The US Food and Drug Administration (FDA) has revoked its emergency use authorization (EUA) that allowed for chloroquine phosphate and hydroxychloroquine sulfate 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.

In a statement, the FDA says the legal criteria for issuing an EUA are no longer met.

“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. 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,” the agency says.

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.

“We’ve made clear throughout the public health emergency that our actions will be guided by science and that our decisions may evolve as we learn more about the SARS-CoV-2 virus, review the latest data, and consider the balance of risks versus benefits of treatments for COVID-19,” said FDA Deputy Commissioner for Medical and Scientific Affairs Anand Shah.

“The FDA always underpins its decision-making with the most trustworthy, high-quality, up-to-date evidence available. We will continue to examine all of the emergency use authorisations the FDA has issued and make changes, as appropriate, based on emerging evidence.”

According to the FDA’s statement, 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 indicate a lack of benefit.

“While additional clinical trials continue to evaluate the potential benefit of these drugs in treating or preventing COVID-19, we determined the emergency use authorisation was no longer appropriate. This action was taken following a rigorous assessment by scientists in our Center for Drug Evaluation and Research,” said Patrizia Cavazzoni, acting director of the FDA’s Center for Drug Evaluation.

Chloroquine and hydroxychloroquine are both 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. Both drugs have been prescribed for years to help patients with these debilitating, or even deadly, diseases, and FDA has determined that these drugs are safe and effective when used for these diseases in accordance with their FDA-approved labeling.

Source: FDA statement