Between March and April 2020, a team led by Dr. Oriol Mitjà and Dr. Bonaventura Clotet launched a pioneering study to assess the effectiveness of hydroxychloroquine (HCQ) as an immediate treatment for people infected and to prevent contagion between contacts. The clinical trial was based on the “Test & Treat” strategy, consisting of the distribution of treatment at the time of diagnosis.

The trial took place during the first wave of the COVID-19 pandemic. It was a randomized Phase 3 study carried out in three of the nine health regions of Catalonia (Spain) with a total population of 4.2 million. A total 672 Covid-19 positive cases and 2,314 of their contacts participated in the study. Participants were randomly assigned to a treatment group in which they received HCQ (Dolquine®) at a dose of 800mg on day 1, followed by a daily dose of 400mg for the next six days, or to a control group that did not receive this treatment.

Results

Treatment with HCQ did not have beneficial effects in the prevention of symptomatic COVID-19 or in the prevention of SARS-CoV-2 infection in healthy contacts exposed to a positive PCR case. These results were of great help to reorientate the many studies based on HCQ that were underway around the world and can now focus on more effective therapies or drug combinations with greater antiviral potency.