No vaccine or treatment has yet been approved to treat COVID-19, which has killed more than 350,000 people worldwide. Even US President Donald Trump is a vocal supporter of the drug.
Four drugs are being tested by the organisation as part of its "Solidarity Trial". However, clinical research is a slow process, and in the meantime doctors across the world have already been treating patients with hydroxychloroquine. They sought an outcome of in-hospital mortality and de-novo ventricular arrhythmias.
The results showed that death rate was higher among patients taking the drugs than those who were not given the medication.
The death rate in the remdesivir group was 7.1%, compared to 11.9% for placebo group - a non-significant difference that does improve a little on the earlier readout from the trial.
The drug's efficacy and safety profile is known in preventing and treating malaria, and in treating some autoimmune conditions, but following the global pandemic researchers have hoped it would prove useful in tackling Covid-19.
Today, the Oxford team added another treatment arm to the study that will look at the use of convalescent plasma that has been collected from donors who have recovered from COVID-19 and contains antibodies against the SARS-CoV-2 virus. The hype surrounding hydroxychloroquine started with a preprint released in March that suggested it could be an effective treatment for COVID-19.
The Solidarity Trial was initiated by the World Health Organization more than two months ago to evaluate the safety and efficacy of four drugs and drug combinations against COVID-19. Patients at more advanced stages of the disease, or receiving other experimental antiviral treatments, were excluded from the large cohort.
She says the World Health Organization hasn't yet seen data that showed a problem with hydroxychloroquine in its own study but The Lancet article raised questions among numerous investigators involved in the WHO's trial.
"A lot of good things have come out about the (Hydroxychloroquine)".
Trump has dismissed concerns about hydroxychloroquine's safety from both government experts and the US Food and Drug Administration (FDA), who highlighted there had been reported poisonings and heart problems from the drug, and announced he is taking hydroxychloroquine himself.
Executive investigators are aiming to uncover slowed disease progression or improved survival associated with any of the now observed drugs-or any new candidates added based on emerging evidence. Hydroxychloroquine will continue to be given to more than 40,000 frontline medical workers in South America, Asia, Africa, and Europe.
The safety data will be reviewed by the Data Safety Monitoring Board.