USFDA revokes emergency use status to two Covid antibody therapies

The USFDA has revised the authorizations for two monoclonal antibody treatments bamlanivimab and etesevimab sold by Eli Lilly and Regeneron's casirivimab and imdevimab – to limit their use to only when the patient is likely to have been infected with or exposed to a variant that is susceptible to these treatments.
"Because data show these treatments are highly unlikely to be active against the omicron variant, which is circulating at a very high frequency throughout the United States, these treatments are not authorized for use in any U.S. states, territories, and jurisdictions at this time," USFDA said in a statement.

"In the future, if patients in certain geographic regions are likely to be infected or exposed to a variant that is susceptible to these treatments, then use of these treatments may be authorized in these regions," the statement added.

Monoclonal antibodies are laboratory-made proteins that mimic the immune system’s ability to fight off harmful pathogens such as viruses, like SARS-CoV-2. And like other infectious organisms, SARS-CoV-2 can mutate over time, rendering certain treatments ineffective against variants such as omicron.

According to the data of the US Centers for Disease Control and Prevention, the omicron variant of SARS-CoV-2 is estimated to account for more than 99% of cases in the US as of January 15.

The USFDA revision of approval was based on the National Institutes of Health (NIH) COVID-19 Treatment Guidelines Panel, an independent panel of national experts, recently recommended against the use of the two monoclonal antibodies because of markedly reduced activity against the omicron variant and because real-time testing to identify rare, non-omicron variants is not routinely available.

USFDA said several other therapies such as Paxlovid, sotrovimab, Veklury (remdesivir), and molnupiravir – are expected to work against the omicron variant, sess whether these treatments are right for their patients.