FDA restricts use of antibody drugs marginalized by omicron


WASHINGTON (AP) — COVID-19 antibody drugs from Regeneron and Eli Lilly should no longer be used because they are unlikely to work against the Omicron variant, which is now responsible for nearly all U.S. infections, U.S. health officials said Monday .

The Food and Drug Administration said it was revoking emergency use approvals for both drugs, which were purchased by the federal government and given to millions of Americans with COVID-19. If the drugs prove effective against future variants, the FDA said it could reauthorize their use.

The regulatory move was expected because both drugmakers had said the infusion drugs are less able to target Omicron due to its mutations. Still, the federal action could trigger a backlash from some Republican governors who have continued to promote the drugs against the advice of health experts.

Omicron’s resistance to the two leading monoclonal antibody drugs has turned the treatment concept for COVID-19 on its head in recent weeks.

Doctors have alternative therapies to fight early COVID-19 cases, including two new antiviral pills from Pfizer and Merck, but both are in short supply. A GlaxoSmithKline antibody drug that remains effective is also in short supply.

The drugs are lab-made versions of virus-blocking antibodies. They are designed to prevent serious illness and death by delivering concentrated doses of one or two antibodies early in an infection. Then-President Donald Trump received Regeneron’s antibody combination after testing positive for the coronavirus in 2020.

The U.S. government temporarily halted distribution of the two drugs in late December as omicron raced around the dominant variant nationwide. But officials resumed distribution after complaints from Republican governors, including Florida’s Ron DeSantis, who claimed the drugs would continue to help some Omicron patients.

DeSantis has heavily promoted antibody drugs as a signature part of his administration’s COVID-19 response, setting up IV sites and praising them at press conferences while speaking out against vaccination mandates and other public health measures. Texas Gov. Greg Abbott has also set up state-sponsored IV sites.

The drugs are not a substitute for vaccination and are generally reserved for those most at risk, including seniors, transplant recipients and people with conditions such as heart disease and diabetes.

Since early January, the US government has shipped out enough doses of the two antibodies to treat more than 300,000 patients.

Both Regeneron and Lilly previously announced that they are developing new antibodies that target Omicron.

The move comes days after regulators expanded the use of remdesivir – the first drug approved for COVID-19 – to treat more patients.

On Friday, the FDA expanded approval of the antiviral to include adults and children with early COVID-19 who are at high risk of ending up in the hospital. Remdesivir was previously restricted to inpatients.

An influential panel of federal experts had already recommended using the infused drug to try to avert hospitalization. The same National Institutes of Health panel guidelines advise against continued use of the Lilly and Regeneron antibody drugs due to their reduced effectiveness against Omicron.

Still, many hospitals will face challenges ramping up remdesivir treatments. The drug requires three consecutive intravenous infusions over three days when used in out-of-hospital patients. This time-consuming process will not be an option for many overcapacity hospitals facing staff shortages.

The FDA made its decision based on a study of 560 patients that showed a nearly 90 percent reduction in hospitalizations when remdesivir was administered within seven days of symptoms. The study predates the Omicron variant, but like other antivirals, remdesivir is expected to retain its performance over the latest variant.


The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.


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