Regeneron Pharmaceuticals on Tuesday morning announced a breakthrough in the search for a Covid-19 treatment. It has identified hundreds of virus-neutralizing antibodies that could potentially be used in a cocktail drug.

“Similar to the approach the company pursued for Mers and Ebola virus, we believe Regeneron’s Covid-19 antibody cocktail may offer efficacy in preventing and treating the virus,” SVB Leerink analyst Geoffrey Porges wrote in a note to investors.

A day earlier, Regeneron (ticker: REGN) said it had started trials with its existing arthritis drug, Kevzara, which might prove useful in treating lung inflammation in Covid-19 patients, keeping them off ventilators and out of intensive care units.

Barron’s spoke with Regeneron CEO Leonard Schleifer on Tuesday morning about the fight against Covid-19, how the company’s technology platform is speeding drug discovery, and how to think about the economics of treatments for pandemic diseases. His comments have been edited.

On the search for a Covid-19 drug:

You have a three-pronged approach. First, try to take existing drugs that may have been developed for other purposes and see if they will work for Covid-19. Second, give people a human antibody that can fight off infection until there are vaccines around. Third, get a vaccine so that the body can make these antibodies itself.

On using existing treatments:

You can break them into two broad categories. People are looking at antivirals. There are drug trials that I’m aware of with Remdesivir, a Gilead Sciences (GILD) drug, which was tried with Ebola. The idea there is you interfere with the functioning of the virus. Another thing you can think about is, are there any drugs that can prevent the virus from wreaking havoc on the body? When the virus gets into the lungs, it causes this massive inflammation. Maybe, just maybe, if you control the inflammation, you’ll be able do something to prevent patients from needing a respirator, and make their fever go away.

“ You have people who are risking their health …with only one goal in mind: How fast can Regeneron produce this and deliver it to the public? ” — Leonard Schleifer

That’s our drug, Kevzara. It was discovered at Regeneron and developed for rheumatoid arthritis with our partner, Sanofi (SNY). Its mechanism of action is that we have these inflammatory mediators in the body called cytokines, and one of the bad ones is interleukin-6, which causes lots of inflammation. This may be what’s causing some of the inflammation in the lungs. In China, as this epidemic started, there was a drug made by Roche Holding (ROG.Switzerland), known as Actemra, which blocks the function of the interleukin-6 receptor. They had rather impressive, albeit uncontrolled, data. They treated 21 people, and all of these people did very well. They all got out of the hospital. A majority improved their ability to breathe, and their fevers went away. People have also tried this drug in Italy, with reportedly good results.

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There are only two drugs in this class currently available. One is Roche’s drug, and the other is our drug, Kevzara. We worked very rapidly to design a trial. We worked closely with the FDA, collaborated with Barda [Biomedical Advanced Research and Development Authority], got help from Gov. [Andrew] Cuomo in New York, and we put in place in record time a clinical trial to see if in fact this approach, blocking the inflammation, might be good.

On when a drug might be available:

If the drug is shown to work in hospitalized patients, we have lots of the drug on hand and can make much more. The best case is that people wouldn’t progress from let’s say needing a little oxygen to going on a respirator. If we all get sick at once, it could be a disaster because we won’t have enough intensive care beds. A drug like this could really slow down the number of people who needed really intensive respiratory therapy. This could go fairly quickly. There are unfortunately a lot of people in the hospital. If we can enroll the study quickly over the next month, you should know within a few weeks of treating people how they’re doing.

On making a custom treatment:

One of the ways a body will fight off infection is to make antibodies. That’s why you like to vaccinate people to prepare them for infection. Another way to do this is to use mice. Through the miracle of genetic engineering, you can inject them with a piece of a virus, and they will generate human antibodies that can be manufactured and given to patients.

We recently applied this approach to go after Ebola. We immunized these mice with a piece of the Ebola virus, took the antibodies, manufactured them at scale, and gave them to patients who literally were dying in the Congo. We compared our drugs to other potential drugs, including Remdesivir from Gilead. The study people found our drug was overwhelmingly effective, and stopped the study. That’s exactly what we plan to do here. We’ve already had remarkable success and gotten hundreds of antibodies that neutralize this virus. We’re going to pick the best and manufacture a cocktail. We hope to get started testing patients in June and manufacturing at large scale by the end of the summer.

On Regeneron’s technology platform for speeding drug discovery:

The guts of this, the engine, is the VelocImmune mice. This is the brainchild of George Yancopoulos. He wrote about this 35 years ago as a graduate student at Columbia University. He joined Regeneron and created these mice through genetic engineering. He perfected them. But there’s more to it than just the mice. There’s end-to-end technology so you can go seamlessly from a new sequence of a virus to an antibody that can be manufactured at scale. Decades of technology. What gives us a big advantage is that we don’t have to parse work out [to outside companies]. That can create delays that turn months into years. We have these capabilities end-to-end, so there’s no friction at any transfer point.

On the economics of developing a Covid-19 treatment:

There are some people who suggest we’re sitting around rubbing our hands together trying to figure out how to profit from the misfortune of this virus. This couldn’t be further from the truth. You have people who are risking their health, and that of their families, by coming to work in the labs and manufacturing facilities to do all that stuff with only one goal in mind: How fast can Regeneron produce this and deliver it to the public? It’s very frustrating for people to have any misimpression that this is easy work, at a time when many of us, including myself, are socially distancing. I’m sitting talking to you from home because I don’t have to be in the lab, while so many dedicated people still have to come to work. They’re heroes and heroines.

People at Barda have realized that if they want to incentivize the industry to steer efforts toward these important diseases, and have shareholders take the risk, they have to have some marketplace. For a disease like Ebola, that might be a strategic stockpile, which we’ll compete for. Government purchases will be a way for companies to reasonably return something to their shareholders. We view that as important, but it’s not driving us. We want to do well by doing good. The rest will take care of itself.

Write to Jack Hough at jack.hough@barrons.com