Monoclonal Antibody Drug Effective Against Omicron, GSK and Vir Say

Preclinical studies show sotrovimab is active against key mutations of the omicron variant of SARS-CoV-2, which causes COVID-19.

GlaxoSmithKline and Vir Biotechnology’s investigational monoclonal antibody sotrovimab retains in vitro activity against the omicron variant of COVID-19, the companies said.

In May, the FDA issued an Emergency Use Authorization (EUA) for sotrovimab to treat COVID-19 in adults and pediatric patients 12 years of age and older who are at high risk for progression to severe COVID-19, including hospitalization or death.

“Sotrovimab is the first monoclonal antibody to report preclinical data demonstrating activity against all tested SARS-CoV-2 variants of concern and interest to date, including Omicron, as well as the still prevalent and highly contagious Delta variant,” said George Scangos, Ph.D., CEO of Vir, in a recent news release.

“Given the less than three-fold neutralization shift demonstrated in the preclinical pseudo-virus assay, which falls below the FDA authorized fact sheet guidance of less than a 5-fold change, we are confident that sotrovimab will continue to provide significant benefit for the early treatment of patients hoping to avoid the most severe consequences of COVID-19,” Scangos added.

GSK and Vir’s preclinical data were generated through pseudo-virus testing of the combined known mutations of the omicron variant, which included the maximum number of changes (37 mutations) identified to date in the spike protein.

“These findings build on the initial preclinical data generated through pseudo-virus testing, provided last week, showing sotrovimab retained in vitro activity against key individual mutations of the omicron variant, including those found in the binding site of sotrovimab,” GSK said.
The sotrovimab antibody binds to an epitope on SARS-CoV-2 shared with SARS-CoV-1 (the virus that causes SARS), indicating that the epitope is highly conserved, which may make it more difficult for resistance to develop, according to GSK. “Sotrovimab, which incorporates Xencor’s Xtend technology, has also been designed to achieve high concentration in the lungs to ensure optimal penetration into airway tissues affected by SARS-CoV-2 and to have an extended half-life,” GSK said.