The Food and Drug Administration on Saturday issued an emergency use authorization to Regeneron for its covid-19 monoclonal antibody cocktail, which is made up of the antibodies casirivimab and imdevimab, citing a reduction in hospitalizations and emergency room visits in patients in a clinical trial as well as a reduction in viral load.
Monoclonal antibodies, which are used to treat other conditions such as cancer or autoimmune disorders, are antibodies created from a single cell and cloned in a lab. They are based on the antibodies naturally created by the body’s immune system, although they are often modified for efficacy and safety. In this case, the casirivimab and imdevimab cocktail is directed against the spike protein in SARS-CoV-2 and is designed to block the virus’ attachment and entry into human cells.
In its authorization, the FDA stated that Regeneron’s treatment could be used to treat mild to moderate covid-19 in adults and kids aged 12 or older (with a weight of at least 88 pounds) who are at high-risk of developing a serious case of the disease. Casirivimab and imdevimab must be administered together via an IV infusion.
The FDA said it based its decision to issue the emergency authorization for the treatment on the data from a randomized, double-blind, placebo-controlled clinical trial of 799 patients. The patients were not hospitalized and had mild to moderate covid-19 symptoms. It’s worth noting that Regeneron’s most famous patient is President Donald Trump, who received the cocktail shortly after he was diagnosed with the disease after months of reckless behavior.
In the clinical trial, patients were divided into three groups. One group of 266 people was given 2,400 milligrams of the cocktail; another group of 267 received 8,000 mg of the cocktail; and a third group of 266 received a placebo. The treatment was administered within three days of receiving a positive covid-19 test. According to the FDA, viral load reduction in patients given the cocktail was larger than those given the placebo on day seven. The agency highlighted, however, that the most important evidence that suggests the cocktail could be effective was the resulting visits to the hospital and emergency room within 28 days after treatment.
On average, only 3% of patients at high-risk for severe illness that had received the cocktail went to the hospital or emergency room within that time frame, the FDA stated, compared to 9% of the patients treated with the placebo. The effects on viral load and reductions in hospitalizations and emergency room visits was similar for patients that received either dose.
Dr. Stephen Hahn, the FDA commissioner, said in a statement announcing the authorization that monoclonal antibody therapies may help outpatients avoid hospitalization and alleviate the burden on the country’s health care system. On Saturday, with at least 83,227 new covid-19 hospitalizations, the U.S. broke its record for hospitalized patients with covid-19 for the 12th straight day, per CNN.
Other highlighted the fact that medical professionals had yet another tool to use against the virus.
“The emergency authorization of these monoclonal antibodies administered together offers health care providers another tool in combating the pandemic,” said Dr. Patrizia Cavazzoni, acting director of the FDA’s Center for Drug Evaluation and Research, in a statement. “We will continue to facilitate the development, evaluation and availability of covid-19 therapies.”
The Regeneron antibody cocktail is the second monoclonal antibody treatment to receive authorization by the FDA this month. Nearly two weeks ago, the agency issued an emergency use authorization to Eli Lilly for bamlanivimab, which also targets SARS-CoV-2’s spike protein. In that authorization, it cited an interim analysis of a clinical trial in which patients receiving the treatment saw reduced hospitalizations and emergency room visits.
Nonetheless, the Regeneron antibody cocktail is not for everyone. It is not authorized for use in patients who are hospitalized; require oxygen therapy due to covid-19; or use chronic oxygen therapy because of an underlying comorbidity who require an increase in baseline oxygen flow rate due to covid-19, the company affirmed in a press release.
In fact, Regeneron found that hospitalized patients had not benefitted from its cocktail. It added that monoclonal antibodies may be associated with worse clinical outcomes when administered to hospitalized patients on high flow oxygen or mechanical ventilation due to covid-19.
Regeneron has received hundreds of millions of dollars from the U.S. government to development and manufacture its treatment. As part of the agreement, the company aims to provide the government with treatment for approximately 300,000 patients—which will be given at no cost to patients, although health care facilities may charge administrative fees—by the end of January.
There’s a big problem, though. According to the Centers for Disease Control and Prevention, the U.S. reported roughly 1.1 million new cases in the last seven days. Although having another tool to use in the pandemic is welcome news, it won’t be of much help if we continue to break records in cases and hospitalizations. As we marvel at the advances of science, let us also do our part to stop the spread.