On May 1, 2020, the Food and Drug Administration (FDA) released its letter to Gilead Sciences granting its request for the emergency use of remdesivir. This emergency use authorization allows remdesivir to be used to treat patients, both adults and children, who have severe cases of COVID-19 that require respiratory assistance. Under the authorization, remdesivir will only be available for IV injection at hospitals for in-patient treatment.
Remdesivir is an antiviral drug that was originally developed to treat patients with Ebola or Marburg, two diseases caused by different viruses that are within the same family as one another. The drug is a nucleotide analogue, a molecule that mimics the structural units of DNA and RNA. Because it mimics the structural units of RNA, remdesivir can be incorporated into new RNA strands as a virus replicates itself. Once remdesivir has been incorporated, it prevents RNA polymerase, the protein that directs RNA replication, from working; thus, the virus cannot replicate itself and subsequently spread to new cells.
While the drug did not show clinical success for its initial disease targets, it has been shown to be active against single-stranded RNA viruses, such as the coronaviruses MERS and SARS. In March, based on their analysis of past clinical trials, the World Health Organization (WHO) included remdesivir as one of the four drugs to be studied in the Solidarity Clinical Trials, an international effort to find a COVID-19 treatment. In addition to the WHO led efforts, there are a number of ongoing clinical trials that are evaluating remdesivir as a potential treatment for COVID-19. Notably, remdesivir was used as part of the treatment for the first US case of COVID-19, with researchers noting no ill effects but highlighting the need for controlled trials to actually determine its safety and effectiveness as a treatment.