得到深刻的一些常见问题的答案IND-enabling studies for cell and gene therapies (CGTs) from a recent Covance presentation. For more information on Covance solutions, visit our Cell & Gene Therapy Education Centerhere.
Introduction
An estimated362 CGTswere in clinical development in the US in early 2020, targeting over 100 diseases. Translating a lab-based innovation into an effective therapy can be challenging; thus having a robust preclinical study program to advance a therapeutic candidate into clinical trials is vital. Read on to get some answers to common questions related to Investigational New Drug (IND)-enabling CGT studies.
1.罐头模型是否可以在体内设计？
在Vivo模型选择中是CGT Ind-use-Lib的关键考虑，我们经常收到有关的问题。当可能时，Covance通常推荐一种混合方法，其使用健康和疾病模型，选择各种因素所规定的物种;最值得注意的是CGT的性质和适用于体内模型的可用性。可以使用犬型模型，并且它们可能更适合再生产品而不是基于病毒的疗法。在考虑基于病毒的产品时，NHP免疫系统可以以与人类免疫系统类似的方式进行响应，并且可能比犬模型更好地存在人蛋白的存在。值得注意的是，其中一项美国销售的基因疗法使用了犬模型，因为存在具有认可的相关犬模型。关于体内模型选择的最终决定是由治疗性候选人所知的。
2. What NHP immunosuppression protocols do you recommend for AAV vector-based products?
A challenge in using NHPs is that they may have been exposed to a variety of other pathogens (e.g. viruses, parasites, etc.) before entering a study. That’s why, even before getting into recommendations about the immunosuppression protocol, we take great care to source ’clean’ animals and ensure we have insight into their viral status. In addition, we reduce the risk of pathogen exposure through irradiation of their food and other procedures. For AAV vector-based products, we often treat with immunosuppressants such as prednisone/prednisolone prior to dosing with the aim of “knocking down” the immune system. We would not knock it out completely, as having some underlying inflammatory activity helps to control for any harbored viruses (e.g. CMV, etc.). In some cases, we’ve also make use of immunosuppressants such as rapamycin, mycophenolate mofetil, or cyclosporin A (alone, or in combination) to ensure appropriate suppression.
3.What safety assessments are needed for explanted primary progenitor cells to ensure that all in vitro transfection virus is removed before implantation?
The focus of the requirement here is around assessment of viral load. The simplest approach would be a PCR assay of the cell and/or supernatant over time, or even an infectivity assay.
4.您在NHP中包含CNS交付疗法的哪种类型的安全药理学评估？
There are a host of physiology, neurological and behavioral assessments we make on NHPs receiving CNS-delivered therapies. Jacket telemetry provides good basic physiological and CNS data, including autonomic tone information. From a neurological perspective, we examine induced reflexes (e.g. toe pinch, patellar reflex, pupillary response, menace reflex, etc.) and can assess nerve conduction velocity using evoked potentials. We also conduct in-cage behavioral assessments of general movement and activity and observations such as changes in limb use or favoring of one limb over another.
5.一种方法 - 例如活检或成像生物标志物 - 可用于在临床上和临床上展示治疗的维持？yaboapp体育官网
yaboapp体育官网尿动过程中，细胞疗法测定所需的组织量通常大于通过活组织检查可获得的组织，从而可能限制其用于评估细胞疗法的维持。然而，对于系统性基因疗法，特别是对于靶向肝脏的那些，常规活组织检查是可能的。作为活组织检查的替代，对于一些临床前细胞生物分布和小动物的归巢研究，可以用生yaboapp体育官网物发光标记标记感兴趣的细胞，并用于体内成像以评估细胞分布。其他有用的成像模式包括超声波，其可以评估潜在的致瘤性，以及Dexa扫描，它提供有关肌肉质量和骨密度密度的信息。这两种后一种分析技术都可以在临床前和临床环境中使用。yaboapp体育官网
6. Do all cell therapies (CAR-Ts, eTCRs, NKs and TILs) require in vivo biodistribution studies?
是 - 生物分布研究是所有细胞（和基因）疗法的Ind-Us-Use-Use-Usibets的原则之一。生物分布研究提供了对施用细胞在体内分布的位置的详细了解，并且可能其状态（例如，分化细胞，肿瘤形成等）。这些动态对于确认施用的细胞药物被正确维护，如果被拒绝，持久性延长，持久性水平，以及评估如果细胞衰落会发生什么。
7. Is the frozen tissue microarray for CAR-T therapies run with the CAR-Ts themselves or with a purified scFv?
Frozen tissue microarrays are generally run with antibody fragments, although they can be run with T-cells themselves, but antibody fragments are the most appropriate approach. Using the purified fragment provides high throughput analysis of cross-reactivity to non-target tissues which is important for assessing off-target binding. The same antibody fragments, or the external antibody domain, can then be used subsequently for microscopic analysis of tissue sample slides.
