Fig. 1
Definition of a potential orally anti-SARS-CoV-2 drug ATV014 and its preclinical characterization. a The chemical structures of remdesivir, GS-441524 and ATV014. b Antiviral activity of RDV, GS-441524, and ATV014 against B.1, Beta, Delta, and Omicron strains of SARS-CoV-2 and corresponding cytotoxicity in Vero E6 cells. c Schematic of the prophylactic efficacy in a K18-hACE2 mice model. K18-hACE2 mice were intranasally inoculated with SARS-CoV-2 Delta variant (5 × 102 PFU virus per mouse) and were immediately oral treated with vehicle, ATV014 (100, 300 mg/kg) or EIDD-2801 (300 mg/kg), before the inoculation and continued for three days (bis in die (BID), n = 4 per group). Following results demonstrated the abundance of SARS-CoV-2 N gene copies in mouse lungs via qRT-PCR (quantitative real-time polymerase chain reaction) and virus viability via FFA (focus forming assay) at 3 dpi. The detection limit of qRT-PCR was 0.5 copies/μL. The red dashed line indicates the limit of detection for the FFA. d Flowsheet of the therapeutic efficacy. K18-hACE2 mice were intranasally inoculated with the SARS-CoV-2 Delta variant (5 × 102 PFU per mouse) and were treated with vehicle, ATV014 (10, 20, 50, 100 or 200 mg/kg), or EIDD-2801 (200 mg/kg) at two hours after SARS-CoV-2 infection (n = 10 per group). Following results showed the abundance of SARS-CoV-2 N gene copies in mouse lungs via qRT-PCR and virus viability via FFA at 3 dpi. e Representative H&E images of lung sections of the lungs of the vehicle-treated, 100 mg/kg ATV014-treated and 200 mg/kg ATV014-treated mice. f Mean plasma concentrations of ATV014 following single intravenous (1.0 mg/kg) and oral (5 and 20 mg/kg) administration of ATV014 in CD1 mice (n = 3 per group). single intravenous (1.0 mg/kg) and oral (20, 40 and 80 mg/kg) administration of ATV014 in SD rats (n = 6 per group) and single intravenous (1 mg/kg) and oral (5, 15, and 45 mg/kg) administration in beagle dogs (n = 6 per group). g Tissue distribution of the key metabolite GS-441524 in male rats after a single oral administration of ATV014 at 80 mg/kg. SI: small intestine; LI: large intestine. Error bars indicate SEM. A Kruskal–Wallis test was used for statistical analysis. ∗P ≤ 0.05; ∗∗P ≤ 0.005; ∗∗∗P ≤ 0.0005; ∗∗∗∗P ≤ 0.0001
