The safety board will review the data again on Oct. 26, and advise the N.I.H. on whether to resume the trial, the statement said. In the meantime, researchers will continue to collect data from people already enrolled in the study.
Several experts praised the trial’s sponsors for halting the trial to address the safety of their product, as AstraZeneca and Johnson & Johnson have done with their vaccines. “They are doing things by the book,” said Dr. Maricar Malinis, an infectious disease physician at Yale.
In a statement sent over email, Molly McCully, a spokeswoman for Eli Lilly, confirmed the pause. “Safety is of the utmost importance to Lilly,” she said. “Lilly is supportive of the decision by the independent D.S.M.B. to cautiously ensure the safety of the patients participating in this study,” she added, referring to the independent panel of experts, known as the data and safety monitoring board.
Eli Lilly is one of several companies pursuing experimental treatments for Covid-19 that use monoclonal antibodies — mass-produced mimics of immune molecules that the human body produces in reaction to the coronavirus.
Eli Lilly’s product is similar to a treatment designed by the drug company Regeneron, which developed an antibody therapy given to President Trump after he tested positive for the coronavirus this month. Mr. Trump has promoted such treatments, without evidence, as a “cure” for his condition, and has suggested that their approval and widespread distribution could be imminent.
The week after the president was treated, both companies applied for emergency clearance for their products from the Food and Drug Administration. (Eli Lilly has applied for authorization of its drug for mild or moderate cases of Covid-19, not for use in hospitalized patients like those enrolled in the halted trial.)
The company is also trialing its antibody treatment in people who have recently tested positive for the coronavirus, and in nursing home residents and workers who may have been exposed.