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Register a new userResponse-adaptive randomization in clinical trials: from myths to practical considerations
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David Robertson
Publication date
2020
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Mathematical Statistics
and research's language is
English
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Response-adaptive randomization (RAR) is part of a wider class of data-dependent sampling algorithms, for which clinical trials are used as a motivating application. In that context, patient allocation to treatments is determined by randomization probabilities that are altered based on the accrued response data in order to achieve experimental goals. RAR has received abundant theoretical attention from the biostatistical literature since the 1930s and has been the subject of numerous debates. In the last decade, it has received renewed consideration from the applied and methodological communities, driven by successful practical examples and its widespread use in machine learning. Papers on the subject can give different views on its usefulness, and reconciling these may be difficult. This work aims to address this gap by providing a unified, broad and up-to-date review of methodological and practical issues to consider when debating the use of RAR in clinical trials.
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In learning-phase clinical trials in drug development, adaptive designs can be efficient and highly informative when used appropriately. In this article, we extend the multiple comparison procedures with modeling techniques (MCP-Mod) procedure with generalized multiple contrast tests (GMCTs) to two-stage adaptive designs for establishing proof-of-concept. The results of an interim analysis of first-stage data are used to adapt the candidate dose-response models and the dosages studied in the second stage. GMCTs are used in both stages to obtain stage-wise p-values, which are then combined to determine an overall p-value. An alternative approach is also considered that combines the t-statistics across stages, employing the conditional rejection probability (CRP) principle to preserve the Type I error probability. Simulation studies demonstrate that the adaptive designs are advantageous compared to the corresponding tests in a non-adaptive design if the selection of the candidate set of dose-response models is not well informed by evidence from preclinical and early-phase studies.
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