GlaxoSmithKline plc and Vir Biotechnology, Inc. announced an update to preclinical data on bioRxiv, a preprint server, demonstrating that sotrovimab, an investigational monoclonal antibody, retains in vitro activity against the full known Omicron spike protein, the new SARS-CoV-2 variant (B.1.1.529).
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The preclinical data was 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.
These data add to the growing body of preclinical evidence demonstrating that sotrovimab retains activity against all tested variants of concern.
George Scangos, PhD, Chief Executive Officer of Vir, said: “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.
"Given the less than three fold neutralization shift demonstrated in the pre clinical 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.â€
Dr Hal Barron, Chief Scientific Officer and President R&D, GSK, said: “From the outset of our collaboration with Vir we hypothesized that sotrovimab would have a high barrier to resistance and thus could deliver best in class potential for the early treatment of patients with COVID 19.
"These pre clinical data demonstrate the potential for our monoclonal antibody to be effective against the latest variant, Omicron, plus all other variants of concern defined to date by the WHO, and we look forward to discussing these results with regulatory authorities around the world.â€
Sotrovimab is an investigational SARS-CoV-2 neutralising monoclonal antibody. The 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.
Sotrovimab, which incorporates Xencor, Inc.’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.
Pre clinical data, published in bioRxiv, demonstrate that sotrovimab retains activity against all currently tested variants of concern and interest of the SARS-CoV-2 virus as defined by WHO, plus others, including but not limited to Delta (B.1.617.2), Delta Plus (AY.1 or AY.2), Mu (B.1.621) and Omicron (B.1.1.529).
GSK and Vir are also partnering to assess the use of sotrovimab in uninfected immunocompromised adults to determine whether sotrovimab can prevent symptomatic COVID 19 infection.
Sotrovimab is authorised for emergency use in the United States. Xevudy (sotrovimab) received a positive scientific opinion from the Committee for Human Medicinal Products in the EU, conditional marketing authorisation by the UK Medicines and Healthcare Products Regulatory Agency, provisional marketing authorisation in Australia, and conditional marketing authorisation in Saudi Arabia.
It has been approved via the Special Approval for Emergency Pathway in Japan.
Temporary authorisations for sotrovimab have been granted in a dozen countries. ■