As variants take hold, FDA revokes authorization of Eli Lilly's solo COVID-19 antibody

Eli Lilly’s COVID-19 neutralizing antibody drug was the first of its kind to score FDA authorization against the illness in early November. Emerging coronavirus variants later threatened to mute the treatment’s effectiveness and now, nearly six months later, the FDA has rescinded its endorsement. 

The federal agency on Friday revoked its emergency authorization for Lilly’s monoclonal antibody therapy bamlanivimab, when administered by itself, to treat adult and certain pediatric COVID-19 patients with mild-to-moderate disease. Lilly itself supports the move and still distributes the antibody in combination with etesevimab.

The decision comes after the FDA ordered Lilly and rival drugmaker Regeneron in late February and early March to monitor their treatments against emerging variants of SARS-CoV-2, the coronavirus that causes COVID-19. 

Some of the variants, especially the B.1.351 version first identified in South Africa, have proven resistant to antibody therapies. Now, the potential benefits of administering Lilly’s drug no longer outweigh the risks as some of those variants take hold in the U.S., the FDA said in its latest order. 

RELATED: FDA orders COVID antibody makers Regeneron, Eli Lilly to track virus variants 

Still, other authorized monoclonal antibody therapies “remain appropriate treatment choices ... and can help keep high-risk patients with COVID-19 out of the hospital,” said Patrizia Cavazzoni, director of the FDA’s Center for Drug Evaluation and Research, said in a statement.

That includes Lilly's combo of bamlanivimab and etesevimab, Cavazzoni said. Lilly's two combined drugs, which it developed specifically to target emerging variants, received the FDA’s OK in February. Regeneron also distributes a combo of casirivimab and imdevimab.

The agency’s decision on Friday likely came as no surprise to Lilly, which actually requested the FDA rescind bamlanivimab’s solo authorization the same day. The Indianapolis-based drugmaker said it’s transitioning its focus toward the combo treatment and will only submit the bamlanivimab-etesevimab duo for authorization moving forward. 

Lilly's solo bamlanivimab and its mix with etesevimab are authorized in 20 countries outside the U.S. The company isn't asking other governments to rescind their authorization of the single treatment at this time.

Amid the increase in variants and supply gains for etesevimab, "we believe now is the right time to complete our planned transition and focus on the administration of these two neutralizing antibodies together,” Daniel Skovronsky, Lilly's chief scientific officer, said in a statement.

Just last week, the drugmaker said that it has stopped supplying bamlanivimab as a solo therapy to the U.S. completely, although the feds had already stopped using it in several states where one variant was running rampant. Under a revised supply deal with the government, Lilly will supply its combo therapy.

All infusion sites in the U.S. now have the ability to obtain doses of mixed therapy, and providers should order additional doses of etesevimab to pair with their solo bamlanivimab supply, Lilly said in a statement Friday.

RELATED: With variants spreading, Eli Lilly cuts solo COVID-19 antibody out of its U.S. supply deal 

The company recently posted strong data backing the combined drug therapy. Based on phase 3 clinical trial data, the bamlanivimab-etesevimab duo slashed hospitalizations by 87% versus placebo.