AstraZeneca sells hundreds of thousands more doses of COVID-19 antibody combo to U.S. for $205M

AstraZeneca has received a total of around $726 million from the U.S. government to develop and supply its COVID-19 antibody drug hopeful. (AstraZeneca)

As AstraZeneca's COVID-19 vaccine woes mount in Europe, the company is expanding its deal with the U.S. to tackle the pandemic fight on the treatment front. 

AstraZeneca pledged 500,000 more doses of its experimental COVID-19 antibody drug, AZD7442, to the U.S. on Tuesday, bringing the country's total potential supply to 700,000 doses this year. The government will pay $205 million for the extra stock, lifting the total U.S. investment in the development and supply of the treatment to around $726 million, AstraZeneca said.

The cocktail, which combines two long-acting antibodies, is in the midst of five late-stage prevention and treatment trials. AZ arrives late to the pandemic antibody game—Regeneron and Eli Lilly have both scored emergency authorizations for their treatments—but the British pharma figures its combo could work longer and succeed where its rivals have failed in severe disease, to hear EVP Mene Pangalos tell it last fall.

AZ's modified agreement with HHS and the Department of Defense follows a deal in October for an initial 100,000 treatment doses. As part of that pact, AstraZeneca also received some $486 million from the HHS' Biomedical Advanced Research and Development Authority (BARDA) to develop and supply the antibody hopeful. 

The U.S. had the option to buy more doses in 2021, and the Defense Department snapped up a separate 100,000 doses, AstraZeneca said.

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Even as a trio of vaccines roll out in the U.S., it will be some time before most people get their shots, and AZ's antibody combo could offer a much-needed stopgap to both treat and prevent COVID-19 in the meantime, CEO Pascal Soriot said in a release. 

AstraZeneca thinks its candidate could have a durability edge over rivals from Lilly and Regeneron, too. AZ's so-called long-acting antibodies were developed using its half-life extension technology, which the company says triples the durability of action compared to conventional antibodies.

To put that into context, Lilly and Regeneron both took full, unmodified antibodies into the clinic, while AZ modified the Fc region of its antibodies. The Fc region doesn't act on the target antigen but can still have biological effects, such as activating the immune system.

AZ made those changes to augment its candidate's half-life, but with the unmodified Fc region a possible source of Lilly and Regeneron's setbacks in severe COVID-19, AZ "may have a better chance of seeing some activity or some efficacy in that more severe patient population,” Pangalos said on an investor call in November.

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What's more, AstraZeneca is testing its candidate as an intramuscular injection rather than an infusion, which could ease administration if the drug scores an emergency nod. Lilly and Regeneron's antibodies launched in November, but uptake has been slower than expected. The meds need to be infused under a healthcare provider's supervision, which is complicated by their authorization in patients with mild-to-moderate illness, who aren’t typically in a hospital.

AstraZeneca meanwhile has brought on some production support from Swiss-based CDMO Lonza. The company in October agreed to produce drug substance for the antibody combo at its new facilities in Portsmouth, New Hampshire, with plans to start that work in the first half of 2021.