The World Health Organization (WHO) has advised against using Gilead’s remdesivir in patients hospitalized with coronavirus, weeks after the drug was shown to have “little or no effect” during the agency’s multicountry Solidarity Trial.

The WHO’s Guideline Development Group (GDP) issued the updated guidance on Friday and said it was based on evidence that found the costly, intravenous drug had no meaningful effect on death rates. The drug must be administered for five to 10 days intravenously and was the first to be granted FDA approval for COVID-19 treatment.

“The … panel found a lack of evidence that remdesivir improved outcomes that matter to patients,” the GDP said Friday, according to Reuters. “Especially, given the costs and resource implications associated with remdesivir… the panel felt the responsibility should be on demonstrating evidence of efficacy, which is not established by the currently available data.”

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The antiviral, known as Veklury, was first approved by the FDA to treat coronavirus patients in October and was part of the regimen given to President Donald Trump during his diagnosis. Gilead had published results from a phase 3 ACTT-1 trial shortly before the approval that “demonstrated faster recovery times” in adults hospitalized with mild to severe coronavirus cases.

As such, the FDA approved it for use in adult and pediatric patients 12 years of age and older weighing at least 88 pounds for treatment of COVID-19 that required hospitalization.

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However, the WHO’s Solidarity Trial showed the drug had little or no effect on 28-day mortality or length of hospital stay for coronavirus patients. It was one of four tested in the trial with the researchers concluding “the main outcomes of mortality, initiation of ventilation and hospitalization duration were not clearly reduced by any study drug.”

The WHO’s conclusions on remdesivir are in contrast with an NIH-led study that found it to shorten patients’ path to recovery by up to four days. Those results were further upheld in a second study and led Gilead to question the WHO’s Solidarity Trial and the new guidance.

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“Veklury is recognized as a standard of care for the treatment of hospitalized patients with COVID-19 in guidelines from numerous credible national organizations,” the company said, according to Reuters. “The WHO guidelines appear to ignore this evidence at a time when cases are dramatically increasing around the world and doctors are relying on Veklury as the first and only approved antiviral treatment for patients with COVID-19.

The guidelines were issued a day after the FDA granted emergency approval to a drug combo that included remdesivir to treat hospitalized coronavirus patients.

Fox News' Kayla Rivas contributed to this report.