According to the agency, the EUA was revoked because a clinical trial demonstrated that the drugs had no benefit on mortality or in speeding recovery. Furthermore, recent data suggested the drugs do not kill or inhibit SARS-CoV-2, therefore the legal criteria for issuing the EUA are no longer met. Based on its ongoing analysis, the FDA determined that the drugs are unlikely to be effective in treating COVID-19 for authorized uses in the EUA. Furthermore, in consideration of ongoing serious cardiac side effects from the drugs, the benefits of chloroquine and hydroxychloroquine no longer outweigh the known and potential risks for authorized use.

The EUA was originally issued on March 28 at the request of the U.S. Biomedical Advanced Research and Development Authority (BARDA). Today, June 15, in consultation with the FDA, BARDA sent a letter to the FDA requesting revocation of the EUA based on new science and data.

The FDA has a responsibility to regularly review the appropriateness of EUAs, and the agency will continue to review emerging information associated with emergency uses for the authorized products, including chloroquine and hydroxychloroquine.