The U.S. Food and Drug Administration (FDA) has revised the Emergency Use Authorization (EUA) for sotrovimab, a monoclonal antibody developed by GlaxoSmithKline (GSK) and Vir Biotechnology, restricting its use in regions where the Omicron BA.2 subvariant of SARS-CoV-2 is prevalent. This decision follows data indicating that sotrovimab is unlikely to be effective against the BA.2 variant, which is now the dominant strain in the United States.
The FDA's decision impacts the treatment landscape for COVID-19, particularly for high-risk individuals who previously relied on sotrovimab to prevent severe disease progression. The agency's determination was based on available evidence, including new live virus data generated by Vir, showing reduced efficacy of the standard 500 mg dose against the Omicron BA.2 variant.
Impact on Treatment Options
With the restriction on sotrovimab, healthcare providers now have limited monoclonal antibody options. Eli Lilly's bebtelovimab remains authorized for use, demonstrating neutralization against the Omicron variant. Additionally, antiviral treatments have been found effective against BA.2 in laboratory tests, providing alternative therapeutic avenues.
Sotrovimab's Development and Usage
Sotrovimab, designed to bind to a conserved epitope on SARS-CoV-2, was initially authorized for emergency use in the United States and received marketing authorization in other countries. Vir Biotechnology reported collaboration revenues of $917.2 million in 2021 from sotrovimab sales under its partnership with GlaxoSmithKline.
Ongoing Efforts and Future Directions
GSK and Vir are currently compiling data to support the use of a higher dose of sotrovimab that may be effective against the Omicron BA.2 subvariant. This data package will be shared with regulatory and health authorities globally for further evaluation.
Broader Implications for Antibody Treatments
The FDA's decision to restrict sotrovimab highlights the challenges of maintaining effective antibody treatments against rapidly evolving viral variants. Previously, the FDA also revised authorizations for monoclonal antibody treatments from Eli Lilly (bamlanivimab and etesevimab) and Regeneron (REGEN-COV) due to their ineffectiveness against the Omicron variant.
Other Monoclonal Antibody Treatments
While some monoclonal antibody treatments have faced setbacks, Eli Lilly's bebtelovimab continues to show promise against Omicron. The U.S. government has an agreement with Lilly to supply up to 600,000 doses of bebtelovimab for at least $720 million.
Considerations for Healthcare Providers
Healthcare providers should consult the FDA website for the most up-to-date information on variant susceptibility and regional variant frequency to guide treatment decisions. Sotrovimab is not authorized for use in patients hospitalized due to COVID-19 or those requiring oxygen therapy or increased respiratory support.
