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The UK regulator MHRA announced on 26 June that it would again permit recruitment to the COPCOV COVID-19 prevention clinical trial. The MHRA decision came 5 weeks after it reacted immediately to the now-discredited paper published in The Lancet suggesting harms with hydroxychloroquine, and paused recruitment of UK participants. But The Lancet paper was based on fabricated data and was swiftly retracted. After this interruption, recruitment around the globe to COPCOV can now resume.

Hand holding pills © 2020 MORU. Photographer: Supa-at Asarath.

A global study (COPCOV) to determine if hydroxychloroquine or chloroquine can prevent COVID-19 will resume enrolment of workers in healthcare facilities and other staff in contact with COVID-19 patients, after getting approval to proceed from the UK medicines agency.

The MHRA (Medicines and Healthcare Products Regulatory Agency) announced on 26 June that it would again permit recruitment to the COPCOV COVID-19 prevention clinical trial. The MHRA decision came 5 weeks after it reacted immediately to the now-discredited paper published in The Lancet suggesting harms with hydroxychloroquine, and paused recruitment of UK participants. But the paper was based on fabricated data and was swiftly retracted. After this interruption, recruitment around the globe to COPCOV can now resume.

Led by the University of Oxford’s Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok, Thailand, the COPCOV study is a double-blind, randomised, placebo-controlled global trial that aims to enrol 40,000 healthcare workers and other at-risk staff to determine definitively if chloroquine and hydroxychloroquine can prevent COVID-19.

There remains no conclusive proof whether the well-established drugs hydroxychloroquine and chloroquine are effective in preventing COVID-19. To date, most studies have focussed on the use of these drugs to treat – and not prevent – COVID-19.

“The results of the large UK RECOVERY trial suggest that in sick patients hospitalised with COVID-19 the corticosteroid drug dexamethasone saves lives but hydroxychloroquine does not. This suggests that inflammation is the main problem in the late stages of the illness whereas the window of opportunity for anti-viral drugs to work may be earlier in the course of the infection. Hydroxychloroquine could still prevent infections, and this needs to be determined in a randomised controlled trial. With 20% of the world’s population living in countries where these drugs are recommended for prevention, the question whether they can prevent COVID-19 or not remains as pertinent as ever,” said COPCOV Co-Principal Investigator Prof Sir Nicholas White, of the University of Oxford who is based at MORU.

The UK arm of the COPCOV study will resume recruitment at the Brighton and Sussex University Hospitals and at the John Radcliffe Hospital in Oxford this week, with more UK sites expected soon.

“Although rates of COVID 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 COPCOV UK lead Investigator Prof Martin Llewelyn, Brighton and Sussex Medical School, UK.

As confirmed COVID-19 cases exceed 10 million globally and continue to rise, protecting healthcare workers from contracting COVID-19 remains vital for the UK and many other countries in the world.

“There remains no preventative drug therapy, no vaccine and no widely available treatment that is effective before a patient is already very sick. If hydroxychloroquine and chloroquine are to work, they are much more likely to affect the disease the earlier they are given, but we need to know one way or another, and soon,” said COPCOV Co-Principal Investigator Dr William Schilling, of the University of Oxford who is also based at MORU.

The COPCOV UK sites are being managed by the Diabetes Trials Unit, University of Oxford. An additional 20 sites are expected to open by September in the UK. Workers in UK healthcare settings wishing to participate in COPCOV should visit the study website

“In the UK, NHS staff and other health care workers will continue to put their own health at risk caring for COVID-19 patients for months to come. Anything that could be done to protect them is worth establishing. Those interested in participating should find out more on the study website where they can register to take part,” said Prof Amanda Adler of the University of Oxford.   

Plans are underway for new COPCOV study sites in Thailand and Southeast Asia, Africa and South America. Results are expected by the end of this year (2020).

To learn more, visit our COPCOV pages

To express interest in setting up a COPCOV site, visit our page how to become a COPCOV site

Press enquiries, contact: John Bleho; +90.537.567.8460 (Mobile/WhatsApp)

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