Abstract：
BACKGROUND: A resurgence of research into phase II trial design in the mid-2000s led to the use of futility designs in a wide variety of disease areas. Phase II futility studies differ from efficacy studies in that their null hypothesis is that treatment, relative to control, does not meet or exceed the level of benefit required to justify additional study. A rejection of the null hypothesis indicates that the treatment should not proceed to a larger confirmatory trial.
METHODS: Bayesian approaches to the design of phase II futility clinical trials are presented and allow for the quantification of key probabilities, such as the predictive probability of current trial success or even the predictive probability of a future trial\'s success.
RESULTS: We provide an illustration of the design and interpretation of a phase II futility study constructed in a Bayesian framework. We focus on the operating characteristics of our motivating trial based on a simulation study, as well as the general interpretation of trial outcomes, type I, and type II errors in this framework.
CONCLUSIONS: Phase II futility clinical trials, when designed under in a Bayesian framework, offer an alternative approach to the design of mid-phase studies which provide unique benefits relative to trials designed in a frequentist framework and designs which focus on treatment efficacy.
METHODS: Bayesian approaches to the design of phase II futility clinical trials are presented and allow for the quantification of key probabilities, such as the predictive probability of current trial success or even the predictive probability of a future trial\'s success.
RESULTS: We provide an illustration of the design and interpretation of a phase II futility study constructed in a Bayesian framework. We focus on the operating characteristics of our motivating trial based on a simulation study, as well as the general interpretation of trial outcomes, type I, and type II errors in this framework.
CONCLUSIONS: Phase II futility clinical trials, when designed under in a Bayesian framework, offer an alternative approach to the design of mid-phase studies which provide unique benefits relative to trials designed in a frequentist framework and designs which focus on treatment efficacy.
摘要：
背景：在2000年代中期，对II期试验设计的研究重新兴起，导致在各种疾病领域中使用无效设计。第二阶段徒性研究与功效研究的不同之处在于，它们的零假设是治疗，相对于控制，不符合或超过证明额外研究合理的获益水平。拒绝零假设表明治疗不应进行更大的确认试验。
方法：介绍了设计II期无效临床试验的贝叶斯方法，并允许对关键概率进行量化，例如当前试验成功的预测概率，甚至未来试验成功的预测概率。
结果：我们提供了在贝叶斯框架中构建的II期徒劳性研究的设计和解释的说明。我们基于模拟研究，重点关注激励试验的运行特点，以及对试验结果的一般解释，I型,和此框架中的II型错误。
结论：II期无效临床试验，当在贝叶斯框架下设计时，为中期研究的设计提供了一种替代方法，该方法相对于在频率论框架中设计的试验和专注于治疗功效的设计提供了独特的益处。
方法：介绍了设计II期无效临床试验的贝叶斯方法，并允许对关键概率进行量化，例如当前试验成功的预测概率，甚至未来试验成功的预测概率。
结果：我们提供了在贝叶斯框架中构建的II期徒劳性研究的设计和解释的说明。我们基于模拟研究，重点关注激励试验的运行特点，以及对试验结果的一般解释，I型,和此框架中的II型错误。
结论：II期无效临床试验，当在贝叶斯框架下设计时，为中期研究的设计提供了一种替代方法，该方法相对于在频率论框架中设计的试验和专注于治疗功效的设计提供了独特的益处。
