Case Studies of Adaptive Design in Vaccine Clinical Trials

• Activity Number: 231
• Type: Topic Contributed
• Date/Time: Monday, July 30, 2012 : 2:00 PM to 3:50 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Xiaoming Li*+
• Companies: Gilead Sciences
• Keywords: Vaccine trial ; adaptive design ; two-stage ; population enrichment

Abstract

Adaptive design has drawn much attention in clinical trial development in recent years, as another tool for efficient clinical study design. Its application in vaccine development is discussed with two real examples. In the first example of a Phase IV trial, a two-stage adaptive design strategy built on the traditional fixed-number-of-events design was proposed for the scenario in which the primary efficacy endpoint is a (rare) single infection/disease event with unknown incidence rate. In the second example, a population enrichment strategy is proposed for a Phase III vaccine efficacy trial to enable the flexibility allowing pre-specified modifications to an ongoing trial to mitigate the potential risk associated with the efficacy assumptions made for different populations at the design stage. While these approaches were developed in the setting of vaccine efficacy trials, they can be readily applicable in other therapeutic areas.