  This article discusses futility analyses for the MCP-Mod methodology.
Formulas are derived for calculating predictive and conditional power for
MCP-Mod, which also cover the case when longitudinal models are used allowing
to utilize incomplete data from patients at interim. A simulation study is
conducted to evaluate the repeated sampling properties of the proposed decision
rules and to assess the benefit of using a longitudinal versus a completer only
model for decision making at interim. The results suggest that the proposed
methods perform adequately and a longitudinal analysis outperforms a completer
only analysis, particularly when the recruitment speed is higher and the
correlation over time is larger. The proposed methodology is illustrated using
real data from a dose-finding study for severe uncontrolled asthma.
