Critics said the study, sponsored by the W.H.O., was too poorly conducted to be definitive.
Remdesivir, the only antiviral drug authorized for treatment of Covid-19 in the United States, fails to prevent deaths among patients, according to a study of more than 11,000 people in 30 countries sponsored by the World Health Organization.
The drug was granted emergency authorization by the Food and Drug Administration on May 1 after a trial by the National Institutes of Health found that remdesivir modestly reduced the time to recovery in hospitalized patients. President Trump received the antiviral after he began showing symptoms earlier this month.
“This puts the issue to rest — there is certainly no mortality benefit,” said Dr. Ilan Schwartz, an infectious disease physician at the University of Alberta in Canada.
But other scientists said the design of the W.H.O.’s sprawling clinical trial, which collected data from hundreds of hospitals, meant the conclusions were not definitive. Conducted in dozens of countries with various health care systems and inconsistent treatment protocols, the data are difficult to analyze and compare, said Dr. Peter Chin-Hong, an infectious disease expert at the University of California, San Francisco. The findings, which were posted online on Thursday, have not yet been peer-reviewed or published in a scientific journal.