COVID-19 Pandemic: Time to Revive the Cyclophilin Inhibitor Alisporivir.

December 2019 saw the emergence of a new epidemic of pneumonia of varying severity, called coronavirus disease 2019 (COVID-19), caused by a newly identified coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV-2). No therapeutic option is available to treat this infection that has already killed > 310 000 people worldwide. This Viewpoint summarizes the strong scientific arguments supporting the use of alisporivir, a nonimmunosuppressive analogue of cyclosporine A with potent cyclophilin inhibition properties that has reached phase 3 clinical development, for the treatment of COVID-19. They include the strong cyclophilin dependency of the life cycle of many coronaviruses, including severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, and preclinical data showing strong antiviral and cytoprotective properties of alisporivir in various models of coronavirus infection, including SARS-CoV-2. Alisporivir should be tested without delay on both virological and clinical endpoints in patients with or at risk of severe forms of SARS-CoV-2 infection.