FDA Revises EUA for GSK/VIR’s Sotrovimab Due to Ineffectiveness Against Omicron BA.2 Variant

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On March 25, GSK and its partner Vir Biotechnology jointly announced that the US FDA had revised the Fact Sheet for the Emergency Use Authorization (EUA) of the monoclonal antibody drug sotrovimab. The FDA has determined, based on all available evidence, including new live virus data generated by Vir, that the 500mg dose of sotrovimab is unlikely to be effective against the Omicron BA.2 variant.

In response, GSK and Vir Biotechnology are preparing a set of data to support the use of higher doses of sotrovimab for the Omicron BA.2 variant, and will share this data with regulatory and health institutions around the world for discussion.

Currently, the U.S. FDA has updated its website information: Based on available data, including the sensitivity of variants to antibody drugs and regional variant frequencies (HHS Regions 1 and 2), the use of sotrovimab is excluded in geographic areas where infections may be caused by non-sensitive SARS-CoV-2 variants. The FDA will continue to monitor the prevalence of circulating variants and provide updates on its website accordingly.

Sotrovimab is a SARS-CoV-2 neutralizing monoclonal antibody that binds to an epitope shared by SARS-CoV-2 and SARS-CoV-1 (the virus that causes SARS). This epitope is highly conserved, which may make the development of resistance more difficult.

It is reported that sotrovimab incorporates Xencor's Xtend technology and is also designed to achieve high concentrations in the lungs to ensure optimal penetration into the airway tissues affected by SARS-CoV-2, with an extended half-life.

Notably, in May 2021, the FDA granted sotrovimab an EUA: as a single-dose intravenous infusion (IV, 500mg) therapy for patients who tested positive with direct SARS-CoV-2 viral detection methods and are at high risk of progressing to severe COVID-19 (including hospitalization or death). It is indicated for adults and pediatric patients (aged ≥12 years, weighing ≥40kg) with mild to moderate COVID-19.

Just this January, GSK and Vir Biotechnology submitted an application to the FDA for the revision of the EUA, incorporating intramuscular (IM) administration for sotrovimab.

Reference Source: US Food and Drug Administration Revises Emergency Use Authorization for Sotrovimab Due to Omicron BA.2 Subvariant