Hydroxycloroquine Trial Restarted As Lead Scientist Says it 'Could Still Prevent Infections'

British regulators have approved the restart of a global trial that will explore whether the drugs hydroxychloroquine and chloroquine are able to prevent coronavirus infections.

The Medicines and Healthcare Products Regulatory Agency (MHRA) announced June 26 that scientists could resume their work on the COPCOV trial.

The trial, which is led by Oxford University's Mahidol Oxford Tropical Medicine Research Unit, is a randomized, placebo-controlled trial that will enroll around 40,000 healthcare workers and other at-risk workers worldwide.

It will test whether or not the drugs, which have been used for years to treat malaria, lupus and rheumatoid arthritis, are effective in preventing COVID-19 in those who do not yet have it.

"Hydroxychloroquine could still prevent infections, and this needs to be determined in a randomised controlled trial," Nicholas White, a professor of tropical medicine and principal investigator in the COPCOV trial, said in a statement. "The question whether (it) can prevent COVID-19 or not remains as pertinent as ever."

Representatives with the COPCOV study could not be immediately reached by Newsweek for further comment.

The MHRA had made its decision to restart the study after Oxford University had sent a request, Alicia Dimas McNulty, a MHRA spokeswoman, told Newsweek in a statement.

The trial had been paused since May 22 after MHRA regulators had asked that the study's investigators provide them with further data justifying continuation of the study.

"The submitted justifications and supporting information were reviewed by the MHRA, with independent advice obtained from the Commission on Human Medicines," according to the statement. "On 26 June it was agreed that sufficient measures had been taken to support the safe recruitment of further participants."

Coronavirus Testing
Adriana Cardenas, a medical technologist processes test samples for the coronavirus at the AdventHealth Tampa labs on June 25, 2020 in Tampa, Florida. A British clinical study testing whether or not hydroxychloroquine and chloroquine are effective drugs for preventing coronavirus infections will resume after being paused for over a month. Octavio Jones/Getty

Medical experts both abroad and in the U.S. have questioned the drugs for their unproven effectiveness in treating the coronavirus, as well as warning of the potential side effects.

The Food and Drug Administration announced June 15 that it was revoking emergency use authorization for the drugs to be used to treat the coronavirus, after trials had shown they were unlikely to help already hospitalized coronavirus patients.

"In light of ongoing serious cardiac adverse events and other potential serious side effects, the known and potential benefits of chloroquine and hydroxychloroquine no longer outweigh the known and potential risks for the authorized use," according to a press release.

But when considered as a potential prevention method, the drugs could prove beneficial, White said.

The two drugs have shown in the laboratory to kill the novel coronavirus, the virus that causes the COVID-19 infection, according to the COPCOV study's website.

Hydroxychloroquine made headlines in May when President Donald Trump told reporters that he had been taking it every day in an effort to ward off the virus, despite warnings from the FDA that the drug should not be used outside of clinical studies.

Past studies that have tried to prove the drugs' effectiveness in treating the virus have been too small to give accurate results.

"COPCOV is a very large study, enrolling 40,000 participants, and will give a definite answer whether the drugs are effective and safe," the website states.

In the COPCOV study, participants will take either the placebo drug or the daily hydroxychloroquine medication every day for three months, with follow-ups with study doctors every 30, 60 and 90 days, said Investigator Phaik Yeong Cheah in a video posted to the COPCOV trial's website.

Both participants and study doctors will not know which medication the patient has been given, according to the video.

Participants will use a mobile app twice each day to record how they're feeling, including their temperature.

The trial will take place over the course of three months, White said in a video posted to the study's website. Recruitment of British workers would resume this week, and study sites in Thailand, Southeast Asia, Africa and South America are being planned.

Results from the COPCOV trial are expected by the end of this year, White said.