The findings, first announced in January, have now been peer-reviewed and published in a major medical journal.
"We are delighted that our full results are now published after peer review. This confirms the robustness of our findings, that tocilizumab and sarilumab can reduce deaths by nearly a quarter, in the sickest patients with COVID," said researcher Dr. Anthony Gordon, chair in anesthesia and critical care at Imperial College London, in the United Kingdom.
In the study, initially reported in November, the arthritis drugs tocilizumab (Actemra) and sarilumab (Kevzara) reduced death among critically ill COVID-19 patients by nearly 9 percentage points, or about 25%. The drugs are immune modulators called IL-6 receptor antagonists.
These drugs also shortened patients' hospital stays significantly.
"On average, patients were discharged from [intensive care units] a week earlier and [left] hospital two weeks earlier," Gordon said, noting that "several thousand patients" had already benefited from the drugs' use through the National Health Service in the United Kingdom.
"Other studies have now confirmed our results and so even more patients will continue to benefit," he said in a college news release.
Of 353 patients in the trial, some were given tocilizumab or sarilumab; others received an inactive placebo.
Thirty-six percent of patients given a placebo died, compared to 27% of patients receiving the drugs (28% for tocilizumab, 22% for sarilumab).
That means for every 12 patients treated, one life would be saved, the study authors explained.
Gordon noted that previous trials using IL-6 receptor agonists showed no clear benefit on disease progress or survival in COVID-19 patients. But those studies included patients whose illness was less severe and treatment started at different stages, he said.
"A crucial difference may be that in our study, critically ill patients were enrolled within 24 hours of starting organ support," Gordon said. "This highlights a potential early window for treatment where the sickest patients may gain the most benefit from immune modulation treatment."
The findings were published Feb. 25 in the New England Journal of Medicine.
For more on COVID-19, head to the U.S. Centers for Disease Control and Prevention.
SOURCE: Imperial College London, news release, Feb. 25, 2021