How Regeneron developed its COVID-19-fighting antibody cocktail

Tuesday, May 4, 2021

Source: Fast Company

Within weeks, the coronavirus crisis was underway, and so was the Regeneron team. “There was a shared sense of urgency across the entire company,” Baum says, with dozens of groups at Regeneron working together. These teams have experience with infectious diseases: Regeneron created the first drug to treat Ebola patients and developed an antibody treatment for MERS, among other pharmaceutical developments. In just 10 months, Regeneron created a COVID-19 antibody cocktail that was granted FDA emergency use authorization. It’s the winner of the pandemic response category of Fast Company’s 2021 World Changing Ideas Awards.

From the start, Regeneron set out to make a “cocktail” of antibodies—meaning more than just one antibody as the therapeutic agent. Antibodies are the proteins our bodies produce when a virus, bacteria, or other infection attacks our immune system. Antibodies bind to certain parts of those intruders, which can prevent them from entering our cells and spreading the virus, or can target them for an immune-system response. “We know that viruses mutate. We know that it’s much easier for a virus to acquire a mutation that will impact one antibody versus two antibodies,” Baum says of the decision to create a cocktail.

Called REGEN-COV, the cocktail came from two discoveries: One of the antibodies was found by studying the plasma of a COVID-19 survivor, and the other was discovered by introducing a pseudo-version of the virus (created by using that genome sequence) to special Regeneron mice that have human immune systems and so produce fully human antibodies. The treatment—which is administered intravenously—also uses two antibodies that bind to “completely different regions” of the viral protein, which makes it harder for the virus to escape those antibodies, and thus that drug. The team still tested other possibilities—one antibody, two that overlap, and two that bind to different regions—to confirm their decision, and within 10 months, the antibody cocktail went from early-stage research to FDA emergency use authorization in November 2020.


That timeline doesn’t compare to the speed of developing treatments like this in the past, says Leah Lipsich, vice president of strategic program development at Regeneron. “A typical program will take you maybe a year and a half to get from discovery to phase 1 clinical data, another year or two in phase 2,” and then confirmatory phase 3 studies also take a few years. “It’s not even comparable, just as the vaccine development that’s been ongoing is not comparable to anything that’s been done previously.” Regeneron recently completed a phase 3 clinical trial that showed its antibody cocktail reduced COVID-19-related deaths and hospitalization by 70% in nonhospitalized patients. Tens of thousands of patients have benefited from the antibody cocktail’s emergency use authorization, and 25,000 people have participated in the clinical trials.

Even with COVID-19 vaccines now available and millions of Americans getting that protection, an antibody cocktail is still crucial. Not everyone will voluntarily get the vaccine, and there’s also a segment of the population who can’t get the vaccine because they are immunocompromised. “If they were to get vaccinated, they would not be able to mount an immune response,” Lipsich says, “That makes them an ideal population for treatment using our antibody cocktail.” Regeneron is also making the cocktail into a shot and recently shared study results that showed a single dose, given as four shots, reduced the risk of developing COVID-19 and reduced the risk for those who tested positive of developing symptoms. (Antibody treatments can’t be administered in a pill form.) And though we might think the pandemic is almost over, COVID-19 will certainly still be around for a while, with even more variants possible. “There’s always going to be a need for treatment.”

View All News »