Clinical benefit of remdesivir treatment in rhesus macaques infected with SARS-CoV-2

Effective therapeutics to treat COVID-19 are urgently needed. Remdesivir is a nucleotide prodrug with in vitro and in vivo efficacy against coronaviruses. Here, we tested the efficacy of remdesivir treatment in a rhesus macaque model of SARS-CoV-2 infection.To evaluate the effect of remdesivir treatment on SARS-CoV-2 disease outcome, we used the recently established rhesus macaque model of SARS-CoV-2 infection that results in transient lower respiratory tract disease. Two groups of six rhesus macaques were infected with SARS-CoV-2 and treated with intravenous remdesivir or an equal volume of vehicle solution. Clinical, virological and histological parameters were assessed to determine treatment efficacy. In contrast to vehicle-treated animals, animals treated with remdesivir did not show signs of respiratory disease and had reduced pulmonary infiltrates on x-ray. Virus titers in bronchoalveolar lavages were significantly reduced 12hrs after the first treatment was administered. At necropsy on day 7 after inoculation, viral loads in the lungs of remdesivir-treated animals were significantly lower and there was a clear reduction in damage to the lung tissue. Therapeutic remdesivir treatment delivered before the peak of virus replication has a clear clinical benefit during SARS-CoV-2 infection in rhesus macaques. These data support early remdesivir treatment in COVID-19 patients to prevent progression to severe pneumonia.