Clinical trials for the prevention and treatment of COVID-19: current state of play.

Since coronavirus disease 2019 (COVID-19) emerged in Wuhan, China in December 2019 and spread around the world, over 1100 clinical studies have been registered globally on clinical trials registries, including over 500 randomised controlled trials. Such rapid development and launch of clinical trials is impressive but presents challenges, including the potential for duplication and competition. There is currently no known effective treatment for COVID-19. In order to focus on those studies most likely to influence clinical practice, we summarise the 31 currently registered randomised trials with a target sample size of at least 1000 participants. We have grouped these trials into four categories: prophylaxis; treatment of outpatients with mild COVID-19; treatment of hospitalised patients with moderate COVID-19; and treatment of hospitalised patients with moderate or severe disease. The most common therapeutic agent being trialled currently is hydroxychloroquine (24 trials with potential sample size of over 25 000 participants), followed by lopinavir-ritonavir (seven trials) and remdesevir (five trials) There are many candidate drugs in pre-clinical and early phase development, and these form a pipeline for future large clinical trials if current candidate therapies prove ineffective or unsafe.