The bisbenzimide compound ridinilazole has antiviral activity against vaccinia and mpox viruses.
- 1Department of Microbial Sciences, University of Surrey, Guildford GU2 7XH, UK
- 2Institute of Infection & Immunity, St George’s School of Health and Medical Sciences, City St George’s, University of London, London, SW19 0RE, UK
- 3Department of Infectious Diseases, King’s College London, London SE1 9RT, UK
Abstract
Mpox remains a significant global public health threat, highlighting the need for new antiviral therapies. Ridinilazole is a symmetric bisbenzimide developed for the treatment of Clostridium difficile infection that has recently been shown to inhibit human cytomegalovirus. Here, we investigated its antiviral activity against orthopoxviruses (OPXV). Ridinilazole potently inhibited vaccinia virus replication in primary human foreskin fibroblasts, with an IC₅₀ of 21 nM and minimal cytotoxicity. Importantly, ridinilazole also reduced infectious monkeypox virus (the causative agent of mpox) yields in primary fibroblasts by more than 150-fold. Mechanistic studies demonstrated that ridinilazole did not affect early viral gene expression or viral DNA replication, but significantly reduced the expression of late viral genes at both transcript and protein levels. These findings identify ridinilazole as an effective inhibitor of OPXV replication and support its potential repurposing as a novel therapeutic for mpox.
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BibTeX
@article{eljesr2026bisbenzimide,
title = {{The bisbenzimide compound ridinilazole has antiviral activity against vaccinia and mpox viruses.}},
author = {Misbah El-Jesr and Lucy Eke and Blair L. Strang and Carlos Maluquer de Motes and Rebecca P. Sumner},
journal = {The Journal of general virology},
year = {2026},
month = nov,
doi = {10.1099/jgv.0.002363},
url = {https://europepmc.org/article/MED/42970349},
note = {CC BY},
}
RIS
TY - JOUR
TI - The bisbenzimide compound ridinilazole has antiviral activity against vaccinia and mpox viruses.
AU - Misbah El-Jesr
AU - Lucy Eke
AU - Blair L. Strang
AU - Carlos Maluquer de Motes
AU - Rebecca P. Sumner
PY - 2026
DA - 2026/11/01
JO - The Journal of general virology
DO - 10.1099/jgv.0.002363
UR - https://europepmc.org/article/MED/42970349
AB - Mpox remains a significant global public health threat, highlighting the need for new antiviral therapies. Ridinilazole is a symmetric bisbenzimide developed for the treatment of Clostridium difficile infection that has recently been shown to inhibit human cytomegalovirus. Here, we investigated its antiviral activity against orthopoxviruses (OPXV). Ridinilazole potently inhibited vaccinia virus replication in primary human foreskin fibroblasts, with an IC₅₀ of 21 nM and minimal cytotoxicity. Importantly, ridinilazole also reduced infectious monkeypox virus (the causative agent of mpox) yields in primary fibroblasts by more than 150-fold. Mechanistic studies demonstrated that ridinilazole did not affect early viral gene expression or viral DNA replication, but significantly reduced the expression of late viral genes at both transcript and protein levels. These findings identify ridinilazole as an effective inhibitor of OPXV replication and support its potential repurposing as a novel therapeutic for mpox.
SN - 0022-1317
SN - 1465-2099
ER -