Shares of Regeneron Pharmaceuticals Inc. undefined were halted in late trading Tuesday after the drug maker said its trial antiviral drug cocktail reduced the coronavirus load and the time needed to ease symptoms in non-hospitalized patients with COVID-19. The cocktail, named REGN-COV2, also showed "positive trends in reducing medical visits," the company said. The drug cocktail is under an ongoing, randomized trial that measures the effect of adding it to usual COVID-19 standard-of-care compared with adding a placebo. The "greatest improvements" were in patients "who had not mounted their own effective immune response prior to treatment," Regeneron said. This trial is part of a larger program that also includes studies of REGN-COV2 for the treatment of hospitalized COVID-19 patients, and for prevention of infection in people exposed to COVID-19, the company said. Regeneron said it plans to "rapidly to discuss results with regulatory authorities." Shares of Regeneron ended the regular trading session up 0.3%.