The world wants answers on Gilead’s Covid-19 drug. Experts worry next studies may increase uncertainty

For weeks, the world has been eagerly awaiting clinical trial results for one experimental drug, remdesivir, to treat Covid-19. On some days, the entire stock market has moved up and down based on limited amounts of data about the therapy from Gilead Sciences.

The signals, so far, have been contradictory. An early peek at one study, based on data from patients treated at a Chicago hospital, suggested patients were doing better than expected on remdesivir. Days later, a summary of results from a study in China showed that patients on the drug did not improve more than those in a control group.