GENEVA (Reuters) – The World Health Organization (WHO) said on Friday it is preparing guidelines on use of the drug remdesivir for COVID-19 and should be able to release them in three to four weeks.

The United States has given full approval for remdesivir to treat infections, the first COVID-19 treatment to receive regulatory endorsement there.

However, a large WHO study earlier this year on COVID-19 patients in hospital found that the drug probably had no effect on their survival rate.

“We would anticipate that the guidelines will be available within three to four weeks,” Janet Diaz, the WHO’s top official for clinical care responses, told a news conference.

A WHO panel will convene next week to look at all evidence of the effectiveness of the drug, made by Gilead Sciences , she added.    WHO chief scientist Soumya Swaminathan said the U.S. FDA drug regulator does not appear to have taken the results of the global health body’s study into account in giving approval.

“We believe our results are very robust,” Swaminathan said. “We hope that people who are doing treatment guidelines in other countries as well as regulators around the world will take note of our study results, in addition to the other evidence,” she said.

“Because you need to look at the global evidence for a drug, before you make decisions.”

(Reporting by John Miller, Stephanie Nebehay and Michael Shields; Writing by Peter Graff; Editing by Kevin Liffey and Andrew Cawthorne)