On Nov. 9, 2020, a National Institutes of Health clinical trial evaluating the safety and effectiveness of hydroxychloroquine for the treatment of adults with coronavirus disease 2019 (COVID-19) formally concluded that the drug provided no clinical benefit to hospitalized patients.

Though found not to cause harm, early findings in Jun. when the trial was stopped indicated that the drug was not improving outcomes in COVID-19 patients. Final data and analyses of the trial, which was funded by the NIH, appeared in the Journal of the American Medical Association.