FDA Restricts Use of GSK and Vir's Sotrovimab Amid Concerns Over Omicron BA.2 Variant

Compiled by Fan Dongdong

Recently, the U.S. FDA announced that it would strictly limit the emergency use authorization of sotrovimab, a COVID-19 antibody therapy jointly developed by GlaxoSmithKline and Vir Biotechnology. The FDA stated that due to sotrovimab's poor efficacy against variant strains, the therapy should not be used in geographic regions where certain variants are prevalent.

Notably, the U.S. FDA did not specify which areas within the United States would be affected by the restriction. On Wednesday, in a healthcare provider fact sheet outlining when sotrovimab can be used, the U.S. FDA stated that it would monitor to determine whether the use of sotrovimab in these geographic regions falls within the authorized scope. Additionally, the U.S. FDA will consider other available information to assist in decision-making, including variant susceptibility.

When the Omicron variant first emerged, sotrovimab was considered one of the few antibody treatments proven effective against it. With the emergence of the Omicron subvariant BA.2, Vir Biotechnology had previously claimed that the sotrovimab therapy demonstrated neutralizing activity against the new variant. However, a recent study indicates that the BA.2 variant is resistant to nearly all available monoclonal antibody treatments.

The repeated outbreaks and the continuous emergence of new variant strains have also无形中posed challenges to各大major COVID-19 therapy manufacturers. At the end of last year, as the Omicron variant wreaked havoc globally, the sotrovimab therapy developed by GSK and Vir Biotechnology suddenly became a popular treatment, while alternative drugs from Eli Lilly and Regeneron were sidelined. Previously, the U.S. government had already announced a $1 billion purchase of the sotrovimab therapy from GSK and Vir Biotechnology.

It is worth noting that this is not the first time the U.S. FDA has restricted the use of COVID-19 antibody therapies to certain regions. Last year, due to the widespread transmission of variants found in Brazil and South Africa within the United States, the U.S. FDA prohibited the use of Eli Lilly's bamlanivimab antibody therapy in some states. Later, the U.S. FDA also fully restricted the use of Eli Lilly’s combination therapy of bamlanivimab and etesevimab. Meanwhile, Regeneron's antibody treatment business has been thriving because it was proven to remain effective against variant strains.

When the Delta variant emerged, Eli Lilly regained authorization for its antibody treatment. However, after Omicron became the dominant strain of the pandemic, the U.S. FDA recently revoked the emergency use authorization for both Eli Lilly’s and Regeneron’s COVID-19 antibody therapies. Earlier this month, though, Eli Lilly received emergency use authorization from the U.S. FDA for a new antibody treatment called bebtelovimab. The company stated that the drug has been proven effective against Omicron and its sub-variants, with the added benefits of requiring a smaller dose and faster administration. Currently, Eli Lilly has agreed to supply 600,000 doses to the U.S. for $720 million.

Despite the fact that Pfizer and Merck's COVID-19 oral drugs have stolen much of the limelight from monoclonal antibody therapies, sotrovimab, as an intravenous therapy, still holds unique advantages. For immunocompromised patients and those with poor vaccine efficacy, treatment with sotrovimab can help reduce the risk of severe illness caused by the virus. This therapy was also one of GSK’s top-selling products in 2021. According to the financial report released by the company this Wednesday, GSK's revenue in 2021 reached £34.1 billion, a year-on-year increase of 5%. Assets related to COVID-19 generated £1.4 billion in income, of which sotrovimab accounted for £958 million.

At the same time, oral antiviral drugs have also become a market contested by major pharmaceutical companies. Merck's molnupiravir and Pfizer's Paxlovid are accelerating production, hoping that sufficient supply can meet clinical needs.

Reference Source: FDA to Limit Use of GlaxoSmithKline and Vir's COVID-19 Antibody Treatment in Certain Geographic Areas