Bioequivalence and Bioavailability Forum

Dear all,

on 20 August a paper was published (pub ahead of print) in Pharm Stat, namely:

Potvin D, Diliberti CE, Hauck WW, Parr AF, Schuirmann DJ, Smith RA. Sequential design approaches for bio­equivalence studies with crossover designs.

Abstract

The planning of bioequivalence (BE) studies, as for any clinical trial, requires a priori specification of an effect size for the determination of power and an assumption about the variance. The specified effect size may be overly optimistic, leading to an underpowered study. The assumed variance can be either too small or too large, leading, respectively, to studies that are underpowered or overly large. There has been much work in the clinical trials field on various types of sequential designs that include sample size reestimation after the trial is started, but these have seen only little use in BE studies. The purpose of this work was to validate at least one such method for crossover design BE studies. Specifically, we considered sample size reestimation for a two-stage trial based on the variance estimated from the first stage. We identified two methods based on Pocock’s method for group sequential trials that met our requirement for at most negligible increase in type I error rate.

Since the authors are well-known, I would expect/hope the article to have higher impact than Gould’s of 1995.