Figure 2. Trends of EMA approvals with adaptive design trials
from 2008 to 2020
Overall, adaptive designs were mainly composed of group sequential
design (17/41, 41.46%) and seamless design (15/41, 36.59%). In the
first period, the number of seamless designs was greater than that of
group sequential design. From 2013 to 2016, the number of both designs
was equal, but the proportion of group sequential design outweighed
seamless design between 2017 and 2020. There was also an increase in the
diversity of adaptive designs since 2017, which indicated that the
planning of design modification had become much more flexible and
adaptable (Figure 3).