Single-Arm Two-Stage Phase 2 Clinical Trials with Go/No-Go/Grey-Zone Outcomes

• Activity Number: 128
• Type: Contributed
• Date/Time: Monday, August 4, 2014 : 8:30 AM to 10:20 AM
• Sponsor: Biopharmaceutical Section
• Author(s): Bob Zhong*+
• Companies: Johnson & Johnson
• Keywords: Phase 2 trials ; two-stage designs ; go/no-go/grey-zone outcomes ; asymmetric alpha spending

Abstract

Phase 2 clinical trials are commonly conducted as pilot studies to evaluate efficacy and safety in selected populations of patients with the disease or condition to be treated or prevented. When designing such a trial considering efficacy conclusions, people naturally think as follows: if efficacy data is very strong, a go decision should be made; if efficacy data is very weak, a no-go decision should be made; if the efficacy data is nether strong nor weak, no decision can be made (grey-zone). The designs presented in this paper match this natural thinking process with go/no-go/grey-zone outcomes. When two-stage designs are used, the stage I sample size is flexible and can cover necessary practical scenarios.