For designing single-arm phase II trials with time-to-event endpoints, a sample size formula is derived for the modified one-sample log-rank test under the proportional hazards model. The derived formula enables new methods for designing trials that allow a flexible choice of the underlying survival distribution. Simulation results showed that the proposed formula provides an accurate estimation of sample size. The sample size calculation has been implemented in an R function for the purpose of trial design. Supplementary materials for this article are available online.

中文翻译：

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比例危害模型下的单臂II期生存试验设计。

为了设计具有到达事件发生时间终点的单臂II期试验，在比例风险模型下，针对修改后的单样本对数秩检验推导了样本量公式。派生的公式使设计试验的新方法成为可能，从而可以灵活选择潜在的生存分布。仿真结果表明，所提出的公式可以准确估计样本量。为了进行试验设计，已在R函数中实现了样本量计算。可在线获得本文的补充材料。