The experimental drug remdesivir has been authorized by US regulators for emergency use against COVID-19, President Donald Trump announced Friday.

“It is really a really promising situation,” Trump said at the White House, where he was joined by Gilead’s CEO Daniel O’Day.

“We are humbled with this first step for hospitalized patients,” said O’Day, adding: “We want to make sure nothing gets in the way of these patients getting the medicine.”

The US Food and Drug Administration (FDA) has granted Emergency Use Authorization (EUA) for the experimental anti-viral drug remdesivir to treat COVID-19.

In an FDA fact sheet for patients and their families and caregivers, the agency on Friday noted that remdesivir has not undergone the same type of review as an FDA-approved or cleared product.

Remdesivir is an investigational antiviral medicine to treat certain people in the hospital with COVID-19, said the FDA, adding the drug was still being studied.

“There is limited information known about the safety and effectiveness of using remdesivir to treat people in the hospital with COVID-19,” said the FDA.

Remdesivir was shown in a clinical trial to shorten the time to recovery in some people.

There are no medicines approved by the FDA as safe and effective to treat people in the hospital who have COVID-19.

Therefore, the FDA has authorized the emergency use of remdesivir for the treatment of COVID-19 under an EUA, said the agency.

Remdesivir is given to patients through a vein one time each day for up to 10 days depending on recommendations of healthcare providers, according to the FDA.

The drug may help decrease the amount of the coronavirus in bodies and help patients get better faster, said the agency.

Possible side effects of remdesivir include infusion-related reactions and increases in levels of liver enzymes, according to the FDA.

“These are not all the possible side effects of remdesivir. Remdesivir is still being studied so it is possible that all of the risks are not known at this time,” said the FDA.

The company has previously announced it was donating some 1.5 million doses for free. This amounts to about 140,000 treatment courses based on a 10-day treatment duration.

Remdesivir, which is administered by an injection, was already available to some patients who enrolled in clinical trials, or who sought it out on a “compassionate use” basis.

The new move allows it to be distributed far more widely and used in both adults and children who are hospitalized with a severe form of COVID-19.

The US has expressed optimism over the use of antiviral drug remdesivir as a possible treatment for COVID-19 after a trial, although its manufacturer warned that the drug was yet to be proven safe and studies indicated its effectiveness remains unclear.

As the US battles to curb the spike in coronavirus cases and death which are currently the highest in the world, the National Institutes of Health (NIH) on Wednesday announced the results of the trial of remdesivir, developed by biotech company Gilead Sciences.

The NIH reported that patients hospitalized around the world with COVID-19 who received remdesivir (1,063 patients in total) had a 31 per cent faster recovery rate of 11 days on average until discharge from hospital, than those receiving a placebo, which took an average of 15 days.

Based on these preliminary results, the death rate for those taking remdesivir was 8 percent compared to 11.6 percent for those taking a placebo.

One of the White House’s top experts in the fight against the pandemic, Anthony Fauci, director of the NIH-affiliated National Institute of Allergy and Infectious Diseases (NIAID), called the findings “quite good news”.

“What it has proven is that a drug can block this virus,” Fauci said.

US President Donald Trump had expressed his wish that the FDA would approve the antiviral as soon as possible so that it can be administered against the virus.

Despite the promises from US authorities, the California-based drug manufacturer emphasized that remdesivir is “an investigational agent that has not been licensed or approved anywhere globally, and it has not been demonstrated to be safe or effective for any use, including for the treatment of COVID-19”.

The company said that it expects to have more data from a second study evaluating the efficacy of 5 and 10-day doses in patients with moderate COVID-19 symptoms by the end of May.

Remdesivir has not been approved for the treatment of any disease, but it was experimentally administered to Ebola patients in the past.

A study published by British medical journal The Lancet on a randomized controlled trial with remdesivir, which was carried out in hospitals in Wuhan, the Chinese city where the pandemic originated last December, suggests that this medicine “is not associated with significant clinical benefits”.

The antiviral did not accelerate the recovery of patients or reduce the death rate when compared to the use of a placebo, said the medical journal of the study, which was carried out from March 6-12 on 237 adults, although the initial target number was 435 patients.

Researchers had to stop the trial as there were not enough patients due to the sharp decline in COVID-19 cases in China, and concluded that “more evidence from ongoing clinical trials is needed to better understand whether remdesivir can provide meaningful clinical benefit”.

(With agency inputs)