COVID-19 Treatment Guidelines Updated for Anti-SARS-CoV-2 Monoclonal Antibodies

The US National Institutes of Health (NIH) announced it continues to recommend anti-SARS-CoV-2 monoclonal antibodies that target the SARS-CoV-2 spike protein and block coronavirus entry into cells that have been evaluated for the treatment of COVID-19. 

However, on April 8, 2021, the NIH confirmed changes to the monoclonal antibody cocktail recommendations.

To date, the US Food and Drug Administration (FDA) has issued Emergency Use Authorizations (EUAs) for the following anti-SARS-CoV-2 monoclonal antibodies and combinations: bamlanivimab alone, bamlanivimab plus etesevimab, and casirivimab plus imdevimab.

The NIH stated ‘data are emerging on the currently available anti-SARS-CoV-2 monoclonal antibodies, including preliminary data from a Phase 3 trial of casirivimab plus imdevimab, and on the in vitro susceptibility of SARS-CoV-2 variants to anti-SARS-CoV-2 monoclonal antibodies.’

After reviewing the available data, the COVID-19 Treatment Guidelines Panel has updated its recommendations on administering anti-SARS-CoV-2 monoclonal antibodies in outpatients with mild to moderate COVID-19 at high risk of disease progression.

Also, the Panel noted that, because of an increasing number of reports of variants that are resistant to bamlanivimab alone, this product would no longer be distributed by the U.S. government.

This Panel now recommends using one of the following combination anti-SARS-CoV-2 monoclonal antibodies to treat outpatients with mild to moderate COVID-19 who are at high risk of clinical progression, as defined by the EUA criteria (listed in alphabetical order):

Bamlanivimab 700 mg plus etesevimab 1,400 mg (AIIa) OR Casirivimab 1,200 mg plus imdevimab 1,200 mg (AIIa).

Furthermore, the NIH says ‘treatment should be started as soon as possible after the patient receives a positive result on a SARS-CoV-2 antigen or nucleic acid amplification test (NAAT) and within ten days of symptom onset.'

There are no comparative data to determine whether there are differences in clinical efficacy or safety between bamlanivimab plus etesevimab and casirivimab plus imdevimab.

There are SARS-CoV-2 variants, particularly those containing the mutation E484K, that reduce the virus’ susceptibility to bamlanivimab and, to a lesser extent, casirivimab and etesevimab in vitro; however, the clinical impact of these mutations is not known.

In regions where SARS-CoV-2 variants with reduced in vitro susceptibility to bamlanivimab plus etesevimab are common, some Panel members would preferentially use casirivimab plus imdevimab while acknowledging that it is not known whether in vitro susceptibility data correlate with clinical outcomes.

If combination products are not available, the use of bamlanivimab monotherapy can be considered for people who meet the EUA criteria on a case-by-case basis, says the NIH.

The Panel recommends against anti-SARS-CoV-2 monoclonal antibodies for patients hospitalized because of COVID-19, except in a clinical trial. However, their use should be considered for persons with mild to moderate COVID-19 who are hospitalized for a reason other than COVID-19 but who otherwise meet the EUA criteria.

PrecisionVaccinations publishes research-based news.