The Food and Drug Administration (FDA) has expanded the Emergency Use Authorization (EUA) for bamlanivimab plus etesevimab to include postexposure prophylaxis for COVID-19 in individuals 12 years of age and older weighing at least 40kg who are at high risk for progression to severe COVID-19, including hospitalization or death.

The monoclonal antibody therapy may be administered to high risk individuals who have not been fully vaccinated against COVID-19 or are not expected to mount an adequate immune response to complete vaccination, and have been exposed to SARS-CoV-2, or who are at high risk of exposure in an institutional setting (eg, nursing home, prison).

The expanded authorization was based on data from Part 1 of the randomized, double-blind, placebo-controlled phase 3 BLAZE-2 trial ( Identifier: NCT04497987), which evaluated bamlanivimab alone for the prevention of COVID-19 in residents and staff of long-term care facilities. Study participants were randomly assigned to receive bamlanivimab 4200mg or placebo as a single intravenous infusion. Results of baseline testing for SARS-CoV-2 were not known until after the therapy was administered.

The study included 966 adults who tested negative for SARS-CoV-2 at baseline in the primary analysis for assessing prevention and 132 adults who tested positive at baseline in the exploratory analysis for assessing treatment. The primary endpoint (cases of symptomatic COVID-19 by day 57) was assessed after all participants in the prevention population reached 8 weeks of follow-up.

Results showed a significantly lower frequency of symptomatic COVID-19 among individuals (residents and staff) who received bamlanivimab compared with those who received placebo (adjusted odds ratio [OR] 0.43; P <.001). For nursing home residents, a significantly lower frequency of symptomatic COVID-19 was observed in the bamlanivimab arm compared with placebo (adjusted OR 0.20; P <.001).

Among those who met the high risk criteria (all residents and high risk staff), bamlanivimab reduced the risk of symptomatic COVID-19 by approximately 72% (adjusted OR 0.28; P <.001) vs placebo. There was less evidence of preventive effect with bamlanivimab in a subgroup of staff who did not meet high risk criteria (adjusted OR 0.64; P =.26).

While BLAZE-2 evaluated bamlanivimab alone, based on findings from the phase 3 BLAZE-1 trial and additional clinical data, it is reasonable to expect that combination with etesevimab should be safe and effective for postexposure prophylaxis. The authorized dosage for postexposure prophylaxis is bamlanivimab 700mg and etesevimab 1400mg administered together as a single intravenous infusion as soon as possible after exposure to SARS-CoV-2.

In August 2021, the FDA updated the EUA for bamlanivimab plus etesevimab to state that the combination should only be administered in states, territories, and US jurisdictions in which the combined frequency of variants resistant to bamlanivimab and etesevimab is less than or equal to 5%.  

Bamlanivimab plus etesevimab continues to be authorized for the treatment of mild to moderate COVID-19 in patients 12 years of age and older weighing at least 40kg who test positive for SARS-CoV-2 and who are at high risk for progressing to severe COVID-19 and/or hospitalization. The updated fact sheet containing guidance on postexposure prophylaxis can be found here.


  1. Emergency Use Authorization for Lilly’s bamlanivimab and etesevimab administered together expanded to include post-exposure prophylaxis for COVID-19. News release. Eli Lilly and Company. Accessed September 17, 2021.
  2. FDA authorizes bamlanivimab and etesevimab monoclonal antibody therapy for post-exposure prophylaxis (prevention) for COVID-19. News release. US Food and Drug Administration. Accessed September 17, 2021.