By Peter Loftus 

Eli Lilly & Co. has asked U.S. health regulators to revoke the authorization for use of its Covid-19 antibody drug bamlanivimab alone because it is less potent against certain coronavirus variants circulating in the U.S.

Instead, Lilly said Friday it will focus on distributing a drug cocktail containing bamlanivimab and a second antibody, named etesevimab, that studies indicate neutralize more of the emerging Covid-19 variants in the U.S. when given together than bamlanivimab alone.

The Food and Drug Administration later Friday granted Lilly's request and revoked its authorization of using bamlanivimab alone, saying its benefits no longer outweighed its risks because of the increase of variants that are resistant to the drug. The agency said combination antibody therapies remain appropriate to use.

The drugmaker's request hints at the extent of the challenge that new strains of the virus could pose to treatments and vaccines. To stay ahead of any variants that could emerge able to evade currently available shots, health authorities have been racing to vaccinate as many people as possible.

Indianapolis-based Lilly said bamlanivimab alone should no longer be administered in the U.S. because of the variant challenge. The company said there weren't any new safety concerns.

"With the growing prevalence of variants in the U.S. that bamlanivimab alone may not fully neutralize, and with sufficient supply of etesevimab, we believe now is the right time to complete our planned transition and focus on the administration of these two neutralizing antibodies together," Lilly Chief Scientific Officer Daniel Skovronsky said.

The variants that the drug cocktail can better neutralize include two closely related strains, known as B.1.427 and B.1.429, that currently account for about 50% of the virus in California and more than 10% in some other states, the company said.

Antibody drugs are essentially clones of immune-system antibodies that the body produces to fight the coronavirus.

Regeneron Pharmaceuticals Inc. also has developed a Covid-19 antibody treatment. They were intended to fill a gap in treatment by helping patients early in the disease, and by potentially preventing disease in people exposed to the virus.

Lilly raced to develop bamlanivimab last year, and the FDA authorized it in November to treat mild to moderate Covid-19 in adult and pediatric patients who are at high risk for worsening to severe disease or hospitalization.

In February, the FDA authorized the combination of bamlanivimab and etesevimab to treat mild to moderate Covid-19, after a study showed the treatment reduced hospitalizations and deaths versus a placebo.

The U.S. government in March restricted distribution of Lilly's bamlanivimab alone in California, Arizona and Nevada because of concerns that variants were blunting its effectiveness. The federal government subsequently stopped distribution of the single antibody nationwide.

Lilly said medical providers shouldn't dispose of bamlanivimab supply, but instead should order etesevimab to pair with it.

Lilly isn't requesting the withdrawal of bamlanivimab alone in other countries but said the combination therapy is preferred.

Write to Peter Loftus at


(END) Dow Jones Newswires

April 16, 2021 17:54 ET (21:54 GMT)

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