By Michael Dabaie

Vir Biotechnology Inc. and GlaxoSmithKline PLC said Wednesday the independent data and safety monitoring board recommended the VIR-7831 arm of the National Institutes of Health's Accelerating Covid-19 Therapeutic Interventions and Vaccines Program Phase 3 clinical trial be closed to enrollment.

Vir shares were down 31%, to $40, in early trading.

The companies said they were informed that while VIR-7831 met initial pre-specified criteria to continue to the next phase of the ACTIV-3 trial and there were no reported safety signals, sensitivity analyses of the available data raised concerns about the magnitude of potential benefit.

The monitoring board recommended the VIR-7831 arm of the trial be closed to enrollment while the data mature, the companies said.

The companies said they would continue discussions with the NIH about appropriate ways to further assess the potential of VIR-7831 in the hospitalized population as all parties gain a fuller understanding of the still-emerging data.

The DSMB recommendation was based on a routine, pre-planned safety and efficacy data review of the first 300 patients hospitalized with Covid-19 enrolled in ACTIV-3.

"While we are disappointed with the recommendation of the DSMB, we are encouraged by the safety profile of VIR-7831 and by the possibility of a benefit on top of remdesivir and corticosteroids in this advanced cohort of patients," said Vir Chief Executive George Scangos.

Write to Michael Dabaie at michael.dabaie@wsj.com

(END) Dow Jones Newswires

03-03-21 0959ET