The US health regulator said on Tuesday GlaxoSmithKline and Vir Biotechnology's antibody therapy is no longer authorised as a Covid-19 treatment, with data suggesting it was unlikely to be effective against the dominant Omicron sub-variant in the country.

The move by the agency, which had already pulled its authorisation for the sotrovimab therapy in much of the US northeast last month, sent shares in Vir Biotechnology 11.5 percent lower...