Authorization of new Covid-19 monoclonal expands arsenal of options against Omicron and its sister variant

The Food and Drug Administration on Friday authorized another Covid-19 monoclonal antibody treatment, which will expand the supply of such treatments that work against the Omicron variant and its sister viruses.

The therapy, bebtelovimab, was developed by Eli Lilly. Like other monoclonals, it’s given intravenously and is meant to keep high-risk patients with Covid-19 from getting so sick they need to be hospitalized.

The federal government on Thursday announced it had struck a deal with Lilly to purchase 600,000 courses of the treatment for at least $720 million. Shipments were expected to start imminently, with 300,000 courses arriving this month and another 300,000 next month. The contract includes an option for another 500,000 courses.

The FDA said that bebtelovimab should be used for patients “for whom alternative Covid-19 treatment options … are not accessible or clinically appropriate.”

Still, the news will provide a bit of relief to providers who have been scrambling to find treatments for their high-risk patients. The two most common antibody therapies from earlier in the pandemic — another Lilly treatment and one from Regneron — lost their effectiveness against the Omicron variant, which quickly became dominant late last year. The government halted distribution of the two therapies.

Another monoclonal treatment — sotrovimab from GlaxoSmithKline and Vir Biotechnology — maintained its power against Omicron, but shortages meant the government has been distributing some 50,000 courses of the treatment each week, even as millions of infections were being reported over the same time frame.

Lilly said lab testing had indicated that bebtelovimab not only worked against the more common Omicron variant — technically known as BA.1 — but also maintained its effectiveness against a sister linage called BA.2. Although that latter accounts for just a small fraction of infections in the United States at this point, it is more transmissible than BA.1 and its prevalence is expected to grow. BA.2 is dominant in countries including India, Denmark, and South Africa.

It’s not clear yet whether sotrovimab works against BA.2.

Other options for treating Covid-19 patients who aren’t yet hospitalized include two antiviral pills, one from Pfizer and one from Merck, and Gilead’s remdesivir, an intravenous antiviral.

With supply constraints, the therapies are typically reserved of people at high risk of severe Covid-19.