ST. LOUIS — The National Institutes of Health released early results on of a trial involving Washington University, showing that two anti-inflammatory drugs reduced the risk of death in patients with severe COVID-19.

The researchers will soon release the findings in a preprint and aim to publish in a peer-reviewed journal this fall, but the NIH released the initial findings on Thursday.

The trial included patients hospitalized with moderate to severe cases. The 518 patients who received the drug infliximab had a mortality rate of 10%, compared with 14.5% in the placebo group. The 509 patients who received the drug abatacept had a mortality rate of 11%, compared with 15% in the placebo group.

When it initially launched, the trial had also included a third drug, cenicriviroc. But that drug was dropped from the trial in September 2021 because it was not showing a benefit.

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COVID-19 can cause severe illness in patients by sparking an abnormally large immune response, and it appears that the immune-modulating drugs can tamp down that reaction. Researchers don’t know the exact mechanism but plan to study that further, said the trial’s protocol chair, Dr. William Powderly, director of the Institute for Clinical and Translational Sciences and co-director of the Division of Infectious Diseases at Washington University School of Medicine.

The study was conducted between October 2020 and December 2021, with nearly 2,000 patients across 46 sites in the U.S. and 23 in Latin America.

The Washington University researchers enrolled 128 participants at BJC HealthCare’s Barnes-Jewish Hospital, making it the largest site in the trial, Powderly said.