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An antibody cocktail is now beginning late-stage clinical trials to evaluate the drug’s ability to prevent and treat coronavirus infection.

The biotechnology company Regeneron announced the late-stage clinical trials of REGN-COV2, its investigational double antibody cocktail for the treatment and prevention of Covid-19, in a news release on Monday.

Specifically the release noted that a Phase 3 trial of the drug will assess its ability to prevent coronavirus infection among uninfected people who have had close contact to an infected person, such as a patient’s housemate. The Phase 3 prevention trial is happening at around 100 sites and expected to include 2,000 patients across the United States, according to Regeneron.

The drug also has moved into the Phase 2/3 portion of two trials testing its ability to treat hospitalized and non-hospitalized patients with Covid-19, according to Regeneron. These trials will involve 1,850 hospitalized patients and 1,050 non-hospitalized patients, and they are expected to be conducted at 150 sites in the United States, Brazil, Mexico and Chile.

“We are running simultaneous adaptive trials in order to move as quickly as possible to provide a potential solution to prevent and treat COVID-19 infections, even in the midst of an ongoing global pandemic,” Dr. George D. Yancopoulos, co-founder, president and chief scientific officer of Regeneron, said in the company’s news release.

The release also noted that the trial is being run jointly with the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

Regeneron receives $450 million to manufacture therapy

O
n Tuesday, Regeneron announced it was awarded a $450 million contract to manufacture and supply the antibody treatment as part of “Operation Warp Speed,” the federal government’s Covid-19 vaccine program.

The agreement with the Biomedical Advanced Research and Development Authority and US Department of Defense supports manufacturing of the drug so that it can be made available immediately in the United States if clinical trials are successful and it receives emergency use authorization or approval from the US Food and Drug Administration.

The company started scaling up production of the treatment in the spring and said that if OK’d be the FDA, it would be available in the United States at no cost.

“This manufacturing and supply agreement with BARDA and the Department of Defense could help REGN-COV2 reach many people quickly, hopefully helping to change the course of this deadly and still-raging pandemic,” Dr. Leonard S. Schleifer, Regeneron co-founder and chief executive officer, said in a statement.

How the therapy works

Antibodies are proteins the body naturally makes to protect the body from a threat like Covid-19. To make what’s called monoclonal antibodies for an antibody cocktail, scientists comb through thousands of antibodies to figure out which ones fight the novel coronavirus most effectively.

In this case, Regeneron’s scientists picked two antibodies, scaled them up and put them into a medicine that it hopes can be used to treat symptoms and possibly even work as protection for vulnerable communities such as the elderly or health care workers.

Entering these late-stage trials means that the drug already has shown positive results in earlier trials in humans assessing safety, which began in June. The Phase 1 safety results included an initial cohort of 30 hospitalized and non-hospitalized patients with Covid-19, according to Regeneron.

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Regeneron said last month that its antibody cocktail will be tested in four separate study populations: people who are hospitalized with Covid-19; people who have symptoms for the disease, but are not hospitalized; people who are healthy but are at a high risk for getting sick; and healthy people who have come into close contact with a person who is sick.

Regeneron is not the first company to get a Covid-19 antibody therapy into human trials. Eli Lilly and AbCellera started testing their antibody treatment in humans June 1. There are a handful of other companies working on additional antibody therapies.

CNN’s Jen Christensen contributed to this report.