Regeneron's antibody cocktail used to treat Trump prevented 50% of people exposed to coronavirus from getting infected

 Regeneron's coronavirus antibody drug reduces the risk of getting COVID-19 after exposure by 50 percent, early data suggests.

The treatment prevented 100 percent of the 186 people who got the drug after being exposed to coronavirus from developing symptomatic COVID-19. 

It comes a week after Eli Lilly said its similar drug prevented 80 percent of nursing home residents from getting COVID-19. 

The Regeneron cocktail also reduced overall infection rates - including asymptomatic ones - by about 50 percent. 

Both Regeneron's and Eli Lilly's drugs have already been given emergency FDA approval for treating mild to moderate COVID-19, but they've been sorely underutilized. 

Regeneron said it would discuss the interim results with health regulators to potentially expand the antibody cocktail's interim approval status to using it as a preventive. 

Its drug could also play a third role: While it's not a substitution for vaccine for most people, if the antibody cocktail gets greenlit as a preventive, it might be the next-best-thing for a small subset of people who have bad reactions to vaccines. 

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Regeneron's antibody cocktail (pictured, in the manufacturing process) cut the risks of developing COVID-19 after exposure by 50% early trial data show. It prevented 100% of symptomatic infections 

Regeneron's antibody drug could stand to find a new life. 

Both it and Eli Lilly's antibody drug were quickly given emergency FDA approval  in November after former President Trump was treated for COVID-19 with Regeneron's therapy, touted it a 'cure' and promised it would be made available to all Americans, for free. 

The federal government purchased hundreds of thousands of doses and shipped them to hospitals across the country. 

Just before President Biden's inauguration, the Trump administration set aside another $2.6 billion to purchase more of the drugs.  

But the drugs have been chronically underutilized. 

The Department of Health and Human Services (HHS) said on January 6 that about 75 percent of doses were unused. 

Doctors cited the narrow window of time at the beginning of a COVID-19 infection as complicating the use of the drugs.  

Antibody therapies are also given as a one-time IV infusion - it's not a drug you can pick up at the pharmacy and take on your own.  

They do reduce risks of hospitalization and death, but hardly rise to the level of 'cures.' 

But they could be game-changing post-exposure drugs.  

Regeneron's ongoing trial tested its antibody cocktail, REGEN-COV, for use as a passive vaccine, which involves direct delivery of virus-fighting antibodies into the body unlike traditional vaccines in which the receiver's immune system is activated to develop its own antibodies.

During the trial, jointly run by Regeneron and the National Institute of Allergy and Infectious Diseases, one death and a COVID-19 related hospitalization were reported among those who received placebo, but there was no such incident in the treatment group, the company said. 

'These data using REGEN-COV as a passive vaccine suggest that it may both reduce transmission of the virus as well as reduce viral and disease burden in those who still get infected,' said George Yancopoulos, president and chief scientific officer of Regeneron.

People who did get infected after receiving the antibody cocktail had lower viral loads and their infections lasted one week. There were only 10 infections among the 186 people who got the IV antibody cocktail. 

By comparison, about 40 percent of the infections in the placebo group are lasted three or four weeks.  

People who got Regeneron's drug also had viral loads that were about 100-times lower, compared to people who got the placebo. 

That's a good sign that not only will viral loads be too low to make the person who got the antibody cocktail sick, they likely won't have enough copies of the virus to shed it and pass it on to others. 

Preventing transmission could become particularly critical as more infectious variants emerge around the world and become dominant. 

CDC officials suspect the UK 'super-covid' variant - which is about 70 percent more contagious than older forms - could be dominant by March. 

It is more infectious, and potentially 30 percent more deadly, but not any less responsive to vaccines, early testing suggests. 

Dr Anthony Fauci warned last week that there are some signs that highly infectious variants from South Africa and Brazil may evade antibodies from vaccines, prior infection and even treatments. 

It is not yet clear whether Regeneron's drug works against new variants.