By Manasi Vaidya in New York.

A placebo-controlled, randomised trial evaluating the use of hydroxychloroquine in patients who have tested positive for Covid-19 and are being admitted to the hospital for Covid illness will begin enrolment next week, said investigator Dr Roy Brower, medical director, Medical Intensive Unit, Johns Hopkins Medicine, Baltimore, Maryland. The trial will enrol approximately 500 patients in multiple hospitals, but the patient number may go higher, he added.

The worldwide pandemic of Covid-19, caused by the novel SARS-CoV-2 virus, started in late 2019 and has since spread all over the globe.

The study is being organised by the Prevention and Early Treatment of Acute Lung Injury (PETAL) network, noted Brower, who is the chair of the PETAL steering committee. The fact that half the network consists of investigators who are emergency medicine physicians means they can enrol trial patients in the emergency room itself, he noted. This may be useful, since giving a treatment like hydroxychloroquine early will most likely be beneficial, he explained. PETAL has conducted several studies in acute respiratory distress syndrome (ARDS) and acute lung injury in the past, he said. The network specifically focuses on conducting clinical trials to prevent ARDS and provide early treatment to improve the outcome of patients who have ARDS. PETAL includes 12 clinical centres, and one clinical coordinating centre, and is funded by the NIH’s National Heart, Lung and Blood Institute.

A randomised, placebo-controlled design is necessary since it is still unknown if the drug works, Brower added. Without such a design, it is difficult to interpret mortality data, which may be influenced by other factors like differences in clinical care in different countries, he explained. There are 18 studies currently listed on that plan to evaluate hydroxychloroquine for Covid-19. None of the trials recruiting is for hospitalised Covid-19 positive patients in the US.

Brower said the main challenge with regards to patient enrolment would likely be related to the equipoise needed among clinicians, and therapies need to be evaluated before being used off-label. While hydroxychloroquine has become the most commonly used off-label medication for Covid, no studies have shown a Covid-specific benefit yet, he noted.

Hydroxychloroquine as a potential treatment for Covid-19 has been in the news since last week, when President Donald Trump tweeted about its use with the antibiotic azithromycin as possibly being a ”game-changer”. However, a report from Shanghai University of a 30-patient randomised trial indicated that after seven days of treatment, throat swabs for Covid-19 nucleic acid were negative in 13 and 14 patients in the hydroxychloroquine and control group, respectively (p > 0.05). Despite the hype, clarity on hydroxychloroquine’s potential is lacking given that a subset of patients in both arms in the Shanghai University study also received other antiviral therapies, which may have an impact but it is not fully understood.

Moreover, while hydroxychloroquine has been used to treat malaria for a long time, the field still does not understand its safety profile in Covid-specific patients, said Brower. Some Covid-19 patients have myocarditis and ARDS, and chloroquine has been associated with heart toxicities, he noted, adding there is a concern that its use could cause more harm than good.

Manasi Vaidya is a Senior Reporter for Clinical Trials Arena parent company GlobalData’s investigative journalism team. A version of this article originally appeared on the Insights module of GlobalData’s Pharmaceutical Intelligence Center. To access more articles like this, visit GlobalData.