Modern Approaches to Clinical Trials Using SAS: Classical, Adaptive, and Bayesian Methods

8.3 Analysis Examples for a Continuous Endpoint

8.3.1 Asthma Trial with 75 Patients Per Group

Consider a phase IIb study in asthma assessing the response of a new entity in a clinical trial. The typical phase II endpoint of interest is FEV₁ (forced expiratory volume in 1 second) which is a common spirometry test that is used in asthma studies. An advantage of the FEV₁ endpoint is that the length of follow-up required to observe changes is much shorter than the typical phase III endpoint of exacerbations. The FEV₁ endpoint is continuous and can be assumed to be normally distributed. The sponsor ran a couple of phase IIa studies for this experimental drug; the first study tested the effect of the maximum tolerated dose (MTD), the second study ...