Bayesian sample size determination in non‐sequential clinical trials: Statistical aspects and some regulatory considerations

The most common Bayesian methods for sample size determination (SSD) are reviewed in the non-sequential context of a confirmatory phase III trial in drug development. After recalling the regulatory viewpoint on SSD, we discuss the relevance of the various priors applied to the planning of clinical trials. We then investigate whether these Bayesian methods could compete with the usual frequentist approach to SSD and be considered as acceptable from a regulatory viewpoint.