Broad-spectrum antiviral brincidofovir inhibits Epstein-Barr virus and related gammaherpesvirus in human and nonhuman primate cells.

Epstein-Barr virus (EBV) is of growing interest for its potential role in neurodegenerative diseases such as multiple sclerosis (MS) and its possible utility as a therapeutic target in herpesvirus-associated chronic diseases. The effects of brincidofovir (BCV) on EBV reactivation were evaluated in vitro using EBV-infected spontaneous lymphoblastoid cell lines (SLCLs) and peripheral blood mononuclear cells (PBMCs) derived from patients with MS and healthy controls. In addition, a B lymphoblastoid cell line and PBMCs from common marmosets (Callithrix jacchus) naturally infected with an EBV-related gammaherpesvirus (Callitrichine herpesvirus 3, CalHV-3) were used to measure BCV efficacy in a nonhuman primate model. BCV significantly inhibited gammaherpesvirus reactivation, with decreased lytic and latent viral transcript expression. These results suggest that BCV may be a useful antiviral for inhibiting EBV activity in patients with MS. Additionally, this work further validates the utility of CalHV-3 in marmosets as a translational model for the investigation of successful EBV-targeting therapeutics.