Clofazimine is a phenazine dye with anti-mycobacterial action (possibly via
DNA binding) but is no longer perscribed in the US. It also has anti-inflammatory activities. State-dependent block of Kv
1.3 channels by clofazimine offers therapeutic potential for selective immunosuppression in the context of autoimmune diseases in which Kv
1.3-expressing T cells play a significant role [3
A report in Nature has identified that clofazimine has anti-coronavirus activity, and that this is synergistic with the antiviral activity of remdesivir
]. The drug was found to inhibit viral spike-mediated cell fusion and viral helicase activity in vitro
, which translated to reduced pulmonary viral load, gut viral shedding and inflammation in an in vivo
infection model. The authors suggest that their data supports the use of clofazimine in an outpatient setting for those infected with SARS-CoV-2, or for hospitalised COVID-19 patients if combined with remdesivir. Based on this evidence it is planned to progress clofazimine + remdesivir directly into Phase 2 clinical trial. A trial of clofazimine + interferon-1β is already underway.