As the Covid-19 pandemic continues into the last month of the year, the numbers of confirmed cases and deaths continue to grow to new highs. Although some drug candidates have been approved, clinical trials disrupted due to Covid-19 continue to see changing numbers.

Figure 1 shows the overall number of disrupted clinical trials. The fastest rate of trial disruption was between early April and mid-May, and the number of trials disrupted by Covid-19 peaked in the week of June 1st. Since then, there has been a slow but progressive decline in the number of clinical trial disruptions.

These disrupted trials can be delayed for numerous reasons but the major reasons include enrollment suspension, as shown by the green line; delayed initiation of planned trials, shown in purple; and slow recruitment of participants, shown in blue in Figure 2.

As of 30 November 2020, the top reason for disrupted clinical trials is slow enrollment, causing delays in 49% of disrupted clinical trials. This is followed by enrollment suspension at 35% and delayed initiation at 16%. Although suspended trials have begun to recruit participants, as indicated by the downward trajectory of the green line, delays in trial initiation and slow recruitment continue. In fact, trials with slow recruitment are still on the rise.

With new vaccines being approved for the treatment of Covid-19, one can only hope that this will not only change the dynamic of the global pandemic but also the outlook of clinical trials, hopefully decreasing the number of disrupted clinical trials.