Gilead Sciences' (NASDAQ: GILD) remdesivir cut the risk of death by 62% in severe COVID-19 patients. After 14 days, 7.6% of severe COVID-19 patients treated with remdisivir had died compared to 12.5% of patient who didn't receive the drug. While the results, which were presented at the Virtual COVID-19 Conference as part of the 23rd International AIDS Conference, sound great, they come from a retrospective analysis comparing results from two different data sources. The remdesivir mortality rate comes from results of patients in Gilead's phase 3 SIMPLE-Severe clinical trial. But that study didn't have a placebo control, so Gilead compared the remdesivir results with a real-world retrospective cohort of severe COVID-19 patients who were treated with standard of care. The results are likely to be in the ballpark of being accurate, but without prospectively enrolling patients and randomizing them to remdesivir or placebo, there's no way to know for sure whether remdesivir was the only factor that contributed to the difference. Gilead admits as much in the press release announcing the result, calling it "an important finding that requires confirmation in prospective clinical trials." Image source: Getty Images. The biotech also released data from its compassionate-use program for remdesivir in children as well as pregnant and postpartum women. Like the SIMPLE-Severe study, the compassionate-use program doesn't have a placebo-treated population to be compared to, and given the small numbers, Gilead didn't even bother trying. Among 77 pediatric patients treated with remdesivir in the program, 73% were discharged by day 28, while 12% remained hospitalized, and 4% had died. An analysis of 86 pregnant and postpartum women treated with remdesivir in the program showed 96% of pregnant and 89% of postpartum women achieved improvement in oxygen support levels. 10 stocks we like better than Gilead SciencesWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Gilead Sciences wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 2, 2020 Brian Orelli, PhD has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Gilead Sciences. The Motley Fool has a disclosure policy.Source