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A global study to test if either chloroquine or hydroxychloroquine can prevent COVID-19 in vital frontline healthcare workers will open to UK participants at hospital sites in Brighton and Oxford today.

Laboratory evidence shows that these well-established drugs might be effective in preventing or treating COVID-19 but there is no conclusive proof. Despite the lack of strong evidence these drugs are being widely recommended, and they are being widely used in some countries– so finding out if they can protect against COVID-19 - yes or no - is of tremendous importance.

Led by the University of Oxford and Wellcome supported Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok, Thailand, the COPCOV study is a double-blind, randomised, placebo-controlled trial that will enrol 40,000+ frontline healthcare workers and staff from Europe, Africa, Asia and South America who have close contact with patients with COVID-19 to determine definitively if chloroquine and hydroxychloroquine are effective in preventing COVID-19.

“COVID-19 is a major risk for frontline healthcare workers around the world,” said COPCOV Co-Principal Investigator Professor Sir Nicholas White, of the University of Oxford who is based at MORU.

“We really do not know if chloroquine or hydroxychloroquine are beneficial or harmful against COVID-19. The best way to find out if they are effective in preventing COVID-19 is in a randomised clinical trial. That’s what COPCOV is – and why we’re doing this study,” said Prof White.

Although many countries have begun to bend the curve of new COVID-19 cases per day downwards, the possibility of a second wave of cases cannot be excluded, and developing additional tools to protect frontline healthcare workers from contracting COVID-19 remains very important for the UK, as well as for many other countries in the world.

“Even though the lockdown has brought the rate of infection right down in the UK, healthcare workers will continue to be at risk of COVID-19, especially as measures are relaxed. A widely available, safe and effective vaccine may be a long way off. If drugs as well tolerated as chloroquine and hydroxychloroquine could reduce the chances of catching COVID-19 this would be incredibly valuable,” said lead COPCOV UK Investigator Prof Martin Llewelyn, Brighton and Sussex Medical School, UK.

Enrolment of the first UK participants in COPCOV is beginning today at the Brighton and Sussex University Hospitals and the John Radcliffe Hospital in Oxford. The COPCOV UK sites are being managed by the Diabetes Trials Unit, University of Oxford, https://copcov.org. An additional four sites are expected to open by the end of May, towards a total of 25 COPCOV sites in the UK, by the end of June. Plans are well underway for new COPCOV study sites in Thailand and Southeast Asia, Italy, Portugal, Africa and South America. Results are expected by the end of this year (2020).

Any adult who works in a UK healthcare facility and is delivering direct care to patients with proven or suspected COVID-19 may participate in COPCOV, as long as they have not been diagnosed with COVID-19 or have an acute respiratory infection (ARI).

After being enrolled in the study and giving their fully informed consent, each COPCOV participant will receive either chloroquine or a placebo (in Asia) or hydroxychloroquine or a placebo (in UK, Europe, Africa) for 3 months. Half the participants will receive the drug, half will receive a placebo. Selection will be random and neither the study team nor the participant will know if the participant is taking the drug or a placebo. This short video explains what happens when you enrol in COPCOV.

Sponsored by the University of Oxford (UK), COPCOV (Chloroquine/ hydroxychloroquine prevention of coronavirus disease (COVID-19)) is funded by a grant by the COVID-19 Bill & Melinda Gates Foundation, Wellcome and MasterCard Therapeutics Accelerator. 

“Hard scientific evidence from large-scale clinical trials is essential. Hydroxychloroquine and chloroquine have shown positive results in small-scale studies and anecdotally, but there are still many unknowns. These trials will give us the best understanding of how safe and effective these drugs might be across different populations and age groups. If – and only if – they are effective, these drugs can be scaled up and rolled out quickly across the world,” said Nick Cammack, COVID-19 Therapeutics Accelerator Lead at Wellcome.

Accord Healthcare, a UK-based medicines manufacturer, has donated over two million tablets of hydroxychloroquine and matched placebo to enable this landmark trial to go ahead.

Dr Anthony Grosso, Vice President & Head of Scientific Affairs, Accord Europe & MENA said: “Based on the known pharmacology of hydroxychloroquine, coupled with the emerging knowledge surrounding SARS-CoV-2 viral replication and COVID-19 pathophysiology, we were very keen to test the effectiveness of this molecule in a preventative, rather than late-stage treatment setting. A large-scale, prospective, randomised, double-blind clinical trial in a high-risk setting is the only way to robustly determine if this medicine can lessen or prevent human infection. Previous studies have not adequately tested this hypothesis; the results of COPCOV are therefore of critical importance to public health.” 

To learn more visit our COPCOV trial page.