The World Health Organization is resuming a clinical trial exploring whether the malaria drug hydroxychloroquine can effectively treat Covid-19, after pausing enrollment in the study to review safety concerns about the drug.
The hydroxychloroquine investigation is just one arm of the agency’s Solidarity Trial, which is testing different therapies to determine which are beneficial in the disease caused by the novel coronavirus. The WHO last week temporarily suspended the hydroxychloroquine arm after a separate study published in the Lancet raised warnings about the drug’s safety.
Like the Lancet study, other observational studies had not found any apparent benefit for the drug in Covid-19. But the Lancet study prompted additional concerns because it found the drug was also associated with higher mortality.
Outside experts, however, have since questioned the sources and analysis of the patient data included in the Lancet study, which were provided by a little-known company called Surgisphere. They cited inconsistencies in the data — some of which have since been corrected — and a lack of transparency about which countries and hospitals provided the information.
The Lancet study led the WHO to pause the hydroxychloroquine study so the trial’s data safety monitoring board could analyze the results generated so far and see if any safety concerns were apparent.
At a press briefing Wednesday, Tedros Adhanom Ghebreyesus, WHO’s director-general, said the board reviewed the available mortality data and found “no reasons to modify the trial.” He said the WHO was telling the investigators involved in the study to resume their work.
More than 400 hospitals in 35 countries are participating in the Solidarity Trial, which involves thousands of patients.
Surgisphere also provided the data for another study, looking at blood pressure medications in Covid-19, published in the New England Journal of Medicine last month. Experts have raised similar concerns about the data analysis underlying that study, and on Tuesday, editors at both the Lancet and the New England Journal issued “expressions of concern” about the studies. Independent review teams have also launched audits of the two studies.
The potential of hydroxychloroquine to treat Covid-19 has become a political flashpoint, with President Trump and his political allies cheering its use, despite no gold-standard clinical trials yet showing it is effective. The WHO’s trial could help settle the question of whether or not the drug works in Covid-19.
Also Wednesday, researchers separately reported the results from another hydroxychloroquine clinical trial, finding that it was not effective at preventing Covid-19 infections if it was given to people after they were exposed to others with the virus.
The Lancet paper was not the only source of concern about the safety risks of the drugs in treating Covid-19. The Food and Drug Administration, for example, has warned that it should not be used outside of hospitalized patients or clinical trials for Covid-19. (Hydroxychloroquine is considered safe to take for malaria, rheumatoid arthritis, and lupus, and has been shown to benefit patients with those conditions.)