US Govt to Buy 1.25M Regeneron Covid-19 Therapies

Scanning electron microscope image of SARS-Cov-2 virus, responsible for Covid-19 infections (NIH.gov)

13 Jan. 2021. The U.S. Department of Health and Human Services is buying up to 1.25 million more doses of Regeneron’s Covid-19 antibody therapy, for $2.63 billion. The antibody therapy, a combination or cocktail of two synthetic monoclonal antibodies is authorized by the Food and Drug Administration to treat people with Covid-19 infections, but not hospitalized.

Regeneron, in Tarrytown, New York, develops synthetic antibodies that stimulate the immune system to prevent or treat infectious diseases. The company’s VelocImmune technology produces these human antibodies with genetically engineered mice. The engineered mice become living production lines, says the company, producing antibodies that respond as a human to a specific pathogen, while not affecting the rest of the animal. The antibodies are then retrieved and combined with human genetic properties for testing as therapies.

The company’s Covid-19 antibody therapy is a combination of two synthetic antibodies, casirivimab and imdevimab, given as a single infusion for neutralizing the SARS-CoV-2 virus responsible for Covid-19 infections. The antibodies attach to separate receptor binding domains of the SARS-CoV-2 spike protein that enters and begins infecting cells. In November 2020, FDA granted an emergency use authorization for the antibody cocktail to treat individuals with Covid-19 infections and mild to moderate symptoms, age 12 and older, but not hospitalized.

Regeneron’s chief scientist George Yancopoulos notes in a company statement that the multi-antibody design of the therapy makes it more likely to remain effective even if the SARS-CoV-2 virus mutates. Yancopoulos says that “as expected, the virus continues to mutate, with the possibility of developing resistance to any one antibody. The Regeneron cocktail of two antibodies, each targeting a different site on the virus, reduces the possibility of the virus becoming resistant.”

As reported by Science & Enterprise in October, clinical trial results show Regeneron’s antibody treatment more effective for recipients with high viral loads and without natural antibodies at the beginning of the trial. The findings also show no statistically reliable difference between higher and lower doses of the antibody cocktail.

FDA authorized the higher dose of 2,400 milligrams or 1,200 milligrams of each antibody. Under the new agreement, HHS is buying 750,000 doses of casirivimab and imdevimab at the 2,400 milligram level, for $2.625 billion. Regeneron says it’s still evaluating efficacy of the lower 1,200 milligram dose. If the data show the lower dose can effectively treat Covid-19 infections, and FDA extends its authorization to the lower dose, the company will be able to supply 1.25 million doses of the antibody cocktail.

That quantity represents all doses scheduled for manufacture and delivery by 30 June 2021. Adding to the 300,000 doses already purchased would increase the total amount purchased by HHS to 1.5 million doses. The company says U.S. government agencies are allocating doses of the therapy to state and territorial health departments.

Regeneron says clinical trials of casirivimab and imdevimab continue among hospitalized patients in the U.K., as well as a test of the cocktail to prevent Covid-19 infections among household contacts of already infected individuals.

More from Science & Enterprise:

• Stem Cells Help Severe Covid-19 Cases Recover
• Large Trial Testing Covid-19 Antibody Therapies
• AbbVie Acquires Coronavirus Antibody Therapy
• Covid-19 Antibody Developer Raises $483M in IPO
• Univ, Industry Labs Study Inhaled Covid-19 Antibodies

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