The World Health Organization (WHO) said on Tuesday that a safety team would review data on hydroxychloroquine by next month, a day after officials cited safety concerns that prompted them to suspend use of the malaria drug in a global trial in COVID-19 patients.

The WHO called time on using the drug in its multi-country trial, called Solidarity, after a study published in British medical journal The Lancet found patients randomised to get hydroxychloroquine (HCQ) had increased mortality rates and higher frequency of irregular heartbeats. U.S. President Donald Trump and others have pushed HCQ as a possible treatment for the disease.

“A final decision on the harm, benefit or lack of benefit of hydroxychloroquine will be made once the evidence has been reviewed by the Data Safety Monitoring Board,” the WHO said. “This review will include data from the Solidarity Trial and other ongoing trials, as well as any evidence published so far. It is expected by mid-June.”