Single-Arm Two- and Three-Stage Phase 2 Clinical Trials with Go/No-Go/Inconclusive Outcomes with Handling of Overrunning/Under-Running

• Activity Number: 172 - Quantitative Decision Making in Clinical Trials
• Type: Contributed
• Date/Time: Monday, July 29, 2019 : 10:30 AM to 12:20 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Bob Zhong* and Wenchuan Guo and Jianan Hui
• Companies: Johnson and Johnson and Bristol-Myers Squibb Company and Boehringer Ingelheim Pharmaceuticals Inc.
• Keywords: Phase 2 trials; two-stage designs; go/no-go/inconclusive outcomes; asymmetric alpha; alpha spending; Optimal designs

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 evidence is very strong, a go decision should be made; if efficacy evidence is very weak, a no-go decision should be made; if the efficacy evidence is nether strong nor weak, no decision can be made (inconclusive). The designs presented in this paper match this natural thinking process with go/no-go/inconclusive outcomes. Both two-/three-stage designs are developed with three outcomes. Additionally, the sample size at the final stage can be modified instead of fixed so that these designs can be used to handle "over-running" or "under-running" practical situations.