Drugmaker Gilead says remdesivir has proved effective at treating patients early in the course of the disease.

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Drugmaker Gilead says remdesivir has proved effective at treating patients early in the course of the disease. / Belga/AFP via Getty Images

In late December, as the omicron variant surged, the roster of early COVID-19 treatments was looking slim. Newly authorized pills for COVID-19 were in short supply. Several monoclonal antibody drugs didn't seem to work.

Then an older drug, remdesivir, emerged as an effective option.

Over the past year and a half, the drug — sold in the U.S. under the brand Veklury — had been used in hospitals to treat very sick patients with COVID-19. But new data from the drugmaker Gilead showed that remdesivir could also help high-risk patients avoid the hospital. In other words, it could help patients with medical conditions like immune suppression and diabetes ward off severe COVID-19 disease.

While the drug had shown mixed results in studies as a treatment for hospitalized patients, it has proved surprisingly effective, according to Gilead's data, at treating patients early in the course of the disease. Public health experts say it could be enormously useful at a time when other early COVID-19 treatments — such as monoclonal antibodies and COVID pills — are unavailable or in short supply. But the drug hasn't gotten much traction among health care providers because it takes significant time, staff and resources to give out.

The appeal of remdesivir

The results of Gilead's study on using remdesivir early in the course of illness, published in The New England Journal of Medicine, were "truly dramatic," says Dr. Jane Kelly, assistant state epidemiologist for South Carolina, who is not affiliated with the study. "It resulted in an 87% lower risk of hospitalization or death than placebo."

Those results put it on par with monoclonal antibodies and Paxlovid, a COVID-19 pill, which are the best available COVID treatments out there. Remdesivir's side effects — mainly, nausea — are tame for most people.

Other traits add to remdesivir's appeal. It's the only early treatment available to children under 12. Plus it works against omicron – while some other early treatment options do not. And, while other early treatments are in short supply, there's plenty of remdesivir to go around.

Federal agencies now recommend remdesivir as one of four options for treating early COVID-19. These medicines, when started within five to 10 days of the onset of symptoms, could help patients who might get very sick from COVID-19 — such as some patients with cancer or chronic lung disease — rid their systems of the virus.

Expensive and hard to give to patients

But remdesivir has drawbacks. It takes more resources to administer than the antiviral pills and comes with substantial upfront costs, which stand in the way of widespread use.

For starters, remdesivir is a drug infusion that must be given intravenously, in a clinical setting. Compared with other outpatient options, the drug takes more space and staff to infuse, says Dr. Cameron Wolfe, an infectious disease specialist and professor of medicine at Duke University.

Duke's infusion clinic, like many others, was set up to treat COVID-19 patients with monoclonal antibodies – a treatment which takes a single infusion session lasting 1 to 2 hours, Wolfe explains. But treating patients with remdesivir takes three such infusion sessions over consecutive days. That means a clinic could treat one patient with remdesivir — or three patients with monoclonal antibodies — in the same amount of time.

To accommodate the remdesivir treatments, the Duke clinic had to expand their hours from five days a week to seven. "You don't want someone to get Dose 1 on a Friday, and wait 72 hours [to get the next dose]," says Wolfe.

Treating patients with monoclonal antibodies is preferred because it's more efficient, says Wolfe. But because the supply of monoclonals is limited, he estimates the clinic infused around 130 people with remdesivir in January.

Then there's the issue of initial costs. Remdesivir is the only early treatment that has a supply that is not currently controlled by the U.S. government. That also means it doesn't get sent to health care providers for free. It's available on the commercial market — so clinics pay around $520 per vial, or $2,080 per course, for the drug up front (a person getting outpatient remdesivir treatment receives two vials on the first day; and one vial each on the next two). Putting it into someone's arm adds to that cost.

For providers to get reimbursed, they "have to bill Medicare or a patient's insurance. That might be a consideration to somebody who might be slapped with a co-pay," says Dr. Peter Chin-Hong, an infectious disease specialist at University of California, San Francisco.

These cost issues add to the hurdles providers face in using COVID-19 medicines to keep patients out of the hospital.

"It's hard enough already with these COVID treatments. You're trying to make sure that patients qualify — that they've got their positive test and they're within that symptom window," says Erin Fox, a senior pharmacy director at University of Utah Health. "But then with remdesivir, you have that added challenge of trying to assure payment."

Remdesivir on the back burner

For these reasons, health care providers consider remdesivir to be low on the list of treatment options — available if necessary, but hard to implement.

Fox says her health system in Utah has treated only about 15 early COVID-19 patients with remdesivir so far. A larger-than-expected shipment of monoclonal antibody treatments received last month, provided free by the U.S. government, puts remdesivir on the back burner for now. "We have it, we want to use it, but we're kind of turning it on and off depending on how much sotrovimab we're getting," Fox says.

Baylor St. Luke's Medical Center in Houston also recently received an influx of other COVID-19 medications, and has ample supplies of monoclonal antibodies and COVID-19 pills, says Dr. Mayar Al Mohajer, chief of infectious diseases there. "We have access to three out of the four therapeutics. So, we didn't feel that providing outpatient remdesivir would provide an extra benefit for us," he says.

Remdesivir's role as a top COVID-19 treatment may be short-lived. "I think 'stopgap' is probably a good description," says Michael Ganio of the American Society of Health System Pharmacists. In other words, its use may be limited to times when monoclonals and pills are in short supply.

Over the next few months, the supply crunch on other highly effective COVID-19 treatments – that can be taken at home as pills or given in a single infusion – is expected to ease. "Those therapies are just easier to administer, and they're going to end up being preferred," Ganio says.

Still, experts say, remdesivir has been a crucial option in this omicron surge, when virus mutations knocked out a few other treatment options. As the virus evolves, the option to use remdesivir could be key again.

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