It's back: Eli Lilly's COVID-19 antibody combo makes its return after 2 months on the sidelines

In the two months since U.S. officials stopped distribution of Eli Lilly's COVID-19 antibody combo, rival Regeneron has taken hold of the market—and GlaxoSmithKline and Vir's newer version has gathered steam. But with a new green light, Eli Lilly's combo can try for a comeback.

Federal officials have reauthorized Eli Lilly's antibody combo bamlanivimab and etesevimab in states where variants that can evade the drugs—including the gamma variant identified in Brazil and the delta-plus variant from India—make up less than 5% of cases.

For now, that means Lilly's duo can be used in more than 20 states including Ohio, Colorado and Connecticut. 

But the combo still can't be used in states like Texas and Florida, where the summer COVID-19 surge has been particularly pronounced, the FDA says.

Studies have shown the drugs "retained neutralization activity" against the delta variant, which is currently responsible for nearly 96% of the cases in the U.S., Eli Lilly said in a statement (PDF). The combo is also effective against the alpha variant, which was first identified in the U.K., Lilly says.

RELATED: Lilly's COVID antibody combo halted nationwide, dealing huge blow to blockbuster program

Eli Lilly scored the first FDA emergency authorization for a COVID-19 monoclonal antibody back in November, and the company's variant woes started in the spring. In April, federal officials stopped use of solo bamlanivimab based on studies showing it couldn't tackle emerging variants.

From there, things only got worse for Eli Lilly's antibody drugs. In May, officials stopped distributing the company's combination in a handful of states. Then in June, the government pulled the combo from the market altogether.

During the second quarter, sales for the company's COVID-19 antibodies fell to $149 million, less than a fifth of the more than $800 million during each of the two prior quarters.

On the flip side, Regeneron's REGEN-COV has been a dominant force in recent months. The combo of casirivimab and imdevimab this summer won an FDA nod as a post-exposure prevention tool, and, in the second quarter, the drugs pulled in a whopping $2.6 billion. 

RELATED: Regeneron's COVID-19 antibodies rake in $2.6B, reflecting their market dominance and blowing away estimates 

Meanwhile, another COVID-19 antibody from GlaxoSmithKline and Vir Biotechnology has entered the scene since Eli Lilly's variant troubles started. GSK and Vir in late May won an FDA authorization for sotrovimab, but they don't have a federal supply deal in place. Orders for the drug have surged this summer, a GSK representative said earlier this month.

Aside from its antibody combo, Eli Lilly also has an FDA emergency authorization for rheumatoid arthritis drug Olumiant in hospitalized patients who require supplemental oxygen.