The U.S. Food and Drug Administration (FDA) issued an emergency use authorization to Regeneron Pharmaceuticals for its monoclonal antibodies -- casirivimab and imdevimab -- to be given together to treat mild to moderate COVID-19 in adults and in kids over age 12.
The treatment should be given to patients who have a positive coronavirus test and face a high risk of getting severe COVID-19, including those who are 65 and older or have certain chronic medical conditions.
“Authorizing these monoclonal antibody therapies may help outpatients avoid hospitalization and alleviate the burden on our health care system,” Stephen Hahn, MD, commissioner of the FDA, said in a statement.
Casirivimab and imdevimab must be given together through an IV. The lab-made proteins mimic the immune system and specifically target the spike protein on SARS-CoV-2, blocking the virus from entering human cells.
In a clinical trial of nearly 800 patients, the antibody treatment was shown to reduce COVID-19 hospitalizations and emergency room visits in patients who had a high risk of their disease getting worse. Within 28 days of treatment, 3% of people who took the treatment were hospitalized, compared with 9% of people who received the placebo.
The antibody combination is not authorized for patients who are hospitalized for COVID-19 or require oxygen. Clinical trials have not shown benefits for using the treatment in hospitalized patients, and in fact, it may lead to worse outcomes for those who need oxygen or ventilation, the FDA says. Possible side effects include a sudden allergic reaction called anaphylaxis and IV-related reactions, fever, chills, hives, itching, and skin reddening or blotching.
Where the antibody drugs will be administered is not clear, particularly because covid-19 patients are contagious and can’t be given the drug at established infusion clinics alongside people with compromised immune systems.
“You can’t send them to places where cancer patients are being treated,” said Mark McClellan, director of the Duke-Margolis Center for Health Policy and a former FDA commissioner. He said that many hospital systems have extra space they could dedicate to the antibody treatments, or could set up pop-up centers. Home-infusion providers such as CVS could administer the drug in nursing homes and people’s residences, he said.
Earlier this month, the FDA also authorized Eli Lilly’s antibody treatment -- called bamlanivimab -- for people who have COVID-19 and have a high risk of getting a severe form of the disease.
“The emergency authorization of these monoclonal antibodies administered together offers health care providers another tool in combating the pandemic,” Patrizia Cavazzoni, MD, acting director of the FDA’s Center for Drug Evaluation and Research, said in a statement.
White House officials at the recent coronavirus task force briefing promised to distribute the treatment fairly and swiftly, basing distribution on a strategy similar to what is used for remdesivir, an antiviral drug for hospitalized patients. The administration’s rollout of remdesivir was plagued by problems in its early phases, including sending doses to hospitals with no eligible patients, but officials said they had learned from those mistakes.
Sources: U.S. Food and Drug Administration (FDA), The Washington Post, WebMD