Adagio Makes Case for Anti-COVID-19 Antibody Based on New Data

Adagio cited three recent independent, in vitro studies showing that ADG20, which is currently undergoing Phase II/III clinical trials, has neutralization activity against Omicron.

With the COVID-19 pandemic entering its third year, few drugs exist that have any neutralizing efficacy against the currently prevalent Omicron variant. Late Wednesday, Adagio Therapeutics reported that its lead monoclonal antibody (mAb) is one of them.

In November, Adagio claimed that none of the mutations found in Omicron were linked with escape from ADG20 neutralization in vitro. So, essentially, the mAb did not protect against the newly emerged variant.

On Wednesday, the Waltham, Massachusetts-based company cited three recent independent, in vitro studies showing that ADG20, which is currently undergoing Phase II/III clinical trials, has neutralization activity against Omicron. With an IC50 (neutralization potency) of approximately 0.4 to 1.1 µg/mL, Adagio said ADG20 is on par with Vir and GlaxoSmithKline’s sotrovimab (currently authorized for the treatment of early COVID-19) and AstraZeneca’s AZD7442.

This neutralization capability is not as potent as it is against other variants of the SARS-CoV-2 virus, but Adagio Co-founder and Chief Scientific Officer Laura Walker, Ph.D. believes there is an important place for the drug in the overall battle.

“While findings may show that ADG20 has reduced potency against Omicron when compared to its high potency against all other variants of concern, including Delta, the data support that ADG20 is among the few mAbs to demonstrate neutralizing activity against the Omicron variant and warrants its continued development,” Walker said in a press release.

The new studies back up previous ones that showed ADG20 retained its neutralizing ability against the Alpha, Beta, Delta and Gamma variants. Adagio previously explained that the antibody’s broad recognition and specific target are thanks to this neutralization capability. The company said ADG20 targets a particular epitope on the virus’s receptor-binding domain that is less impacted by “immune pressure” because it is not being targeted by any known class of antibodies.

Adagio also gave an update on the EVADE and STAMP clinical trials, saying that it is pausing enrollment of new patients in the 300 mg dose arm of both studies while it updates its protocols. The company is in discussions with the U.S. Food and Drug Administration regarding dosing strategy, which includes increasing the dose of ADG20 in light of Omicron’s spread.

The Omicron variant, which emerged on Thanksgiving weekend in the U.S., made up 98.3% of the nation’s newly reported cases for the week ending January 8, the Centers for Disease Control and Prevention (CDC) reported. While most experts now agree that Omicron causes less severe disease than its predecessor variants, it is also at least 4 times more contagious in its early stages.

“We, from the beginning, predicted exactly what is happening now,” Adagio Co-founder and CEO Tillman Gerngross said in a previous statement. “We said that the Greek alphabet has 24 letters, and we have a long way to go.” Well said, Mr. Gerngross. Well said.

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