Flexible Modification of Survival Trials

• Activity Number: 504
• Type: Topic Contributed
• Date/Time: Wednesday, August 4, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Mikhail P. Salganik*+ and Cyrus R. Mehta
• Companies: Cytel Inc.
• Keywords: Survival ; Flexible ; Adaptive ; Trial

Abstract

In clinical trials with survival outcomes investigators may sometimes be allowed to increase the accrual duration, accrual rate and duration of a trial if the results of the interim analysis "look promising". Several possible approaches to the design of these adaptive trials have been developed (e.g. Li, Shih, and Wang, 2005, Wassmer , 2006). In theory the investigator/sponsor is allowed nearly complete flexibility in modifying the on-going trial without compromising the type I error. In practice the implementation of the adaptive designs often relies on pre-specification of the adaptation algorithm in the protocol. We discuss the implementation of the adaptive design that allows sponsor to retain substantial influence over the adaptation process without un-blinding the data to the sponsor. We will illustrate the method with an actual clinical trial.