key: cord-1044726-xqlnavay
authors: Shionoya, Kaho; Yamasaki, Masako; Iwanami, Shoya; Ito, Yusuke; Fukushi, Shuetsu; Ohashi, Hirofumi; Saso, Wakana; Tanaka, Tomohiro; Aoki, Shin; Kuramochi, Kouji; Iwami, Shingo; Takahashi, Yoshimasa; Suzuki, Tadaki; Muramatsu, Masamichi; Takeda, Makoto; Wakita, Takaji; Watashi, Koichi
title: Anti-severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) potency of Mefloquine as an entry inhibitor in vitro
date: 2020-11-20
journal: bioRxiv
DOI: 10.1101/2020.11.19.389726
sha: f09768733b374e8c16acce23a5c3d3e942e7e110
doc_id: 1044726
cord_uid: xqlnavay

Coronavirus disease 2019 (COVID-19) has caused serious public health, social, and economic damage worldwide and effective drugs that prevent or cure COVID-19 are urgently needed. Approved drugs including Hydroxychloroquine, Remdesivir or Interferon were reported to inhibit the infection or propagation of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), however, their clinical efficacies have not yet been well demonstrated. To identify drugs with higher antiviral potency, we screened approved anti-parasitic/anti-protozoal drugs and identified an anti-malarial drug, Mefloquine, which showed the highest anti-SARS-CoV-2 activity among the tested compounds. Mefloquine showed higher anti-SARS-CoV-2 activity than Hydroxychloroquine in VeroE6/TMPRSS2 and Calu-3 cells, with IC50 = 1.28 μM, IC90 = 2.31 μM, and IC99 = 4.39 μM in VeroE6/TMPRSS2 cells. Mefloquine inhibited viral entry after viral attachment to the target cell. Combined treatment with Mefloquine and Nelfinavir, a replication inhibitor, showed synergistic antiviral activity. Our mathematical modeling based on the drug concentration in the lung predicted that Mefloquine administration at a standard treatment dosage could decline viral dynamics in patients, reduce cumulative viral load to 7% and shorten the time until virus elimination by 6.1 days. These data cumulatively underscore Mefloquine as an anti-SARS-CoV-2 entry inhibitor.

In this study, we mainly used VeroE6/TMPRSS2 cells, which is established by 

Aiming to identify drugs with greater anti-SARS-CoV-2 potential than HCQ, we 

We next compared the antiviral activities of MFQ with that of HCQ and an 138 additional Chloroquine derivative, Primaquine (PRQ), as a reference. 

The octanol-water partition coefficient (log P) values of MFQ, HCQ, Quinine, 

The pseudovirus assay showed that SARS-CoV-2 Spike-dependent viral entry was 219 significantly inhibited by the TMPRSS2 inhibitor Camostat, and by MFQ to similar 220 levels to those of E-64d (Fig. 3E, left) . However, the assay sensitivity itself was 

Cumulative viral load, which is the area under the curve for the viral load over the 259 time course, was calculated to be reduced by 6.98% (Fig. 5C) . The time until the 260 viral load declines beneath the detectable level is 15.2 days without treatment, but 261 it was calculated to be shortened to 9.10 days after MFQ treatment (Fig. 5D ). 

Chloroquine analogues in drug discovery: new directions of uses