Federal regulators Friday authorized the antiviral drug remdesivir for covid-19 outpatients at high risk of being hospitalized, providing a new treatment option for doctors struggling with shortages of effective drugs to counter the coronavirus.
The Food and Drug Administration said the intravenous treatment, which had been limited to patients in the hospital, could be administered to outpatients with mild-to-moderate illness.
Remdesivir, manufactured by Gilead Sciences, was among the first coronavirus treatments authorized in 2020. The drug received full agency approval later that year for people 12 and older. Treatment of younger children is permitted under an emergency use authorization, but Friday's expansion to outpatients includes both age groups.
The FDA action was welcomed by physicians scrambling to keep covid patients out of the hospital as waves of infections crowd medical facilities. Among the hurdles for doctors: Two of the three authorized monoclonal antibody treatments are ineffective against omicron; there are shortages of the one antibody drug that still works; and demand for recently cleared antiviral pills sharply exceeds supply.
"The good news is it's another tool in the treatment toolbox," said Helen Boucher, an infectious-disease physician at Tufts Medical Center.
Tufts began offering remdesivir, also called Veklury, on an outpatient basis late last year, Boucher said. Several other large medical centers also are administering it.
Because the medication had been approved for inpatient care, physicians are permitted to prescribe it "off-label" for patients not in the hospital. Boucher said she expects many more doctors and hospitals to begin treating outpatients with the medication now that the FDA has explicitly approved use for outpatients.
David Boulware, an infectious-disease physician at the University of Minnesota Medical School, said the expanded FDA clearance was important to ensure reimbursement from Medicare and private insurers. Sometimes, payers are reluctant to cover medications used off-label.
Boulware noted, however, that using the medication in an outpatient setting has logistical challenges.
"It is possible, but three daily infusions now make the one-time monoclonal antibody infusion seem simple," Boulware said.
For the remdesivir treatment, patients must go to a clinic or hospital three days in a row, which may be difficult for some people. And the drug must be administered by skilled staff, which can present a logistical challenge as many hospitals are hobbled by personnel shortages.
The FDA action Friday followed recent publication of a study in the New England Journal of Medicine that showed remdesivir can be beneficial when given on an outpatient basis. The study found that the drug reduced hospitalization and death by 87% when given soon after a coronavirus diagnosis compared with patients who did not get the drug.
The findings from the study are based on research that predates the delta variant, which spread quickly during summer, and omicron, which is now responsible for more than 95% of coronavirus cases in the United States. But researchers have said remdesivir will probably remain effective even as omicron proves resistant to some monoclonal antibody therapies.
The findings were based on a study, sponsored by Gilead, involving 562 unvaccinated coronavirus patients from September 2020 to April 2021, who were randomly selected to receive the three-day infusion therapy or a placebo.
All of the participants were at high risk for developing a severe case because they were 60 or older, or had at least one other condition that makes the coronavirus more dangerous, such as high blood pressure, cardiovascular disease, diabetes or obesity.
The FDA said in a statement the treatment is not a substitute for vaccines, which remain the most potent protection against coronavirus.
But along with the two new anti-covid pills, the broader use of remdesivir will "bolster the arsenal of therapeutics to treat covid-19 and respond to the surge of the omicron variant," Patrizia Cavazzoni, director of the FDA's Center for Drug Evaluation and Research, said. She added that the drug can be administered at "skilled nursing facilities, home health-care settings and outpatient facilities such as infusion centers."
Tufts' Boucher said her hospital is administering remdesivir in an outpatient respiratory infection clinic originally set up for the monoclonal antibody therapies. Other large medical centers also already use remdesivir on an outpatient basis, she said.
Updated treatment guidelines issued earlier this week by the National Institutes of Health for outpatients with mild-to-moderate covid encourage use of remdesivir, while noting that the FDA had not yet authorized it for those patients.
The guidelines also recommend use of a monoclonal antibody, called sotrovimab, that is effective against omicron. That medication is given as a single intravenous infusion as soon as possible after onset of symptoms and within 10 days of symptom onset. It is made by GlaxoSmithKline and Vir Biotechnology.
Also recommended are two newly authorized pills to treat the coronavirus - one by Pfizer and the other by Merck and its partner, Ridgeback Biotherapeutics. But those oral medications, like sotrovimab, are in short supply.
The guidelines discouraged use of two of the three monoclonal antibody treatments authorized for early stage coronavirus because the therapies probably will not work against the omicron variant. The guidelines said monoclonal antibody therapies by Regeneron Pharmaceuticals and Eli Lilly “are predicted to have markedly reduced activities” against omicron.