A global clinical trial of anti-malarial drugs hydroxychloroquine and chloroquine is set to resume after securing approval from UK regulators.
Although studies suggest hydroxychloroquine is not a life-saver for people who are already ill with coronavirus, researchers want to continue examining whether it might prevent infections.
President Donald Trump has come under fire after touting hydroxychloroquine as a treatment for COVID-19. He even briefly started taking it as a prophylaxis against the infection.
UK regulators say hydroxychloroquine and chloroquine can be given to healthcare workers in a clinical study, named COPCOV, to test the theory. The cheap and widely available drugs have been safely used to prevent malaria infection for over 50 years.
The study is led by researchers at the University of Oxford’s Mahidol Oxford Tropical Medicine Research Unit in Bangkok, Thailand. They will dispense chloroquine, hydroxychloroquine or a placebo to more than 40,000 healthcare workers from Europe, Africa, Asia and South America.
The study will determine whether a daily prophylactic dose of these drugs can protect healthcare workers from catching COVID-19 infection.
Oxford University Professor Sir Nicholas White, a lead researcher in the trial, said studies of both drugs as preventative treatments are not conclusive.
“Hydroxychloroquine could still prevent infections, and this needs to be determined in a randomized controlled trial. The question whether [it] can prevent COVID-19 or not remains as pertinent as ever,” White said in a statement.
Co-investigator Professor Martin Llewelyn, from the Brighton and Sussex Medical School, said: “Although rates of coronavirus are low just now in the UK, healthcare workers are still being affected across the NHS and a second wave of infection this winter is widely expected.
“In terms of finding an intervention that could protect key workers by this winter, hydroxychloroquine is by far the most realistic prospect. The recent post-exposure prophylaxis study confirmed its safety and indicated that it could be protective if given as pre-exposure prophylaxis. This is what COPCOV will find out,” said Llewelyn.
Medicines and Healthcare Products Regulatory Agency (MHRA) had paused recruitment for the study amid concerns about the side-effects of hydroxychloroquine following the release of findings from a widely publicized and discredited study conducted by British medical journal The Lancet.
It concluded the drug was not beneficial and increased the risk of irregular heart rhythms and death. After the study was published the World Health Organization (WHO) suspended its coronavirus treatment trials of the anti-malaria drug.
After concerns were raised about the data, some of the study’s authors said they could no longer stand by their paper in The Lancet as the healthcare firm Surgisphere that was involved in the work would not allow an independent review. It has been called one of the biggest retractions in modern history.The New England Journal of Medicine retracted another paper that had data from Surgisphere.
Hydroxychloroquine was approved by the U.S. Food and Drug Administration (FDA) for emergency treatment in severely ill coronavirus patients, although it carried warnings of cardiovascular problems and other health issues. It revoked the drug’s emergency use designation in mid-June.
European countries like France, Italy and Belgium banned or warned against using the drug as treatment, citing adverse side effects with unproven benefits.
Another clinical trial recently discovered that a cheap steroid called dexamethasone can help save the lives of patients who are seriously ill with the virus. It has also been around for decades, and became the first medicine proven to reduce the death rate among hospitalized patients.