Fig. 3

Example 3. A DDP segment: a phase II randomized population enrichment trial (Simon & Simon, 2013) followed by a phase III RCT in the selected subpopulation. The results of the phase II trial trigger termination of the DDP segment or continuation to a phase III trial. B Simulation scenario with a continuous biomarker. As biomarker levels increase, the probability of treatment response increases. The population with biomarker levels ≥ 0.6 benefits from the experimental treatment compared to the standard of care (SOC; dashed horizontal line), whereas patients with biomarker levels < 0.6 have better probability of response under the SOC. C The probabilities that each cutoff is selected at the end of the phase II trial. Selection of the optimal cutoff point (0.6) is shown in green. The probability of a negative result of the phase II trial, without evidence of treatment effects, is shown in red. D Power of the DDP segment