The Food and Drug Administration (FDA) approved the antiviral remdesivir, even after one study by the World Health Organization (WHO) showed limited benefit.
A preliminary study from the WHO Solidarity trial of more than 11,000 participants found that remdesivir had little effect on how long people stayed in the hospital and no effect on death.
Without a COVID-19 vaccine approved in the United States, doctors are anxious for an effective treatment for COVID-19.
Last week, the Food and Drug Administration (FDA) approved the antiviral remdesivir as a treatment for COVID-19 in adults and children 12 years and older, paving the way for wider use of the drug.
Dr. Lanny Hsieh, clinical professor of infectious diseases at UCI Health, said the FDA’s move is “very exciting.”
“Putting together all of the scientific evidence we have on remdesivir to date, it remains the standard of care for hospitalized patients with COVID-19,” she said. “Ultimately, it is our patients who would benefit from this FDA approval.”
However, research so far on remdesivir is mixed, and the drug is far from a cure for COVID-19.
Mixed study results for remdesivir
In May, the FDA issued an emergency use authorization (EUA) for remdesivir, marketed in the United States under the brand name Veklury. This allowed the drug to be used to treat those with severe COVID-19.
The agency broadened the EUA in August to allow for its use on all hospitalized patients with COVID-19, regardless of how severe their illness.
President Trump took remdesivir along with several other treatments when he was hospitalized for COVID-19 in early October.
The FDA based its decision on three randomized controlled trials.
One study of 1,062 participants with mild, moderate, or severe COVID-19 was published earlier in October in the New England Journal of Medicine.
Results from this trial show that remdesivir reduced the length of hospital stay by about 5 days — from 15 down to 10.
Patients taking remdesivir also had a lower chance of dying after 28 days — 11.4 percent compared with 15.2 percent in patients receiving an inactive placebo.
“This [study], along with other trials reviewed by the FDA, has led to remdesivir’s approval,” Hsieh said, who is the principal investigator on the remdesivir clinical trial at UCI Medical Center.
The two other trials reviewed by the FDA had similar results. One of these also showed that a 5-day course of remdesivir worked just as well as taking the drug for 10 days.
However, preliminary results from the World Health Organization (WHO) Solidarity trial of more than 11,000 participants found that remdesivir had little effect on how long they stayed in the hospital and no effect on death.
This study was published as a preprint on medRxiv and hasn’t yet been peer-reviewed, so the results should be viewed with some caution. The WHO plans to publish it in the New England Journal of Medicine.
Given the results of the WHO study, Dr. Eric Topol, a professor of molecular medicine at the Scripps Research Translational Institute, questioned whether the FDA should have granted remdesivir a full approval.
“How can Remdesivir get a full [FDA] approval when there are such mixed data? Not supportive of this decision at all,” he wrote on Twitter. “Does it work early? Does it work late? Does it work anytime? So much unresolved.”
However, Hsieh said the WHO’s study had several limitations, including not comparing remdesivir’s effects to a placebo, and looking at several potential treatments in the same study.
“Although interesting, Solidarity’s findings do not take away from the results of [the NEJM trial],” she said, “which is a study that is conducted with the most scientific rigor to date.”
Antivirals work best early in COVID-19
Without a COVID-19 vaccine approved in the United States, doctors are anxious for an effective treatment for COVID-19. Remdesivir’s approval finally gives them something to work with.
“Given the limited arsenal of effective or even marginally effective treatments for COVID-19, and the fact that we don’t have a fully curative therapy or a vaccine, it is good to have more options,” said Dr. Matthew G. Heinz, a hospital physician and internist in Tucson, Arizona.
But he said remdesivir is still difficult to get in some parts of the country, especially in rural areas.
And it’s expensive. A 5-day course of treatment can cost $3,120 for people with private insurance, reports Vox.
Remdesivir is also not without risks. In some people, it can cause elevated liver enzymes, which could be a sign of liver damage. The most common side effect, though, is nausea.
“In specific situations for certain patients, I do think [remdesivir] is reasonable to use,” Heinz said, “because it can inhibit viral replication — if given at the right time point.”
Remdesivir blocks the coronavirus from replicating, so it works best if given early.
“Remdesivir is likely going to be more useful for stopping serious progression of the disease,” Heinz said. “But to give it to someone who’s already critical — getting intubated or who has already been intubated — may not work.”
The drug is less effective in later stages of severe COVID-19, when the damage is caused more by an overactive immune response than by the virus itself.
At this point, doctors turn to other treatments that target the immune system. One of these is the corticosteroid dexamethasone, which dampens the immune response and has been shown to reduce deaths from COVID-19.
Although remdesivir isn’t completely effective against COVID-19, many doctors on the front line are glad to have it as an option.
“Given that it’s not shown to have significant safety concerns, and at least one good study does show some benefit, it is reasonable to have remdesivir as an available treatment — while we wait for better ones,” Heinz said.