Research Article
Jacques Medioni, Caroline T
Abstract
Background: Phase III trials can fail, leading to termination of drug development. This can result from heterogeneous subpopulations such as a drug-sensitive and a drug-insensitive subpopulation of patients or biological subtypes. Methods: Traditional phase II methods do not detect heterogeneity of subpopulations. We proposed a new adaptive design for phase II trials, adapted from Simon’s “Minimax” design, where heterogeneity between two subpopulations could be highlighted. Results: Drug inefficacy in one or two subpopulations could be determined at stage one and two and drug efficacy at stage two. Single Simon design and two independent Simon designs were compared to the adaptive design using calculated type I and II errors, expected and maximum sample size, and the probability of detecting drug-insensitive subpopulations. For the adaptive design, the type I and II errors calculated were similar to those of a single Simon design, sample size was smaller than with the two independent Simon designs (between 25 and 40% fewer patients) and the probability of detecting drug-insensitive subpopulations remained at 40%. An example with real data is presented. Conclusion: In the event of different subpopulations of patients or biological subtypes, our adaptive design can help select the drug sensitive subpopulation in one single trial.