FDA Approves Emergency Use of Monoclonal Antibody Sotrovimab for COVID-19

The EUA was granted based on an interim analysis from the phase 1/2/3 COMET-ICE trial, which evaluated sotrovimab in 583 non-hospitalized adults with mild to moderate COVID-19 at high risk of progression to severe disease.

The Food and Drug Administration (FDA) has granted Emergency Use Authorization (EUA) to sotrovimab, an investigational monoclonal antibody, for the treatment of mild to moderate COVID-19 in patients 12 years of age and older weighing at least 40kg with positive results of direct SARS-CoV-2 viral testing and who are at high risk for progression to severe COVID-19.

Sotrovimab is a recombinant human IgG1-kappa monoclonal antibody that binds to a conserved epitope on the spike protein receptor binding domain of SARS-CoV-2. The Fc domain of sotrovimab includes M428L and N434S amino acid substitutions (LS modification) that extend antibody half-life.

The EUA was granted based on an interim analysis from the randomized, double-blind, placebo-controlled phase 1/2/3 COMET-ICE trial (ClinicalTrials.gov Identifier: NCT04545060), which evaluated the efficacy and safety of sotrovimab in 583 non-hospitalized adults with mild to moderate COVID-19 at high risk of progression to severe disease. Patients were randomly assigned 1:1 to receive a single intravenous infusion of sotrovimab 500mg or placebo. The primary endpoint was progression of COVID-19 through day 29, defined as the need for hospitalization for greater than 24 hours for acute management of illness or death from any cause.

Interim findings showed that treatment with sotrovimab demonstrated an 85% reduction in the risk of COVID-19 progression (P =.002); 3 (1%) patients in the sotrovimab arm progressed to hospitalization or death vs 21 (7%) patients in the placebo arm. As for safety, the most common adverse reactions in the sotrovimab arm were rash (2%) and diarrhea (1%), all of which were mild or moderate.

“Our distinctive scientific approach has led to a single monoclonal antibody that, based on an interim analysis, resulted in an 85% reduction in all-cause hospitalizations or death, and has demonstrated, in vitro, that it retains activity against all known variants of concern, including the emerging variant from India,” said George Scangos, PhD, CEO of Vir.

The authorized dosage of sotrovimab is a single intravenous infusion of 500mg administered as soon as possible after a positive SARS-CoV-2 test and within 10 days of symptom onset. Sotrovimab is associated with the risk of serious hypersensitivity reaction, including anaphylaxis and should be administered by a qualified health care professional. A fact sheet that details the criteria for patient selection as well as important safety information can be found here.

Sotrovimab is not authorized for use in patients who are hospitalized due to COVID-19, require oxygen therapy due to COVID-19, or require an increase in baseline oxygen flow rate due to COVID-19 (in patients on chronic oxygen therapy due to underlying non-COVID-19 related comorbidity).


  1. Coronavirus (COVID-19) update: FDA authorizes additional monoclonal antibody for treatment of COVID-19. [press release]. Silver Spring, MD: US Food and Drug Administration; May 26, 2021. 
  2. GSK and Vir Biotechnology announce sotrovimab (VIR-7831) receives Emergency Use Authorization from the US FDA for treatment of mild-to-moderate COVID-19 in high-risk adults and pediatric patients. [press release]. London, UK and San Francisco, CA: GlaxoSmithKline plc and Vir Biotechnology, Inc.; May 26, 2021.
  3. Sotrovimab (VIR-7831), an investigational antibody utilizing Xencor’s Xtend™ technology, receives U.S. FDA emergency use authorization for the treatment of COVID-19. [press release]. Monrovia, CA: Xencor, Inc.; May 26, 2021.
  4. Sotrovimab [package insert]. Research Triangle Park, NC: GlaxoSmithKline LLC; 2021.

This article originally appeared on MPR