Figure 2.

Six toxicity-efficacy scenarios. The desired targeted response, or efficacy, rate is in the lower-right of each panel. After dose-escalation, five DECs are simulated according to a common toxicity curve (short dashed). The MTD is indicated with a star. For three DECs, the targeted response rate is not achievable (long dashed; efficacy curve A); for two, it is achievable (solid; efficacy curve B). Acceptable dose levels in efficacy curve B, i.e. those with efficacy greater than the stated target and DLT rate no greater than 0.30, are boxed.