Since FDA initially authorized CQ and HCQ for emergency use on March 28, 2020, new scientific and clinical data, as well as published literature, have raised questions regarding whether CQ and HCQ may be effective in treating COVID-19 and whether CQ and HCQ’s known and potential benefits outweigh the known and potential risks associated with their authorized use. FDA has reviewed this information and data as part of its ongoing assessment of whether an EUA remains appropriate.
Based on its review, the Agency has determined the following:
- The suggested dosing regimens for CQ and HCQ as detailed in the Fact Sheets are unlikely to produce an antiviral effect.
- Earlier reports of decreased viral shedding with HCQ or CQ treatment have not been consistently replicated and recent data from a randomized controlled trial assessing probability of negative conversion showed no difference between HCQ and standard of care alone.
- Current U.S. treatment guidelines do not recommend the use of HCQ or CQ in hospitalized patients with COVID-19 outside of a clinical trial, and the NIH guidelines now recommend against such use outside of a clinical trial.
- Recent data from a large randomized controlled trial showed no evidence of benefit for mortality or other outcomes such as hospital length of stay or need for mechanical ventilation of HCQ treatment in hospitalized patients with COVID-19.
Therefore, based on the totality of scientific evidence available, it is no longer reasonable to believe that CQ and HCQ may be effective in treating COVID-19 for the authorized uses detailed in EUA 039. Further, in considering the known safety profile for both CQ and HCQ and the ongoing reports of serious cardiac adverse events, in addition to several new reports of methemoglobinemia in COVID-19 patients, it is no longer reasonable to believe that the known and potential benefits of CQ and HCQ outweigh the known and potential risks associated with the authorized use.
BARDA has received few reports from healthcare providers and/or provider designees detailing outcome data as requested in the EUA. Interpretation of these data is limited due to the low number of patients with a reported outcome and the absence of a comparison group. A review of recent published literature describing observational studies does not provide informative findings given residual confounding and other methodological issues.
Based on the above, FDA concludes that the criteria for Emergency Use Authorization as outlined in Section 564(c)(2) of the FD&C Act are no longer met and is revoking EUA 039 for CQ and HCQ for the treatment of COVID-19.