Effect Estimation Under Treatment Discontinuation in Noninferiority Trials

• Activity Number: 582
• Type: Topic Contributed
• Date/Time: Wednesday, August 7, 2013 : 2:00 PM to 3:50 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Gerd Rosenkranz*+
• Companies: Novartis Pharma AG
• Keywords: non-inferiority trials ; treatment discontinuation ; principal stratification

Abstract

To establish the effect of an investigational treatment, randomized, controlled clinical trials are designed where patients are expected to follow a pre-defined treatment schedule for both the new treatment and a control. During the conduct of the trial some patients may decide that continuing treatment as per protocol is no longer warranted for various reasons or an investigator may conclude that further treatment is no longer in the best interest of the patient. These situations result in discontinuation of treatment and as a consequence in missing data. Even if patients are further observed according to the original schedule to avoid missing data - as expected by Health Authorities - it is not obvious how to make best use of the data after treatment discontinuation for estimating a treatment effect. This presentation discusses a proposal based on the concept of principal stratification (Frangakis and Rubin, 2002).