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.

Report of the European Medicines Agency Conference on RNA-Based Medicines

RNA-based medicines have potential to treat a large variety of diseases, and research in the field is very dynamic. Proactively, The European Medicines Agency (EMA) organized a virtual conference on February 2, 2023 to promote the development of RNA-based medicines. The initiative addresses the goal of the EMA Regulatory Science Strategy to 2025 to "catalyse the integration of science and technology in medicines development." The conference focused on RNA technologies (excluding RNA vaccines) and involved different stakeholders, including representatives from academia, industry, regulatory authorities, and patient organizations. The conference comprised presentations and discussion sessions conducted by panels of subject matter experts. In this meeting report, we summarize the presentations and recap the main themes of the panel discussions.

Drug repurposing for rare: progress and opportunities for the rare disease community

Repurposing is one of the key opportunities to address the unmet rare diseases therapeutic need. Based on cases of drug repurposing in small population conditions, and previous work in drug repurposing, we analyzed the most important lessons learned, such as the sharing of clinical observations, reaching out to regulatory scientific advice at an early stage, and public-private collaboration. In addition, current upcoming trends in the field of drug repurposing in rare diseases were analyzed, including the role these trends could play in the rare diseases' ecosystem. Specifically, we cover the opportunities of innovation platforms, the use of real-world data, the use of artificial intelligence, regulatory initiatives in repurposing, and patient engagement throughout the repurposing project. The outcomes from these emerging activities will help progress the field of drug repurposing for the benefit of patients, public health and medicines development.

A full-document analysis of the semantic relation between European Public Assessment Reports and EMA guidelines using a BERT language model

In the European Union, the Committee for Medicinal Products for Human Use of the European Medicines Agency (EMA) develop guidelines to guide drug development, supporting development of efficacious and safe medicines. A European Public Assessment Report (EPAR) is published for every medicine application that has been granted or refused marketing authorisation within the EU. In this work, we study the use of text embeddings and similarity metrics to investigate the semantic similarity between EPARs and EMA guidelines. All 1024 EPARs for initial marketing authorisations from 2008 to 2022 was compared to the 669 current EMA scientific guidelines. Documents were converted to plain text and split into overlapping chunks, generating 265,757 EPAR and 27,649 guideline text chunks. Using a Sentence BERT language model, the chunks were transformed into embeddings and fed into an in-house piecewise matching algorithm to estimate the full-document semantic distance. In an analysis of the document distance scores and product characteristics using a linear regression model, EPARs of anti-virals for systemic use (ATC code J05) and antihemorrhagic medicines (B02) present with statistically significant lower overall semantic distance to guidelines compared to other therapeutic areas, also when adjusting for product age and EPAR length. In conclusion, we believe our approach provides meaningful insight into the interplay between EMA scientific guidelines and the assessment made during regulatory review, and could potentially be used to answer more specific questions such as which therapeutic areas could benefit from additional regulatory guidance.

Community Use of Repurposed Drugs Before and During COVID-19 Pandemic in the Netherlands: An Interrupted Time-Series Analysis

Background

Repurposing registered drugs could reduce coronavirus disease (COVID-19) burden before novel drugs are authorized. Little is known about how the pandemic and imposed restrictions changed their dispensing. We aimed to investigate the impact of COVID-19 pandemic on repurposed drugs dispensing in the Netherlands.

Methods

We performed interrupted time-series study using University of Groningen prescription database IADB.nl to evaluate dispensing trends of 24 repurposed drugs before (2017-February 2020) and after (March 2020-2021) the pandemic' start. Primary outcomes were monthly prevalence and incidence rates. An autoregressive integrated moving average model assessed the effect of pandemic and stringency index (measuring strictness of government's restriction policies).

Results

Annual number of IADB.nl population ranged from 919,697 to 952,400. Generally, dispensing of common long-term-used drugs was not significantly affected by pandemic. The prevalence of antibacterials (-4.20 users per 1000 people), antivirals (-0.04), corticosteroids (-1.29), prednisolone (-1.32), calcium channel blocker (-0.41), and diuretics (-1.29) was lower than expected after the pandemic's start, while the prevalence of ivermectin (0.07), sulfonylureas (0.15), sodium-glucose co-transporter-2 (SGLT2) inhibitor (0.17), and anticoagulants (1.95) was higher than expected. The pandemic was associated with statistically significant decreases in the incidence of antibacterials (-1.21), corticosteroids (-0.60), prednisolone (-0.64) and anticoagulants (-0.02), and increases in ivermectin (0.02), aggregated antidiabetic drugs (0.13), and SGLT2 inhibitors (0.06). These trends were positively associated with pandemic and negatively associated with stringency index.

Conclusion

Dispensing of most drugs was not significantly associated with pandemic and government's response. Despite some statistically significant disruptions, these were not necessarily clinically relevant due to small absolute differences observed.

Repurposed drug studies on the primary prevention of SARS-CoV-2 infection during the pandemic: systematic review and meta-analysis

OBJECTIVE

Current evidence on the effectiveness of SARS-CoV-2 prophylaxis is inconclusive. We aimed to systematically evaluate published studies on repurposed drugs for the prevention of laboratory-confirmed SARS-CoV-2 infection and/or COVID-19 among healthy adults.

DESIGN

Systematic review.

ELIGIBILITY

Quantitative experimental and observational intervention studies that evaluated the effectiveness of repurposed drugs for the primary prevention of SARS-CoV-2 infection and/or COVID-19 disease.

DATA SOURCE

PubMed and Embase (1 January 2020-28 September 2022).

RISK OF BIAS

Cochrane Risk of Bias 2.0 and Risk of Bias in Non-Randomised Studies of Interventions tools were applied to assess the quality of studies.

DATA ANALYSIS

Meta-analyses for each eligible drug were performed if ≥2 similar study designs were available.

RESULTS

In all, 65 (25 trials, 40 observational) and 29 publications were eligible for review and meta-analyses, respectively. Most studies pertained to hydroxychloroquine (32), ACE inhibitor (ACEi) or angiotensin receptor blocker (ARB) (11), statin (8), and ivermectin (8). In trials, hydroxychloroquine prophylaxis reduced laboratory-confirmed SARS-CoV-2 infection (risk ratio: 0.82 (95% CI 0.74 to 0.90), I2=48%), a result largely driven by one clinical trial (weight: 60.5%). Such beneficial effects were not observed in observational studies, nor for prognostic clinical outcomes. Ivermectin did not significantly reduce the risk of SARS-CoV-2 infection (RR: 0.35 (95% CI 0.10 to 1.26), I2=96%) and findings for clinical outcomes were inconsistent. Neither ACEi or ARB were beneficial in reducing SARS-CoV-2 infection. Most of the evidence from clinical trials was of moderate quality and of lower quality in observational studies.

CONCLUSIONS

Results from our analysis are insufficient to support an evidence-based repurposed drug policy for SARS-CoV-2 prophylaxis because of inconsistency. In the view of scarce supportive evidence on repurposing drugs for COVID-19, alternative strategies such as immunisation of vulnerable people are warranted to prevent the future waves of infection.

PROSPERO REGISTRATION NUMBER

CRD42021292797.

Single-arm trials supporting the approval of anticancer medicinal products in the European Union: contextualization of trial results and observed clinical benefit

BACKGROUND

Single-arm trials (SATs) can sometimes be used to support marketing authorization of anticancer medicinal products in the European Union. The level and durability of antitumor activity of the product as well as context are important aspects to determine the relevance of trial results. The aim of this study is to provide details on the contextualization of trial results and to evaluate the magnitude of benefit of medicinal products approved based on SATs.

MATERIALS AND METHODS

We focused on anticancer medicinal products for solid tumors approved on the basis of SAT results (2012-2021). Data were retrieved from European public assessment reports and/or published literature. The benefit of these medicinal products was evaluated via the European Society for Medical Oncology (ESMO)-Magnitude of Clinical Benefit Scale (MCBS).

RESULTS

Eighteen medicinal products were approved based on 21 SATs-few medicinal products were supported by >1 SAT. For the majority of clinical trials, a clinically relevant treatment effect was (pre)specified (71.4%) and most often an accompanying sample size calculation was provided. For 10 studies, each testing a different medicinal product, a justification for the threshold for a clinically relevant treatment effect could be identified. At least 12 out of 18 applications included information to facilitate the contextualization of trial results, including six supportive studies. Of the pivotal SATs analyzed (n = 21), three were assigned an ESMO-MCBS score of 4, which corresponds to 'substantial' benefit.

CONCLUSIONS

The clinical relevance of the treatment effects shown by medicinal products for solid tumors tested in SATs is dependent on the effect size and context. To better facilitate regulatory decision making, prespecifying and motivating a clinically relevant effect and aligning the sample size to that effect is important. External controls may facilitate in the contextualization process, but the associated limitations must be addressed.

The IRDiRC Chrysalis Task Force: making rare disease research attractive to companies

Background

The International Rare Diseases Research Consortium (IRDiRC) is an international initiative that aims to use research to facilitate rapid diagnosis and treatment of rare diseases.

Objective

IRDiRC launched the Chrysalis Task Force to identify key financial and nonfinancial factors that make rare disease research and development attractive to companies.

Methods

The Chrysalis Task Force was comprised of thought leaders from companies, patient advocacy groups, regulatory agencies, and research funders. The Task Force created a survey that was distributed to companies of different sizes with varied investment portfolios and interests in rare disease research. Based on the survey results, the Task Force then conducted targeted interviews.

Results

The survey and interview respondents identified several factors that make rare disease research and development attractive (e.g. a good understanding of the underlying biology) as well as barriers (e.g. absence of an advocacy organization representing the affected community's needs). The concept of Return On Investment allowed the exploration of factors that were weighed differently by survey and interview respondents, depending on a number of intrinsic and extrinsic issues.

Conclusions

The Chrysalis Task Force identified factors attributable to rare disease research and development that may be of interest to and actionable by funders, academic researchers, patients and their families, companies, regulators, and payers in the medium term to short term. By addressing the identified challenges, involved parties may seek solutions to significantly advance the research and development of treatments for rare diseases.

Medication Use and Clinical Outcomes by the Dutch Institute for Clinical Auditing Medicines Program: Quantitative Analysis

BACKGROUND

The Dutch Institute for Clinical Auditing (DICA) Medicines Program was set up in September 2018 to evaluate expensive medicine use in daily practice in terms of real-world effectiveness using only existing data sources.

OBJECTIVE

The aim of this study is to describe the potential of the addition of declaration data to quality registries to provide participating centers with benchmark information about the use of medicines and outcomes among patients.

METHODS

A total of 3 national population-based registries were linked to clinical and financial data from the hospital pharmacy, the Dutch diagnosis treatment combinations information system including in-hospital activities, and survival data from health care insurers. The first results of the real-world data (RWD) linkage are presented using descriptive statistics to assess patient, tumor, and treatment characteristics. Time-to-next-treatment (TTNT) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

A total of 21 Dutch hospitals participated in the DICA Medicines Program, which included 7412 patients with colorectal cancer, 1981 patients with metastasized colon cancer, 3860 patients with lung cancer, 1253 patients with metastasized breast cancer, and 7564 patients with rheumatic disease. The data were used for hospital benchmarking to gain insights into medication use in specific patient populations, treatment information, clinical outcomes, and costs. Detailed treatment information (duration and treatment steps) led to insights into differences between hospitals in daily clinical practices. Furthermore, exploratory analyses on clinical outcomes (TTNT and OS) were possible.

CONCLUSIONS

The DICA Medicines Program shows that it is possible to gather and link RWD about medicines to 4 disease-specific population-based registries. Since these RWD became available with minimal registration burden and effort for hospitals, this method can be explored in other population-based registries to evaluate real-world efficacy.

Novel insights into the epidemiology of epidermolysis bullosa (EB) from the Dutch EB Registry: EB more common than previously assumed?

Background

Epidermolysis bullosa (EB) is a heterogeneous group of rare and incurable genetic disorders characterized by fragility of the skin and mucosae, resulting in blisters and erosions. Several epidemiological studies in other populations have been carried out, reporting varying and sometimes inconclusive figures, highlighting the need for standardized epidemiological analyses in well‐characterized cohorts.

Objectives

To evaluate the epidemiological data on EB in the Netherlands, extracted from the molecularly well‐characterized cohort in the Dutch EB Registry.

Methods

In this observational study all EB‐patients that were based in the Netherlands and captured in the Dutch EB Registry between 1988 and 2018 were included. The epidemiological outcomes were based on complete diagnostic data (clinical features, immunofluorescence, electron microscopy and mutation analysis), with longitudinal follow‐up.

Results

A total of 464 EB‐patients (287 families) were included. The incidence and point‐prevalence of EB in the Netherlands were 41.3 per million live births and 22.4 per million population, respectively. EB Simplex (EBS), Junctional EB (JEB), Dystrophic EB (DEB) and Kindler EB were diagnosed in 45.7%, 18.8%, 34.7% and 0.9% of the EB‐patients, respectively, with an incidence and point‐prevalence of 17.5 and 11.9 (EBS), 9.3 and 2.1 (JEB), 14.1 and 8.3 (DEB), 0.5 and 0.2 (Kindler EB). In 90.5% of the EB‐patients the diagnosis was genetically confirmed. During the investigated time period 73 EB‐patients died, 72.6% of whom as a direct consequence of their EB.

Conclusion

The epidemiological outcomes of EB in the Netherlands are high, attributed to a high detection rate in a well‐organized set‐up, indicating that EB might be more common than previously assumed. These epidemiological data help to understand the extensive need for (specialized) medical care of EB‐patients and is invaluable for the design and execution of therapeutic trials. This study emphasizes the importance of thorough reporting systems and registries worldwide.

Linked Commentary: L. Bruckner‐Tuderman. J Eur Acad Dermatol Venereol 2021; 35: 783–784. https://doi.org/10.1111/jdv.17165.

Carriers with functional null mutations in LAMA3 have localized enamel abnormalities due to haploinsufficiency

The hereditary blistering disease junctional epidermolysis bullosa (JEB) is always accompanied by structural enamel abnormalities of primary and secondary dentition, characterized as amelogenesis imperfecta. Autosomal recessive mutations in LAMA3, LAMB3 and LAMC2 encoding the heterotrimer laminin 332 (LM-332) are among the genes causing JEB. While examining pedigrees of JEB patients with LAMA3 mutations, we observed that heterozygous carriers of functional null mutations displayed subtle enamel pitting in the absence of skin fragility or other JEB symptoms. Here, we report two new LAMA3 functional null mutations: nonsense c.2377C>T p.(Arg793Ter) and splice-site c.4684+1G>A mutation in heterozygous carriers exhibiting enamel pitting. Both parents had offspring affected with JEB and displayed subtle enamel pitting of secondary dentition without any sign of skin blistering. The reported enamel abnormality in LAMA3 mutation carriers could be attributed to a half dose effect of the laminin α3 chain (haploinsufficiency).

Localized and generalized forms of blistering in junctional epidermolysis bullosa due to COL17A1 mutations in the Netherlands

BACKGROUND

Mutations in the gene COL17A1 coding for type XVII collagen cause non-Herlitz junctional epidermolysis bullosa (nH-JEB).

OBJECTIVES

Here we give an overview of the genotype-phenotype correlation in 12 patients from the Netherlands with type XVII collagen-deficient nH-JEB.

PATIENT AND METHODS

Family and personal history and clinical presentation were recorded from each patient, and skin biopsies of intact and bullous skin were taken for immunofluorescence and electron microscopy. The mutations were identified by analysing the patient's DNA isolated from peripheral blood cells.

RESULTS

DNA analysis identified five novel deletions: 1284delA, 1365delC, 3236delT, 3600-3601delCT and 4425delT. Interestingly, we identified a new patient, homozygous for 4425delT, with an exceptionally mild blistering phenotype. All together, three patients had more localized blistering confined to hands, lower legs and face, absent or very mild nail dystrophy, normal primary hair and sparse secondary hair. Nine patients had generalized blistering, nail dystrophy, sparse primary and absent secondary hair. All 12 patients had amelogenesis imperfecta (enamel pitting). Immunofluorescence (IF) antigen mapping with monoclonal antibodies 1A8C and 1D1 that bind to type XVII collagen, but not to its 97-kDa fragment was completely negative in patients with generalized blistering, whereas reduced in patients with localized blistering.

CONCLUSIONS

Our data reveal that in patients with COL17A1 mutations a localized nH-JEB phenotype can be differentiated from a generalized nH-JEB phenotype by IF antigen mapping. The data are important for genetic counselling at early age when the clinical phenotype is not yet clear.

Features of epidermolysis bullosa simplex due to mutations in the ectodomain of type XVII collagen

BACKGROUND

Mutations in COL17A1, coding for type XVII collagen, cause junctional epidermolysis bullosa with an ultrastructural plane of cleavage through the lamina lucida of the epidermal basement membrane.

OBJECTIVES

To identify the COL17A1 mutations in a child with reduced type XVII collagen expression and intraepidermal blister formation.

PATIENT AND METHODS

Protein expression and level of tissue separation were studied by immunofluorescence and electron microscopy. The mutations were identified by analysing the patient's DNA and mRNA.

RESULTS

Immunofluorescence microscopy performed on nonlesional skin demonstrated absence of the type XVII collagen endodomain and presence, although reduced, of the shed ectodomain. Electron microscopy showed that the plane of cleavage was through the basal cells, not through the lamina lucida. Two heterozygous mutations were identified in COL17A1: a new 3'-acceptor splice-site mutation in intron 21 (1877-2A-->C), and a deletion in exon 48 (3432delT). The splice-site mutation in intron 21 results in alternative transcripts of which two are in-frame, with deletions of the first nine codons of exon 22 and the entire exon 22, respectively. By Western blot analysis, a type XVII collagen molecule was detected that was slightly smaller than normal.

CONCLUSIONS

Occasionally mutations in the COL17A1 gene may result in split levels suggesting epidermolysis bullosa simplex rather than junctional epidermolysis bullosa.

A very mild form of non-Herlitz junctional epidermolysis bullosa: BP180 rescue by outsplicing of mutated exon 30 coding for the COL15 domain

Mutations in the gene COL17A1 cause non-Herlitz junctional epidermolysis bullosa. Here, we describe a patient who, despite two heterozygous mutations in COL17A1, has an extremely mild form of the disease missing most of the characteristic clinical features. DNA analysis revealed a frame-shift mutation 3432delT and a nonsense mutation 2356C-->T (Q751X). cDNA analysis showed that the deleterious effect of the latter mutation was skirted by deleting the premature termination codon containing exon 30. In this way, the reading frame was restored, resulting in a 36 nucleotides shorter mRNA transcript. Immunoblot analysis showed expression of the 180-kDa bullous pemphigoid antigen (BP180) with a slightly higher SDS-PAGE mobility, in line with the deletion of 12 amino acids from the COL15 domain. Immunofluorescence of skin sections showed diminished, but correctly localised expression of BP180, and this, in concert with the mild clinical phenotype, suggests that this COL15 mutated BP180 is still partly functional.