By Michael Dabaie

Regeneron Pharmaceuticals Inc. said Tuesday initial results were positive from an ongoing Phase 3 clinical trial evaluating REGEN-COV.

The trial is looking at REGEN-COV, a casirivimab and imdevimab antibody cocktail, used as a passive vaccine for the prevention of Covid-19 in people at high risk of infection due to household exposure to a Covid-19 patient, the company said.

Shares were up 1.6%, to $556.80, in premarket trading.

Data showed a reduction in overall infections seen within the first week, with 100% prevention of symptomatic infections and markedly decreased levels and duration of viral shedding in asymptomatic infections that still occurred in REGEN-COV group, Regeneron said.

Confirmatory Phase 3 results are expected early in second quarter, the company said.

"These data using REGEN-COV as a passive vaccine suggest that it may both reduce transmission of the virus as well as reduce viral and disease burden in those who still get infected," said George D. Yancopoulos, president and chief scientific officer at Regeneron.

The trial is being run jointly with the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

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

(END) Dow Jones Newswires

01-26-21 0803ET