HHV-8) and polyomaviruses (JC and BK virus), while it is on par with BCV.
NPP-669 has a metabolic half-life of 202 min in rat hepatocytes, which was significantly improved compared to BCV.
NPP-669 is also significantly more potent than the parent drug CDV against HCMV.
NPP-669 (0.1 mg/kg) inhibits the replication of HAdV-C6 in the liver of immunosuppressed Syrian hamsters and prevents the resulting pathology.