- Adagio Therapeutics, a startup formed last year to develop antibody drugs for coronavirus infections, has raised $336 million in one of the larger financing rounds for a privately held biotech this year.
- The substantial raise will support a large, adaptive clinical trial testing the ability of Adagio's antibody drug, ADG20, to treat mild-to-moderate COVID-19. Adagio also hired a chief financial officer and is now backed by several "crossover" investors, implying it could soon go public. Adagio is "continuously evaluating all options" and focused on ADG20, CEO Tillman Gerngross told BioPharma Dive.
- Multiple antibody drugs are available to treat COVID-19 and some could soon be cleared to help prevent infections as well. But unlike those treatments, Adagio's lead drug has been designed to neutralize a wide range of coronaviruses, which could make it useful against variants as well as in future outbreaks.
There are already two antibody drugs from Regeneron and Eli Lilly available for COVID-19, and the Food and Drug Administration could soon clear a third, from Vir Biotechnology and GlaxoSmithKline. Multiple highly protective coronavirus vaccines are widely available in the U.S., with more likely coming, and over half of U.S. adults have now received at least one dose.
All of which suggests there is little room for a fourth COVID-19 antibody drug to make an impact in the U.S.
But Adagio still sees an opportunity. Vaccine hesitancy, along with weaker protection in people with compromised immune systems and growing prevalence of variants, could mean antibody drugs are still needed for COVID-19 treatment. Meanwhile, outside the U.S. and several developed countries, vaccination campaigns haven't ramped up as quickly.
There are some differences between Adagio's antibody drugs and the others from Regeneron, Lilly and Vir, too. The two currently available antibody drugs require either an infusion at a healthcare setting or multiple intramuscular shots, while Adagio's is given via a single injection. The protective effects for Eli Lilly and Regeneron's drugs last a few months, whereas Adagio's — like Vir's — has been engineered to last longer.
Adagio's drug also binds to a different target than the rest, meaning, its makers claim, ADG20 could neutralize a variety of coronaviruses and retain its potency against variants. One of Lilly's antibody drugs, bamlanivimab, was recently withdrawn from the market due to diminished potency against certain variants.
"Irrespective of vaccine adoption and natural immunity there will be millions of people infected by SARS-CoV-2 that will require treatment," said Adagio CEO and co-founder Tillman Gerngross, in an email to BioPharma Dive. "In that world, convenience, duration of protection, cost and resistance to variants will be the key attributes and ADG20 is a class leader in each of those attributes." (Preclinical work on the drug was published in Science in February.)
Adagio's pitch has led to an unusually fast rise for the company. It was formed last year with a license to a portfolio of coronavirus-fighting drugs from Adimab, the Gerngross-run antibody developer whose technology is used by dozens of biotechs and pharmaceutical companies. Adagio has already brought its first candidate to a human trial — a 1,728-participant, multi-stage U.S. study called STAMP. With the new raise, the startup has another $336 million help fund the effort.
Still, there are significant challenges. Unlike its larger competitors, Adagio doesn't have the backing of the U.S. government or a large pharmaceutical partner to help manufacture its drugs at scale. It can currently make 200,000 doses this year, and aims to produce 3.5 million more in 2022.
"We are constantly looking for more capacity," Gerngross said. The company has been in touch with various governments and industry players, but has "not been compelled to partner with anyone" yet, he added.
Identifying the right patients and treating them quickly enough also remains a logistical problem for antibody drugs, which are most helpful when administered no more than a few days after symptoms start. Even as use has picked up — the Biden administration, for instance, in March announced a $150 million plan to help increase access in vulnerable communities — they remain underused. Less than half of the doses the U.S. government pre-ordered from Lilly and Regeneron have reportedly been administered.
Adagio argues improved convenience will lead to wider adoption. "We took the time to develop an intramuscular formulation," Gerngross said, while others "had to make trade offs" in the interest of speed "and they are starting to pay a price." Intravenous administration, in particular, has been a "real challenge," he said.
Later this year, the startup will test whether ADG20 can prevent infections, though Gerngross wouldn't disclose the details of the planned trial. He did note, though, that Adagio won't test its drug in patients who are already hospitalized, a setting where multiple drugs have struggled to show a benefit.
The company will report results from the STAMP trial throughout 2021, Gerngross said, and, if all goes well, will seek emergency FDA clearance by the end of the year.