Exceptional clinical responses produced by the first chimeric antigen receptor T [CAR‐T] cell therapies, and their entry into commercial markets prompted a logarithmic increase in the number of next generation CAR‐T clinical trials. As a result, there is a growing interest in understanding the analytical approaches utilized for reliable monitoring of these “living” drugs, and the challenges encountered during their clinical development. Multiparametric flow cytometry (MFC) assays have played a crucial role in understanding the phenotype and function of first approved CAR‐T therapies. Herein, three main areas for monitoring CAR‐T therapies in clinical trials are discussed: (1) analytical considerations critical for development of MFC assays for the reliable enumeration of CAR‐T levels, (2) operational challenges associated with clinical trial sampling and transportation, and (3) differential cellular kinetics observed by MFC and qPCR analyses and their relationship with efficacy (measurable residual disease levels). Initial experiences described here may enable design of fit‐for‐purpose tools and help to more rapidly advance the development of next generation CAR‐T therapies.

中文翻译：

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通过多参数流式细胞术监测临床试验中的 CAR-T 细胞动力学：优势和挑战。

第一种嵌合抗原受体 T [CAR-T] 细胞疗法产生的异常临床反应及其进入商业市场促使下一代 CAR-T 临床试验的数量呈对数增长。因此，人们越来越有兴趣了解用于可靠监测这些“活”药物的分析方法，以及在临床开发过程中遇到的挑战。多参数流式细胞术 (MFC) 分析在了解首次批准的 CAR-T 疗法的表型和功能方面发挥了至关重要的作用。本文讨论了在临床试验中监测 CAR-T 疗法的三个主要领域：（1）对于开发 MFC 分析以可靠地计算 CAR-T 水平至关重要的分析考虑因素，(2) 与临床试验取样和运输相关的操作挑战，以及 (3) 通过 MFC 和 qPCR 分析观察到的差异细胞动力学及其与疗效的关系（可测量的残留疾病水平）。此处描述的初步经验可能有助于设计适合用途的工具，并有助于更快地推进下一代 CAR-T 疗法的开发。