Eli Lilly's COVID-19 antibody shows it can prevent the disease. But will doctors use it?

Eli Lilly’s bamlanivimab was the first antibody drug the FDA authorized to treat COVID-19. Now, the Indianapolis pharma has data showing the therapy prevents symptomatic infections.

The catch? The data are limited to long-term care facilities, where vaccination is now underway—and despite their utility, antibody therapies are having a tough time catching on.

Bamlanivimab cut the risk of developing symptomatic COVID-19 by 57% among residents and staffers of long-term care facilities in a phase 3 trial conducted by the National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID), Lilly said Thursday. The risk reduction was higher at 80% among the subgroup of nursing home residents.

“The results of this innovative study further support the belief that bamlanivimab—and potentially other monoclonal antibodies—can reduce symptoms and may even prevent COVID-19,” Myron Cohen, M.D., co-principal investigator of the NIAID’s CoVPN antibody trial program, said in a statement.

Talks of potential additional emergency use authorization could follow, and Lilly said it’ll publish the full results at a medical meeting and in a peer-reviewed journal.

The data show antibodies could be useful as a COVID prevention tool in vulnerable populations as an additional tool to vaccines, SVB Leerink analyst Geoffrey Porges said in a note Thursday. Unfortunately, Lilly would need to clear some hurdles to get its therapy to patients.

“[T]his hinges on quick, targeted distribution of antibodies to high-risk individuals by the U.S. government, which is a significant unknown factor,” Porges said, “and infused administration continues to post a challenge to distribution.”

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While vaccines work by triggering the body to develop neutralizing antibodies, the Lilly drug gives the virus-fighting molecules directly to a person, saving the time before vaccine’s effect kicks in and potentially helping people whose immune system may not be strong enough to launch an adequate response to vaccines, such as nursing home residents.

But bamlanivimab's use in this patient group might not be that relevant because long-term care facility residents and employees are already given high priority in vaccination campaigns.

Back in November, the FDA granted bamlanivimab emergency use authorization in the outpatient setting to treat COVID patients at high risk of developing severe disease. That authorization is for the drug at 700 mg injection.

In the current Blaze-2 trial, the drug was given at 4200 mg. The study enrolled 965 participants who tested negative for SARS-CoV-2—the coronavirus behind COVID—including 299 nursing home residents and 666 staffers. The risk reduction data were recorded after eight weeks of follow-up. At the time, four COVID-related deaths had been recorded among the residents, and they all occurred in the placebo arm, Lilly said.

Manufacturing antibody drugs is difficult; hence their high prices. Lilly was said to be building production capacity for bamlanivimab to around 1 million 700-mg doses by year-end 2020, and the prevention dose strength—at six times the treatment dose—is an important consideration for supply, Porges noted.

RELATED: Lilly and Regeneron COVID-19 antibodies are available all over the U.S. Why aren't they getting to more patients?

Besides AbCellera-partnered bamlanivimab, Lilly has another antibody called etesevimab, which it licensed from China’s Junshi Biosciences. The two drugs form an antibody cocktail that also worked in non-hospitalized patients.

Regeneron has REGN-2, a dual-drug antibody cocktail that also bears and FDA emergency use authorization. Porges figures Lilly’s positive data bode well for the Regeneron therapy in its own COVID-19 prevention trial, which is slated to read out before July.

So far, however, adoption of these two antibody products has been slow. States have attributed the weak interest to the fact that they're hour-long infusions done under a healthcare provider's supervision, as well as low awareness—vaccines seem to grab all the attention.

Experts have also raised concerns that current antibodies may be less effective against new variants of the coronavirus. That's why Porges said he prefers the Regeneron cocktail over Lilly's single drug bamlanivimab, because two antibodies make it more difficult for the virus to develop resistance.