Christine Espiritu

TL;DR: Phosphoramidate prodrugs of the 5'-phosphate derivative of the β-d- 2'-deoxy-2'-α-fluoro-2-β-C-methyluridine nucleoside showed significant potency in the HCV subgenomic replicon assay and produced high levels of triphosphates 6 in primary hepatocytes and in the livers of rats, dogs, and monkeys when administered in vivo.

TL;DR: A phosphoramidate prodrug of 2′-deoxy-2′-α-fluoro-β-C-methyluridine-5′-monophosphate, PSI-7851, demonstrates potent anti-hepatitis C virus (HCV) activity both in vitro and in vivo.

TL;DR: Data from the JFH-1 replicon variants showed that amino acid changes within the finger and palm domains together with S282T were required to confer resistance to PSI-7977, while the mutations on the thumb domain serve to enhance the replication capacity of the S282 T replicons.

TL;DR: Clearance studies using replicon cells demonstrated that PSI-7851 was able to clear cells of HCV replicon RNA and prevent viral rebound, and cross-resistance studies using Replicon mutants conferring resistance to modified nucleoside analogs showed thatPSI- 7851 was less active against the S282T replicon mutant, whereas cells expressing a replicon containing the S96T/N142T mutation remained fully susceptible to PSI.

TL;DR: The crystal structure provides understanding of a drug efficacy mechanism related to the induction and stabilization of protein–protein interactions and enables structure-guided design to improve antiviral potency and drug-like properties.