Dive Brief:

• Adagio Therapeutics CEO Tillman Gerngross has agreed “in principle” to resign as head of the COVID-19 drug developer amid confusion over whether its most advanced antibody treatment works against the omicron variant.

• The company’s board of directors plans to appoint current chief operating officer David Hering, a former Pfizer executive who joined Adagio last summer, as interim CEO, according to a Feb. 18 statement from Adagio, which plans to provide more information in “the near term.”

• Adagio, which Gerngross co-founded in 2020 as a spinout of his company Adimab, raised nearly $800 million on the promise it could develop a better antibody medicine for COVID-19. That work has led to ADG20, the company’s lead candidate now in late-stage testing. But doubts of its potential emerged in December, when Adagio said the drug was much weaker against omicron than expected, a position it has since qualified.

Dive Insight:

Gerngross built Adagio with threats like omicron in mind, aiming to use Adimab’s technology and antibodies it licensed from the privately held company to develop a medicine that could work against different coronaviruses as well as different strains. The company parlayed that plan into an unusually fast ascent, going public a year after its founding in one of 2021’s largest initial stock offerings.

In late November, soon after omicron’s emergence, Adagio expressed confidence ADG20 would work well, noting that the mutations which made the variant more concerning weren’t associated with escape from the drug’s grasp.

That made the company’s Dec. 14 announcement of a 300-fold reduction in ADG20’s ability to neutralize omicron compared to other strains more surprising. Shares in Adagio collapsed, erasing roughly $3 billion in market capitalization.

Adagio stopped recruiting new study volunteers into two late-stage studies in response as it discussed updates to the trial plans with regulators.

By January, however, the company attempted to recalculate its assessment of ADG20’s potential. Subsequent laboratory studies by other groups found that, while neutralization was reduced versus omicron, the drug did retain some activity.

In a new statement Monday, Adagio said it will analyze clinical data for the 300 mg dose being tested in its two late-stage trials, results that should be available in March. Additionally, the company plans to evaluate higher doses of the drug, as well as explore modifying it to better bind to omicron.

Adagio said it may also develop new antibody drug candidates for use as a standalone treatment or in combination.

Notably, however, the company said that ADG20 has “markedly reduced neutralization activity” against the BA.2 lineage of omicron, the potential impact and spread of which is currently unclear.

Other antibody drug developers have struggled to keep up with variants, too. The U.S. government stopped distribution of treatments from Regeneron and Eli Lilly due to their reduced effectiveness versus omicron, although the Food and Drug Administration recently approved a new Lilly antibody drug that’s meant to work better.

Shares in Adagio rose by 2.5% on Tuesday morning.