GlaxoSmithKline and Vir's sotrovimab stands up to omicron despite other COVID antibodies falling short

GlaxoSmithKline GSK House in Brentford, UK
GlaxoSmithKline and Vir Biotechnology earned emergency authorization for its COVID-19 antibody from the FDA in May but didn’t win a contract to supply it to the U.S. until three weeks ago. (GlaxoSmithKline)

Amid a report that the COVID-19 antibody treatment from Regeneron loses its effectiveness against the omicron variant, GlaxoSmithKline and Vir Biotechnology said on Tuesday that their antibody drug is effective against omicron’s full range of mutations.

The study was performed in a lab, in vitro, against a synthesized version of the virus and showed that the treatment retained activity against all 37 mutations identified on omicron’s spike protein.

Last week, Regeneron said that it’s REGEN-COV may need to be modified to retain its efficacy against the variant.

“Sotrovimab is the first monoclonal antibody to record demonstrated activity against all SARS CoV-2 variants of concern and interest to date, including omicron,” Vir CEO George Scangos said in a conference call on Tuesday. “Sotrovimab was deliberately designed with a mutating virus in mind.”

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Vir has used the testing system for more than a decade to evaluate the effects of antibody neutralization and “viral entry inhibition,” said Vir's chief scientific officer Skip Virgin. He added that in vitro activity against spike variants using the system correlates to findings from live virus assays for SARS CoV-2.

Testing against the actual omicron variant will take “weeks, not months,” Scangos said.

GSK and Vir earned emergency authorization for sotrovimab from the FDA in May but didn’t win a contract to supply it to the United States until three weeks ago. The deal was for $1 billion, but the companies didn’t reveal how many doses that included.

At the time, GSK said it had secured deals to provide more than 750,000 doses worldwide, with agreements in place with Japan, Australia and Canada, among others. In July, the European Commission announced the purchase of 220,000 doses, which came two months after it began a rolling review of the treatment.

GSK still awaits approval for its antibodies in Europe, while the bloc has green-lighted antibody treatments from Celltrion and Regeneron-Roche.

RELATED: GlaxoSmithKline and Vir finally score $1B supply deal for COVID antibody—6 months after FDA nod

Continued emergence of omicron could spark a rush of sales for GSK-Vir's antibody therapy.

“Having activity against omicron is table stakes, moving the future for government contracts,” Scangos said.

GSK and Vir also released data recently that shows sovrotimab has similar efficacy when injected into the muscle as it does when it is provided intravenously, potentially allowing for a more convenient option.