Zscharnack Matthias, Krause Christoph, Aust Gabriela, Thümmler Christian, Peinemann Frank, Keller Thomas, Smink Jeske J, Holland Heidrun, Somerson Jeremy S, Knauer Jens, Schulz Ronny M, Lehmann Jörg
Translational Centre for Regenerative Medicine (TRM), University of Leipzig, Leipzig, Germany.
Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany.
J Transl Med. 2015 May 20;13:160. doi: 10.1186/s12967-015-0517-x.
The clinical development of advanced therapy medicinal products (ATMPs), a new class of drugs, requires initial safety studies that deviate from standard non-clinical safety protocols. The study provides a strategy to address the safety aspects of biodistribution and tumorigenicity of ATMPs under good laboratory practice (GLP) conditions avoiding cell product manipulation. Moreover, the strategy was applied on a human ATMP for cartilage repair.
The testing strategy addresses biodistribution and tumorigenicity using a multi-step analysis without any cell manipulation to exclude changes of test item characteristics. As a safeguard measurement for meeting regulatory expectations, the project design and goals were discussed continuously with the regulatory authority using a staggered scientific advice concept. Subsequently, the strategy was applied to co.don chondrosphere® (huChon spheroid), a tissue-engineered matrix-free ATMP of human normal chondrocytes. In both the biodistribution and tumorigenicity studies, huChon spheroids were implanted subcutaneously into 40 immunodeficient mice. Biodistribution was studied 1 month after implantation. A skin disc containing the huChon spheroid, two surrounding skin rings and selected organs were analyzed by validated, gender-specific, highly-sensitive triplex qPCR and by immunohistochemistry (IHC).
No human DNA was detected in distant skin rings and analyzed organs. IHC revealed no direct or indirect indications of cell migration. Tumorigenicity was assessed 6 months after huChon spheroid implantation by palpation, macroscopic inspection, histology and IHC. No mice from the huChon spheroid group developed a tumor at the implantation site. In two mice, benign tumors were detected that were negative for HLA-ABC, suggesting that they were of spontaneous murine origin.
In summary, the presented strategy using a multi-step analysis was confirmed to be suitable for safety studies of ATMPs.
先进治疗药物产品（ATMPs）作为一类新型药物，其临床开发需要开展偏离标准非临床安全方案的初始安全性研究。本研究提供了一种策略，可在良好实验室规范（GLP）条件下，避免对细胞产品进行操作，来解决ATMPs生物分布和致瘤性的安全问题。此外，该策略已应用于一种用于软骨修复的人源ATMP。
该测试策略采用多步骤分析来解决生物分布和致瘤性问题，无需对细胞进行任何操作，以排除测试项目特性的变化。作为满足监管期望的保障措施，项目设计和目标通过交错式科学建议概念与监管机构持续进行讨论。随后，该策略应用于co.don chondrosphere®（huChon spheroid），这是一种由人正常软骨细胞构建的无组织工程基质的ATMP。在生物分布和致瘤性研究中，将huChon spheroids皮下植入40只免疫缺陷小鼠体内。植入1个月后研究生物分布情况。通过经过验证的、针对不同性别的高灵敏度三重定量聚合酶链反应（qPCR）和免疫组织化学（IHC）分析含有huChon spheroid的皮肤圆盘、两个周围皮肤环和选定器官。
在远处皮肤环和分析的器官中未检测到人类DNA。免疫组织化学未显示细胞迁移的直接或间接迹象。在huChon spheroid植入6个月后，通过触诊、宏观检查、组织学和免疫组织化学评估致瘤性。huChon spheroid组的小鼠在植入部位均未发生肿瘤。在两只小鼠中检测到良性肿瘤，这些肿瘤的人类白细胞抗原ABC（HLA-ABC）呈阴性，表明它们起源于自发性小鼠肿瘤。
总之，所提出的采用多步骤分析的策略被证实适用于ATMPs的安全性研究。
