By Peter Loftus

Eli Lilly & Co. said Monday it began the first study of an experimental drug derived from a blood sample of an early U.S. survivor of Covid-19, a new effort to take advantage of the molecular defenses developed by recovered patients.

The Indianapolis company said the testing aims to assess the drug's potential to treat patients hospitalized with the coronavirus.

The drugmaker also plans eventually to test whether the antibody-based drug could prevent disease in people at risk of infection, an approach that could serve as a bridge toward curbing the pandemic until a successful vaccine is developed.

Lilly's experimental drug is part of a broader push to harness the power of proteins known as antibodies that are found in the plasma of people who have recovered from coronavirus infection. Antibodies are agents of the immune system that counteract pathogens including viruses.

Researchers are also studying the use of plasma from recovered patients as a treatment for infections and a plasma-based therapy that has been used previously for other diseases.

In Lilly's case, the experimental therapy -- code-named LY-CoV555 -- doesn't contain the plasma of recovered patients. Instead, the drug's design was triggered by antibodies in the plasma.

Researchers at AbCellera Biologics Inc., a Canadian company that partnered with Lilly in March, and the U.S. National Institute of Allergy and Infectious Diseases identified an antibody with virus-fighting potential in a blood sample taken from one of the first U.S. patients who recovered from Covid-19.

Lilly's scientists then essentially cloned the antibody to make the new therapy. Its goal is to block the virus from attaching to and entering human cells, thus neutralizing it.

"We're not experienced in vaccines, or antiviral small molecules," Lilly Chief Scientific Officer Daniel Skovronsky said in an interview. "But we're really good at antibodies, engineering them, testing them, manufacturing them. That's a capability we have, so the opportunity to work on antibodies against Covid-19 made total sense."

The drug is taken intravenously.

The first study will primarily track safety and side effects, but will also test whether the treatment can reduce the length of hospital stays and curb the number of patients admitted to intensive care and in need of ventilators. Researchers expect to enroll up to 32 patients in the study.

One of the sites for the first study is at NYU Grossman School of Medicine in New York.

"What we're doing here is taking patients with Covid, offering the opportunity to participate in a new treatment, hopefully to help them recover more quickly and uneventfully from their infection," said Dr. Mark J. Mulligan, director of the infectious-disease and vaccine-research units at NYU Langone Health.

Dr. Mulligan said Gilead Sciences Inc.'s remdesivir has been shown to have some benefit in Covid-19 patients, but it is a moderate effect. Remdesivir was authorized for emergency use last month. "We'd like to have stronger therapies," he said.

If the first study is successful, Lilly said it plans to test the antibody in a second study that includes treating patients who aren't in a hospital.

Other studies would examine whether the drug can prevent people from getting sick, focusing on vulnerable patient populations who aren't optimal candidates for vaccines

Lilly and AbCellera also have developed other antibodies that Lilly plans to test in coming months in Covid-19 patients, either alone or in combination with each other.

Lilly said it is starting large-scale manufacturing of the therapy, so that if studies prove successful, it will have several hundred thousand doses available by the end of the year.

Write to Peter Loftus at peter.loftus@wsj.com

(END) Dow Jones Newswires

June 01, 2020 06:44 ET (10:44 GMT)

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