Two monoclonal antibodies administered separately were effective in preventing hospitalization among high-risk patients with COVID-19, according to a real-world study published July 19 in The Journal of Infectious Diseases and funded by Rochester, Minn.-based Mayo Clinic.
The study observed patients who received bamlanivimab or casirivimab-imdevimab. The FDA granted emergency use authorization to bamlanivimab, made by Eli Lilly, in November. Two weeks later, the agency granted emergency use authorization to casirivimab-imdevimab, an antibody cocktail made by Regeneron.
The researchers studied 3,596 Mayo Clinic patients with COVID-19, with the median age being 62. All of the patients had at least one condition making them high-risk, and just over half had multiple comorbidities.
The patients received an infusion of either bamlanivimab or casirivimab-imdevimab. After 28 days, the hospitalization rate due to COVID-19 was 2.56 percent.
The research team did not observe a significant difference in the hospitalization rate between the two treatments.
An important detail to consider is that the study was conducted between November and February, which was before certain coronavirus variants had emerged or become widespread.
Another important detail to consider is that the FDA no longer authorizes bamlanivimab alone. In March, the U.S. government stopped its distribution of bamlanivimab alone, saying that the increasing emergence of coronavirus variants has made the treatment ineffective. The antibody is still allowed to be administered along with etesevimab, another Eli Lilly antibody. The FDA granted that antibody cocktail emergency use authorization in February.