Hydroxychloroquine emerged as one of the earliest potential treatments for coronavirus, but medical experts still cannot agree on its safety and efficacy. What do clinical trial results reveal about this drug and its future role in the battle against COVID-19?
Hydroxychloroquine May Not Prevent COVID-19 After Exposure
Chief investigators of the RECOVERY Trial, Professors Peter Horby and Martin Landray of Oxford University, performed a randomized clinical trial of 1542 patients treated with hydroxychloroquine compared to 3132 patients who received usual care. After months of data collection and evaluation, Horby and Landray announced their assessment on June 4, 2020.
“We have concluded that there is no beneficial effect of hydroxychloroquine in patients hospitalized with COVID-19. We have therefore decided to stop enrolling participants to the hydroxychloroquine arm of the RECOVERY Trial with immediate effect.”
The RECOVERY Trial found no significant difference in mortality, with the death of 25.7% of patients treated with hydroxychloroquine compared to 23.5% of patients treated with usual care. As Horby and Landray explained, “These data convincingly rule out any meaningful mortality benefit of hydroxychloroquine in patients hospitalized with COVID-19.”
Another randomized, double-blind, placebo-controlled trial enrolled 821 asymptomatic participants across the United States and parts of Canada to test hydroxychloroquine as postexposure prophylaxis. Overall, the likelihood of COVID-19 infection did not differ significantly between patients receiving hydroxychloroquine (11.8%) and those receiving placebo (14.3%).
This led researchers to conclude that hydroxychloroquine may not effectively prevent COVID-19 in people who have already been exposed to the virus.
Study Questioning Safety of Hydroxychloroquine Has Been Retracted
A study published in The Lancet on May 22 created widespread controversy when it suggested that hydroxychloroquine increases the risk of mortality and dangerous disturbances in heart rhythms. However, after errors were discovered in the data and the company providing the primary data, U.S-based Surgisphere, refused to cooperate with requests for an audit, the study’s authors requested that the paper be retracted.
The World Health Organization paused enrollment in its hydroxychloroquine investigation after The Lancet study was originally published. The trial’s data safety monitoring board analyzed the results to identify any apparent safety concerns. According to Tedros Adhanom Ghebreyesus, WHO’s director-general, the board found “no reasons to modify the trial.”
Now the WHO has officially resumed its hydroxychloroquine clinical trial, one of the many arms of the agency’s Solidarity Trial.
Its website states, “On 3 June 2020, WHO’s Director-General announced that on the basis of the available mortality data, the members of the committee have recommended that there are no reasons to modify the trial protocol. The Executive Group received this recommendation and endorsed the continuation of all arms of the Solidarity Trial, including hydroxychloroquine.”