FDA recently revoked a multi-month Emergency Use Authorization (the EUA) for use of chloroquine and hydroxychloroquine as an experimental treatment for patients suffering from COVID-19. FDA explained in its revocation letter that based on an analysis of months of data, it was determined that the drugs may not be effective to treat COVID-19, and, in fact, the known and potential risks outweighed the drugs' potential benefits. This revocation covers only the EUA and does not affect the FDA approval of chloroquine and hydroxychloroquine for other uses. Indeed, there are additional clinical trials that continue to evaluate the potential benefit of these drugs in treating or preventing COVID-19.

An EUA may be issued by FDA if it concludes that based on the totality of the scientific evidence available, the product may be effective in diagnosing, treating or preventing such disease or condition, and "the known and potential benefits of the product, when used to diagnose, prevent, or treat such disease or condition, outweigh the known and potential risks of the product . . ."

On March 28, 2020, based on a recommendation from the Biomedical Advanced Research and Development Authority (BARDA) within Health and Human Services, FDA issued the EUA that allowed the use of oral formulations of chloroquine phosphate and hydroxychloroquine sulfate (referred to herein as "chloroquine" and "hydroxychloroquine") that was donated to the Strategic National Stockpile (SNS) to be used to treat hospitalized patients with COVID-19. FDA decided to revoke the EUA based on the updated recommendation from BARDA.

An eleven (11) page memo explaining the scientific bases behind BARDA's recommendation and FDA's decision to revoke the EUA is appended to FDA's revocation letter. FDA summarized the below bases for concluding that the risks of chloroquine and hydroxychloroquine as a treatment for COVID-19 outweigh the risks.

  • The suggested dosing regimen for the chloroquine and hydroxychloroquine are "unlikely to produce an antiviral effect."
  • Earlier observed decrease in viral shedding with the drug treatments could not be consistently replicated.
  • Current US treatment guidelines and NIH guidelines do not recommend the use of the chloroquine and hydroxychloroquine outside of a clinical trial.
  • Recent data from a large randomized controlled trial showed no evidence of benefit for mortality or other beneficial outcomes.

In addition to the revocation letter and memo, FDA has also published a FAQ sheet regarding the revocation of the EUA.

What Does This Mean For Chloroquine and Hydroxychloroquine Moving Forward?

Treatments using chloroquine and hydroxychloroquine that began under authorization of the EUA may be continued to finish the treatment course. Although the EUA has been revoked, the use of chloroquine and hydroxychloroquine that were distributed form the SNS under the EUA is still authorized to treat any hospitalized patient to whom the authorized product has already been administered during the COVID-19 public health emergency, to the extent found necessary by the patient's attending physician.

In addition, chloroquine and hydroxychloroquine are still FDA approved drugs to treat specific indications. Both chloroquine and hydroxychloroquine are FDA-approved to treat or prevent malaria. Hydroxychloroquine is also approved to treat certain autoimmune conditions. The approvals by the FDA to treat these conditions has not been affected by FDA's revocation of the EUA and they may still be prescribed. Indeed, FDA noted in its press release accompanying this revocation, that "FDA approved products may be prescribed by physicians for off-label uses if they determine it is appropriate for treating their patients, including during COVID." There are ongoing clinical trials that continue to evaluate the potential benefit of these drugs in treating or preventing COVID-19.

Hydroxychloroquine that was distributed from SNS and constitutes an FDA-approved product, i.e., FDA-approved hydroxychloroquine, may still be distributed into interstate commerce. However, the specific chloroquine product that was authorized under the EUA has not been approved by FDA for any indication and therefore cannot be distributed into interstate commerce.

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