The Cytel blog keeps you up to speed with the latest developments in biostatistics and clinical biometrics.

Unblinded Sample Size Re-Estimation in Bioequivalence Trials with Small Samples

August 26, 2016

 

At the recent JSM in Chicago, Cytel’s Sam Hsaio and Lingyun Liu alongside Genentech's Romeo Maciuca, presented a framework for inference in adaptive bioequivalence trials with unblinded sample size re-estimation.

 

The Problem

In bioequivalence trials where the variance is often unknown, and the sample size small, using boundaries derived under the assumption of a normally distributed test statistic may lead to type I error inflation. This problem can be overcome with p-value combination methods, however these approaches generally do not directly provide confidence intervals for the geometric mean ratio on the scale of the original pharmacokinetic endpoint.

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Adaptive SSR: Debunking the inefficiency myth

March 3, 2016
 'The aim of a discussion should not be victory but progress.'

This principle, expressed by the French essayist Joseph Joubert, applies effectively to the spirit of scientific debate. More specifically, within the clinical development space, the field of adaptive designs has seen its fair share of both discussion and progress. In this blog we’ll take a look at one debated area- the efficiency of Adaptive SSR designs.

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