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病是一种罕见的遗传性疾病， 皮肤和粘膜的组织受影响的人出生时有开放性伤口和水泡， 随着时间的推移而复发和/或慢性化。皮肤和粘膜上皮愈合时会留下疤痕， 手指和脚趾的融合（假并指）和关节挛缩、小口畸形和食管 狭窄非皮肤并发症包括发育不良、贫血和骨质减少/骨质疏松症。过程 RDEB是持续的，存活到成年的患者有很高的风险发展为攻击性的。 可能致命的鳞状细胞癌预期寿命缩短是患者的常态 RDEB。目前还没有批准的RDEB疾病改善治疗。目前的治疗是姑息性的， 促进伤口愈合，营养支持，尽早治疗并发症。 RDEB是由COL 7A 1突变引起的，导致功能性VII型胶原缺乏或缺乏 （Col 7），在皮肤和粘膜中上皮细胞与真皮的粘附中的组成部分。 RDEB的开放性伤口的缓解可以通过功能性Col 7在RDEB中被替换来获得。 皮肤然而，只有当受影响的患者的细胞在遗传上是正常的， 纠正，并有足够数量的可再生细胞移植回伤口。本试验性1期研究将 评估一种此类方法在具有常见的RDEB患者中的安全性和有效性。 突变c.7485+5G>A。使用离体方法，患者的皮肤细胞将被遗传校正， 在一个有效的一步过程中，将其重编程为诱导多能干细胞（iPSC）。iPSC将在 分化为表达Col 7的功能性角质形成细胞和成纤维细胞。这些角质细胞和成纤维细胞 将使用由AVITA Medical开发的新型皮肤喷雾装置移植到患者体内。 本研究的主要目的是评价这种治疗方法的安全性。在处理之后， 将对患者进行为期1年的监测，以确定是否发生鳞状细胞癌或畸胎瘤。 治疗区域、免疫反应和其他不良事件。第二个目标是提供证据- 概念数据表明，使用遗传校正的iPSC衍生的角质形成细胞和成纤维细胞将发挥作用， 通常是RDEB患者慢性伤口的有效治疗方法。Col 7的表达和 评价处理后锚定原纤维的形成。此外，伤口闭合和 将研究与标准伤口护理相比的伤口闭合。我们假设这种治疗方法 安全且耐受性良好，并导致表达Col 7的组织学正常皮肤再生， 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。 影响内脏器官的其他单基因疾病的治疗，其中难以监测不良反应， 基于iPSC的治疗的效果将使它们不太可能成为第一目标。

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.