Janssen Pharmaceutical Companies of Johnson and Johnson, Spring House, PA 19002, USA.
Contemp Clin Trials. 2012 Nov;33(6):1272-9. doi: 10.1016/j.cct.2012.07.006. Epub 2012 Jul 14.
Phase IIA 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. The efficacy objective is to find preliminarily evidence of the effectiveness or ineffectiveness of study treatments. Go/no-go decisions will be made during or at the end of these trials. Interim analyses (multiple stages) are usually built-in to terminate futile treatments. The designs presented in this paper match the efficacy objective with go/no-go decisions. This is achieved by setting up the threshold as the minimal effective response rate. Asymmetric type I error spending at this threshold is also possible. When two-stage designs are used, the stage I sample size is flexible and can cover all practical scenarios.
IIA 期临床试验通常作为先导研究，在目标疾病或病症的特定患者人群中评估疗效和安全性，以便治疗或预防该疾病或病症。其疗效目标是初步证明研究治疗的有效性或无效性。这些试验期间或结束时将做出去留决定。中期分析（多阶段）通常内置用于终止无效治疗。本文提出的设计方案将疗效目标与去留决定相匹配。这是通过将阈值设定为最小有效反应率来实现的。在这个阈值处，也可能出现不对称的 I 类错误消耗。当使用两阶段设计时，I 期样本量具有灵活性，可以涵盖所有实际情况。
