GSK, Vir Biotechnology to halt enrollment in US COVID-19 antibody trial sub-study

The companies will now wait for more data from this sub-study after an independent panel found that while their drug, VIR-7831, met the criteria to move into the next stage of testing and was safe to use, there was lack of evidence to support how well it would work.

Vir and GSK will continue discussions with the U.S. National Institutes of Health, which is backing the late-stage study, to evaluate the next steps to assess the treatment's effectiveness in hospitalized COVID-19 patients, the drugmakers said.

Shares of Vir plummeted by more than a quarter to around $41. London-listed GSK's stock was unchanged.

"The absence of safety concerns and the possibility of a benefit on top of remdesivir and corticosteroids in this advanced cohort of patients are encouraging," Vir CEO George Scangos said.

GSK and San Francisco-based Vir are working together on another therapy as part of their collaboration to develop COVID-19 treatments based on monoclonal antibodies.

Monoclonal antibodies are synthetically manufactured copies of the human body's natural infection-fighting proteins, and are already being used to treat some types of cancers.

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