One company's quest for an antibody drug to fight COVID-19

On a Saturday afternoon in March as COVID-19 was bearing down on New York City, a dozen scientists anxiously crowded around a computer in a suburban drug company’s lab. They had spent weeks frantically getting blood from early survivors across the globe and from mice with human-like immune systems — all to test thousands of potential treatments.

Now it was time for results.

The screen flashed totals of glowing green dots, hundreds or thousands in most samples. Then they saw some 10s, some twos and finally, zeroes.

The researchers cheered and their boss sent out for champagne.

No dots meant no infected cells. The scientists had found antibodies that block the coronavirus.

This was the start of a drug that would, eventually, go into the arms of a U.S. president and others fighting off COVID-19.

Antibodies are substances the immune system makes to bind to and help eliminate a virus, but it takes several weeks after infection or vaccination for the most effective ones to form. Drugs like the one these scientists at Regeneron Pharmaceuticals Inc. were developing are intended to help right away, by supplying concentrated doses of one or two antibodies that work best.

The drugs, administered by IV, are being tested to prevent infection in people at high risk of it who can’t yet get a vaccine, such as housemates of COVID-19 patients. They’re also being tried as a treatment soon after infection to avoid serious illness.

They are some of the most complex medicines that exist, made in a tedious, high-tech process with the risk of ruin at every step. Unlike chemicals that are simply mixed in a lab, antibodies are coaxed from living cells. Companies have used cells from a whole menagerie — monkeys, hamsters, mice, horses, cows, llamas.

Each drug starts with a single...