  As a reaction to the pandemic of the severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2), a multitude of clinical trials for the treatment of
SARS-CoV-2 or the resulting corona disease (COVID-19) are globally at various
stages from planning to completion. Although some attempts were made to
standardize study designs, this was hindered by the ferocity of the pandemic
and the need to set up trials quickly. We take the view that a successful
treatment of COVID-19 patients (i) increases the probability of a recovery or
improvement within a certain time interval, say 28 days; (ii) aims to expedite
favourable events within this time frame; and (iii) does not increase mortality
over this time period. On this background we discuss the choice of endpoint and
its analysis. Furthermore, we consider consequences of this choice for other
design aspects including sample size and power and provide some guidance on the
application of adaptive designs in this particular context.
