Fig. 2

Example 2. A DDP segment: a phase I dose-finding study followed by a single-arm phase II trial. The DDP is discontinued after the phase I trial (i.e., treatment not recommended for phase II) if the lowest dose has a high toxicity estimate (> 0.25). The DDP segment is discontinued after the phase II trial if the trial does not detect efficacy (ORR ≤ 0.4). B The dose–response (solid line) and dose-toxicity (dashed line) relationship of the drug. Horizontal lines denote the ORR of the standard of care (dashed line), the experimental treatment (dotted-dashed line), and toxicity threshold (dotted line). Both the 3rd and 4th dose levels are safe (p ≤ 0.25) and effective (ORR > 0.4). C The power of the DDP segment (i.e., the probability that the phase I trial selects dose 3 or 4 and the subsequent phase II trial detects a treatment effect). D The probability that a dose is selected at completion of the phase I trial (clear bars). The panel also illustrates the probability that the phase II trial detects a treatment effect and recommends the drug for a phase III trial (solid subset of clear bars). E The probability that a patient enrolled in the DDP segment will be given an unsafe or ineffective dose