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arXiv 2606.02410stat.MEstat.AP
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二元终点两臂II期临床试验的最优序贯两阶段贝叶斯因子设计

Optimal sequential two-stage Bayes Factor Design for two-arm clinical Phase II Trials with binary Endpoints

Riko Kelter

AI总结:

提出一种无模拟方法,基于贝叶斯因子优化两臂II期试验的两阶段设计,通过精确表达式计算操作特征并最小化零假设下的期望样本量。

摘要:

两臂II期临床试验通常受益于允许因无效而提前停止的中期分析,但此类设计的贝叶斯校准通常基于计算密集的蒙特卡洛模拟。本研究开发了一种无模拟方法,以贝叶斯因子作为主要证据度量,在二元终点的两臂II期试验中获得贝叶斯最优两阶段设计。基于固定样本两臂贝叶斯因子设计的近期矩阵搜索方法和单臂两阶段设计的早期校正公式,所提出的方法推导了具有单一无效中期分析的两阶段两臂设计操作特征的精确表达式。通过校正因提前停止而移除的轨迹对应的固定样本量,获得贝叶斯功效和I型错误,从而得到完全数值校准程序,完全避免蒙特卡洛误差。所得方法在可接受的中期和最终样本量上搜索,以识别满足贝叶斯功效、I型错误和有利于零假设的令人信服证据概率的目标约束的最优设计,同时最小化零假设下的期望样本量。该方法在现实II期场景中进行了说明,包括对系统性硬化症中riociguat试验的详细重新分析。总体而言,该方法将无模拟贝叶斯因子设计方法扩展到实际重要的两臂两阶段II期试验,并为贝叶斯设计校准和敏感性分析提供了透明基础。

英文摘要:

Two-arm phase II clinical trials often benefit from an interim analysis that allows early stopping for futility, but Bayesian calibration of such designs is usually based on computationally intensive Monte Carlo simulation. In this work, a simulation-free methodology is developed to obtain Bayesian optimal two-stage designs in two-arm phase II trials with binary endpoints using Bayes factors as the primary measure of evidence. Building on recent matrix-search methods for fixed-sample two-arm Bayes factor designs and earlier correction formulas for one-arm two-stage designs, the proposed approach derives exact expressions for the operating characteristics of a two-stage two-arm design with a single futility interim. Bayesian power and type-I error are obtained by correcting the corresponding fixed-sample quantities for trajectories that would have been removed by early stopping, yielding a fully numerical calibration procedure that avoids Monte Carlo error entirely. The resulting method searches over admissible interim and final sample sizes to identify the optimal design that satisfies target constraints on Bayesian power, type-I error, and the probability of compelling evidence in favour of the null hypothesis, while minimizing the expected sample size under the null hypothesis. The methodology is illustrated in realistic phase II settings, including a detailed re-analysis of the riociguat trial in systemic sclerosis. Overall, the approach extends simulation-free Bayes factor design methodology to the practically important setting of two-arm two-stage phase II trials and provides a transparent basis for Bayesian design calibration and sensitivity analysis.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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