Signage is displayed on the exterior of the Novartis AG Institutes for BioMedical Research building in Cambridge, Massachusetts, U.S., on Friday, Aug. 5, 2016.

Novartis has won the go-ahead from the U.S. Food and Drug Administration to conduct a randomized trial of malaria drug hydroxychloroquine against COVID-19 disease, the Swiss drugmaker said on Monday, to see if it helps patients.

The decades-old generic medicine got FDA emergency use authorization this month for its unapproved use for coronavirus disease, but so far there is no scientific proof it works. There are currently no approved COVID-19 medicines.

Novartis plans to start recruiting 440 patients for its Phase III, or late-stage, trial within weeks at more than a dozen U.S. sites. Results will be reported as soon as possible, the company added.

Use of the drug, also approved to treat lupus and rheumatoid arthritis, has soared after having been promoted by President Donald Trump, with some worried the administration's advocacy for an unproven medicine for COVID-19 has short-circuited the FDA's oversight process.

"We recognize the importance of answering the scientific question of whether hydroxychloroquine will be beneficial for patients with COVID-19 disease," said John Tsai, Novartis's top drug developer. "We mobilized quickly to address this question in a randomized, double-blind, placebo-controlled study."

Companies such as Novartis, Roche and Gilead Sciences are testing older medicines developed to treat other diseases, for signs they could be repurposed to tackle the coronavirus epidemic. Gilead just expanded a trial of its Ebola drug remdesivir.

Still, some fear the championing of hydroxychloroquine by Trump and others as a potential "game changer" against COVID-19 has overshadowed dangerous side effects like vision loss and heart problems. Novartis CEO Vas Narasimhan has also said the medicine is one of his biggest hopes against the viral epidemic.

There are several additional studies of hydroxychloroquine underway, including at the University of Washington and University of Minnesota, as well as work by the National Institutes of Health in the United States.

Novartis's Sandoz generics unit has pledged to donate 130 million doses of the medicine for use. Sanofi has also said it will donate 100 million doses of hydroxychloroquine to 50 countries.