Identification of SARS-CoV-2 entry inhibitors among already approved drugs

Yang, Li; Pei, Rong-juan; Li, Heng; Ma, Xin-na; Zhou, Yu; Zhu, Feng-hua; He, Pei-lan; Tang, Wei; Zhang, Ye-cheng; Xiong, Jin; Xiao, Shu-qi; Tong, Xian-kun; Zhang, Bo; Zuo, Jian-ping

To discover effective drugs for COVID-19 treatment amongst already clinically approved drugs, we developed a high throughput screening assay for SARS-CoV-2 virus entry inhibitors using SARS2-S pseudotyped virus. An approved drug library of 1800 small molecular drugs was screened for SARS2 entry inhibitors and 15 active drugs were identified as specific SARS2-S pseudovirus entry inhibitors. Antiviral tests using native SARS-CoV-2 virus in Vero E6 cells confirmed that 7 of these drugs (clemastine, amiodarone, trimeprazine, bosutinib, toremifene, flupenthixol, and azelastine) significantly inhibited SARS2 replication, reducing supernatant viral RNA load with a promising level of activity. Three of the drugs were classified as histamine receptor antagonists with clemastine showing the strongest anti-SARS2 activity (EC(50) = 0.95 ± 0.83 µM). Our work suggests that these 7 drugs could enter into further in vivo studies and clinical investigations for COVID-19 treatment.