Large scale screening discovers clofoctol as an inhibitor of SARS-CoV-2 replication that reduces COVID-19-like pathology

Drug repurposing has the advantage of shortening regulatory preclinical development steps. Here, we screened a library of drug compounds, already registered in one or several geographical areas, to identify those exhibiting antiviral activity against SARS-CoV-2 with relevant potency. Of the 1,942 compounds tested, 21 exhibited a substantial antiviral activity in Vero-81 cells. Among them, clofoctol, an antibacterial drug used for the treatment of bacterial respiratory tract infections, was further investigated due to favorable safety profile and pharmacokinetic properties. Notably, the peak concentration of clofoctol that can be achieved in human lungs is more than 20 times higher than its IC50 measured against SARS-CoV-2 in human pulmonary cells. This compound inhibits SARS-CoV-2 at a post-entry step. Lastly, therapeutic treatment of human ACE2 receptor transgenic mice decreased viral load, reduced inflammatory gene expression and lowered pulmonary pathology. Altogether, these data strongly support clofoctol as a therapeutic candidate for the treatment of COVID-19 patients. SummaryAntivirals targeting SARS-CoV-2 are sorely needed. In this study, we screened a library of drug compounds and identified clofoctol as an antiviral against SARS-CoV-2. We further demonstrated that, in vivo, this compound reduces inflammatory gene expression and lowers pulmonary pathology.

Modulators of hERAP2 discovered by high-throughput screening.

Endoplasmic reticulum aminopeptidase 2, ERAP2, is an emerging pharmacological target in cancer immunotherapy and control of autoinflammatory diseases, as it is involved in antigen processing. It has been linked to the risk of development of spondyloarthritis, and it associates with the immune infiltration of tumours and strongly predicts the overall survival for patients receiving check-point inhibitor therapy. While some selective inhibitors of its homolog ERAP1 are available, no selective modulator of ERAP2 has been disclosed so far. In order to identify such compounds, we screened an in-house focused library of 1920 compounds designed to target metalloenzymes. Structure-Activity Relationships and docking around two hits led to the discovery of selective inhibitors of ERAP2. Amid those, some bind to yet untapped amino-acids in the S1 pocket. Importantly, we disclose also the first activator of small substrates hydrolysis by ERAP2. Inhibitors and activators identified in this study could serve as useful starting points for optimization.