A box of Plaquenil, Sanofi's commercial name for the anti-malaria drug hydroxychloroquine. Used for years to treat malaria and autoimmune disorders. Photo: AFP / Alain Pitton / NurPhoto

French pharmaceutical giant Sanofi said Friday  it would offer 100 million doses of hydroxychloroquine, a treatment for rheumatoid arthritis and lupus, to governments worldwide if studies show it can safely to be used to treat COVID-19 patients.

Other companies have also pledged to offer the drugs, with Switzerland’s Novartis proposing 130 million doses of chloroquine, and Israeli generic producer Teva promising 10 million doses of HQC for US hospitals.

Both hydroxychloroquine, which Sanofi sells under the brand name Plaquenil, and the related compound chloroquine, an anti-malarial drug, are being studied worldwide as potential weapons in the coronavirus fight.

But proposals to put them to use immediately for more patients have proven highly controversial, with many experts warning there is not yet enough evidence of their safety or effectiveness against COVID-19.

A French doctor in particular, Didier Raoult, has raised hopes by treating patients with a combination of hydroxychloroquine (HQC) and the antibiotic azithromycin, an initiative that many health officials refuse to endorse in the absence of more rigorous studies.

On Thursday, French President Emmanuel Macron met Raoult and his team in Marseille to discuss their latest findings, though the president did not comment publicly on the meeting afterward.

Sanofi acknowledged that “interpretations of the available preliminary data on hydroxychloroquine in the management of COVID-19 differ widely.

“While hydroxychloroquine is generating a lot of hope for patients around the world, it should be remembered that there are no results from ongoing studies, and the results may be positive or negative.”

But chief executive Paul Hudson said in a statement, “If the trials prove positive, we hope our donation will play a critical role for patients.”

Sanofi is also working on a potential vaccine for the new coronavirus, which has killed more than 94,000 people worldwide since cases were first reported in China last December.