Diacerein 1% Ointment for the Treatment of Epidermolysis Bullosa Simplex: A Randomized, Controlled Trial.

BACKGROUND: In epidermolysis bullosa simplex (EBS), epithelial structural fragility results in blisters and erosions. Diacerein 1% ointment has been shown to reduce this blistering. OBJECTIVE: To evaluate the efficacy and safety of diacerein 1% ointment in the treatment of EBS. METHODS: A double-blind study of 54 patients with EBS were randomized to diacerein 1% or vehicle ointment once daily. The primary endpoint ( ≥60% reduction in body surface area of EBS) and the key secondary endpoint ( ≥2-point reduction in the Investigator’s Global Assessment) were evaluated at 8 weeks. RESULTS: There was no difference in the proportion of patients achieving either key efficacy endpoint between the diacerein 1% and vehicle groups (P>0.05). No difference in treatment emergent adverse events were noted between the groups. In post hoc analysis stratified by EBS subtypes, an IGA score of 0 or 1 was reported in 6 of 13 patients with severe EBS in the diacerein group (46.2%), compared with 2 of 13 patients with severe EBS in the vehicle group (15.4%); (relative risk= 3.08, 95% CI = 0.71, 13.4). CONCLUSIONS: Although there was no significant difference in outcomes between the groups, further study may elucidate the effects of diacerein on EBS lesions, especially in patients with severe EBS. Teng J, Paller AS, Bruckner AL, et al. Diacerein 1% ointment for the treatment of epidermolysis bullosa simplex: a randomized, controlled trial. J Drugs Dermatol. 2023;22(6):599-604. doi:10.36849/JDD.7108.

Evaluation of Systemic Gentamicin as Translational Readthrough Therapy for a Patient With Epidermolysis Bullosa Simplex With Muscular Dystrophy Owing to PLEC1 Pathogenic Nonsense Variants.

IMPORTANCE: Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD) is an autosomal recessive disorder caused by pathogenic variants in PLEC1, which encodes plectin. It is characterized by mild mucocutaneous fragility and blistering and muscle weakness. Translational readthrough-inducing drugs, such as repurposed aminoglycoside antibiotics, may represent a valuable therapeutic alternative for untreatable rare diseases caused by nonsense variants. OBJECTIVE: To evaluate whether systemic gentamicin, at a dose of 7.5 mg/kg/d for 14 consecutive days, is clinically beneficial in a patient with EBS-MD. DESIGN, SETTING, AND PARTICIPANTS: A single patient in Madrid, Spain, received 2 treatment courses with gentamicin on July 2019 and February 2020 with a follow-up period of 120 and 150 days, respectively. RESULTS: In this case report of a woman in her 30s with EBS-MD, before gentamicin treatment, the patient had mucocutaneous involvement, skeletal and respiratory muscle weakness, and myalgia that negatively affected her quality of life. Outcomes were evaluated with extensive laboratory tests and clinical scales. No nephrotoxic or ototoxic effects were detected after intravenous gentamicin administration. Gentamicin treatment was followed by plectin expression in the skin for at least 5 months. Although minimal changes were noted in skeletal muscle function (as measured by the Hammersmith functional motor scale and its expanded version: 6/40 to 7/40 and from 10/66 to 11/66, respectively) and respiratory musculature (maximal inspiratory and expiratory pressures D0 vs D16, MIP: 2.86 vs 3.63 KPa and MEP: 2.93 vs 4.63 KPa), myalgia disappeared (VAS dropped from 6 to 0), and quality of life improved (EuroQoL-5D-3L pain and anxiety dropped from 2 to 1). CONCLUSIONS AND RELEVANCE: The findings of this single case report suggest that gentamicin treatment may help suppress PLEC1 premature termination codons and induce plectin expression in EBS-MD primary keratinocytes and skin. Our study suggests that gentamicin may play an important role in treating EBS-MD owing to nonsense variants.

Transcriptomic Repositioning Analysis Identifies mTOR Inhibitor as Potential Therapy for Epidermolysis Bullosa Simplex.

Expression-based systematic drug repositioning has been explored to predict novel treatments for a number of skin disorders. In this study, we utilize this approach to identify, to our knowledge, previously unreported therapies for epidermolysis bullosa simplex (EBS). RNA sequencing analysis was performed on skin biopsies of acute blisters (<1 week old) (n = 9) and nonblistered epidermis (n = 11) obtained from 11 patients with EBS. Transcriptomic analysis of blistered epidermis in patients with EBS revealed a set of 1,276 genes dysregulated in EBS blisters. The IL-6, IL-8, and IL-10 pathways were upregulated in the epidermis from EBS. Consistent with this, predicted upstream regulators included TNF-α, IL-1ß, IL-2, IL-6, phosphatidylinositol 3-kinase, and mTOR. The 1,276 gene EBS blister signature was integrated with molecular signatures from cell lines treated with 2,423 drugs using the Connectivity Map CLUE platform. The mTOR inhibitors and phosphatidylinositol 3-kinase inhibitors most opposed the EBS signature. To determine whether mTOR inhibitors could be used clinically in EBS, we conducted an independent pilot study of two patients with EBS treated with topical sirolimus for painful plantar keratoderma due to chronic blistering. Both individuals experienced marked clinical improvement and a notable reduction of keratoderma. In summary, a computational drug repositioning analysis successfully identified, to our knowledge, previously unreported targets in the treatment of EBS.

Drug Repurposing Reveals mTOR Inhibition as a Promising Strategy for Epidermolysis Bullosa Simplex.

Drug repurposing has the potential to discover new treatments for diseases with high unmet medical needs. Lee et al. (2021) combined transcriptomics and computational analysis of drug-target databases to identify novel therapies for epidermolysis bullosa simplex. Differential gene expression analysis of blister epidermis identified the phosphoinositide 3-kinase/protein kinase B/mTOR signaling pathway as central. A pilot study using a topical mTOR inhibitor showed marked improvement.

A cell-based drug discovery assay identifies inhibition of cell stress responses as a new approach to treatment of epidermolysis bullosa simplex.

In the skin fragility disorder epidermolysis bullosa simplex (EBS), mutations in keratin 14 (K14, also known as KRT14) or keratin 5 (K5, also known as KRT5) lead to keratinocyte rupture and skin blistering. Severe forms of EBS are associated with cytoplasmic protein aggregates, with elevated kinase activation of ERK1 and ERK2 (ERK1/2; also known as MAPK3 and MAPK1, respectively), suggesting intrinsic stress caused by misfolded keratin protein. Human keratinocyte EBS reporter cells stably expressing GFP-tagged EBS-mimetic mutant K14 were used to optimize a semi-automated system to quantify the effects of test compounds on keratin aggregates. Screening of a protein kinase inhibitor library identified several candidates that reduced aggregates and impacted on epidermal growth factor receptor (EGFR) signalling. EGF ligand exposure induced keratin aggregates in EBS reporter keratinocytes, which was reversible by EGFR inhibition. EBS keratinocytes treated with a known EGFR inhibitor, afatinib, were driven out of activation and towards quiescence with minimal cell death. Aggregate reduction was accompanied by denser keratin filament networks with enhanced intercellular cohesion and resilience, which when extrapolated to a whole tissue context would predict reduced epidermal fragility in EBS patients. This assay system provides a powerful tool for discovery and development of new pathway intervention therapeutic avenues for EBS.

Topical Diacerein Ointment for Epidermolysis Bullosa Simplex: A Review

Epidermolysis bullosa (EB) is a group of rare mucocutaneous fragility disorders often presenting in infancy and early childhood with painful blistering of the skin and mucous membranes. The severity of EB blister burden varies by disease subtype. Studies have shown that patients with generalized severe epidermolysis bullosa simplex (EBS), a variant characterized by extreme fragility, develop blisters in the setting of overproduced, mutated K14 protein, a component of the intermediate filament integral in keratinocyte stability, and constitutive activation of interleukin (IL)-1 , a pro-inflammatory cytokine that promotes the hyperproliferation of keratinocytes. Diacerein, a rhein prodrug and anthraquinone, has been shown to reduce expression of K14 and inhibit IL-1 converting enzyme. In clinical trials, topical 1% diacerein was shown to be an effective and safe, non-invasive treatment for patients suffering from EBS. This review examines the clinical trials of topical diacerein and its role in EBS. Diacerein ointment was granted US FDA Rare Pediatric Disease designation in May 2018 and Fast Track development designation in August 2018.

Epidermolysis bullosa simplex generalized severe induces a T helper 17 response and is improved by apremilast treatment.

BACKGROUND: Epidermolysis bullosa simplex generalized severe (EBS-gen sev) is a genetic disorder caused by mutation in the KRT5 or KRT14 genes. Although it is usually considered a mechanical disease, recent data argue for additional inflammatory mechanisms. OBJECTIVES: To assess the inflammation in the skin of patients with EBS-gen sev. METHODS: A first immunohistochemical retrospective study was performed on frozen skin samples from 17 patients with EBS-gen sev. A second multicentre prospective study was conducted on 10 patients with severe EBS-gen sev. Blister fluid and epidermis were processed for immunochemical analysis and quantitative real-time polymerase chain reaction. Cytokine expression was analysed in blister fluid and compared with that in controls. RESULTS: Histological analysis showed a constant dermal perivascular CD4+ lymphocyte infiltrate in skin biopsies of both blister (n = 17) and rubbed skin (n = 5), an epidermal infiltration of neutrophils and eosinophils in 70% of cases, and increased immunostaining for CXCL9 and CXCL10 in blistering skin. High levels of T helper 17 cytokines were detected in lesional skin. Three adult patients with EBS-gen sev were treated with apremilast, with a dramatic improvement of skin blistering and good tolerance. CONCLUSIONS: Our study demonstrates the importance of inflammation in patients with EBS-gen sev and underlines the key role for T helper 17 cells in its pathogenesis. In addition, this study provides promising new therapeutic approaches for this disabling disorder.

Basal pharmacokinetic parameters of topically applied diacerein in pediatric patients with generalized severe epidermolysis bullosa simplex.

Generalized severe epidermolysis bullosa simplex (EBS-gen sev) is caused by mutations within either the KRT5 or KRT14 gene, phenotypically resulting in blistering and wounding of the skin and mucous membranes after minor mechanical friction. In a clinical phase 2/3 trial, diacerein has recently been shown to significantly reduce blister numbers upon topical application. In this study we addressed basic pharmacokinetic parameters of locally applied diacerein in vitro and in vivo. Ex vivo experiments using a Franz diffusion cell confirmed the uptake and bio-transformation of diacerein to rhein in a porcine skin model. Rhein, the active metabolite of diacerein, was also detected in both urine and serum samples of two EBS-gen sev patients who topically applied a 1% diacerein ointment over a period of 4 weeks. The accumulated systemic levels of rhein in EBS-gen sev patients were lower than reported levels after oral application. These preliminary findings point towards the uptake and prolonged persistance of diacerein / rhein within the intended target organ - the skin. Further, they imply an acceptable safety profile at the systemic level. TRIAL REGISTRATION: DRKS. DRKS00005412 . Registered 6 November 2013.

Diacerein orphan drug development for epidermolysis bullosa simplex: A phase 2/3 randomized, placebo-controlled, double-blind clinical trial.

BACKGROUND: Epidermolysis bullosa simplex (EBS) is a rare genetic, blistering skin disease for which there is no cure. Treatments that address the pathophysiology of EBS are needed. OBJECTIVE: Compare the impact of 1% diacerein cream with placebo in reducing the number of blisters in EBS. METHODS: In a randomized, placebo-controlled, phase 2/3 trial we used a 1% diacerein topical formulation to treat defined skin areas in 17 patients. In a 2-period crossover trial, patients were randomized to either placebo or diacerein for a 4-week treatment and a 3-month follow-up in period 1. After a washout, patients were crossed over during period 2. The prespecified primary end point was the proportion of patients with a reduction of number of blisters by more than 40% from baseline in selected areas over the treatment episode. RESULTS: Of the patients receiving diacerein, 86% in episode 1 and 37.5% in episode 2 met the primary end point (vs 14% and 17% with placebo, respectively). This effect was still significant after the follow-up. Changes in absolute blister numbers were significant for the diacerein group only. No adverse effects were observed. LIMITATIONS: Low patient numbers and no invasive data acquisition because of clinical burden in children. CONCLUSION: This trial provides evidence of the impact of 1% diacerein cream in the treatment of EBS.

Randomized, split-body, single-blinded clinical trial of topical broccoli sprout extract: Assessing the feasibility of its use in keratin-based disorders.

BACKGROUND: Epidermolysis bullosa simplex is a skin-blistering disorder caused by mutations in keratin (K)14 or K5. Treatment with nuclear factor (erythroid-derived 2)-like 2 inducer sulforaphane ameliorated skin blistering in Krt14-null mice, correlating with induction of K17. To be therapeutically useful for epidermolysis bullosa simplex, topical broccoli sprout extract (BSE), enriched for sulforaphane, would ideally induce the expression of homologous keratins (eg, K6, K17, K16) in the basal layer of human epidermis without impacting expression of defective keratins (K5/K14). OBJECTIVE: The purpose of this 1-week, randomized, split-body, single-blinded, placebo-controlled trial was to assess the impact of BSE on keratin expression. METHODS: Five subjects (34-71 years old) applied BSE (500 nmol of sulforaphane/mL) or vehicle alone to the inner aspect of the arm daily. Expression of keratin, nuclear factor (erythroid-derived 2)-like 2, and other markers was assessed using reverse transcription-polymerase chain reaction and indirect immunofluorescence. RESULTS: One subject (age 71 years) was excluded a posteriori because of poor tissue quality. Topical BSE activated nuclear factor (erythroid-derived 2)-like 2 and up-regulated K17 in the epidermis of all subjects, had variable effects on K16 and K6 expression, and did not alter expression of K14 or K5. LIMITATIONS: Small sample size is a limitation. CONCLUSION: BSE represents an attractive therapeutic candidate for K14-associated epidermolysis bullosa simplex.

Whole-transcriptome gene expression profiling in an epidermolysis bullosa simplex Dowling-Meara model keratinocyte cell line uncovered novel, potential therapeutic targets and affected pathways.

BACKGROUND: To be able to develop effective therapeutics for epidermolysis bullosa simplex (EBS), it is necessary to elucidate the molecular pathomechanisms that give rise to the disease's characteristic severe skin-blistering phenotype. RESULTS: Starting with a whole-transcriptome microarray analysis of an EBS Dowling-Meara model cell line (KEB7), we identified 207 genes showing differential expression relative to control keratinocytes. A complementary qRT-PCR study of 156 candidates confirmed 76.58 % of the selected genes to be significantly up-regulated or down-regulated (p-value <0.05) within biological replicates. Our hit list contains previously identified genes involved in epithelial cell proliferation, cell-substrate adhesion, and responses to diverse biological stimuli. In addition, we identified novel candidate genes and potential affected pathways not previously considered as relevant to EBS pathology. CONCLUSIONS: Our results broaden our understanding of the molecular processes dysregulated in EBS.

MMP-9 and CXCL8/IL-8 are potential therapeutic targets in epidermolysis bullosa simplex.

Epidermolysis bullosa refers to a group of genodermatoses that affects the integrity of epithelial layers, phenotypically resulting in severe skin blistering. Dowling-Meara, the major subtype of epidermolysis bullosa simplex, is inherited in an autosomal dominant manner and can be caused by mutations in either the keratin-5 (K5) or the keratin-14 (K14) gene. Currently, no therapeutic approach is known, and the main objective of this study was to identify novel therapeutic targets. We used microarray analysis, semi-quantitative real-time PCR, western blot and ELISA to identify differentially regulated genes in two K14 mutant cell lines carrying the mutations K14 R125P and K14 R125H, respectively. We found kallikrein-related peptidases and matrix metalloproteinases to be upregulated. We also found elevated expression of chemokines, and we observed deregulation of the Cdc42 pathway as well as aberrant expression of cytokeratins and junction proteins. We further demonstrated, that expression of these genes is dependent on interleukin-1 ß signaling. To evaluate these data in vivo we analysed the blister fluids of epidermolysis bullosa simplex patients vs. healthy controls and identified matrix metalloproteinase-9 and the chemokine CXCL8/IL-8 as potential therapeutic targets.

Topical diacerein for epidermolysis bullosa: a randomized controlled pilot study.

Blistering in epidermolysis bullosa simplex type Dowling-Meara (EBS-DM) is associated with an inflammatory phenotype, which can be disrupted by diacerein in vitro. In this pilot study we hypothesized, that a topical formulation of diacerein 1% reduces blistering. Five patients initially applied diacerein underneath both armpits. Then, each participant received 1% diacerein-cream for one armpit, and placebo for the other (randomized withdrawal). The number of blisters was reduced significantly (left: -78%; right: -66% of baseline) within two weeks and remained significantly below the initial level even during withdrawal in four patients. These findings point to a relevant effect of diacerein and provide important information for a confirmative study.

Botulinum toxin in the treatment of sweat-worsened foot problems in patients with epidermolysis bullosa simplex and pachyonychia congenita.

BACKGROUND: Painful foot blistering is a common problem in patients with epidermolysis bullosa simplex (EBS) and pachyonychia congenita (PC). Hyperhidrosis, a condition which can be effectively blocked by plantar injections of botulinum toxin (Btx), often exacerbates the blistering. OBJECTIVES: A retrospective evaluation of the effects of Btx injections in 14 patients with EBS and PC with foot blisters and painful callosities. METHODS: After informed consent, patients with EBS (n = 6) and PC (n = 8), aged 7-66 years, who had received Btx therapy at our centre since 2003, were included. The treatment consisted of multiple plantar injections of Btx A or Btx B after prior regional or general anaesthesia. Patients were interviewed about the treatment effect and were asked to score the improvement from 0 to 5, where 5 is 'excellent'. One patient with PC with painful callosities was studied by magnetic resonance (MR) spectroscopic microimaging before and after Btx injections to disclose any underlying blisters. RESULTS: In total, 76 treatments were evaluated (one to 19 sessions per patient). Thirteen patients (93%) reported reduced plantar blistering and pain; the improvement score was ≥ 4 in four of six patients with EBS and six of eight patients with PC. The mean effect duration was 3 months. No adverse events, apart from mild anticholinergic side-effects in two patients, were noted. MR spectroscopic microimaging showed disappearance of intraepidermal blistering after Btx therapy. CONCLUSIONS: Plantar injection of Btx is an efficient, long-lasting and safe treatment of painful blistering and callosities in EBS and PC that can be given repeatedly without loss of efficacy.