At the start of the COVID-19 pandemic, scientists raced to find potential treatments for the deadly virus. One possible candidate: hydroxychloroquine, an anti-malarial drug.

In a new study, researchers from Intermountain Healthcare and University of Utah Health found that hydroxychloroquine provided no benefit to COVID-19 patients when compared to azithromycin, an antibiotic used to treat bacterial infections.

The trial, which was run in parallel with a National Institutes of Health trial comparing hydroxychloroquine to a placebo, was stopped early given overwhelming evidence of its ineffectiveness in treating the disease.

“We saw enormous early interest in hydroxychloroquine, but now we can definitively say that it doesn’t help COVID-19 patients,” said Samuel M. Brown, MD, MS, principal investigator of the trial and director of the Center for Humanizing Critical Care at Intermountain Healthcare.

In the study, researchers identified 85 patients with COVID-19 at 13 Intermountain hospitals and University of Utah Hospital over an 11-week span. Patients were randomized into two groups: one group was given a five-day treatment of hydroxychloroquine; the other was given a five-day treatment of azithromycin.

Researchers found that outcomes for COVID-19 patients may have been worse in those given hydroxychloroquine than those treated with azithromycin.

Results of the study were published in the Annals of the American Thoracic Society.