Do we need bamlanivimab? Is etesevimab a key to treating Covid-19?

Treatments for subjects with Covid-19 are required. One approach is neutralizing monoclonal antibodies. Bamlanivimab and etesevimab are monoclonal antibodies to SARS-CoV-2.

This evaluation is of the phase 3 BLAZE-1 clinical trial, which was of bamlanivimab plus etesevimab in adult ambulatory participants with a risk factor for, and mild to moderate, Covid-19 illness. The primary outcome was Covid 19 related hospitalization of ≥ 24 hours or death from any cause by day 29, and this occurred in 2.1% subjects in the bamlanivimab/etesevimab group, compared to 7.0% in the placebo group.

In the pandemic, the attempts by the FDA to shorten approval processes for medicines and by journals to make information available in a timely manner are admirable. However, these shortened processes made negotiating the details of BLAZE-1 and producing accurate and critical appraisals difficult. It seems to me that if there are any benefits of bamlanivimab alone in Covid-19, they are not clear-cut. Bamlanivimab has limited effects against the beta and gamma variants and is not effective against the delta variant. Thus, the benefits of bamlanivimab/etesevimab in the phase 3 of the BLAZE-1 may be solely due to etesevimab, and this needs to be tested.