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The US Food and Drug Administration has granted an emergency use authorization (EUA) for Eli Lilly and Company’s experimental monoclonal antibody treatment for COVID-19. The antibody, called bamlanivimab, neutralizes SARS-CoV-2 by binding to its spike protein and thereby preventing the virus from gaining a foothold into human cells.
“This is welcome news and supports growing evidence that potent neutralizing antibodies can benefit those in the early stages of infection,” Scripps Research antibody scientist Dennis Burton said in an email.
Bamlanivimab is the first drug discovered during the pandemic to receive an EUA—every other treatment granted the status so far had been previously studied or approved for other diseases.
It was discovered and developed in just 8 months, a process that began in late February, when the Canadian start-up AbCellera Biologics started probing a plasma sample donated by a person who had recovered from a coronavirus infection. The company identified hundreds of antibodies in the plasma that seemed to target the coronavirus. With the help of researchers at Lilly, and later at the US National Institute of Allergy and Infectious Diseases, AbCellera progressively winnowed that pool down to its top pick.
By the end of May, Lilly had launched a clinical trial to test the antibody in people hospitalized with COVID-19. The drug was not effective in that population, but another Phase 2 study in people with mild or moderate COVID-19 found that it reduced the amount of coronavirus detected in a nasopharyngeal swab. In a result that scientists found puzzling, the effect was only statistically significant at the medium dose of 2,800 mg, not the low or high doses of 700 and 7,000 mg.
But the FDA authorized use of bamlanivimab at its the lowest dose, 700 mg. In its announcement, the agency said that the more important marker from Lilly’s studies was the reduction in hospitalizations and emergency room visits from 10% in the placebo group to 3% in those who got bamlanivimab.
The EUA “is incredibly exciting,” says Janice Reichert, executive director of the Antibody Society, a trade organization. Reichert had expected marketed drugs that target inflammatory molecules to be approved for treating COVID-19 before the newly created antibodies. But trials testing those repurposed drugs have largely been unsuccessful so far.
The need for new therapies is urgent. The US reported over 130,000 new coronavirus infections on Monday alone. “We are in a tough spot,” says Tillman Gerngross, CEO of Adagio Therapeutics, a start-up developing an antibody therapy that targets multiple kinds of coronavirus. “We are back to where hospitals are being taxed to an extent where they are struggling to keep up with the patient demand, so anything that helps is good, and there is no question that antibodies are going to play some role in that.”
Lilly and Regeneron, a company making its own antibody therapy for treating coronavirus infections, both applied for an EUA in early October, just days after US President Donald J. Trump was treated with Regeneron’s experimental therapy REGN-COV2. Regeneron is still waiting on an EUA for that treatment.
There’s an important difference between the two companies’ treatments that scientists will be watching closely. Lilly’s therapy is a single antibody, whereas Regeneron is developing a cocktail that contains two antibodies that target different surfaces of the coronavirus spike protein. The cocktail approach is intended to address concerns that the virus could mutate its spike protein to easily resist a single antibody.
Scripps’s Burton notes that there’s a chance that the EUA for Lilly’s drug will make it harder for other drug companies to recruit people to clinical trials for their own antibody therapies. But antibodies are hard to produce in large volumes, and though Lilly plans to manufacture up to 1 million doses of bamlanivimab this year, it will likely fall short of demand. There are dozens of companies working on similar therapies, and Reichert says that there will likely be room for many of them to make successful drugs.
The US government has already made a $375 million preorder for 300,000 doses of bamlanivimab—a deal that works out to about $1,250 per dose. The therapy will be distributed to people in the US for free, but the expensive cost could hinder its adoption worldwide. “We need to find ways to make large quantities of effective antibodies available to low- and middle-income countries,” Burton says.