US FDA revokes EUA for chloroquine and hydroxychloroquine

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

The agency determined that the legal criteria for issuing a EUA are no longer met. In a press statement, the drug regulator said that 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 authorised uses in the EUA.

“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 authorised use,” informed the statement.

This is the statutory standard for issuance of an EUA. 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 recently sent a letter to the FDA requesting revocation of the EUA based on up to date science and data.

The statement updated, “The FDA has a responsibility to regularly review the appropriateness of an EUA, and as such, the agency will review emerging information associated with the emergency uses for the authorised products. Recent results from a large randomised clinical trial in hospitalised patients, a population similar to the population for which chloroquine and hydroxychloroquine were authorised for emergency use, 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. The totality of scientific evidence currently available indicates a lack of benefit.”

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. FDA has determined that these drugs are safe and effective when used for these diseases in accordance with their FDA-approved labelling.