TABLE 3.
Summary of in vitro studies for nafamostat
| Drug | EC50 (µM) | CC50 (µM) | Cell line | Postinfection treatment time (h) | MOI | Virus quantification method | fu*PK/EC50 | Reference |
|---|---|---|---|---|---|---|---|---|
| Nafamostat | 22.5 | >100 | VeroE6 | 48 | 0.05 | qRT‐PCR | 0.0115 | 17 |
| Nafamostat | 39.54 | 3639.15 | VeroE6 | 48 | 0.025 | Immunofluorescencea | 0.0066 | 18 |
| Nafamostat | 31.6 | N.R. | VeroE6/TMPRSS2 | 72 (pretreatment) | 0.01 | Cytopathic effect | 0.0082 | 9 |
| Nafamostat | >100 | N.R. | VeroE6/TMPRSS2 | 72 (no pretreatment) | 0.01 | Cytopathic effect | <0.0026 | 9 |
| Nafamostat | 3.16 | N.R. | Calu‐3 | 120 (no pretreatment) | 0.01/0.1 | Cytopathic effect | 0.0821 | 9 |
| Nafamostat | 0.0068 | N.R. | Calu‐3 | 120 (pretreatment) | 0.01 | Cytopathic effect | 38.14 | 9 |
| Nafamostat | 0.0115 | N.R. | Calu‐3 | 120 (pretreatment) | 0.1 | Cytopathic effect | 22.55 | 9 |
| Nafamostat | 13.88 | N.R. | Vero | N.R. | N.R. | N.R. | 0.0187 | 19 |
| Nafamostat | 0.0022 | >25 | Calu‐3 | 24 | 0.1 | Immunofluorescencea | 117.89 | 19 |
Abbreviations: CC50, the drug concentration that reduces the total cell number by 50%; EC50, the drug concentration that inhibits 50% of the virus; MOI, multiplicity of infection; N.R., not reported; PK, pharmacokinetic; qRT‐PCR, quantitative real‐time reverse transcription–polymerase chain reaction; TMPRSS2, transmembrane serine protease 2.
a
Labeling the viral N protein; VeroE6/TMPRSS2: VeroE6 cells expressing TMPRSS2.