FDA rescinds emergency authorization for COVID-19 antibody treatment bamlanivimab

The Food and Drug Administration (FDA) rescinded its emergency use authorization for the monoclonal antibody bamlanivimab to be used on its own as treatment against COVID-19 due to variants’ resistance to the therapy.

The federal agency declared its cancelation of bamlanivimab-only COVID-19 therapy hours after the company Eli Lilly requested the FDA revoke the emergency authorization because the variants resistant to the treatment have become more common. 

With the number of resistant infections growing, the agency concluded that the benefits of treating COVID-19 with only bamlanivimab “no longer outweigh the known and potential risks for its authorized use.” 

The FDA cited data that as of mid-March about 20 percent of variants in the U.S. were expected to be resistant to bamlanivimab, compared to 5 percent in January.

But the FDA still grants bamlanivimab and another monoclonal antibody, etesevimab, to be used together to treat COVID-19 under an emergency use authorization. In a March study, Eli Lilly determined the combination of monoclonal antibodies — lab-created proteins that copy how the immune system responds to viruses — reduced the risk of hospitalization and death from COVID-19 by 87 percent.

“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,” Patrizia Cavazzoni, the director of the FDA’s Center for Drug Evaluation and Research, said in a release. 

“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,” Cavazzoni added. 

The emergency use authorization for bamlanivimab-only COVID-19 treatment, granted in November, was the first monoclonal antibody approved to treat mild to moderate COVID-19 cases. It originally allowed it to be used alone for mild-to-moderate COVID-19 adult patients and some children at high risk of severe coronavirus illness or hospitalization. 

The federal agency said it will work with the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) to monitor how variants impact the treatments authorized for emergency use. 

Eli Lilly called for the FDA to end emergency authorization for bamlanivimab-only COVID-19 treatment “due the evolving variant landscape in the U.S. and the full availability of bamlanivimab and etesevimab together.” The company noted its request for authorization to be revoked was “not due to any new safety concern.”

The company reported that more than 400,000 patients were treated with bamlanivimab, saying it potentially prevented more than 20,000 hospitalizations and at least 10,000 deaths in the U.S.

“With the growing prevalence of variants in the U.S. that bamlanivimab alone may not fully neutralize, and with sufficient supply of etesevimab, we believe now is the right time to complete our planned transition and focus on the administration of these two neutralizing antibodies together,” Eli Lilly’s Chief Scientific Officer and President of Lilly Research Laboratories Daniel Skovronsky said in the release. 

Eli Lilly’s request came after the Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response declared in March the U.S. had stopped using bamlanivimab alone to treat COVID-19.