Figure 2.
Diagrams of the marker-stratified design. Equal randomized marker-stratified design has a fixed 1:1 randomization ratio throughout the trial to assign patients into the targeted therapy and the standard therapy, respectively. On the other hand, the randomization ratio for the Bayesian adaptive randomized marker-stratified design varies during the trial. As illustrated, the randomization ratio in the marker positive group could change from 1:1 to 2:1 and to 3:1 while, in the marker negative group, they could change from 1:1 to 1:2 to 1:3 assuming that the targeted therapy is more effective for the marker positive patients and the standard therapy is more effective for the marker negative patients.
