The Food and Drug Administration (FDA) has revoked the Emergency Use Authorization (EUA) for bamlanivimab, an investigational monoclonal antibody therapy, for use as monotherapy in the treatment of mild to moderate COVID-19, based on emerging data suggesting an increased frequency of resistant SARS-CoV-2 variants.

In November 2020, the FDA issued an EUA for bamlanivimab monotherapy for the treatment of mild to moderate COVID-19 in adults and pediatric patients with positive results of direct SARS-CoV-2 viral testing who are 12 years of age and older weighing at least 40kg, and who are at high risk for progressing to severe COVID-19 and/or hospitalization. However, the Agency has determined that the known and potential benefits of bamlanivimab monotherapy no longer outweigh the known and potential risks for its authorized use.

According to recent data from the Centers for Disease Control and Prevention’s (CDC) national surveillance program, there has been an increase in the frequency of SARS-CoV-2 variants that are expected to be resistant to bamlanivimab. As of mid-March 2021, the CDC reported that roughly 20% of the viruses sequenced in the US were observed to be resistant to bamlanivimab monotherapy, an increase from approximately 5% seen in mid-January 2021. At this time, there are no testing technologies available to healthcare providers to aid in the detection of these variants prior to initiating monoclonal antibody therapy.

Alternative authorized monoclonal antibody therapies remain available for the treatment of COVID-19. These include casirivimab in combination with imdevimab and bamlanivimab in combination with etesevimab. The National Institutes of Health (NIH) recently provided updated COVID-19 Treatment Guidelines on the use of anti-SARS-CoV-2 monoclonal antibodies in outpatients with mild to moderate COVID-19 who are at high risk of disease progression.

“While the risk-benefit assessment for using bamlanivimab alone is no longer favorable due to the increased frequency of resistant variants, other monoclonal antibody therapies authorized for emergency use remain appropriate treatment choices when used in accordance with the authorized labeling and can help keep high risk patients with COVID-19 out of the hospital,” said Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research. “We urge the American public to seek out these therapies when needed while we continue to use the best data available to provide patients with safe and effective treatments during this pandemic.” 


Coronavirus (COVID-19) update: FDA revokes emergency use authorization for monoclonal antibody bamlanivimab. [press release]. Silver Spring, MD: US Food and Drug Administration; April 16, 2021.