FDA approved drugs with broad anti-coronaviral activity inhibit SARS-CoV-2 in vitro

Stuart Weston; Rob Haupt; James Logue; Krystal Matthews; Matthew B. Frieman

Our initial screening started at 50µM and used an 8-point, 1:2 dilution series with infections being performed at either MOI 0.01 or 0.004. Cells were pre-treated with drug for 2 h prior to infection. 3 days post-infection CellTiter-Glo (CTG) assays were performed to determine relative cell viability between drug and vehicle control treated cells. Uninfected samples were used to measure the cytotoxicity of compound alone. From the relative luminescence data of the CTG assay, percent inhibition (of cell death caused by viral infection) could be measured and plotted along with the percent cytotoxicity of drug alone. Fig. 1 shows these plotted graphs from one representative of three independent screens. For those drugs demonstrating a cell toxicity rate lower than 30%, we were able to calculate IC50 values from these graphs for 17 of the 20 drugs which is summarized in Table 1 .