In vitro effect of a non-immunosuppressive FKBP ligand, FK1706, on SARS-CoV-2 replication in combination with antivirals

FKBP, a naturally occurring ubiquitous intracellular protein, has been proposed as a potential target for coronavirus replication. A non-immunosuppressive FKBP ligand, FK1706, was studied in vitro in a Vero cell model to assess potential activity alone and in combination with antivirals against SARS-CoV-2 replication. When combined with remdesivir, synergistic activity was seen (summary synergy score 24.7<underline>+</underline>9.56). FK1706 warrants in vivo testing as a potential new combination therapeutic for the treatment of COVID-19 infections.