The Randomised, Embedded, Multifactorial Adaptive Platform (REMAP-CAP) trial is the largest randomized clinical trial in critically ill patients with COVID-19 to report the effects of lopinavir-ritonavir, hydroxychloroquine and combination therapy of lopinavir-ritonavir and hydroxychloroquine compared with no antiviral therapy. We found that, among critically ill patients with COVID-19, lopinavirritonavir, hydroxychloroquine and combination therapy reduced organ support-free days and survival compared to no COVID-19 antiviral therapy.