Shares of Gilead Sciences Inc. GILD, +0.01% rose nearly 4% in the extended session Wednesday after the pharma company said it had started two clinical studies to gauge the safety and efficacy of its remdesivir drug in adults diagnosed with COVID-19. Beginning in March, the studies will enroll about 1,000 patients at medical centers primarily in Asian countries as well as countries with a high numbers of diagnosed cases, Gilead said in a statement. The initiation of these studies follows the U.S. Food and Drug Administration's rapid review and acceptance of Gilead's investigational new drug filing for remdesivir. The new studies expand ongoing research into remdesivir, including trials in China and Japan and a NIH-sponsored study announced earlier this week that is the first in the U.S. Remdesivir, a broad-spectrum anti-viral drug, is not yet licensed or approved anywhere. Shares of Gilead ended the regular trading day up 6.6%.