Study of the Safety, Tolerability, and Efficacy of an iPS Cell-based Therapy for Recessive Dystrophic Epidermolysis Bullosa Delivered with a Spray on Skin Device

隐性营养不良性大疱性表皮松解症(RDEB)是一种罕见的以脆性为特征的遗传性疾病 皮肤和粘膜。受影响的人出生时就有开放性伤口和水泡， 随着时间的推移变得反复和/或慢性。皮肤和粘膜上皮都会愈合，形成疤痕，导致 手指和脚趾融合(假指)和关节痉挛、小孔和食道 严苛。非皮肤并发症包括发育不良、贫血和骨量减少/骨质疏松。这一过程 RDEB是坚持不懈的，患者存活到成年后有很高的风险发展为攻击性 鳞状细胞癌可能是致命的。预期寿命缩短是患有以下疾病的患者的常态 RDEB。目前还没有得到批准的治疗RDEB的疾病修正疗法。目前的治疗方法是姑息和集中治疗。 促进伤口愈合，营养支持，及早治疗并发症。 RDEB是由COL7A1突变引起的，导致功能性VII型胶原缺失或缺失 (Col7)，是皮肤和粘膜中上皮细胞与真皮粘连的不可或缺的组成部分。 如果在RDEB的开放性伤口中更换功能性Col7，则RDEB的开放性伤口可能会得到缓解 皮肤。然而，只有当受影响患者的细胞是遗传的时，才能实现持久的缓解 修复后，有足够数量的可再生细胞重新植入伤口。这项试验性的第一阶段研究将 评估一种这样的方法在RDEB患者中的安全性和有效性 突变C.7485+5G&gt；A；使用体外方法，患者的皮肤细胞将得到基因纠正和 在高效的一步过程中重新编程为诱导多能干细胞(IPSCs)。IPSC将会是 分化为功能性角质形成细胞和表达Col7的成纤维细胞。这些角质形成细胞和成纤维细胞 将使用Avita Medical开发的一种新型皮肤喷雾设备移植到患者身上。 这项研究的主要目的是评估这种治疗方法的安全性。经过治疗， 患者将接受为期一年的监测，以确定是否有鳞状细胞癌或畸胎瘤的发展 治疗区域、免疫反应和其他不良事件。次要目标是提供以下证据： 概念数据，使用经过基因矫正的IPSC来源的角质形成细胞和成纤维细胞将发挥作用 对于RDEB患者的慢性创面是一种有效的治疗方法。COL7和COL7基因的表达 将评估治疗后锚定纤维的形成情况。此外，伤口的闭合和耐久性 将研究伤口闭合与标准伤口护理的比较。我们假设这种治疗将是 安全和耐受性良好，并导致组织学上正常的皮肤再生，表达Col7 容易再次受伤。如果成功，这项工作将为基于IPSC的开发奠定基础 对影响内脏的其他单基因疾病的治疗，在这些疾病中，监测的困难是不利的 基于ipsc的疗法的效果将使他们不太可能成为第一个目标。

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genetic disorder characterized by fragility of the skin and mucous membranes. Affected individuals are born with open wounds and blisters which become recurrent and/or chronic over time. Both the skin and mucosal epithelia heal with scarring, causing fusion of the fingers and toes (pseudosyndactyly) and joint contractures, microstomia, and esophageal strictures. Non-skin complications include failure to thrive, anemia, and osteopenia/osteoporosis. The course of RDEB is unremitting, and patients surviving into adulthood have a high risk of developing aggressive squamous cell carcinomas that can be fatal. Shortened life-expectancy is the norm for patients with RDEB. There is no approved disease-modifying treatment for RDEB. Current therapies are palliative and focus on promoting wound healing, nutritional support, and treating complications as early as possible. RDEB is caused by mutations in COL7A1, leading to absence or deficiency of functional collagen VII (Col7), an integral component in the adhesion of epithelia to dermis in the skin and mucous membranes. Remission from the open wounds of RDEB could be obtained if functional Col7 is replaced in the skin. However, a durable remission can only be attained if an affected patient’s cells are genetically corrected, and a sufficient number of renewable cells engraft back into wounds. This pilot, phase 1 study will evaluate the safety and efficacy of one such approach in patients with RDEB who have the common mutation c.7485+5G>A. Using an ex vivo approach, the patient’s skin cells will be genetically corrected and reprogrammed into induced pluripotent stem cells (iPSCs) in an efficient one step process. The iPSCs will be differentiated into functional keratinocytes and fibroblasts expressing Col7. These keratinocytes and fibroblasts will be transplanted to the patient using a novel Spray-on-Skin device developed by AVITA Medical. The primary objective of this study is to evaluate the safety of this treatment approach. After treatment, patients will be monitored for 1 year for the development of squamous cell carcinoma or teratomas within the treated areas, immune reactions, and other adverse events. The secondary objectives are to provide proof-of- concept data that the use of genetically corrected iPSC-derived keratinocytes and fibroblasts will function normally and are an effective treatment for chronic wounds in patients with RDEB. The expression of Col7 and formation of anchoring fibrils after treatment will be evaluated. In addition, wound closure and the durability of wound closure compared to standard wound care will be studied. We hypothesize that this treatment will be safe and well-tolerated and lead to the regeneration of histologically normal skin expressing Col7 that is not prone to re-wounding. If successful, this work will lay the foundation for the development of iPSC-based therapies for other monogenic diseases affecting internal organs, where the difficulty in monitoring adverse effects of an iPSC-based therapy would make them unlikely first targets.