In response to the global coronavirus disease 2019 (COVID-19) emergency, clinical trial research assessing the efficacy and safety of clinical candidate interventions to treat COVID-19 are emerging at an unprecedented rate. As of April 21, 2020, well over 500 clinical trials have been registered at the various international and national clinical trial registry sites. Findings from randomised clinical trials that have been published as of April 21, 2020, have investigated the efficacy of lopinavir–ritonavir compared with standard of care,1 hydroxychloroquine compared with best supportive care,2 favipiravir compared with arbidol,3 and lopinavir–ritonavir compared with arbidol.4 Other non-randomised trials have investigated hydroxychloroquine versus hydroxychloroquine combined with azithromycin.5 Over 300 trials are enrolling participants and cover further investigations of the above drugs and promising therapies such as remdesivir, IL-6 inhibitors (tocilizumab and sarilumab), convalescent plasma therapy, stem-cell transfusion, vaccine candidates, several other well known direct acting antiv irals, and traditional Chinese medicines. Most of these trials will offer comparative efficacy data versus standard of care according to local COVID-19 treatment guidelines, but a handful of randomised controlled trials will also provide headto-head evidence between high profile interventions. The figure shows the network of completed, ongoing, and planned COVID-19 interventional clinical trials of these interventions or intervention groups that are being explored in at least two trials.