Development of a stem-cell derived thymic cell therapy to treat patients with athymia

项目总结 无胸腺患者，或那些出生时没有胸腺的患者，完全缺乏功能T细胞；这样的患者 会在没有功能T细胞的情况下在生命的头两年内死于与 免疫缺陷。运动障碍的原因有几种，包括22q11.2缺失(即DiGeorge综合征)， 据估计，每3,000到6,000名活产儿中就有1人发生这种情况，报告显示产前出生的比例甚至更高(AS 频率为1/992)。大约0.5%-1%的患者完全缺乏T细胞，称为完全T细胞 迪乔治。这些患者都需要植入胸腺来恢复免疫系统中的T细胞，以防止死亡。 目前的治疗方法依赖于在心内直视手术期间采集儿童的初级组织，以及 这种方法不可扩展，而且受到组织稀缺性的限制。此外，供应进一步受到限制，因为有 供者和受者之间必须有最低限度的人类白细胞抗原配型，这可能有助于胸腺植入后 自身免疫力。Thymmune Treateutics，Inc.(“Thymmune”)已经开发出胸腺方面的专利见解 从多能干细胞(IPSCs)分化而来，并正在利用这一知识开发基于细胞的 针对手足徐动症患者的治疗(“THY-001”)，解决与当前 治疗方法(即组织的收集和可获得性)。Thymmune团队总共有100+ 多年的药物开发经验支持了这一努力。重要的是，我们以前的开发工作已经 研究表明，在移植后，我们的胸腺上皮祖细胞(TEP)在体内分化为胸腺 上皮细胞(TECs)，形成胸腺样组织，尽管这些移植物的组成各不相同。在这 SBIR快速通道提案，Thymmune将改进其现有协议，以可扩展的方式生产其TEP 和可重复性的方式为临床应用所必需，并建立了这种胸腺生成的潜力 肌萎缩侧索症的体内治疗。在第一阶段，我们将为TEP制定一套完整的区分协议 悬浮条件，以实现THY-001的工业放大并得出一组可使用的生物标志物 在预期将THY-001带入临床的法规要求的情况下，定义细胞产品。在第二阶段 工作中，我们将测试我们按照优化的协议开发的IPSC-TEP的体内功能 也是在第二阶段，我们将开发一种胸腺在骨骼肌中植入的方案。 移植以来目前用于动物胸腺细胞组织治疗实验的组织移植 直接进入肾被膜下，这在临床上是不可行的。该SBIR快速通道提案将 建立商业生产TEP的必要方案，确定其在体内的效力， 并建立了一种可翻译的移植方法来推进THY-001，胸腺干细胞 衍生胸腺细胞疗法治疗肌无力患者。在此工作之后，我们将测试我们的细胞产品 在大型临床前动物模型中，并准备提交IND前和IND申请。

PROJECT SUMMARY Athymic patients, or those born without a thymus, have a complete absence of functional T cells; such patients will die within the first two years of life without functional T cells from complications associated with immunodeficiency. There are several causes of athymia, including 22q11.2 deletion (i.e., DiGeorge Syndrome), which is estimated to occur in 1 in 3,000 to 6,000 live births with reports suggesting even higher prenatally (as frequent as 1 in 992). Roughly 0.5-1% of these patients have a complete lack of T cells called Complete DiGeorge. These patients all require a thymic implant to restore T cells in their immune system to prevent death. Current treatment approaches rely on harvesting primary tissue from children during open-heart procedures, an approach that is not scalable and is limited by scarcity of tissues. Moreover, supply is further limited as there must be minimal HLA matching between donor and recipient, which may contribute to post-thymus implant autoimmunity. Thymmune Therapeutics, Inc. (“Thymmune”) has developed proprietary insights in thymic differentiation from pluripotent stem cells (iPSCs) and is using this knowledge to develop a cell-based therapy (“THY-001”) for patients with athymia that addresses the key issues associated with current treatment methods (i.e., collection and availability of tissues). The Thymmune team has a collective 100+ years of drug development experience to support this effort. Importantly, our previous development work has shown that upon transplantation, our thymic epithelial progenitor cells (TEPs) differentiate in vivo into thymic epithelial cells (TECs), forming thymic like tissues, though the composition of these grafts are variable. In this SBIR Fast Track proposal, Thymmune will improve upon its existing protocol to produce its TEPs in a scalable and reproducible manner necessary for clinical applications and establish the thymopoietic potential of this therapy in vivo for the treatment of athymia. In Phase I, we will develop a differentiation protocol for TEPs in full suspension conditions to enable industrial scale-up of THY-001 and derive a set of biomarkers that can be used to define the cell product in anticipation of regulatory requirements for taking THY-001 into the clinic. In Phase II work, we will test the in vivo function of the iPSC-TEPs that we have developed following our optimized protocol developed in Phase I. Also in Phase II, we will develop a protocol for thymic engraftment in skeletal muscle transplantation since current practices for thymic cell tissue therapy experiments in animals transplant tissue directly into the subrenal capsule, which is not a clinically viable site. This SBIR Fast Track proposal will establish the necessary protocols for commercial production of TEPs, determine their efficacy in vivo, and establish a translatable method for transplantation to advance THY-001, Thymmune’s stem-cell derived thymic cell therapy to treat patients with athymia. Following this work, we will test our cell product in large pre-clinical animal model and prepare for submission of pre-IND and IND applications.