The World Health Organisation (WHO) will resume its trial of hydroxychloroquine for potential use against the coronavirus, its chief said yesterday, after those running the study briefly stopped giving it to new patients over concerns.
The UN agency last month paused the part of its large study of treatments against Covid-19 in which newly enrolled patients were getting the anti-malarial drug to treat Covid-19 due to fears it increased death rates and irregular heartbeats.
The study continued with other medicines.
But the WHO's director-general, Tedros Adhanom Ghebreyesus, said its experts had advised the continuation of all trials including hydroxychloroquine, whose highest-profile backer for use against Covid-19 is US President Donald Trump.
"The executive group will communicate with the principal investigators in the trial about resuming the hydroxychloroquine arm of the trial," Dr Tedros told an online media briefing, referring to WHO's initiative to hold clinical tests of potential Covid-19 treatments on some 3,500 patients in 35 countries.
The WHO's decision to suspend its trial prompted others to follow suit, including Sanofi, which said on May 29 it was suspending recruitment for its trials.
A Sanofi spokesman said it would run consultations in the coming days to reassess its position following the WHO's decision yesterday.
The WHO's chief scientist, Soumya Swaminathan, called for other trials of the drug to proceed.
"We owe it to patients to have a definitive answer on whether or not a drug works," she said, adding that safety monitoring should also continue.
However, in the first large, high-quality study to test hydroxychloroquine in people in close contact with someone with the disease, results published yesterday by the 'New England Journal of Medicine' show that it was no better than placebo pills at preventing illness from the coronavirus.
The drug did not seem to cause serious harm, though - about 40pc of people on it had side-effects, mostly mild stomach problems.
"We were disappointed. We would have liked for this to work," said the study leader, Dr David Boulware, an infectious disease specialist at the University of Minnesota. "But our objective was to answer the question and to conduct a high-quality study," because the evidence on the drug so far has been inconclusive.
Dr Boulware's study involved 821 people in the US and Canada living with someone diagnosed with Covid-19 or at high risk of getting it because of their job.
After 14 days in the study, 12pc on the drug developed Covid-19 symptoms versus 14pc in the placebo group, but the difference is so small it could have occurred by chance, Dr Boulware said.
"There's basically no effect. It does not prevent infection," he said of the drug. Even if it were to give some slim advantage, "we'd want a much larger effect" to justify its use and risk of side-effects for preventing illness, he said.