The US Food and Drug Administration (FDA) has revoked the emergency use authorization (EUA) that allowed for chloroquine phosphate and hydroxychloroquine sulfate to be used to treat certain hospitalized patients with COVID-19 when a clinical trial was unavailable or participation in a clinical trial was not feasible.

“Based on its ongoing analysis of the EUA and emerging scientific data, the FDA determined that chloroquine and hydroxychloroquine are unlikely to be effective in treating COVID-19 for the authorized uses in the EUA,” said the FDA in a June 15, 2020 statement. “Additionally, in light of ongoing serious cardiac adverse events and other potential serious side effects, the known and potential benefits of chloroquine and hydroxychloroquine no longer outweigh the known and potential risks for the authorized use.”

The Biomedical Advanced Research and Development Authority (BARDA) within the US Department of Health and Human Services originally requested the EUA covering chloroquine and hydroxychloroquine, and the FDA granted the EUA on March 28, 2020 based on the science and data available at the time. In consultation with the FDA, BARDA sent a letter to the FDA requesting revocation of the EUA based on up-to-date science and data.

The FDA pointed to recent results from a large randomized clinical trial in hospitalized patients, a population similar to the population for which chloroquine and hydroxychloroquine were authorized for emergency use, which demonstrated that hydroxychloroquine showed no benefit on mortality or in speeding recovery. This outcome was consistent with other new data, including data showing that the suggested dosing regimens for chloroquine and hydroxychloroquine are unlikely to kill or inhibit the virus that causes COVID-19.

Chloroquine and hydroxychloroquine are both FDA-approved to treat or prevent malaria. Hydroxychloroquine is also approved to treat autoimmune conditions such as chronic discoid lupus erythematosus, systemic lupus erythematosus in adults, and rheumatoid arthritis.

In a related development, in a press briefing this week (June 17, 2020), the World Health Organization (WHO) reported that it has stopped research on evaluating hydroxychloroquine as a treatment for COVID-19 in hospitalized patients by pointing to several studies that the drug had no impact.

The WHO has 3,500 patients from 17 countries enrolled in a global clinical trial, the Solidarity Trial, in which one arm of the trial was evaluating hydroxychloroquine in COVID-19 patients. On the basis of that trial and another trial in France evaluating hydroxychloroquine in COVID-19 patients, an executive group decided to stop the hydroxychloroquine arm of the Solidarity trial.

In a statement, a WHO official said that “hydroxychloroquine, when compared with the standard of care in the treatment of hospitalized COVID patients does not result in the reduction of the mortality of those patients.”

The decision does not apply to the use or the evaluation of hydroxychloroquine as post-exposure prophylaxis in patients exposed to COVID-19.

Source: US Food and Drug Administration and the World Health Organization