A scalable and cGMP-compatible autologous organotypic cell therapy for Dystrophic Epidermolysis Bullosa.

We present Dystrophic Epidermolysis Bullosa Cell Therapy (DEBCT), a scalable platform producing autologous organotypic iPS cell-derived induced skin composite (iSC) grafts for definitive treatment. Clinical-grade manufacturing integrates CRISPR-mediated genetic correction with reprogramming into one step, accelerating derivation of COL7A1-edited iPS cells from patients. Differentiation into epidermal, dermal and melanocyte progenitors is followed by CD49f-enrichment, minimizing maturation heterogeneity. Mouse xenografting of iSCs from four patients with different mutations demonstrates disease modifying activity at 1 month. Next-generation sequencing, biodistribution and tumorigenicity assays establish a favorable safety profile at 1-9 months. Single cell transcriptomics reveals that iSCs are composed of the major skin cell lineages and include prominent holoclone stem cell-like signatures of keratinocytes, and the recently described Gibbin-dependent signature of fibroblasts. The latter correlates with enhanced graftability of iSCs. In conclusion, DEBCT overcomes manufacturing and safety roadblocks and establishes a reproducible, safe, and cGMP-compatible therapeutic approach to heal lesions of DEB patients.

Histological and molecular restoration of type VII collagen in Recessive dystrophic epidermolysis bullosa mouse skin by topical injection of keratinocyte-like cells differentiated from human adipose-derived mesenchymal stromal cells.

BACKGROUND: Recessive dystrophic epidermolysis bullosa (RDEB) is a severe skin fragility disorder caused by mutations in the COL7A1 gene, which encodes type VII collagen (COL7), the main constituent of anchoring fibrils for attaching the epidermis to the dermis. Persistent skin erosions frequently result in intractable ulcers in RDEB patients. Adipose-derived mesenchymal stromal cells (AD-MSCs) are easily harvested in large quantities and have low immunogenicity. Therefore, they are suitable for clinical use, including applications involving allogeneic cell transplantation. Keratinocyte-like cells transdifferentiated from AD-MSCs (KC-AD-MSCs) express more COL7 than undifferentiated AD-MSCs and facilitate skin wound healing with less contracture. Therefore, these cells can be used for skin ulcer treatment in RDEB patients. OBJECTIVE: We investigated whether KC-AD-MSCs transplantation ameliorated the RDEB phenotype severity in the grafted skin of a RDEB mouse model (col7a1-null) on the back of the immunodeficient mouse. METHODS: KC-AD-MSCs were intradermally injected into the region surrounding the skin grafts, and this procedure was repeated after 7 days. After a further 7-day interval, the skin grafts were harvested. RESULTS: Neodeposition of COL7 and generation of anchoring fibrils at the dermal-epidermal junction were observed, although experiments were based on qualitative. CONCLUSION: KC-AD-MSCs may correct the COL7 insufficiency, repair defective/reduced anchoring fibrils, and improve skin integrity in RDEB patients.

Unravelling drivers of cutaneous squamous cell carcinoma in recessive dystrophic epidermolysis bullosa.

Epidermolysis bullosa (EB) is an umbrella term for a group of rare inherited skin disorders characterised by mucocutaneous fragility. Patients suffer from blisters and chronic wounds that arise spontaneously or following minor mechanical trauma, often resulting in inflammation, scarring and fibrosis due to poor healing. The recessive form of dystrophic EB (RDEB) has a particularly severe phenotype and is caused by mutations in the COL7A1 gene, encoding the collagen VII protein, which is responsible for adhering the epidermis and dermis together. One of the most feared and devastating complications of RDEB is the development of an aggressive form of cutaneous squamous cell carcinoma (cSCC), which is the main cause of mortality in this patient group. However, pathological drivers behind the development and progression of RDEB-associated cSCC (RDEB-cSCC) remain somewhat of an enigma, and the evidence to date points towards a complex process. Currently, there is no cure for RDEB-cSCC, and treatments primarily focus on prevention, symptom management and support. Therefore, there is an urgent need for a comprehensive understanding of this cancer's pathogenesis, with the aim of facilitating the discovery of drug targets. This review explores the current knowledge of RDEB-cSCC, emphasising the important role of the immune system, genetics, fibrosis, and the tumour-promoting microenvironment, all ultimately intricately interconnected.

Creation and characterization of novel rat model for recessive dystrophic epidermolysis bullosa: Frameshift mutation of the Col7a1 gene leads to severe blistered phenotype.

Recessive dystrophic epidermolysis bullosa is a rare genodermatosis caused by a mutation of the Col7a1 gene. The Col7a1 gene codes for collagen type VII protein, a major component of anchoring fibrils. Mutations of the Col7a1 gene can cause aberrant collagen type VII formation, causing an associated lack or absence of anchoring fibrils. This presents clinically as chronic blistering, scarring, and fibrosis, often leading to the development of cutaneous squamous cell carcinoma. Patients also experience persistent pain and pruritus. Pain management and supportive bandaging remain the primary treatment options. The pathology of recessive dystrophic epidermolysis bullosa was first described in the 1980s, and there has since been a multitude of encouraging treatment options developed. However, in vivo research has been hindered by inadequate models of the disease. The various mouse models in existence possess longevity and surface area constraints, or do not adequately model a normal human disease state. In this paper, we describe a novel rat model of recessive dystrophic epidermolysis bullosa that offers an alternative to previous murine models. An 8-base pair deletion was induced in the Col7a1 gene of Lewis rats, which was subsequently found to cause a premature stop codon downstream. Homozygous mutants presented with a fragile and chronically blistered phenotype postnatally. Further histological analysis revealed subepidermal clefting and the absence of anchoring fibrils. The generation of this novel model offers researchers an easily maintained organism that possesses a larger surface area for experimental topical and transfused therapies to be tested, which may provide great utility in the future study of this debilitating disease.

Practical considerations relevant to treatment with the gene therapy beremagene geperpavec-svdt for dystrophic epidermolysis bullosa.

BACKGROUND/PURPOSE: Dystrophic epidermolysis bullosa (DEB), a rare genetic skin disease caused by loss-of-function mutations in COL7A1, the gene encoding type VII collagen (COL7), is characterized by skin blistering, scarring, and extracutaneous manifestations that markedly reduce patient quality-of-life. Beremagene geperpavec-svdt ('B-VEC') is a gene therapy employing a non-integrating, replication-defective herpes simplex virus type 1 (HSV-1)-based vector encoding two copies of full-length human COL7A1 to restore COL7 protein after topical administration to DEB wounds. B-VEC was approved in the United States in 2023 as the first topical gene therapy and the first approved treatment for DEB. However, few providers have experience with use of this gene therapy. METHODS: Data was obtained through literature review and the experience of providers who participated in the B-VEC clinical study or initiated treatment after B-VEC approval. RESULTS: This review discusses the burden of disease, describes the clinical trial outcomes of B-VEC, and provides physician and patient/caregiver recommendations as a practical guide for the real-world use of B-VEC, which can be administered in-office or at the patient's home. CONCLUSIONS: By continuing to optimize the practical aspects of B-VEC administration, the focus will continue to shift to patient-centric considerations and improved patient outcomes.

Epidermolysis Bullosa: Two rare case reports of COL7A1 and EBS-GEN SEV KRT14 variants with review of literature.

EPIDERMOLYSIS: Bullosa is a rare hereditary skin condition that causes blisters. Genes encoding structural proteins at or near the dermal-epidermal junction are mutated recessively or dominantly, and this is the primary cause of EB. Herein, two Chinese boys were diagnosed with the condition, each with a different variant in a gene that serves as a reference for EB genetic counseling. Skincare significantly impacted their prognosis and quality of life. CASE PRESENTATION: Two Chinese boys, with phenotypically normal parents, have been diagnosed with distinct blister symptoms, one with Dominant Dystrophic Epidermolysis Bullosa and the other with a severe form of Epidermolysis Bullosa Simplex. The first patient had a G-to-A variant in the COL7A1 allele, at nucleotide position 6163 which was named "G2055A". The proband is heterozygous for Dystrophic Epidermolysis Bullosa due to a COL7A1 allele with a glycine substitution at the triple helix domain. A similar variant has been discovered in his mother, indicating its potential transmission to future generations. Another patient had severe Epidermolysis Bullosa Simplex with a rare c.377T > A  variant resulting in substitution of amino acid p.Leu126Arg (NM_000526.5 (c.377T > G, p.Leu126Arg) in the Keratin 14 gene. In prior literature, Keratin 14 has been associated with an excellent prognosis. However, our patient with this infrequent variant tragically died from sepsis at 21 days old. There has been a reported occurrence of the variant only once. CONCLUSION: Our study reveals that Epidermolysis Bullosa patients with COL7A1 c.6163G > A and KRT14 c.377T>A variants have different clinical presentations, with dominant forms of Dystrophic EB having milder phenotypes than recessive ones. Thus, the better prognosis in the c.6163G > A patient. Furthermore, c.377T>A patient was more prone to infection than the patient with c.6163G>A gene variant. Genetic testing is crucial for identifying the specific variant responsible and improving treatment options.

Dominant dystrophic epidermolysis bullosa is associated with glycolytically active GATA3+ T helper 2 cells which may contribute to pruritus in lesional skin.

BACKGROUND: Dominant dystrophic epidermolysis bullosa (DDEB) is characterized by trauma-induced blisters and, in some individuals, intense pruritus. Precisely what causes itch in DDEB and optimal ways to reduce it have not been fully determined. OBJECTIVES: To characterize DDEB skin transcriptomes to identify therapeutic targets to reduce pruritus in patients. METHODS: Using bulk RNA sequencing, we evaluated affected and unaffected skin biopsy samples from six patients with DDEB (all with the very itchy pruriginosa subtype) and four healthy individuals. Single-cell transcriptomes of affected (n = 2) and unaffected (n = 1) DDEB skin and healthy skin (n = 2) were obtained. Dupilumab treatment was provided for three patients. RESULTS: The skin bulk transcriptome showed significant enrichment of T helper (Th)1/2 and Th17 pathways in affected DDEB skin compared with nonlesional DDEB skin and healthy skin. Single-cell transcriptomics showed an association of glycolytically active GATA3+ Th2 cells in affected DDEB skin. Treatment with dupilumab in three people with DDEB led to significantly reduced visual analogue scale (VAS) itch scores after 12 weeks (mean VAS 3.83) compared with pretreatment (mean VAS 7.83). Bulk RNAseq and quantitative polymerase chain reaction showed that healthy skin and dupilumab-treated epidermolysis bullosa (EB) pruriginosa skin have similar transcriptomic profiles and reduced Th1/Th2 and Th17 pathway enrichment. CONCLUSIONS: Single-cell RNAseq helps define an enhanced DDEB-associated Th2 profile and rationalizes drug repurposing of anti-Th2 drugs in treating DDEB pruritus.

Dominant dystrophic epidermolysis bullosa (DDEB) is a rare inherited skin disease that causes fragile skin that blisters easily, often triggered by minor injuries. These blisters are accompanied by intense itching, which can be distressing. The underlying cause of DDEB lies in genetic mutations in a gene called COL7A1. This gene encodes 'type VII collagen', a protein crucial for attaching the outer skin layer (epidermis) to the layer beneath (dermis). Although the genetic basis of DDEB is understood, the causes of itch are not known. As well as this, effective treatments for DDEB are lacking, which has driven scientists to explore innovative approaches like repurposing existing drugs. Drug repurposing involves using medications that have already been approved for other health conditions. One such drug is dupilumab, which is used for severe atopic dermatitis (eczema). Dupilumab targets immune cells called Th2 cells, which play a role in inflammation and allergies. While dupilumab has shown promise in relieving DDEB itching, the way it works in this condition is unclear. This study, carried out by a group of researchers in Taiwan, looked at gene expression in DDEB-affected and unaffected skin, and compared it to gene expression in healthy skin samples. We found heightened activity in Th2 immune cells and abnormal gene signals related to itching, similar to atopic dermatitis. These findings support using dupilumab and other anti-inflammatory drugs to alleviate itching in DDEB. Clinical trials will be crucial to evaluate the effectiveness of these drugs for managing DDEB symptoms. This research opens doors for enhanced treatment options and improving the quality of life of people living with DDEB.

Methods for Decreasing Preweaning Mortality in a Fragile Mouse Model of Hypomorphic Collagen VII Deficiency.

Preweaning mortality is a widespread problem in laboratory mouse breeding, particularly in the case of fragile mouse models. While numerous studies explore alternative care methods to increase the survivability of common mouse strains, there remains a paucity of research into the care of mice with fragile health conditions that result from induced or natural genetic mutations. In this study, standard husbandry practices were enhanced by the addition of a softened diet, a nutritionally fortified dietary supplement, soft bedding, gentle handling techniques, decreased handling, lengthened weaning age, and dam productivity tracking. This alternative care plan was shown to increase the survival of a fragile recessive dystrophic epidermolysis bullosa mouse model, and some aspects could be used in developing a care plan for other fragile mouse strains.

Intravenous gentamicin therapy induces functional type VII collagen in patients with recessive dystrophic epidermolysis bullosa: an open-label clinical trial.

BACKGROUND: Recessive dystrophic epidermolysis bullosa (RDEB) is an incurable widespread blistering skin disorder caused by mutations in the gene encoding for type VII collagen (C7), the major component of anchoring fibrils. OBJECTIVES: To evaluate the efficacy and safety of intravenous (IV) gentamicin readthrough therapy in patients with RDEB harbouring nonsense mutations. The primary outcomes were increased expression of C7 in patients' skin and safety assessments (ototoxicity, nephrotoxicity, autoimmune response); secondary outcomes included measuring wound healing in target wounds and assessment by a validated Epidermolysis Bullosa Disease Activity and Scarring Index (EBDASI) scoring system. METHODS: An open-label pilot trial to assess two different IV gentamicin regimens between August 2018 and March 2020 with follow-up through to 180 days post-treatment was carried out. Three patients with RDEB with confirmed nonsense mutations in COL7A1 in either one or two alleles and decreased baseline expression of C7 at the dermal-epidermal junction (DEJ) of their skin participated in the study. Three patients received gentamicin 7.5 mg kg-1 daily for 14 days and two of the three patients further received 7.5 mg kg-1 IV gentamicin twice weekly for 12 weeks. Patients who had pre-existing auditory or renal impairment, were currently using ototoxic or nephrotoxic medications, or had allergies to aminoglycosides or sulfate compounds were excluded. RESULTS: After gentamicin treatment, skin biopsies from all three patients (age range 18-28 years) exhibited increased C7 in their DEJ. With both regimens, the new C7 persisted for at least 6 months post-treatment. At 1 and 3 months post-treatment, 100% of the monitored wounds exhibited > 85% closure. Both IV gentamicin infusion regimens decreased EBDASI total activity scores. Of the patients assessed with the EBDASI, all exhibited decreased total activity scores 3 months post-treatment. All three patients completed the study; no adverse effects or anti-C7 antibodies were detected. CONCLUSIONS: IV gentamicin induced the readthrough of nonsense mutations in patients with RDEB and restored functional C7 in their skin, enhanced wound healing and improved clinical parameters. IV gentamicin may be a safe, efficacious, low-cost and readily available treatment for this population of patients with RDEB.

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare and life-threatening inherited skin disease that causes widespread skin blisters that heal with scarring. RDEB affects around 1 in every 100,000 individuals globally. The condition is caused by a mutation in the gene coding for type VII collagen (C7), resulting in a deficiency of C7. C7 is a vital component of the skin as it is responsible for holding the skin's upper two layers together. To date, there are no approved systemic treatments that can cure RDEB. This study, from the United States, aimed to evaluate the effectiveness and safety of intravenous (medicine delivered directly into a patient's vein) gentamicin (an antibiotic) for people with RDEB who have nonsense mutations in their genes (a type of mutation that prevents the production of complete proteins by introducing an inappropriate 'stop signal'). We gave gentamicin to three patients with RDEB every day for 14 days, and two of the three patients further received intravenous gentamicin twice a week for 12 weeks. After gentamicin treatment, all three patients showed increased expression of C7. With both regimens, the new C7 stayed for at least 6 months after the treatment. At 1 and 3 months after treatment, 100% of the wounds being monitored in the patients had closed by more than 85%. All three patients completed the study, and no side-effects were experienced. In conclusion, intravenous gentamicin increased the production of C7 and improved wound healing and quality of life in patients with RDEB carrying nonsense mutations. Intravenous gentamicin may offer a safe, effective, low-cost and readily available therapy in patients with RDEB.

Self-improving dystrophic epidermolysis bullosa with a novel heterozygous missense variant in the COL7A1 gene in a Taiwanese family.

Self-improving dystrophic epidermolysis bullosa (DEB) is a genodermatosis that is inherited autosomal dominantly or recessively, and its clinical symptoms may improve or subside spontaneously. Herein, we report a case of self-improving DEB with COL7A1 p.Gly2025Asp variant. The diagnosis was made through histopathological, electron microscopic examination, and genetic testing. The same variant is also noted on his father, who presents with dystrophic toenails without any blisters. This study highlights that idiopathic nail dystrophy could be linked to congenital or hereditary disease. Furthermore, we conducted a review of the literature on the characteristics of reported cases of self-improving DEB with a personal or family history of nail dystrophy. The results supported our findings that nail dystrophy may be the sole manifestation in some family members. We suggest that individuals suffering from idiopathic nail dystrophy may seek genetic counselling when planning pregnancy to early evaluate the potential risk of hereditary diseases.

Ocular Gene Therapy in a Patient with Dystrophic Epidermolysis Bullosa.

Dystrophic epidermolysis bullosa is a rare genetic disease caused by damaging variants in COL7A1, which encodes type VII collagen. Blistering and scarring of the ocular surface develop, potentially leading to blindness. Beremagene geperpavec (B-VEC) is a replication-deficient herpes simplex virus type 1-based gene therapy engineered to deliver functional human type VII collagen. Here, we report the case of a patient with cicatrizing conjunctivitis in both eyes caused by dystrophic epidermolysis bullosa who received ophthalmic administration of B-VEC, which was associated with improved visual acuity after surgery.

Patients suffering from dystrophic epidermolysis bullosa are prone to developing autoantibodies against skin proteins: A longitudinal confirmational study.

Epidermolysis bullosa (EB) is a heritable skin blistering disease caused by variants in genes coding for proteins that secure cell-cell adhesion and attachment of the epidermis to the dermis. Interestingly, several proteins involved in inherited EB are also associated with autoimmune blistering diseases (AIBD). In this study, we present a long-term follow-up of 15 patients suffering from recessive dystrophic or junctional EB. From these patients, 62 sera were analysed for the presence of autoantibodies associated with AIBD. We show that patients suffering from recessive dystrophic EB (RDEB) are more susceptible to developing autoantibodies against skin proteins than patients suffering from junctional EB (70% vs. 20%, respectively). Interestingly, no correlation with age was observed. Most patients showed reactivity to Type XVII collagen/linear IgA bullous dermatosis autoantigen (n = 5; 33%), followed by BP230 (n = 4; 27%), Type VII collagen (n = 4; 27%) and laminin-332 (n = 1; 7%). The pathogenicity of these autoantibodies remains a subject for future experiments.

Gamma-Secretase Inhibitors Downregulate the Profibrotic NOTCH Signaling Pathway in Recessive Dystrophic Epidermolysis Bullosa.

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare skin fragility disorder caused by mutations in COL7A1. RDEB is hallmarked by trauma-induced unremitting blistering, chronic wounds with inflammation, and progressive fibrosis, leading to severe disease complications. There is currently no cure for RDEB-associated fibrosis. Our previous studies and increasing evidence highlighted the profibrotic role of NOTCH pathway in different skin disorders, including RDEB. In this study, we further investigated the role of NOTCH signaling in RDEB pathogenesis and explored the effects of its inhibition by γ-secretase inhibitors DAPT and PF-03084014 (nirogacestat). Our analyses demonstrated that JAG1 and cleaved NOTCH1 are upregulated in primary RDEB fibroblasts (ie, RDEB-derived fibroblasts) compared with controls, and their protein levels are further increased by TGF-ß1 stimulation. Functional assays unveiled the involvement of JAG1/NOTCH1 axis in RDEB fibrosis and demonstrated that its blockade counteracts a variety of fibrotic traits. In particular, RDEB-derived fibroblasts treated with PF-03084014 showed (i) a significant reduction of contractility, (ii) a diminished secretion of TGF-ß1 and collagens, and (iii) the downregulation of several fibrotic proteins. Although less marked than PF-03084014-treated cells, RDEB-derived fibroblasts exhibited a reduction of fibrotic traits also upon DAPT treatment. This study provides potential therapeutic strategies to antagonize RDEB fibrosis onset and progression.

Accelerated Aging and Microsatellite Instability in Recessive Dystrophic Epidermolysis Bullosa-Associated Cutaneous Squamous Cell Carcinoma.

Recessive dystrophic epidermolysis bullosa (RDEB) is a severely debilitating disorder caused by pathogenic variants in COL7A1 and is characterized by extreme skin fragility, chronic inflammation, and fibrosis. A majority of patients with RDEB develop squamous cell carcinoma, a highly aggressive skin cancer with limited treatment options currently available. In this study, we utilized an approach leveraging whole-genome sequencing and RNA sequencing across 3 different tissues in a single patient with RDEB to gain insight into possible mechanisms of RDEB-associated squamous cell carcinoma progression and to identify potential therapeutic options. As a result, we identified PLK-1 as a possible candidate for targeted therapy and discovered microsatellite instability and accelerated aging as factors potentially contributing to the aggressive nature and early onset of RDEB squamous cell carcinoma. By integrating multitissue genomic and transcriptomic analyses in a single patient, we demonstrate the promise of bridging the gap between genomic research and clinical applications for developing tailored therapies for patients with rare genetic disorders such as RDEB.

Estimated Spending on Beremagene Geperpavec for Dystrophic Epidermolysis Bullosa.

Importance: New gene therapies can offer substantial benefits to patients, particularly those with rare diseases who have few therapeutic options. In May 2023, the US Food and Drug Administration (FDA) approved the first topical gene therapy, beremagene geperpavec (B-VEC), for treating both autosomal recessive and autosomal dominant dystrophic epidermolysis bullosa (DEB). However, FDA approval was based on limited data in patients with autosomal dominant disease, even though they comprise approximately 50% of all DEB cases. Objective: To estimate projected spending in the US on B-VEC therapy for treating autosomal recessive and autosomal dominant DEB. Design, Setting, and Participants: This economic evaluation used data from the National Epidermolysis Bullosa Registry to estimate the current population of US patients with autosomal dominant and autosomal recessive DEB, with the aim of estimating US spending on B-VEC therapy from an all-payers perspective during 1- and 3-year periods after FDA approval. A base-case cost of $300 000 per patient per year was assumed based on a report from the manufacturer (Krystal Biotech). Exposure: Treatment with B-VEC. Main Outcomes and Measures: Estimated overall spending on B-VEC in the first year and over a 3-year period after FDA approval. Several prespecified sensitivity analyses with different assumptions about the eligible patient population and the cost of therapy were performed, and lifetime total costs of treatment per patient were estimated. Results: The estimated number of US patients with DEB who were eligible for treatment with B-VEC in the first year after FDA approval was 894. The estimated total expenditure for B-VEC therapy was $268 million (range, $179 million-$357 million). Over a 3-year period, estimated spending was $805 million (range, $537 million-$1.1 billion). Estimated lifetime total costs per patient were $15 million (range, $10 million-$20 million) per patient with autosomal recessive DEB and $17 million (range, $11 million-$22 million) for patients with autosomal dominant DEB. Conclusions and Relevance: Results of this economic evaluation suggest that the FDA's broad indication for the use of B-VEC in treating both autosomal recessive and autosomal dominant DEB will have significant implications for payers.

Induced pluripotent stem cell (iPSC) line MLi005-A derived from a patient with dominant dystrophic epidermolysis bullosa (DDEB).

We have generated MLi005-A, a new induced pluripotent stem cell (iPSC) line derived from skin fibroblasts of a male patient with dominant dystrophic epidermolysis bullosa (DDEB). This iPSC line may be used as a model system for studies on skin integrity, the extracellular matrix and skin barrier function. The characterization of the MLi005-A cell line consisted of molecular karyotyping, next-generation sequencing of the COL7A1 alleles, pluripotency and differentiation potentials testing by immunofluorescence of associated markers in vitro. The MLi-005A line has been also tested for ability to differentiate into fibroblasts and keratinocytes and markers associated with these cell types.