• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

J Antimicrob Chemother . Efficacy comparison of 3CL protease inhibitors ensitrelvir and nirmatrelvir against SARS-CoV-2 in vitro and in vivo

tetano

Editor, Senior Moderator
J Antimicrob Chemother


. 2023 Feb 10;dkad027.
doi: 10.1093/jac/dkad027. Online ahead of print.
Efficacy comparison of 3CL protease inhibitors ensitrelvir and nirmatrelvir against SARS-CoV-2 in vitro and in vivo


Takayuki Kuroda[SUP] 1 [/SUP], Haruaki Nobori[SUP] 1 [/SUP], Keita Fukao[SUP] 1 [/SUP], Kaoru Baba[SUP] 2 [/SUP], Kazumi Matsumoto[SUP] 2 [/SUP], Shinpei Yoshida[SUP] 1 [/SUP], Yukari Tanaka[SUP] 1 [/SUP], Ryosuke Watari[SUP] 1 [/SUP], Ryoko Oka[SUP] 1 [/SUP], Yasuyuki Kasai[SUP] 1 [/SUP], Kae Inoue[SUP] 2 [/SUP], Sho Kawashima[SUP] 1 [/SUP], Alice Shimba[SUP] 1 [/SUP], Yoko Hayasaki-Kajiwara[SUP] 1 [/SUP], Miki Tanimura[SUP] 1 [/SUP], Qianhui Zhang[SUP] 1 [/SUP], Yuki Tachibana[SUP] 1 [/SUP], Teruhisa Kato[SUP] 1 [/SUP], Takao Shishido[SUP] 1 [/SUP]



Affiliations

Abstract

Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become established in the human population, making the need to develop safe and effective treatments critical. We have developed the small-molecule antiviral ensitrelvir, which targets the 3C-like (3CL) protease of SARS-CoV-2. This study evaluated the in vitro and in vivo efficacy of ensitrelvir compared with that of another SARS-CoV-2 3CL PI, nirmatrelvir.
Methods: Cultured cells, BALB/cAJcl mice and Syrian hamsters were infected with various SARS-CoV-2 strains, including the ancestral strain WK-521, mouse-adapted SARS-CoV-2 (MA-P10) strain, Delta strain and Omicron strain. Ensitrelvir efficacy was compared with that of nirmatrelvir. Effective concentrations were determined in vitro based on virus-induced cytopathic effects, viral titres and RNA levels. Lung viral titres, nasal turbinate titres, body-weight changes, and animal survival were also monitored.
Results: Ensitrelvir and nirmatrelvir showed comparable antiviral activity in multiple cell lines. Both ensitrelvir and nirmatrelvir reduced virus levels in the lungs of mice and the nasal turbinates and lungs of hamsters. However, ensitrelvir demonstrated comparable or better in vivo efficacy than that of nirmatrelvir when present at similar or slightly lower unbound-drug plasma concentrations.
Conclusions: Direct in vitro and in vivo efficacy comparisons of 3CL PIs revealed that ensitrelvir demonstrated comparable in vitro efficacy to that of nirmatrelvir in cell culture and exhibited equal to or greater in vivo efficacy in terms of unbound-drug plasma concentration in both animal models evaluated. The results suggest that ensitrelvir may become an important resource for treating individuals infected with SARS-CoV-2.
 
Back
Top Bottom