Hydroxychloroquine Versus Placebo in COVID-19 Patients at Risk for Severe Disease

A new human coronavirus responsible for pneumonia, SARS-CoV-2, emerged in China in December 2019 and has spread rapidly. COVID-19, the disease caused by this virus, has a very polymorphous clinical presentation, which ranges from upper respiratory tract infections to acute respiratory distress syndrome. It may appear serious straightaway or may evolve in two stages, with a worsening 7 to 10 days after the first clinical signs, potentially linked to a cytokine storm and accompanied by a high risk of thrombosis. The global mortality rate of COVID-19 is between 3% and 4%, with severe forms being more frequent among older patients. Management is symptomatic as no antiviral treatment has demonstrated any clinical benefit in this condition. Hydroxychloroquine is a derivative of chloroquine commonly used in some autoimmune diseases, such as systemic lupus erythematosus. It is active in vitro in cellular models of infection by many viruses such as HIV, hepatitis C or SARS-CoV. However, its interest in viral infections in humans has not been demonstrated.

Very recently, a preliminary uncontrolled study evaluated the effect of hydroxychloroquine on viral shedding in subjects with COVID-19. Among 20 patients treated with hydroxychloroquine at a dose of 600 mg per day, the percentage of patients with detectable SARS-CoV-2 RNA in the nasopharynx decreased from 100% at inclusion (start of treatment) to 43% six days later. In comparison, 15 of 16 untreated patients had a positive RT-PCR six days after inclusion. Furthermore, hydroxychloroquine has immunomodulating and anti-inflammatory properties, which could theoretically prevent or limit secondary worsening.

The research hypothesis is that treatment with hydroxychloroquine improves prognosis and reduces the risk of death or use for invasive ventilation in patients with COVID-19.