Hydroxychloroquine, an antimalarial drug touted by some to treat COVID-19, is not an effective treatment for adult patients hospitalized with the illness, according to a national, multi-hospital study published Monday in the Journal of the American Medical Association.

The study, to which physician-scientists from the University of Pittsburgh Medical Center contributed, found that hydroxychloroquine is not significantly more effective than placebo in improving clinical outcomes of patients who were hospitalized with respiratory issues as a result of COVID-19.

More than 30 hospitals participated in the study, and 479 patients who were hospitalized between April and June were enrolled in the study, receiving either 10 doses of hydroxychloroquine or placebo over five days. After one month of starting the study, 10.4% of patients treated with the antimalarial drug and 10.6% of patients who received a placebo had died.

In the early stages of the pandemic, some in and outside the medical community posited that hydroxychloroquine could inhibit the reproduction of SARS-CoV-2, the coronavirus that causes the COVID-19 illness. That doesn't hold up to research, UPMC and other researchers said.

“Our study — which is supported by the gold-standard in medical research: a blinded, randomized clinical trial — puts to rest any lingering hope that hydroxychloroquine is an effective treatment against COVID-19,” study co-author Dr. Donald Yealy, UPMC's senior medical director and chairman of emergency medicine, said.

“This allows us to focus our research and funding toward other, more promising treatments while reinforcing the public health tenants of mask-wearing, physical distancing and hand hygiene to prevent the spread of this disease.”

While the paper was just recently published, the National Heart, Lung and Blood Institute put an end to the study itself in June after data showed hydroxychloroquine was not likely to improve patients' health outcomes.