One Saturday afternoon in March as COVID-19 was heading to New York City, a dozen scientists crowded restlessly around a computer in the lab of a suburban drug company. They had spent weeks frantically receiving blood from the first survivors around the world and from mice with human-like immune systems, all to try thousands of possible treatments.
Now was the time for results.
The screen showed a total of bright green dots, hundreds or thousands in most samples. Then they saw about 10s, about two, and finally zero.
Investigators cheered and his boss sent champagne.
No point meant there were no infected cells. Scientists had found antibodies that block the coronavirus.
This was the start of a drug that would eventually go into the arms of an American president and others fighting COVID-19.
Antibodies are substances that the immune system makes to bind 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 from Regeneron Pharmaceuticals Inc. were developing. they aim to help immediately by providing concentrated doses of one or two antibodies that work better.
Drugs, administered by IV, are being tested to prevent infection in people at high risk for it and who still cannot get a vaccine, such as housemates of patients with COVID-19. It is also being tried as a treatment shortly after infection to prevent serious illness.
They are some of the most complex drugs that exist, made in a tedious and high-tech process with a risk of ruin at every step. Unlike chemicals that are simply mixed in a laboratory, antibodies are converted into living cells. Companies have used cells from a whole menagerie: monkeys, hamsters, mice, horses, cows, llamas.
Each drug begins with a single coronavirus survivor.
Eli Lilly, for example, worked with AbCellera, a Canadian company that obtained a potent antibody from an early case there. GlaxoSmithKline and Vir Biotechnology found a frozen for years in a Swiss laboratory of a survivor of SARS, another coronavirus that caused a fatal outbreak in 2003.
Regeneron’s two-antibody drug is unique: one came from a COVID-19 survivor in Singapore and the other from the company’s genetically modified mice.
People make hundreds or thousands of types of antibodies after infection, but “most are not very good” at blocking the coronavirus, said Christos Kyratsous, a microbiologist who helped lead Regeneron’s work. “He’s looking for the needle in the barn” to find one that does, he said.
The search began in January, when Chinese scientists identified the new virus. Dr. Sumathi Sivapalasingam, a Regeneron scientist who had worked at the U.S. Centers for Disease Control and Prevention, began looking for blood samples from people who had been infected long enough to have made good antibodies.
“We were basically calling people from all over the world,” China, Thailand, the UK and Europe, with no luck, said.
Seriously, they got a call from Dr. David Lye, of the National Center for Infectious Diseases in Singapore. I knew Regeneron had antibodies against Middle East respiratory syndrome or MERS, a similar coronavirus disease. COVID-19 cases were starting to mount and “I was thinking about what to do about it,” because no treatment had been proven to help, Lye said.
Scientists quickly ruled out the use of MERS antibodies, but agreed to look for some for the new virus. Lye asked three of his patients, two men and a woman who had recovered from COVID-19 pneumonia, to donate blood.
It was weird. Blood cells survive for about two days and the flight to New York takes 18 hours. Samples should be cleared through customs and taken to Regeneron’s lab in Tarrytown, New York.
“It was exciting” but terrifying, Lye said. “I was worried if a flight delay or any error on the way would make the samples useless.”
“The blood was hot in the tube” when a messenger transported her to Singapore airport, Sivapalasingam said.
It arrived on March 13, the day COVID-19 was declared a national emergency in the United States. Sivapalasingam was working late at home when he received an email from his lab mates.
“They were jumping for joy because the cells were fresh, viable and perfect,” he said.
Meanwhile, others were working on what Regeneron’s chief executive calls his “magic mice,” animals bred to have human-like immune systems. When they are vaccinated with a piece of the virus, they don’t get sick, but they make “antibodies almost identical to what humans would produce,” Kyratsous said. It takes between 20 and 30 of these mice to develop a drug.
The blood of mice and patients contains B cells and each makes a specific antibody that is transported to its surface. The goal is to find antibodies that adhere to the virus and prevent cell infection.
Scientists first create B cells by mixing them with some of the spiky protein that covers the virus and classifying the cells with antibodies that connect. The researchers then decode the genetic recipes for each antibody. Genes are introduced into a hamster cell type widely used in the pharmaceutical industry, as they grow very rapidly and produce the chosen antibody as mini-biofactories.
Then comes the big challenge: testing each antibody by mixing it with uninfected cells and a “pseudovirus,” a domesticated virus that has been modified to carry spike protein and glow green if it enters a cell. lula.
Each antibody goes into a well in a grated plastic container like a massive tray of ice cubes. A computer connected to a microscope explains how many cells in each well are infected to see how successfully each antibody blocked the virus.
These are the results Kristen Pascal went to the lab to get on Saturday, March 14th.
He recalled that he had “brought pizza and cake for Pine Day,” a day when scientists celebrate because the 3, 1, and 4 are the first three digits of the pine, an important number in math.
Kyratsous, other managers and co-founder of the company, Dr. George Yancopoulos, hovered behind the chair while the computer counted bright spots.
“I’m getting maybe 1 and 2,000 green dots in each well,” then some reached 10 and others two, he said. When they saw some zeros, Yancopoulos ordered the champagne.
“We had very, very good antibodies,” he said. “We knew we were in good shape, that we would actually be able to make a difference.”
These antibodies came only from mice. Two weeks later, the process was repeated at human samples in Singapore.
In all, Regeneron tested more than 3,300 antibodies, pitting the finalists against each other as gladiators in the lab, before choosing two that bind to the spike protein at different points to make it harder for the virus to escape.
“There was a great sense of relief because you selected the best antibodies … but it was very, very stressful because you can’t go back,” Kyratsous said. “These are the ones that will go into production.”
Dan Van Plew’s job is to take what he calls “the recipe” from the Tarrytown lab, go through his “test kitchen” at the Regeneron production plant near Albany, New York, and find out how to mass produce it as a drug. It’s like making a few handmade cupcakes to taste and then getting a big wedding order, “so now I have to figure out how to make a thousand for a VFW room,” he said.
First, fast-growing hamster cells that contain the genetic prescription of the chosen antibody are placed in a container called a bioreactor. “Try to mimic a body,” keeping cells at body temperature, boiling in the air to supply oxygen, removing carbon dioxide, and supplying nutrients at the right rate for cells to multiply, he explained.
They are slowly moving to larger and larger bioreactors, “it looks like a very large microbrewery,” Van Plew said, until the cells are so dense that they go from reproducing to producing the antibody.
Pollution is a constant risk.
“At some point, I probably have 1,500 people touching the process, either touching the product or running a biorector,” and all the cars they drive, the shoes they wear, or the things they touch are a potential danger. dit.
When the final bioreactor is done, the contents are purified to remove pieces of the cells so that only antibodies remain, which are packaged in vials.
Production took 45 days: “light speed compared to the standard process,” which is usually three to five months, he said.
Studies in humans began in early June. In October, President Donald Trump obtained the drug under provisions on “compassionate use,” but there is no way to know if it served him well because most patients recover on their own and also received other experimental treatments. The Food and Drug Administration has allowed the use of antibodies against Regeneron and Eli Lilly antibodies urgently for mild and moderately ill patients who do not need hospitalization while continuing studies. Trials in hospitalized patients with more serious illnesses stalled on the concern that drugs would not help in this situation.
Regeneron sells other antibodies to heart disease, cancer and other conditions. The MERS outbreak in 2012 was the first time that an infectious disease was attempted quickly. MERS turned out not to spread easily from person to person, “so as a company we were very lucky” and the company never expanded production, Kyratsous said.
When Ebola struck in 2014, Regeneron developed antibodies and made its first production in an outbreak situation. But it took nine months, and then the cases dwindled. Another outbreak was needed in 2018 to demonstrate the value of this drug.
When the new coronavirus appeared, many of the same scientists were waiting.
“We knew exactly what to do … we had done it before,” Kyratsous said. “I think Regeneron was expecting a moment like this.”
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You can follow Marilynn Marchione on Twitter at http://twitter.com/MMarchioneAP
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The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.