FDA Revokes COVID-19 Emergency Authorization for Lone Bamlanivimab

The US Food and Drug Administration (FDA) has revoked the emergency use authorization (EUA) for investigational monoclonal antibody therapy bamlanivimab as a lone therapy for the treatment of mild-to-moderate COVID-19 in adults and indicated pediatric patients.

The decision is based on continued assessment of emerging data—specifically geared toward SARS-CoV-2 variants that show resistance to lone bamlanivimab and reduced likelihood of treatment efficacy—that indicates a change in known and potential benefits of the monoclonal antibody versus the known and potential risks of its emergency use.

The Eli Lilly and Co. investigational therapy was originally granted its EUA on November 9, 2020, for the treatment of COVID-19 in adults and pediatric patients aged ≥12 years old weighing at least 40 kg, with positive SARS-CoV-2, and who are at high risk for progressing to severe COVID-19.

The decision proceeded a request from Eli Lilly to revoke the EUA, as they modified contracts with the federal government to assure adequate supply of etesevimab in combination with bamlanivimab—another available monoclonal antibody regimen from the company.

"Lilly moved quickly to make bamlanivimab alone available as a potentially lifesaving medicine at a time when Americans were hardest hit by COVID-19," Daniel Skovronsky, MD, PhD, Lilly's chief scientific officer and president of Lilly Research Laboratories, said in a statement. "With the growing prevalence of variants in the US 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."

As the FDA stressed in this EUA revocation, monoclonal antibody therapy is still authorized and even approved in some iterations for the very same treatment of COVID-19, including combination casirivimab and imdevimab (REGEN-COV) and combinated bamlanivimab and etesevimab. No emerging data would indicate that the benefit of these combination therapy regimens is compromised significantly by the prevalence of SARS-CoV-2 variants.

Since last month, approximately 1 in 5 sequenced SARS-CoV-2 viruses in the US were reported as variants likely resistant to lone bamlanivimab—a significant jump from the approximate 1 in 20 reported in mid-January this year.

Because no testing technologies are available for healthcare providers to test for SARS-CoV-2 variants prior to monoclonal antibody treatment, the FDA reasoned authorized regimens should entail those known to work broadly against all nationwide-circulating variants.

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

“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.”