The U.S. health regulator said on Tuesday GlaxoSmithKline GSK.L and Vir Biotechnology's VIR.O antibody therapy was no longer authorized as a COVID-19 treatment, with data suggesting it was unlikely to be effective against the dominant Omicron sub-variant in the country.
The agency pulled its authorization for the therapy, sotrovimab, in much of the U.S. northeast last month.
The highly contagious BA.2 coronavirus sub-variant is estimated to make up about three of every four COVID-19 cases in the United States, according to the latest government data.
GlaxoSmithKline and Vir have said treatment with sotrovimab retains neutralizing activity against the BA.2 sub-variant, but others, including researchers from Columbia University, disagree.
GSK spokeswoman Lyndsay Meyer said on Tuesday as COVID continues to evolve and new variants emerge, the company expects governments and health systems will continue to need a diverse arsenal of vaccine and therapeutic options, and the company will continue to work with them to ensure ongoing access to sotrovimab.
Shares of Vir Biotechnology, which was yet to respond to a Reuters request for comment, fell nearly 10 per cent in afternoon trading.
Last month, the companies said they were preparing a package of data in support of a higher dose for sotrovimab than the currently authorized 500 mg for the BA.2 sub-variant.
The U.S. Food and Drug Administration's move on Tuesday comes as a blow as GlaxoSmithKline and Vir saw high demand for sotrovimab after it became one of the few COVID treatments shown to have worked against the Omicron variant.
(Reporting by Leroy Leo and Bhanvi Satija in Bengaluru; Editing by Shounak Dasgupta and Vinay Dwivedi)
