U.S. drugmaker Eli Lilly said Tuesday that the government-sponsored clinical trial of its COVID-19 antibody treatment has been paused because of a safety concern.

"Out of an abundance of caution, the ACTIV-3 independent data safety monitoring board (DSMB) has recommended a pause in enrollment," Lilly spokeswoman Molly McCully said in an emailed statement.

"Lilly is supportive of the decision by the independent DSMB to cautiously ensure the safety of the patients participating in this study."

Lilly's drug is similar to the Regeneron Pharmaceuticals treatment President Donald Trump received after he contracted COVID-19.

Lilly had already asked U.S. regulators to authorize its antibody therapy, LY-CoV555, for emergency use after publishing data in September showing it helped cut hospitalization and emergency room visits for COVID-19 patients. The treatment is being developed with Canadian biotech AbCellera.

Lilly shares were down nearly 3%.