A CFTR potentiator in patients with cystic fibrosis and the G551D mutation (original) (raw)
Discovery of novel potent ΔF508-CFTR correctors that target the nucleotide binding domain
EMBO Molecular Medicine, 2013
The deletion of Phe508 (DF508) in the first nucleotide binding domain (NBD1) of CFTR is the most common mutation associated with cystic fibrosis. The DF508-CFTR mutant is recognized as improperly folded and targeted for proteasomal degradation. Based on molecular dynamics simulation results, we hypothesized that interaction between DF508-NBD1 and housekeeping proteins prevents DF508-CFTR delivery to the plasma membrane. Based on this assumption we applied structure-based virtual screening to identify new low-molecular-weight compounds that should bind to DF508-NBD1 and act as protein-protein interaction inhibitors. Using different functional assays for CFTR activity, we demonstrated that in silico-selected compounds induced functional expression of DF508-CFTR in transfected HeLa cells, human bronchial CF cells in primary culture, and in the nasal epithelium of homozygous DF508-CFTR mice. The proposed compounds disrupt keratin8-DF508-CFTR interaction in DF508-CFTR HeLa cells. Structural analysis of DF508-NBD1 in the presence of these compounds suggests their binding to NBD1. We conclude that our strategy leads to the discovery of new compounds that are among the most potent correctors of DF508-CFTR trafficking defect known to date.
Towards personalized agriculture: what chemical genomics can bring to plant biotechnology
Frontiers in plant science, 2014
In contrast to the dominant drug paradigm in which compounds were developed to "fit all," new models focused around personalized medicine are appearing in which treatments are developed and customized for individual patients. The agricultural biotechnology industry (Ag-biotech) should also think about these new personalized models. For example, most common herbicides are generic in action, which led to the development of genetically modified crops to add specificity. The ease and accessibility of modern genomic analysis, when wedded to accessible large chemical space, should facilitate the discovery of chemicals that are more selective in their utility. Is it possible to develop species-selective herbicides and growth regulators? More generally put, is plant research at a stage where chemicals can be developed that streamline plant development and growth to various environments? We believe the advent of chemical genomics now opens up these and other opportunities to "...
Scandinavian journal of gastroenterology, 2015
Objective. Volume output failure is a feature of decreasing exocrine pancreatic function. This parameter is assessed by secretin-stimulated MRI in several studies. Our purpose was to evaluate ultrasonography of the fluid in the descending duodenum and Wirsung duct (WD) after secretin stimulation as a measure of pancreatic fluid flow in patients expected to have severe output failure. Material and methods. We included subjects with chronic pancreatitis (CP), cystic fibrosis (CF) and a group of healthy controls in a prospective observation study. Transabdominal ultrasonography was performed before and during 15 min after secretin i.v. duodenal juice was collected by endoscopic short test (EST), and bicarbonate concentration measured. Patient groups were classified according to exocrine pancreatic function. Results. Pancreatic insufficient CF (CFI) patients and CP insufficient (CPI) patients showed less duodenal fluid filling compared to other groups (p < 0.001). Measures of the WD ...
PLoS ONE, 2014
Current anti-inflammatory strategies for the treatment of pulmonary disease in cystic fibrosis (CF) are limited; thus, there is continued interest in identifying additional molecular targets for therapeutic intervention. Given the emerging role of sphingolipids (SLs) in various respiratory disorders, including CF, drugs that selectively target the enzymes associated with SL metabolism are under development. Miglustat, a well-characterized iminosugar-based inhibitor of b-glucosidase 2 (GBA2), has shown promise in CF treatment because it reduces the inflammatory response to infection by P. aeruginosa and restores F508del-CFTR chloride channel activity. This study aimed to probe the molecular basis for the anti-inflammatory activity of miglustat by examining specifically the role of GBA2 following the infection of CF bronchial epithelial cells by P. aeruginosa. We also report the anti-inflammatory activity of another potent inhibitor of GBA2 activity, namely N-(5adamantane-1-yl-methoxy)pentyl)-deoxynojirimycin (Genz-529648). In CF bronchial cells, inhibition of GBA2 by miglustat or Genz-529648 significantly reduced the induction of IL-8 mRNA levels and protein release following infection by P. aeruginosa. Hence, the present data demonstrate that the anti-inflammatory effects of miglustat and Genz-529648 are likely exerted through inhibition of GBA2. Citation: Loberto N, Tebon M, Lampronti I, Marchetti N, Aureli M, et al. (2014) GBA2-Encoded b-Glucosidase Activity Is Involved in the Inflammatory Response to Pseudomonas aeruginosa. PLoS ONE 9(8): e104763.
An Update of Childhood Genetic Disorders
Journal of Nursing Scholarship, 2013
Purpose: Thousands of single gene, mitochondrial, and chromosomal disorders have been described in children. The purpose of this article is twofold. The first is to increase nurses' awareness of new developments in genetic disorders that are commonly seen in practice and taught in schools of nursing. The second is to illustrate important genetic concepts of relevance to nurses who care for infants, children, or adolescents. Organizing Construct: This article is organized into four sections: one that describes new developments in a well-known disorder, a second that discusses the process and potential outcomes of diagnosing a very rare disorder, and the third and fourth sections that describe select conditions caused by single gene mutations. Methods: Clinical expertise was paired with literature review to present evidence-based current information. Implications for nursing practice are highlighted throughout the article. Citations of publicly available evidencebased online resources are used so nurses can continue to use these in their practices.
PLoS ONE, 2013
In the airways of those with cystic fibrosis (CF), the leading pathophysiological hypothesis is that an ion channel defect results in a relative decrease in airway surface liquid (ASL) volume, producing thick and sticky mucus that facilitates the establishment and progression of early fatal lung disease. This hypothesis predicts that any successful CF airway treatment for this fundamental channel defect should increase the ASL volume, but up until now there has been no method of measuring this volume that would be compatible with in vivo monitoring. In order to accurately monitor the volume of the ASL, we have developed a new x-ray phase contrast imaging method that utilizes a highly attenuating reference grid. In this study we used this imaging method to examine the effect of a current clinical CF treatment, aerosolized hypertonic saline, on ASL depth in ex vivo normal mouse tracheas, as the first step towards non-invasive in vivo ASL imaging. The ex vivo tracheas were treated with hypertonic saline, isotonic saline or no treatment using a nebuliser integrated within a small animal ventilator circuit. Those tracheas exposed to hypertonic saline showed a transient increase in the ASL depth, which continued for nine minutes post-treatment, before returning to baseline by twelve minutes. These findings are consistent with existing measurements on epithelial cell cultures, and therefore suggest promise for the future development of in vivo testing of treatments. Our grid-based imaging technique measures the ASL depth with micron resolution, and can directly observe the effect of treatments expected to increase ASL depth, prior to any changes in overall lung health. The ability to non-invasively observe micron changes in the airway surface, particularly if achieved in an in vivo setting, may have potential in pre-clinical research designed to bring new treatments for CF and other airway diseases to clinical trials.
State of progress in treating cystic fibrosis respiratory disease
BMC Medicine, 2012
Since the discovery of the gene associated with cystic fibrosis (CF), there has been tremendous progress in the care of patients with this disease. New therapies have entered the market and are part of the standard treatment of patients with CF, and have been associated with marked improvement in survival. Now there are even more promising therapies directed at different components of the pathophysiology of this disease. In this review, our current knowledge of the pathophysiology of lung disease in patients with CF is described, along with the current treatment of CF lung disease, and the therapies in development that offer great promise to our patients.
Pharmacogenomic information in drug labels: European Medicines Agency perspective
The Pharmacogenomics Journal, 2015
Pharmacogenomics (PGx) has a growing impact on healthcare and constitutes one of the major pillars of personalised medicine. For the purpose of improved individualised drug treatment, there is an increasing effort to develop drugs suitable for specific subpopulations and to incorporate pharmacogenomic drug labels in existing and novel medicines. Here, we review the pharmacogenomic drug labels of all 517 medicinal products centrally approved in the European Union (EU) since the establishment of the European Medicines Agency in 1995. We identified all pharmacogenomic-related information mentioned in the product labels and classified it according to its main effect and function on drug treatment, that is, metabolism, transport and pharmacodynamics, and according to the place of the respective section of the Summary of Product Characteristics (SmPC). The labels are preferentially present in drugs having antineoplastic properties. We find that the number of drugs with pharmacogenomic labels in EU increases now steadily and that it will be an important task for the future to refine the legislation on how this information should be utilised for improvement of drug therapy.
PLoS ONE, 2014
To determine if oral dosing with the CFTR-potentiator ivacaftor (VX-770, Kalydeco) improves CFTR-dependent sweating in CF subjects carrying G551D or R117H-5T mutations, we optically measured sweat secretion from 32-143 individually identified glands in each of 8 CF subjects; 6 F508del/G551D, one G551D/R117H-5T, and one I507del/R117H-5T. Two subjects were tested only (2) ivacaftor, 3 only (+) ivacaftor and 3 (+/2) ivacaftor (1-5 tests per condition). The total number of gland measurements was 852 (2) ivacaftor and 906 (+) ivacaftor. A healthy control was tested 4 times (51 glands). For each gland we measured both CFTR-independent (M-sweat) and CFTR-dependent (C-sweat); C-sweat was stimulated with a badrenergic cocktail that elevated [cAMP] i while blocking muscarinic receptors. Absent ivacaftor, almost all CF glands produced M-sweat on all tests, but only 1/593 glands produced C-sweat (10 tests, 5 subjects). By contrast, 6/6 subjects (113/ 342 glands) produced C-sweat in the (+) ivacaftor condition, but with large inter-subject differences; 3-74% of glands responded with C/M sweat ratios 0.04%-2.57% of the average WT ratio of 0.265. Sweat volume losses cause proportionally larger underestimates of CFTR function at lower sweat rates. The losses were reduced by measuring C/M ratios in 12 glands from each subject that had the highest M-sweat rates. Remaining losses were estimated from single channel data and used to correct the C/M ratios, giving estimates of CFTR function (+) ivacaftor = 1.6%-7.7% of the WT average. These estimates are in accord with single channel data and transcript analysis, and suggest that significant clinical benefit can be produced by low levels of CFTR function.
PLoS ONE, 2013
To assess CFTR function in vivo, we developed a bioassay that monitors and compares CFTR-dependent and CFTRindependent sweat secretion in parallel for multiple (,50) individual, identified glands in each subject. Sweating was stimulated by intradermally injected agonists and quantified by optically measuring spherical sweat bubbles in an oil-layer that contained dispersed, water soluble dye particles that partitioned into the sweat bubbles, making them highly visible. CFTR-independent secretion (M-sweat) was stimulated with methacholine, which binds to muscarinic receptors and elevates cytosolic calcium. CFTR-dependent secretion (C-sweat) was stimulated with a b-adrenergic cocktail that elevates cytosolic cAMP while blocking muscarinic receptors. A C-sweat/M-sweat ratio was determined on a gland-by-gland basis to compensate for differences unrelated to CFTR function, such as gland size. The average ratio provides an approximately linear readout of CFTR function: the heterozygote ratio is ,0.5 the control ratio and for CF subjects the ratio is zero. During assay development, we measured C/M ratios in 6 healthy controls, 4 CF heterozygotes, 18 CF subjects and 4 subjects with 'CFTR-related' conditions. The assay discriminated all groups clearly. It also revealed consistent differences in the C/M ratio among subjects within groups. We hypothesize that these differences reflect, at least in part, levels of CFTR expression, which are known to vary widely. When C-sweat rates become very low the C/M ratio also tended to decrease; we hypothesize that this nonlinearity reflects ductal fluid absorption. We also discovered that M-sweating potentiates the subsequent C-sweat response. We then used potentiation as a surrogate for drugs that can increase CFTR-dependent secretion. This bioassay provides an additional method for assessing CFTR function in vivo, and is well suited for withinsubject tests of systemic, CFTR-directed therapeutics.
Novel opportunities for CFTR-targeting drug development using organoids
Rare diseases (Austin, Tex.), 2013
Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR mutations lead to production of non-functional CFTR, reduced amounts of normal functioning CFTR or misfolded CFTR with defects in trafficking or function. For decades, CF treatment has been focused on the symptoms of CF, but pharmacotherapy using small molecules that target the basic defect of CF, the mutant CFTR protein, is now possible for a limited amount of subjects with CF. This raises the exciting possibility that the majority of people with CF may receive effective treatment targeting the different CFTR mutants in the future. We recently described a functional CFTR assay using rectal biopsies from subjects with CF that were cultured in vitro into self-organizing mini-guts or organoids. We here describe how this model may assist in the discovery of new CFTR-targeting drugs, the subjects that may benefit from these drugs, and the mechanisms underlying variabi...
Nature Genetics, 2013
Allelic heterogeneity in disease-causing genes presents a substantial challenge to the translation of genomic variation into clinical practice. Few of the almost 2,000 variants in the cystic fibrosis transmembrane conductance regulator gene CFTR have empirical evidence that they cause cystic fibrosis. To address this gap, we collected both genotype and phenotype data for 39,696 individuals with cystic fibrosis in registries and clinics in North America and Europe. In these individuals, 59 CFTR variants had an allele frequency of ≥0.0%. These variants were evaluated for both clinical severity and functional consequence, with 27 (80%) meeting both clinical and functional criteria consistent with disease. Assessment of disease penetrance in 2,88 fathers of individuals with cystic fibrosis enabled assignment of 2 of the remaining 32 variants as neutral, whereas the other 20 variants remained of indeterminate effect. This study illustrates that sourcing data directly from well-phenotyped subjects can address the gap in our ability to interpret clinically relevant genomic variation.
Sinonasal Manifestations in Cystic Fibrosis
International Journal of Otolaryngology, 2012
Cystic fibrosis is a genetic disease, characterized by accumulation of thickened mucous secretions in exocrine glands. Although the major clinical manifestations of the disease are pancreatic and pulmonary disease, the majority of cystic fibrosis patients will develop sinonasal manifestations as well. This paper outlines the etiology, evaluation, and management of the nasal and sinus manifestations in patients with cystic fibrosis.
Ivacaftor Therapy in CF Patients: Single Center Experience
Advances in Medicine, 2014
Ivacaftor is the first novel cystic fibrosis pharmaceutical that acts at the molecular level to potentiate cystic fibrosis transmembrane conductance regulator (CFTR) function and was first approved for clinical use in 2012. We are sharing our single center experience of five patients: four from pediatric age group and one adult patient. All patients had both subjective and objective improvements in their health. Despite established lung disease, our patients had significant improvement in both their FEV1 (forced expiratory volume in 1 second) and FEF 25-75 and BMI (body mass index). Larger studies demonstrated only 6.7% improvement in mean FEV1 after starting Ivacaftor therapy but their patient population had normal lung function to begin with. In contrast our case series demonstrates that, in patients with established lung disease and diminished lung function, Ivacaftor can be expected to result in much higher recovery in lung function. Mean FEV1 improved by 35% in our case series. Ivacaftor is extremely expensive, costing $300,000 per patient per year requiring lifelong therapy, hence requiring prior authorizations from most third-party payers in the USA. The knowledge shared from our experience will be useful for other clinicians to petition healthcare policymakers on behalf of their patients.
Molecular biology of the cell, 2016
More than 2000 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) have been described that confer a range of molecular cell biological and functional phenotypes. Most of these mutations lead to compromised anion conductance at the apical plasma membrane of secretory epithelia and cause cystic fibrosis (CF) with variable disease severity. Based on the molecular phenotypic complexity of CFTR mutants and their susceptibility to pharmacotherapy, it has been recognized that mutations may impose combinatorial defects in CFTR channel biology. This notion led to the conclusion that the combination of pharmacotherapies addressing single defects (e.g., transcription, translation, folding, and/or gating) may show improved clinical benefit over available low-efficacy monotherapies. Indeed, recent phase 3 clinical trials combining ivacaftor (a gating potentiator) and lumacaftor (a folding corrector) have proven efficacious in CF patients harboring the most common mutatio...
Respiratory Research
Background Several small molecule corrector and potentiator drugs have recently been licensed for Cystic Fibrosis (CF) therapy. However, other aspects of the disease, especially inflammation, are less effectively treated by these drugs. We hypothesized that small molecule drugs could function either alone or as an adjuvant to licensed therapies to treat these aspects of the disease, perhaps emulating the effects of gene therapy in CF cells. The cardiac glycoside digitoxin, which has been shown to inhibit TNFα/NFκB signaling in CF lung epithelial cells, may serve as such a therapy. Methods IB3–1 CF lung epithelial cells were treated with different Vertex (VX) drugs, digitoxin, and various drug mixtures, and ELISA assays were used to assess suppression of baseline and TNFα-activated secretion of cytokines and chemokines. Transcriptional responses to these drugs were assessed by RNA-seq and compared with gene expression in AAV-[wildtype]CFTR-treated IB3–1 (S9) cells. We also compared i...
A G542X cystic fibrosis mouse model for examining nonsense mutation directed therapies
PLOS ONE
Nonsense mutations are present in 10% of patients with CF, produce a premature termination codon in CFTR mRNA causing early termination of translation, and lead to lack of CFTR function. There are no currently available animal models which contain a nonsense mutation in the endogenous Cftr locus that can be utilized to test nonsense mutation therapies. In this study, we create a CF mouse model carrying the G542X nonsense mutation in Cftr using CRISPR/Cas9 gene editing. The G542X mouse model has reduced Cftr mRNA levels, demonstrates absence of CFTR function, and displays characteristic manifestations of CF mice such as reduced growth and intestinal obstruction. Importantly, CFTR restoration is observed in G542X intestinal organoids treated with G418, an aminoglycoside with translational readthrough capabilities. The G542X mouse model provides an invaluable resource for the identification of potential therapies of CF nonsense mutations as well as the assessment of in vivo effectiveness of these potential therapies targeting nonsense mutations.
European Respiratory Review
In this article we analyse the current authorised treatments and trends in early drug development for cystic fibrosis (CF) in the European Union for the time period 2000–2016. The analysis indicates a significant improvement in the innovation and development of new potential medicines for CF, shifting from products that act on the symptoms of the disease towards new therapies targeting the cause of CF. However, within these new innovative medicines, results for CF transmembrane conductance regulator (CFTR) modulators indicate that one major challenge for turning a CF concept product into an actual medicine for the benefit of patients resides in the fact that, although pre-clinical models have shown good predictability for certain mutations, a good correlation to clinical end-points or biomarkers (e.g. forced expiratory volume in 1 s and sweat chloride) for all mutations has not yet been achieved. In this respect, the use of alternative end-points and innovative nonclinical models co...
BMC Sports Science, Medicine and Rehabilitation
Background: In people with cystic fibrosis (CF), higher exercise capacity is associated with better health-related quality of life (HRQoL), reduced risk of hospitalisation for a respiratory infection and survival. Therefore, optimisation of exercise capacity is an important treatment goal. The Australian and New Zealand clinical practice guidelines recommend that people with CF complete 30 to 60 min of moderate intensity aerobic exercise on most days of the week. This recommendation can be difficult to achieve by people with CF because of time constraints, and intolerable breathlessness and muscle fatigue during continuous exercise. In contrast, a low-volume, high intensity interval training (HIIT) program may be a more achievable and efficient training method to improve exercise capacity in people with CF. Methods: A randomised controlled trial will be undertaken. Forty people with CF (aged ≥15 years) will be randomly allocated, on a 1:1 ratio, to either the experimental or control group. Regardless of their group allocation, all participants will be asked to continue with their usual daily treatment for the study duration. Those in the experimental group will complete 8 weeks of thrice weekly HIIT on a cycle ergometer. Those in the control group will receive weekly contact with the investigators. The primary outcome of this study is exercise capacity. Secondary outcomes are HRQoL, exercise self-efficacy, feelings of anxiety, depression and enjoyment. These outcomes will be recorded at baseline (i.e. prior to randomisation) and following the 8week intervention period. The study will also report other outcomes of the HIIT program (cardiovascular responses, symptom response, post-exercise muscle soreness and tolerance) and behaviour change techniques such as reinforcement, feedback and goal setting, used during the HIIT program. Discussion: This study will determine the effects of 8-weeks of supervised, low-volume HIIT, completed on a cycle ergometer on measures of exercise capacity, HRQoL, exercise self-efficacy, feelings of anxiety, depression and enjoyment. If effective, this type of training could be an attractive alternative to traditional continuous training because it may be more achievable and time efficient. Trial registration: Australian and New Zealand Clinical Trials Registry (ANZCTR):12617001271392 (04/09/2017).
Reference percentiles for FEV1 and BMI in European children and adults with cystic fibrosis
Orphanet Journal of Rare Diseases, 2012
Background: The clinical course of Cystic Fibrosis (CF) is usually measured using the percent predicted FEV 1 and BMI Z-score referenced against a healthy population, since achieving normality is the ultimate goal of CF care. Referencing against age and sex matched CF peers may provide valuable information for patients and for comparison between CF centers or populations. Here, we used a large database of European CF patients to compute CF specific reference equations for FEV 1 and BMI, derived CF-specific percentile charts and compared these European data to their nearest international equivalents. Methods: 34859 FEV 1 and 40947 BMI observations were used to compute European CF specific percentiles. Quantile regression was applied to raw measurements as a function of sex, age and height. Results were compared with the North American equivalent for FEV 1 and with the WHO 2007 normative values for BMI. Results: FEV 1 and BMI percentiles illustrated the large variability between CF patients receiving the best current care. The European CF specific percentiles for FEV 1 were significantly different from those in the USA from an earlier era, with higher lung function in Europe. The CF specific percentiles for BMI declined relative to the WHO standard in older children. Lung function and BMI were similar in the two largest contributing European Countries (France and Germany). Conclusion: The CF specific percentile approach applied to FEV 1 and BMI allows referencing patients with respect to their peers. These data allow peer to peer and population comparisons in CF patients.
Healthcare
Treatment adherence in adults with cystic fibrosis (CF) is poor. One of the reasons identified for lack of adherence to nebulised treatments is that patients may not experience any immediate relief in their symptoms or notice changes as a result of taking their treatment, thus many report that they do not perceive there to be consequences of non adherence. The aim of the study was to investigate the temporal relationships between symptoms and adherence to nebulised treatments in adults with CF using an N-of-1 observational design. Six participants were recruited for a six-week period during which time they completed a daily online respiratory symptom questionnaire. Adherence to treatment was measured throughout the duration of the study using an eTrack® nebuliser that logged date and time of treatments taken. Data generated from each participant was analysed separately. There were significant relationships between pain and adherence for three participants, tiredness and adherence fo...
Antibiotics, 2015
The lack of new antibacterial drugs entering the market and their misuse have resulted in the emergence of drug-resistant bacteria, posing a major health crisis worldwide. In particular, meticillin-resistant Staphylococcus aureus (MRSA), a pathogen responsible for numerous human infections, has become endemic in hospitals worldwide. Drug repurposing, the finding of new therapeutic indications for approved drugs, is deemed a plausible solution to accelerate drug discovery and development in this area. Towards this end, we screened 1163 drugs approved by the Food and Drug Administration (FDA) for bioactivities against MRSA in a 10 μM single-point assay. After excluding known antibiotics and antiseptics, six compounds were identified and their MICs were determined against a panel of clinical MRSA strains. A toxicity assay using human keratinocytes was also conducted to gauge their potential for repurposing as topical agents for treating MRSA skin infections.
Frontiers in pharmacology, 2018
Ivacaftor is a drug used to treat cystic fibrosis (CF) patients carrying specific gating mutations. Interpatient variability in the lung response has been shown to be partly explained by rs7512462 in the Solute Carrier Family 26 Member 9 () gene. In an independent and larger cohort, we aimed to evaluate whether variants contribute to the variability of the lung phenotype and if they influence the lung response to ivacaftor. We genotyped the French CF Gene Modifier Study cohort ( = 4,840) to investigate whether variants were involved in the lung phenotype heterogeneity. Their influence in the response to ivacaftor was tested in the 30 treated patients who met the inclusion criteria: older than 6 years of age, percent-predicted forced expiratory volume measured in 1 s (FEV) in the 3 months before treatment initiation ranging between 40 and 90%. Response to treatment was determined by the change in FEV from baseline, averaged in 15-75 days, and the 1st-year post-treatment. We observed ...
Novel outcome measures for clinical trials in cystic fibrosis
Pediatric Pulmonology, 2014
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Conflicts of Interest: Harm Tiddens has received research grants from Novartis, Gilead, Roche and Chiesi for the "BV Kindergeneeskunde" of the Erasmus Medical Center Sophia Children's Hospital in the last 3 years. The BV Kindergeneeskunde has also received honoraria for participation in expert panels for Novartis, Gilead, Roche, Insmed, Pharmaxis, and Vertex. Michael Puderbach has received support from DFG, BMBF, and Mukoviszidose e.V. grand, as well as honoraria for participation in an expert panel for Novartis. Jose Venegas has received honoraria for lecturing for Bayer and for participating in an expert panel for Novartis. He has also received research funding from Air Liquide. Felix Ratjen has received honoraria for serving as a consultant and lecturing for Novartis. Scott Donaldson has received research grants from the NIH/NHLBI and CFF, and funding from research contracts with Vertex Pharmaceuticals, MPEX Pharmaceuticals, Gilead Sciences, Novartis and Parion Sciences. Stephanie Davis has served on advisory boards for Novartis, Vertex Pharmaceuticals and as a non-paid consultant for Eli Lilly. She has given lectures that were sponsored through educational grants from Vertex Pharmaceuticals and Gilead. She has also received research grants from the NIH and CFF. Steven Rowe has received funding for the design and conduct of clinical trials from Vertex Pharmaceuticals, PTC Therapeutics, N30 Pharmaceuticals and Novartis. His present work is supported by CFF (CLANCY05Y2) and NIH (R01HL116213). Scott D. Sagel has received research grants from the NIH/NHLBI and CFF. Mark Higgins and David Waltz were employees of Novartis at the time of this work and are currently employees of Vertex Pharmaceuticals, Inc.
Italian Journal of Pediatrics
Background For a number of persons with rare diseases (RDs) a definite diagnosis remains undiscovered with relevant physical, psychological and social consequences. Undiagnosed RDs (URDs) require other than specialised clinical centres, outstanding molecular investigations, common protocols and dedicated actions at national and international levels; thus, many “Undiagnosed RDs programs” have been gradually developed on the grounds of a well-structured multidisciplinary approach. Methods The Italian Undiagnosed Rare Diseases Network (IURDN) was established in 2016 to improve the level of diagnosis of persons with URD living in Italy. Six Italian Centres of Expertise represented the network. The National Centre for Rare Diseases at the Istituto Superiore di Sanità coordinates the whole project. The software PhenoTips was used to collect the information of the clinical cases. Results One hundred and ten cases were analysed between March 2016 and June 2019. The age of onset of the disea...
Cystic fibrosis: current therapeutic targets and future approaches
Journal of Translational Medicine, 2017
Objectives: Study of currently approved drugs and exploration of future clinical development pipeline therapeutics for cystic fibrosis, and possible limitations in their use. Methods: Extensive literature search using individual and a combination of key words related to cystic fibrosis therapeutics. Key findings: Cystic fibrosis is an autosomal recessive disorder due to mutations in CFTR gene leading to abnormality of chloride channels in mucus and sweat producing cells. Respiratory system and GIT are primarily involved but eventually multiple organs are affected leading to life threatening complications. Management requires drug therapy, extensive physiotherapy and nutritional support. Previously, the focus was on symptomatic improvement and complication prevention but recently the protein rectifiers are being studied which are claimed to correct underlying structural and functional abnormalities. Some improvement is observed by the corrector drugs. Other promising approaches are gene therapy, targeting of cellular interactomes, and newer drugs for symptomatic improvement. Conclusions: The treatment has a long way to go as most of the existing therapeutics is for older children. Other limiting factors include mutation class, genetic profile, drug interactions, adverse effects, and cost. Novel approaches like gene transfer/gene editing, disease modeling and search for alternative targets are warranted.
Pharmacogenomics in the Era of Next Generation Sequencing – from Byte to Bedside
Drug Metabolism Reviews
Pharmacogenetic research has resulted in the identification of a multitude of genetic variants that impact drug response or toxicity. These polymorphisms are mostly common and have been included as actionable information in the labels of numerous drugs. In addition to common variants, recent advances in Next Generation Sequencing (NGS) technologies have resulted in the identification of a plethora of rare and population-specific pharmacogenetic variations with unclear functional consequences that are not accessible by conventional forward genetics strategies. In this review, we discuss how comprehensive sequencing information can be translated into personalized pharmacogenomic advice in the age of NGS. Specifically, we provide an update of the functional impacts of rare pharmacogenetic variability and how this information can be leveraged to improve pharmacogenetic guidance. Furthermore, we critically discuss the current status of implementation of pharmacogenetic testing across drug development and layers of care. We identify major gaps and provide perspectives on how these can be minimized to optimize the utilization of NGS data for personalized clinical decision-support.
ATP‐Sensitive Potassium Channels and Their Physiological and Pathophysiological Roles
Comprehensive Physiology
ATP sensitive potassium channels (K ATP) are so named because they open as cellular ATP levels fall. This leads to membrane hyperpolarisation and thus links cellular metabolism to membrane excitability. They also respond to MgADP and are regulated by a number of cell signalling pathways. They have a rich and diverse pharmacology with a number of agents acting as specific inhibitors and activators. K ATP channels are formed of pore-forming subunits, Kir6.1 and Kir6.2, and a large auxiliary subunit, the sulphonylurea receptor (SUR1, SUR2A and SUR2B). The Kir6.0 subunits are a member of the inwardly rectifying family of potassium channels and the sulphonylurea receptor is part of the ATP binding cassette family of proteins. Four SURs and four Kir6.x form an octameric channel complex and the association of a particular SUR with a specific Kir6.x subunit constitutes the K ATP current in a particular tissue. A combination of mutagenesis work combined with structural studies has identified how these channels work as molecular machines. They have a variety of physiological roles including controlling the release of insulin from pancreatic β cells and regulating blood vessel tone and blood pressure. Furthermore, mutations in the genes underlie human diseases such as congenital diabetes and hyperinsulinism. Additionally, opening of these channels is protective in a number of pathological conditions such as myocardial ischaemia and stroke. Didactic Synopsis Major teaching points ATP-sensitive potassium channels (K ATP) are widely distributed and characteristically are activated by falling cellular ATP levels. K ATP channels link membrane excitability to cellular metabolism. K ATP channels have a rich and diverse pharmacology with specific inhibitors such as glibenclamide and openers such as diazoxide. The channel is an octamer formed of four inwardly rectifying potassium channels of the Kir6.0 family and four sulphonylurea receptor subunits, a member of the ATP binding cassette family of proteins. Extensive mutagenesis experiments and recent structural studies have defined many aspects of how the channel works as a molecular machine. K ATP channels are key to the release of insulin from pancreatic β cells. K ATP channels in the heart are involved in adaptation to exercise and cellular protection and in vascular smooth muscle controlling vascular tone and blood pressure. K ATP channels are present in the brain and may be involved in neuroprotection and nutrient sensing. Mutations in K ATP channel subunits can result in human disease and includes disorders of insulin handling, cardiac arrhythmia, cardiomyopathy and neurological abnormalities.
Frontiers in Cellular and Infection Microbiology, 2017
The function of cystic fibrosis transmembrane conductance regulator (CFTR) channels is crucial in human airways. However unfortunately, chronic Pseudomonas aeruginosa infection has been shown to impair CFTR proteins in non-CF airway epithelial cells (AEC) and to alter the efficiency of new treatments with CFTR modulators designed to correct the basic CFTR default in AEC from cystic fibrosis (CF) patients carrying the F508del mutation. Our aim was first to compare the effect of laboratory strains, clinical isolates, engineered and natural mutants to determine the role of the LasR quorum sensing system in CFTR impairment, and second, to test the efficiency of a quorum sensing inhibitor to counteract the deleterious impact of P. aeruginosa both on wt-CFTR and on the rescue of F508del-CFTR by correctors. We first report that exoproducts from either the laboratory PAO1 strain or a clinical ≪Early≫ isolate (from an early stage of infection) altered CFTR expression, localization and function in AEC expressing wt-CFTR. Genetic inactivation of the quorum-sensing LasR in PAO1 (PAO1 lasR) or in a natural clinical mutant (≪Late≫ CF-adapted clinical isolate) abolished wt-CFTR impairment. PAO1 exoproducts also dampened F508del-CFTR rescue by VRT-325 or Vx-809 correctors in CF cells, whereas PAO1 lasR had no impact. Importantly, treatment of P. aeruginosa cultures with a quorum sensing inhibitor (HDMF) prevented the negative effect of P. aeruginosa exoproducts on wt-CFTR and preserved CFTR rescue by correctors in CF AEC. These findings indicate that LasR-interfering strategies could be of benefits to counteract the deleterious effect of P. aeruginosa in infected patients.
The activin A antagonist follistatin inhibits cystic fibrosis-like lung inflammation and pathology
Immunology and cell biology, 2015
Cystic fibrosis (CF) is the most common life-limiting genetically acquired respiratory disorder. Patients with CF have thick mucus obstructing the airways leading to recurrent infections, bronchiectasis and neutrophilic airway inflammation culminating in deteriorating lung function. Current management targets airway infection and mucus clearance, but despite recent advances in care, life expectancy is still only 40 years. We investigated whether activin A is elevated in CF lung disease and whether inhibiting activin A with its natural antagonist follistatin retards lung disease progression. We measured serum activin A levels, lung function and nutritional status in CF patients. We studied the effect of activin A on CF lung pathogenesis by treating newborn CF transgenic mice (β-ENaC) intranasally with the natural activin A antagonist follistatin. Activin A levels were elevated in the serum of adult CF patients, and correlated inversely with lung function and body mass index. Follista...
Journal of Biomolecular Screening, 2016
Drug candidates exhibiting well-defined pharmacokinetic and pharmacodynamic profiles that are otherwise safe often fail to demonstrate proof-of-concept in phase II and III trials. Innovation in drug discovery and development has been identified as a critical need for improving the efficiency of drug discovery, especially through collaborations between academia, government agencies, and industry. To address the innovation challenge, we describe a comprehensive, unbiased, integrated, and iterative quantitative systems pharmacology (QSP)–driven drug discovery and development strategy and platform that we have implemented at the University of Pittsburgh Drug Discovery Institute. Intrinsic to QSP is its integrated use of multiscale experimental and computational methods to identify mechanisms of disease progression and to test predicted therapeutic strategies likely to achieve clinical validation for appropriate subpopulations of patients. The QSP platform can address biological heteroge...
Manipulating proteostasis to repair the F508del-CFTR defect in cystic fibrosis
Molecular and Cellular Pediatrics, 2016
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Pediatric Research
BACKGROUND: There is a need to prognosticate the severity of cystic fibrosis (CF) detected by newborn screening (NBS) by early assessment of CF transmembrane conductance regulator (CFTR) protein function. We introduce novel instrumentation and protocol for evaluating CFTR activity as reflected by β-adrenergically stimulated sweat secretion. METHODS: A pixilated image sensor detects sweat rates. Compounds necessary for maximum sweat gland stimulation are applied by iontophoresis, replacing ID injections. Results are compared to a validated β-adrenergic assay that measures sweat secretion by evaporation (evaporimetry). RESULTS: Ten healthy controls (HC), 6 heterozygous (carriers), 5 with CFTR-related metabolic syndrome (CRMS)/CF screen-positive, inconclusive diagnosis (CFSPID), and 12 CF individuals completed testing. All individuals with minimal and residual function CFTR mutations had low ratios of β-adrenergically stimulated sweat rate to cholinergically stimulated sweat rate (β/chol) as measured by either assay. CONCLUSIONS: β-Adrenergic assays quantitate CFTR dysfunction in the secretory pathway of sweat glands in CF and CRMS/ CFSPID populations. This novel image-sensor and iontophoresis protocol detect CFTR function with minimal and residual function and is a feasible test for young children because it is insensible to movement and it decreases the number of injections. It may also assist to distinguish between CF and CRMS/CFSPID diagnosis.
Sixty-five years since the New York heat wave: Advances in sweat testing for cystic fibrosis
Pediatric Pulmonology, 2013
The sweat test remains important as a diagnostic test for cystic fibrosis (CF) and has contributed greatly to our understanding of CF as a disease of epithelial electrolyte transport. The standardization of the sweat test, by Gibson and Cooke [Gibson and Cooke (1959) Pediatrics 1959;23:5], followed observations of excessive dehydration amongst patients with CF and confirmed the utility as a diagnostic test. Quantitative pilocarpine iontophoresis remains the gold standard for sweat induction, but there are a number of collection and analytical methods. The pathophysiology of electrolyte transport in sweat was described by Quinton [Quinton (1983) Nature 1983;301:421-422], and this complemented the developments in genetics that discovered the cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial-based electrolyte transport protein. Knowledge of CF has since increased rapidly and further developments in sweat testing include: new collection methods, further standardization of the technique with international recommendations and age related reference intervals. More recently, sweat chloride values have been used as proof of effect for the new drugs that activate CFTR. However, there remain issues with adherence to sweat test guidelines in many countries and there are gaps in our knowledge, including reference intervals for some age groups and stability of sweat samples in transport. Furthermore, modern methods of elemental quantification need to be explored as alternatives to the original analytical methods for sweat electrolyte measurement. The purpose of this review is therefore to describe the development of the sweat test and consider future directions. Pediatr Pulmonol.
Scientific reports, 2017
Adult-onset vitelliform macular dystrophy (AVMD) is a common and benign macular degeneration which can be caused by BEST1 mutation. Here, we investigated the clinical characteristics associated with a newly identified BEST1 mutation, p.Ile38Ser and confirmed the associated physiological functional defects. The 51-year-old patient presented bilateral small subretinal yellow deposits. Consistent with AVMD, the corresponding lesions showed hyperautofluorescence, late staining in fluorescein angiography, and subretinal hyper-reflective materials in spectral-domain optical coherence tomography. Genetic analysis demonstrated that the patient presented with a heterozygous p.Ile38Ser BEST1 mutation. Surface biotinylation and patch clamp experiments were performed in transfected HEK293T cells. Although, the identified BEST1 mutant maintains normal membrane expression, p.Ile38Ser mutant showed significantly smaller currents than wild type (WT). However, it showed larger currents than other BE...
Genomics and Transcriptomics: The Powerful Technologies in Precision Medicine
International Journal of General Medicine
In a clinical trial, people with the same disease can show different responses after treatment with the same drug and exactly under the same conditions. Some of them may improve, some may not show any response, and occasionally side effects may be observed. In other words, people with the same disease process under the same therapeutic conditions may have different responses. Today, some diseases are resistant to conventional (standard) treatment procedures. Why do people with the same disease show different responses to the treatment with the same drug? This is primarily due to differences in molecular pathways (especially genetic variations) associated with the disease. On the other hand, designing and delivery of a new drug is a time-consuming and costly process, so any mistake in any stage of this process can have irreparable consequences for pharmaceutical companies and consumer patients. Therefore, we can achieve more accurate and reliable treatments by acquiring precise insight into different aspects of precision medicine including genomics and transcriptomics. The aim of this paper is to address the role of genomics and transcriptomics in precision medicine.
Hepatology, 2016
ABCB4 (MDR3) is an adenosine triphosphate (ATP)-binding cassette (ABC) transporter expressed at the canalicular membrane of hepatocytes, where it mediates phosphatidylcholine (PC) secretion. Variations in the ABCB4 gene are responsible for several biliary diseases, including progressive familial intrahepatic cholestasis type 3 (PFIC3), a rare disease that can be lethal in the absence of liver transplantation. In this study, we investigated the effect and potential rescue of ABCB4 missense variations that reside in the highly conserved motifs of ABC transporters, involved in ATP binding. Five disease-causing variations in these motifs have been identified in ABCB4 (G535D, G536R, S1076C, S1176L, and G1178S), three of which are homologous to the gating mutations of cystic fibrosis transmembrane conductance regulator (CFTR or ABCC7; i.e., G551D, S1251N, and G1349D), that were previously shown to be function defective and corrected by ivacaftor (VX-770; Kalydeco), a clinically approved CFTR potentiator. Three-dimensional structural modeling predicted that all five ABCB4 variants would disrupt critical interactions in the binding of ATP and thereby impair ATPinduced nucleotide-binding domain dimerization and ABCB4 function. This prediction was confirmed by expression in cell models, which showed that the ABCB4 mutants were normally processed and targeted to the plasma membrane, whereas their PC secretion activity was dramatically decreased. As also hypothesized on the basis of molecular modeling, PC secretion activity of the mutants was rescued by the CFTR potentiator, ivacaftor (VX-770). Conclusion: Diseasecausing variations in the ATP-binding sites of ABCB4 cause defects in PC secretion, which can be rescued by ivacaftor. These results provide the first experimental evidence that ivacaftor is a potential therapy for selected patients who harbor mutations in the ATP-binding sites of ABCB4. (HEPATOLOGY 2017;65:560-570) A BCB4, also called MDR3 (multidrug resistance protein 3), is a phospholipid floppase almost exclusively expressed at the canalicular membrane of hepatocytes where its function is to translocate phosphatidylcholine (PC) into bile. (1,2) Variations in the ABCB4 gene sequence cause several chronic and progressive liver diseases. (3) The most severe is progressive familial intrahepatic cholestasis type 3 (PFIC3), which develops early in childhood and most often requires liver transplantation (LT). Less-severe disorders are intrahepatic cholestasis of pregnancy (ICP) and low-phospholipid-associated
Annals of the American Thoracic Society, 2016
Remarkable advances in the management of individuals born with cystic fibrosis (CF) would not have been realized without empiric trial and error by CF clinicians with treatments developed and available for other purposes. As the testing and registration of CF-specific treatments have increased, so too have associated health care costs, particularly those of chronic medications. The transition of CF from a lethal pediatric disease to a life-shortening one with an adult majority, concurrent with sharp increases in chronic medication costs, has placed many CF treatments under increased scrutiny by third-party payers, particularly when prescribed to individuals from CF subpopulations that may not have been included in registration trials. Despite overall health improvements in the CF cohort and the increasing availability of CF-specific therapies, many physicians remain tasked with managing the health of patients from subpopulations that may be too young, too sick, or too complicated to have been included in clinical trials. An understanding of why particular CF subpopulations may have been excluded from registration trials, as well as consideration of a treatment's described mechanism of action, can support assessment for the potential for benefit (and risk) in these populations and help physicians advocate for patient access to treatments.
A small molecule that induces translational readthrough of CFTR nonsense mutations by eRF1 depletion
Nature Communications
Premature termination codons (PTCs) prevent translation of a full-length protein and trigger nonsense-mediated mRNA decay (NMD). Nonsense suppression (also termed readthrough) therapy restores protein function by selectively suppressing translation termination at PTCs. Poor efficacy of current readthrough agents prompted us to search for better compounds. An NMD-sensitive NanoLuc readthrough reporter was used to screen 771,345 compounds. Among the 180 compounds identified with readthrough activity, SRI-37240 and its more potent derivative SRI-41315, induce a prolonged pause at stop codons and suppress PTCs associated with cystic fibrosis in immortalized and primary human bronchial epithelial cells, restoring CFTR expression and function. SRI-41315 suppresses PTCs by reducing the abundance of the termination factor eRF1. SRI-41315 also potentiates aminoglycoside-mediated readthrough, leading to synergistic increases in CFTR activity. Combining readthrough agents that target distinct ...
Chemically modified hCFTR mRNAs recuperate lung function in a mouse model of cystic fibrosis
Scientific Reports
Gene therapy has always been a promising therapeutic approach for Cystic Fibrosis (CF). However, numerous trials using DNA or viral vectors encoding the correct protein resulted in a general low efficacy. In the last years, chemically modified messenger RNA (cmRNA) has been proven to be a highly potent, pulmonary drug. Consequently, we first explored the expression, function and immunogenicity of human (h)CFTR encoded by cmRNA hCFTR in vitro and ex vivo, quantified the expression by flow cytometry, determined its function using a YFP based assay and checked the immune response in human whole blood. Similarly, we examined the function of cmRNA hCFTR in vivo after intratracheal (i.t.) or intravenous (i.v.) injection of the assembled cmRNA hCFTR together with Chitosan-coated PLGA (poly-D, L-lactide-co-glycolide 75:25 (Resomer RG 752 H)) nanoparticles (NPs) by FlexiVent. The amount of expression of human hCFTR encoded by cmRNA hCFTR was quantified by hCFTR ELISA, and cmRNA hCFTR values were assessed by RT-qPCR. Thereby, we observed a significant improvement of lung function, especially in regards to FEV 0.1 , suggesting NP-cmRNA hCFTR as promising therapeutic option for CF patients independent of their CFTR genotype. Cystic fibrosis (CF), the most common life-limiting autosomal-recessive disease in the Caucasian population (1/2,500 newborns), affects more than 80,000 people worldwide 1. It is caused by different mutations within the gene encoding for the CF transmembrane conductance regulator (CFTR). Those mutations result in impaired anion secretion and hyper-absorption of sodium ions across epithelia 2,3. Chronic lung disease and slow lung degradation are the major contributing factors to both mortality and strongly reduced quality of life 4,5. With currently available therapies, the mean survival is between 35 and 45 years 6,7. Since the CFTR gene was first cloned in 1989, many efforts have been made to deal with the mutations at a cellular and genetic level 8,9. Gene therapy approaches made it quickly to the clinic aiming to deliver viral CFTR-encoding vectors (such as adenoviruses (Ad) or adeno-associated viruses (AAV)) to CF patients 10. However, none of the clinical studies and current treatments seem to provide sufficient human (h)CFTR expression to prevent the ultimately lethal CF symptoms in the respiratory tract of CF patients. Furthermore, repeated administration of viral vectors or DNA may lead to the development of unwanted immune reactions, mainly due to viral capsids and vector-encoded proteins 10-12. Newly designed viral vectors circumvent those problems and can be administered repeatedly, but from a clinical perspective, the field is still in need of a therapeutic tool that combines efficient expression in lungs and other (affected) organs and cells while avoiding immunogenicity and genotoxicity completely 13-15. The non-viral
Modified hCFTR mRNA restores normal lung function in a mouse model of cystic fibrosis
Being a classic monogenic disease, gene therapy has always been a promising therapeutic approach for Cystic Fibrosis (CF). However, numerous trials using DNA or viral vectors encoding the correct protein resulted in a general low efficacy. In the last years, chemically modified messenger RNA (cmRNA) has been proven to be a highly potent, pulmonary effective drug. We thus explored the expression of human (h)CFTR encoded by hCFTR cmRNA in vitro, analyzed by flow cytometry and Western Blot and its function with a YFP assay. Very similar effects could be observed in vivo when hCFTR cmRNA was assembled with Chitosan-coated PLGA to nanoparticles (NPs) and intratracheally (i.t.) or intravenously (i.v) injected, the latter one as an alternative administration route to circumvent the clogged airways of CF patients. This significantly improved lung function, which suggests that hCFTR cmRNA-NPs are a promising therapeutic option for CF patients independent of their CFTR genotype.
Real-World Outcomes of Ivacaftor Treatment in People with Cystic Fibrosis: A Systematic Review
Journal of Clinical Medicine
Cystic fibrosis (CF) is a rare, progressive, multi-organ genetic disease. Ivacaftor, a small-molecule CF transmembrane conductance regulator modulator, was the first medication to treat the underlying cause of CF. Since its approval, real-world clinical experience on the use of ivacaftor has been documented in large registries and smaller studies. Here, we systematically review data from real-world observational studies of ivacaftor treatment in people with CF (pwCF). Searches of MEDLINE and Embase identified 368 publications reporting real-world studies that enrolled six or more pwCF treated with ivacaftor published between January 2012 and September 2019. Overall, 75 publications providing data from 57 unique studies met inclusion criteria and were reviewed. Studies reporting within-group change for pwCF treated with ivacaftor consistently showed improvements in lung function, nutritional parameters, and patient-reported respiratory and sino-nasal symptoms. Benefits were evident a...
Clinical care for primary ciliary dyskinesia: current challenges and future directions
European Respiratory Review
Primary ciliary dyskinesia (PCD) is a rare genetic disease that affects the motility of cilia, leading to impaired mucociliary clearance. It is estimated that the vast majority of patients with PCD have not been diagnosed as such, providing a major obstacle to delivering appropriate care. Challenges in diagnosing PCD include lack of disease-specific symptoms and absence of a single, “gold standard”, diagnostic test. Management of patients is currently not based on high-level evidence because research findings are mostly derived from small observational studies with limited follow-up period. In this review, we provide a critical overview of the available literature on clinical care for PCD patients, including recent advances. We identify barriers to PCD research and make suggestions for overcoming challenges.
Chronic Rhinosinusitis in Cystic Fibrosis: Diagnosis and Medical Management
Medical Sciences
Chronic rhinosinusitis (CRS) is nearly ubiquitous in patients with cystic fibrosis (CF). CF CRS is a challenging entity to define, diagnose, and treat, as patients often have severe refractory sinus disease in addition to complex medical comorbidities. The purpose of this article is to review the literature on the medical management of CF CRS and determine how to best identify, diagnose, and manage CF CRS. Ultimately, the treatment of these patients requires a multi-disciplinary approach involving the pulmonologist and otolaryngologist.
Current Treatment Options for Cystic Fibrosis-Related Liver Disease
International Journal of Molecular Sciences
Cystic Fibrosis-related liver disease (CFLD) has become a leading cause of morbidity and mortality in patients with Cystic Fibrosis (CF), and affects children and adults. The understanding of the pathogenesis of CFLD is key in order to develop efficacious treatments. However, it remains complex, and has not been clarified to the last. The search for a drug might be additionally complicated due to the diverse clinical picture and lack of a unified definition of CFLD. Although ursodeoxycholic acid has been used for decades, its efficacy in CFLD is controversial, and the potential of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators and targeted gene therapy in CFLD needs to be defined in the near future. This review focuses on the current knowledge on treatment strategies for CFLD based on pathomechanistic viewpoints.
Organization of Patient Management and Fungal Epidemiology in Cystic Fibrosis
Mycopathologia
The achievement of a better life for cystic fibrosis (CF) patients is mainly caused by a better management and infection control over the last three decades. Herein, we want to summarize the cornerstones for an effective management of CF patients and to give an overview of the knowledge about the fungal epidemiology in this clinical context in Europe. Data from a retrospective analysis encompassing 66,616 samples from 3235 CF patients followed-up in 9 CF centers from different European countries are shown.
Role of Neutrophils in Cystic Fibrosis Lung Disease
Role of Neutrophils in Disease Pathogenesis, 2017
Cystic fibrosis (CF) is a genetic syndrome caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene. In CF patients, chief morbidity and mortality are due to pulmonary manifestations. CFTR lack/dysfunction brings an altered ion flux through the airway epithelium and ablation of mucociliary clearance, which in turn ensues in colonization and infection by opportunistic bacterial pathogens and subsequent neutrophil-dominated inflammation. This response eventually leads to the damage of the lung tissue. A host of inflammatory mediators attract, activate, and reprogramme neutrophils to survive (avoiding apoptosis) and produce a wealth of proteases and radical oxygen species. The protease/antiprotease imbalance and oxidative stress have multiple downstream effects, including impaired mucus clearance, increased and self-perpetuating inflammation, and impaired immune responses, thus facilitating and fostering bacterial infections. On the other hand, CFTR lack or dysfunction is likely responsible for alterations in neutrophils concerning chemotaxis, phagocytosis, oxidative burst, degranulation, and neutrophil extracellular trap (NET) formation. A good opportunity to reveal new and non-invasive biomarkers of CF lung disease is the evaluation of circulating neutrophils. Indeed, neutrophil responses are now investigated as outcomes of the aetiological therapies in CF, such as hypertonic saline, antiproteases, CFTR correctors and potentiators.
Three-Dimensional Airway Spheroids and Organoids for Cystic Fibrosis Research
Journal of Respiration
Cystic fibrosis (CF) is an autosomal recessive multi-organ disease caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, with morbidity and mortality primacy related to the lung disease. The CFTR protein, a chloride/bicarbonate channel, is expressed at the apical side of airway epithelial cells and is mainly involved in appropriate ion and fluid transport across the epithelium. Although many animal and cellular models have been developed to study the pathophysiological consequences of the lack/dysfunction of CFTR, only the three-dimensional (3D) structures termed “spheroids” and “organoids” can enable the reconstruction of airway mucosa to model organ development, disease pathophysiology, and drug screening. Airway spheroids and organoids can be derived from different sources, including adult lungs and induced pluripotent stem cells (iPSCs), each with its advantages and limits. Here, we review the major features of airway spheroids and organoids, anticipatin...
PLoS ONE, 2019
Cystic fibrosis (CF) is caused by mutations in the gene encoding the epithelial chloride channel CF transmembrane conductance regulator (CFTR) protein. The most common mutation is a deletion of three nucleotides leading to the loss of phenylalanine at position 508 (p.Phe508del) in the protein. This study evaluates eluforsen, a novel, single-stranded, 33-nucleotide antisense oligonucleotide designed to restore CFTR function, in in vitro and in vivo models of p.Phe508del CF. The aims of the study were to demonstrate cellular uptake of eluforsen, and its efficacy in functional restoration of p.Phe508del-CFTR both in vitro and in vivo. In vitro, the effect of eluforsen was investigated in human CF pancreatic adenocarcinoma cells and human bronchial epithelial cells. Two mouse models were used to evaluate eluforsen in vivo. In vitro, eluforsen improved chloride efflux in CF pancreatic adenocarcinoma cell cultures and increased short-circuit current in primary human bronchial epithelial c...
The Pharmacokinetic Interaction between Ivacaftor and Ritonavir in Healthy Volunteers
British journal of clinical pharmacology, 2017
The aim of this study was to determine the pharmacokinetic interaction between ivacaftor and ritonavir. A liquid chromatography mass spectrometry (LC-MS) method was developed for the measurement of ivacaftor in plasma. An open-label, sequential, cross-over study was conducted with 12 healthy volunteers. Three pharmacokinetic profiles were assessed for each volunteer: ivacaftor 150 mg alone (study A) ivacaftor 150 mg plus ritonavir 50 mg daily (study B) and ivacaftor 150 mg plus ritonavir 50 mg daily after two weeks of ritonavir 50 mg daily (study C). Addition of ritonavir 50 mg daily to ivacaftor 150 mg resulted in significant inhibition of the metabolism ivacaftor. Area under the plasma concentration-time curve from time 0 to infinity (AUC0-inf obv ) was significantly increased in both studies B and C compared to study A (GMR [95% CI] 19.71 [13.18-31.33] and 19.74 [14.0-27.93] respectively). Elimination half-life (T1/2 ) was significantly longer in both studies B and C compared to ...
Translational research in pediatric pulmonary disease, 2017
Clinical and Translational Medicine
As readers of this journal know, translational research is the application of basic science findings to improve clinical care; a process that was once called "bench-to-bedside" research. In my field of pediatric pulmonary disease, the rapid advancement of basic science understanding into improved clinical care has been, to use an appropriate term, breathtaking. In this perspective article, I will describe a few of these advances, as they relate to specific pulmonary diseases.
ERJ Open Research
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator gene (CFTR) that result in diminished quantity and/or function of the CFTR anion channel. F508del-CFTR, the most common CF-causing mutation (found in ∼90% of patients), causes severe processing and trafficking defects, resulting in decreased CFTR quantity and function. CFTR modulators are medications that increase the amount of mature CFTR protein (correctors) or enhance channel function (potentiators) at the cell surface.Combinations of CFTR correctors and potentiators (i.e. lumacaftor/ivacaftor, tezacaftor/ivacaftor) have demonstrated clinical benefit in subsets of patients. However, none are approved for patients with CF heterozygous for F508del-CFTR and a minimal function mutation, i.e. a mutation that produces either no protein or protein that is unresponsive to currently approved CFTR modulators. Next-generation CFTR correctors VX-659 and VX-445, each in triple combination with tezacaftor...
Diabetes, obesity & metabolism, 2018
Impaired glucose tolerance (IGT) in cystic fibrosis (CF) manifests as postprandial hyperglycaemia. Pancreatic enzyme supplementation reduces the latter; restoring incretin secretion and slowing gastric emptying. We aimed to determine the acute effect of exenatide on postprandial glycaemia in young people with CF and IGT. Six participants with CF and IGT were studied on 2 days, in a double-blind randomized crossover trial. After overnight fasting, they received exenatide 2.5 mcg or placebo (0.9% saline) subcutaneously 15 minutes before a pancake meal labelled with C octanoate and pancreatic enzyme replacement. The primary outcomes, area under the curve over 240 minutes (AUC ) for blood glucose (P < 0.0001) and peak blood glucose (7.65 mM ± 0.34 [mean ± SE] vs 9.53 mM ± 0.63, P < 0.0001), were markedly lower after exenatide than placebo. AUC for insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) was also lower after exenati...
Assays of CFTR Function In Vitro, Ex Vivo and In Vivo
International Journal of Molecular Sciences
Cystic fibrosis, a multi-organ genetic disease, is characterized by abnormal function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel at the apical membrane of several epithelia. In recent years, therapeutic strategies have been developed to correct the CFTR defect. To evaluate CFTR function at baseline for diagnosis, or the efficacy of CFTR-restoring therapy, reliable tests are needed to measure CFTR function, in vitro, ex vivo and in vivo. In vitro techniques either directly or indirectly measure ion fluxes; direct measurement of ion fluxes and quenching of fluorescence in cell-based assays, change in transmembrane voltage or current in patch clamp or Ussing chamber, swelling of CFTR-containing organoids by secondary water influx upon CFTR activation. Several cell or tissue types can be used. Ex vivo and in vivo assays similarly evaluate current (intestinal current measurement) and membrane potential differences (nasal potential differ...
European Respiratory Journal
Positive results in pre-clinical studies of the triple combination of elexacaftor, tezacaftor and ivacaftor, performed in airway epithelial cell cultures obtained from patients harbouring the class II cystic fibrosis transmembrane conductance regulator (CFTR) mutation F508del-CFTR, translated to impressive clinical outcomes for subjects carrying this mutation in clinical trials and approval of Trikafta.Encouraged by this correlation, we were prompted to evaluate the effect of the elexacaftor, tezacaftor and ivacaftor triple combination on primary nasal epithelial cultures obtained from individuals with rare class II CF-causing mutations (G85E, M1101K and N1303K) for which Trikafta is not approved.Cultures from individuals homozygous for M1101K responded better than cultures harbouring G85E and N1303K after treatment with the triple combination with respect to improvement in regulated channel function and protein processing. A similar genotype-specific effect of the triple combinatio...
Diretrizes brasileiras de diagnóstico e tratamento da fibrose cística
2017
A fibrose cistica (FC) e uma doenca genetica autossomica recessiva caracterizada pela disfuncao do gene CFTR. Trata-se de uma doenca multissistemica que ocorre mais frequentemente em populacoes descendentes de caucasianos. Nas ultimas decadas, diversos avancos no diagnostico e tratamento da FC mudaram drasticamente o cenario dessa doenca, com aumento expressivo da sobrevida e qualidade de vida. Atualmente, o Brasil dispoe de um programa de ampla cobertura para a triagem neonatal de FC e centros de referencia distribuidos na maior parte desses estados para seguimento dos individuos. Antigamente confinada a faixa etaria pediatrica, tem-se observado um aumento de pacientes adultos com FC tanto pelo maior numero de diagnosticos de formas atipicas, de expressao fenotipica mais leve, assim como pelo aumento da expectativa de vida com os novos tratamentos. Entretanto, ainda se observa uma grande heterogeneidade no acesso aos metodos diagnosticos e terapeuticos para FC entre as diferentes r...
Structural mechanisms of CFTR function and dysfunction
The Journal of General Physiology, 2018
Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) chloride channel plays a critical role in regulating transepithelial movement of water and electrolyte in exocrine tissues. Malfunction of the channel because of mutations of thecftrgene results in CF, the most prevalent lethal genetic disease among Caucasians. Recently, the publication of atomic structures of CFTR in two distinct conformations provides, for the first time, a clear overview of the protein. However, given the highly dynamic nature of the interactions among CFTR’s various domains, better understanding of the functional significance of these structures requires an integration of these new structural insights with previously established biochemical/biophysical studies, which is the goal of this review.
Cystic Fibrosis: Biology and Therapeutics
Chronic Lung Diseases, 2020
Cystic fibrosis could be a common life-bound autosomal recessive hereditary condition, with highest occurrence in Europe, North America, and Australia. The root of illness is mutation of a gene that encodes a chloride-conducting transmembrane channel known as the cystic fibrosis transmembrane conductance regulator (CFTR) that regulates anion transfer and mucociliary clearance within the airways. Operational failure of CFTR ends up in mucus withholding and chronic contagion, followed by local airway swelling that is harmful to the lungs. CFTR operational impairment principally affects epithelial cells, though there is proof of a function in immune cells. Cystic fibrosis influences numerous body systems, and morbidity and mortality are typically due to bronchiectasis, tiny airways obstacle, and progressive respiratory abnormality. Necessary comorbidities due to epithelial cell operational impairment occur within the pancreas (malassimilation), liver (biliary cirrhosis), sweat glands (heat shock), and vas deferens (sterility). The progress and delivery of medication that recover the clearance of mucus from the lungs and treat the ensuing infection, together with rectification of pancreatic insufficiency and malnutrition via multidisciplinary requisites, have resulted in noteworthy enhancements of life and clinical conclusion in patients with cystic fibrosis. Inventive and transformational treatments that aim on the fundamental defect in cystic fibrosis have currently been grown and are useful in lung surgery and dropping pulmonary
A deep learning approach to identify gene targets of a therapeutic for human splicing disorders
Nature Communications, 2021
Pre-mRNA splicing is a key controller of human gene expression. Disturbances in splicing due to mutation lead to dysregulated protein expression and contribute to a substantial fraction of human disease. Several classes of splicing modulator compounds (SMCs) have been recently identified and establish that pre-mRNA splicing represents a target for therapy. We describe herein the identification of BPN-15477, a SMC that restores correct splicing of ELP1 exon 20. Using transcriptome sequencing from treated fibroblast cells and a machine learning approach, we identify BPN-15477 responsive sequence signatures. We then leverage this model to discover 155 human disease genes harboring ClinVar mutations predicted to alter pre-mRNA splicing as targets for BPN-15477. Splicing assays confirm successful correction of splicing defects caused by mutations in CFTR, LIPA, MLH1 and MAPT. Subsequent validations in two disease-relevant cellular models demonstrate that BPN-15477 increases functional pr...
Scientific Reports, 2021
C407 is a compound that corrects the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein carrying the p.Phe508del (F508del) mutation. We investigated the corrector effect of c407 and its derivatives on F508del-CFTR protein. Molecular docking and dynamics simulations combined with site-directed mutagenesis suggested that c407 stabilizes the F508del-Nucleotide Binding Domain 1 (NBD1) during the co-translational folding process by occupying the position of the p.Phe1068 side chain located at the fourth intracellular loop (ICL4). After CFTR domains assembly, c407 occupies the position of the missing p.Phe508 side chain. C407 alone or in combination with the F508del-CFTR corrector VX-809, increased CFTR activity in cell lines but not in primary respiratory cells carrying the F508del mutation. A structure-based approach resulted in the synthesis of an extended c407 analog G1, designed to improve the interaction with ICL4. G1 significantly increased CFTR activity and respons...
Gene Therapy: A Possible Alternative to CFTR Modulators?
Frontiers in Pharmacology, 2021
Cystic fibrosis (CF) is a rare genetic disease that affects several organs, but lung disease is the major cause of morbidity and mortality. The gene responsible for CF, the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene, has been discovered in 1989. Since then, gene therapy i.e., defective gene replacement by a functional one, remained the ultimate goal but unfortunately, it has not yet been achieved. However, patients care and symptomatic treatments considerably increased CF patients’ life expectancy ranging from 5 years old in the 1960s to 40 today. In the last decade, research works on CFTR protein structure and activity led to the development of new drugs which, by readdressing CFTR to the plasma membrane (correctors) or by enhancing its transport activity (potentiators), allow, alone or in combination, an improvement of CF patients’ lung function and quality of life. While expected, it is not yet known whether taking these drugs from an early age and for years ...
Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung
Antibiotics, 2021
The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated stat...
Allergen Immunotherapy (AIT): a prototype of Precision Medicine
World Allergy Organization Journal, 2015
In recent years, asthma research has focused intensely on the severe part of the disease spectrum, leading to new treatments, mostly therapeutic monoclonal antibodies. However, severe asthma accounts for not more than 2% of asthma in the pediatric population. Therefore, non-severe asthma remains a major health problem in children, not only for patients and parents but also for healthcare professionals such as general practitioners, pediatricians and allergists who take care of these patients. It is thus essential to identify and put in context novel concepts, applicable to the treatment of these patients. Recent evidence suggests benefits from using anti-inflammatory treatment even for the mildest cases, for whom until now only symptomatic bronchodilation was recommended. Likewise, "reliever" medication may be better combined with an inhaled corticosteroid (ICS). Among "new" treatments (for children), ICS formulation in ultrafine particles has showed promise and tiotropium is gaining access to the pediatric population. Maintenance and reliever therapy (MART) is an option for moderate disease. Most importantly, personalized response to medications appears to be considerable, therefore, it may need to be taken into account. Overall, these new options provide opportunities for multiple new management strategies. The deployment of such strategies in different populations remains to be evaluated.
Frontiers in pharmacology, 2018
Cystic fibrosis (CF) is a genetic lethal disease, originated from the defective function of the CFTR protein, a chloride and bicarbonate permeable transmembrane channel. CF mutations affect CFTR protein through a variety of molecular mechanisms which result in different functional defects. Current therapeutic approaches are targeted to specific groups of patients that share a common functional defect. We seek to develop an innovative therapeutic approach for the treatment of CF using anionophores, small molecules that facilitate the transmembrane transport of anions. We have characterized the anion transport mechanism of a synthetic molecule based on the structure of prodigiosine, a red pigment produced by bacteria. Anionophore-driven chloride efflux from large unilamellar vesicles is consistent with activity of an uniporter carrier that facilitates the transport of anions through lipid membranes down the electrochemical gradient. There are no evidences of transport coupling with pr...
International Journal of Molecular Sciences, 2020
Cystic fibrosis (CF) is a genetic disease characterized by the lack of cystic fibrosis transmembrane conductance regulator (CFTR) protein expressed in epithelial cells. The resulting defective chloride and bicarbonate secretion and imbalance of the transepithelial homeostasis lead to abnormal airway surface liquid (ASL) composition and properties. The reduced ASL volume impairs ciliary beating with the consequent accumulation of sticky mucus. This situation prevents the normal mucociliary clearance, favouring the survival and proliferation of bacteria and contributing to the genesis of CF lung disease. Here, we have explored the potential of small molecules capable of facilitating the transmembrane transport of chloride and bicarbonate in order to replace the defective transport activity elicited by CFTR in CF airway epithelia. Primary human bronchial epithelial cells obtained from CF and non-CF patients were differentiated into a mucociliated epithelia in order to assess the effect...
Cystic Fibrosis Human Organs-on-a-Chip
Micromachines, 2021
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene: the gene product responsible for transporting chloride and bicarbonate ions through the apical membrane of most epithelial cells. Major clinical features of CF include respiratory failure, pancreatic exocrine insufficiency, and intestinal disease. Many CF animal models have been generated, but some models fail to fully capture the phenotypic manifestations of human CF disease. Other models that better capture the key characteristics of the human CF phenotype are cost prohibitive or require special care to maintain. Important differences have been reported between the pathophysiology seen in human CF patients and in animal models. These limitations present significant limitations to translational research. This review outlines the study of CF using patient-derived organs-on-a-chip to overcome some of these limitations. Recently developed microfluidic-...
CFTR Modulators: The Changing Face of Cystic Fibrosis in the Era of Precision Medicine
Frontiers in Pharmacology, 2020
Cystic fibrosis (CF) is a lethal inherited disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, which result in impairment of CFTR mRNA and protein expression, function, stability or a combination of these. Although CF leads to multifaceted clinical manifestations, the respiratory disorder represents the major cause of morbidity and mortality of these patients. The life expectancy of CF patients has substantially lengthened due to early diagnosis and improvements in symptomatic therapeutic regimens. Quality of life remains nevertheless limited, as these individuals are subjected to considerable clinical, psychosocial and economic burdens. Since the discovery of the CFTR gene in 1989, tremendous efforts have been made to develop therapies acting more upstream on the pathogenesis cascade, thereby overcoming the underlying dysfunctions caused by CFTR mutations. In this line, the advances in cell-based high-throughput screenings have been facilitating the fast-tracking of CFTR modulators. These modulator drugs have the ability to enhance or even restore the functional expression of specific CF-causing mutations, and they have been classified into five main groups depending on their effects on CFTR mutations: potentiators, correctors, stabilizers, read-through agents, and amplifiers. To date, four CFTR modulators have reached the market, and these pharmaceutical therapies are transforming patients' lives with short-and long-term improvements in clinical outcomes. Such breakthroughs have paved the way for the development of novel CFTR modulators, which are currently under experimental and clinical investigations. Furthermore, recent insights into the CFTR structure will be useful for the rational design of next-generation modulator drugs. This review aims to provide a summary of recent developments in CFTR-directed therapeutics. Barriers and future directions are also discussed in order to optimize treatment adherence, identify feasible and sustainable solutions for equitable access to these therapies, and continue to expand the pipeline of novel modulators that may result in effective precision medicine for all individuals with CF.
Challenges with optimizing nutrition in cystic fibrosis
Expert Review of Respiratory Medicine, 2019
Introduction. Optimizing nutrition remains the cornerstone of therapy for patients with cystic fibrosis (CF) since it is associated with better pulmonary function and survival. However, a significant proportion of patients still fail to achieve normal growth and nutritional status. Areas covered. This review describes the current challenges in providing effective nutritional therapy in CF with a focus on the current issues related to energy imbalance, dietary composition, adherence to nutritional recommendations, pancreatic enzyme replacement therapy, and the effects of modulators of the CF transmembrane conductance regulator. Expert opinion. CF is a multisystemic disease that requires a personalized nutritional approach with accurate evaluation of energy balance. There is an urgent need for evidence-based recommendations on the dietary composition, in consideration of the increasing prevalence of overweight, diabetes and the potential effects of fatty acids on inflammation and immune response. More research into new pancreatic enzyme formulations is also required.
Allergy, 2017
Precision medicine (PM) is increasingly recognized as the way forward for optimizing patient care. Introduced in the field of oncology, it is now considered of major interest in other medical domains like allergy and chronic airway diseases, which face an urgent need to improve the level of disease control, enhance patient satisfaction and increase effectiveness of preventive interventions. The combination of personalized care, prediction of treatment success, prevention of disease and patient participation in the elaboration of the treatment plan is expected to substantially improve the therapeutic approach for individuals suffering from chronic disabling conditions. Given the emerging data on the impact of patient stratification on treatment outcomes, European and American regulatory bodies support the principles of PM and its potential advantage over current treatment strategies. The aim of the current document was to propose a consensus on the position and gradual implementation...
A Precision Medicine Approach to Optimize Modulator Therapy for Rare CFTR Folding Mutants
Journal of Personalized Medicine, 2021
Trikafta, a triple-combination drug, consisting of folding correctors VX-661 (tezacaftor), VX-445 (elexacaftor) and the gating potentiator VX-770 (ivacaftor) provided unprecedented clinical benefits for patients with the most common cystic fibrosis (CF) mutation, F508del. Trikafta indications were recently expanded to additional 177 mutations in the CF transmembrane conductance regulator (CFTR). To minimize life-long pharmacological and financial burden of drug administration, if possible, we determined the necessary and sufficient modulator combination that can achieve maximal benefit in preclinical setting for selected mutants. To this end, the biochemical and functional rescue of single corrector-responsive rare mutants were investigated in a bronchial epithelial cell line and patient-derived human primary nasal epithelia (HNE), respectively. The plasma membrane density of P67L-, L206W- or S549R-CFTR corrected by VX-661 or other type I correctors was moderately increased by VX-44...
American Journal of Respiratory and Critical Care Medicine, 2021
Rationale: Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was shown to be efficacious and safe in patients >12 years of age with cystic fibrosis and at least one F508del-CFTR (cystic fibrosis transmembrane conductance regulator) allele, but it has not been evaluated in children ,12 years of age. Objectives: To assess the safety, pharmacokinetics, and efficacy of ELX/TEZ/IVA in children 6 through 11 years of age with F508del-minimal function or F508del-F508del genotypes. Methods: In this 24-week open-label phase 3 study, children (N 5 66) weighing ,30 kg received 50% of the ELX/TEZ/IVA adult daily dose (ELX 100 mg once daily, TEZ 50 mg once daily, and IVA 75 mg every 12 h) whereas children weighing >30 kg received the full adult daily dose (ELX 200 mg once daily, TEZ 100 mg once daily, and IVA 150 mg every 12 h). Measurements and Main Results: The primary endpoint was safety and tolerability. The safety and pharmacokinetic profiles of ELX/TEZ/IVA were generally consistent with those observed in older patients. The most commonly reported adverse events included cough, headache, and pyrexia; in most of the children who had adverse events, these were mild or moderate in severity. Through Week 24, ELX/TEZ/IVA treatment improved the percentage of predicted FEV 1 (10.2 percentage points; 95% confidence interval [CI], 7.9 to 12.6), Cystic Fibrosis Questionnaire-Revised respiratory domain score (7.0 points; 95% CI, 4.7 to 9.2), lung clearance index 2.5 (21.71 units; 95% CI, 22.11 to 21.30), and sweat chloride (260.9 mmol/L; 95% CI, 263.7 to 258.2); body mass index-forage z-score increased over the 24-week treatment period when compared with the pretreatment baseline. Conclusions: Our results show ELX/TEZ/IVA is safe and efficacious in children 6 through 11 years of age with at least one F508del-CFTR allele, supporting its use in this patient population. Clinical trial registered with www.clinicaltrials.gov (NCT03691779).
Correction of CFTR function in intestinal organoids to guide treatment of cystic fibrosis
European Respiratory Journal, 2020
RationaleGiven the vast number of cystic fibrosis transmembrane conductance regulator (CFTR) mutations, biomarkers predicting benefit from CFTR modulator therapies are needed for subjects with cystic fibrosis (CF).ObjectivesTo study CFTR function in organoids of subjects with common and rare CFTR mutations and evaluate correlations between CFTR function and clinical data.MethodsIntestinal organoids were grown from rectal biopsies in a cohort of 97 subjects with CF. Residual CFTR function was measured by quantifying organoid swelling induced by forskolin and response to modulators by quantifying organoid swelling induced by CFTR correctors, potentiator and their combination. Organoid data were correlated with clinical data from the literature.ResultsAcross 28 genotypes, residual CFTR function correlated (r2=0.87) with sweat chloride values. When studying the same genotypes, CFTR function rescue by CFTR modulators in organoids correlated tightly with mean improvement in lung function ...
The impact of ivacaftor on sinonasal pathology in S1251N-mediated cystic fibrosis patients
PLOS ONE, 2020
Importance Sinonasal symptoms in patients suffering from cystic fibrosis can negatively influence the quality of life and sinuses can be a niche for pathogens causing infection and inflammation leading to a decrease of lung function. Ivacaftor, a potentiator of the Cystic Fibrosis Transmembrane Conductance Regulator protein, has shown improvement in pulmonary function in cystic fibrosis patients with different forms of class III gating mutations. However, the effects of ivacaftor on sinonasal pathology have hardly been studied. Objective To determine the impact of ivacaftor therapy on sinonasal pathology in patients with cystic fibrosis with an S1251N mutation.
Review of Gastrointestinal Motility in Cystic Fibrosis
Journal of Cystic Fibrosis, 2021
Gastrointestinal manifestations in patients with cystic fibrosis (CF) are extremely common and have recently become a research focus. Gastrointestinal (GI) dysfunction is poorly understood in the CF population, despite many speculations including the role of luminal pH, bacterial overgrowth, and abnormal microbiome. Nevertheless, dysmotility is emerging as a possible key player in CF intestinal symptoms. Our review article aims to explore the sequelae of defective cystic fibrosis transmembrane conductance regulator (CFTR) genes on the GI tract as studied in both animals and humans, describe various presentations of intestinal dysmotility in CF, review newer diagnostic motility techniques including intraluminal manometry, and review the current literature regarding the potential role of dysmotility in CF-related intestinal pathologies.
Best practices in the treatment of early cystic fibrosis lung disease
Therapeutic Advances in Respiratory Disease, 2016
For many years, management of cystic fibrosis (CF) lung disease was focused on symptomatic treatment of chronic lung infection, which is characterized by cough and sputum production, leading to progressive lung damage. With increasing survival and better knowledge of the pathogenesis of CF lung disease, it has become clear that treatment has to start very early because lung damage occurs in young patients, often before obvious symptoms appear. The arrival of new cystic fibrosis transmembrane conductance-regulator (CFTR)-correcting therapies will bring more opportunities to prevent the disease, apart from only treating chronic lung infection. In this review, a summary of the current knowledge of early CF lung disease is provided, based on animal model studies, as well as on data obtained from well structured follow-up programs after newborn screening (NBS). The most important clinical guidelines for treating young CF patients are also summarized.
Pulmonary Therapy, 2021
Introduction: Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator that has demonstrated clinical benefits in phase 3 trials. We report results from a real-world study (BRIO) to assess the effectiveness of ivacaftor in people with cystic fibrosis (pwCF) in France. Methods: BRIO was an observational study conducted at 35 centers in France. Both pwCF initiating ivacaftor treatment and those already taking ivacaftor were included and prospectively followed for 24 months. The primary objective was to evaluate the effect of ivacaftor on percent predicted forced expiratory volume in 1 s (ppFEV 1); secondary objectives were The members of the ''on behalf of the BRIO Study Group'' was processed under acknowledgements section.
Health and Quality of Life Outcomes, 2015
Background: Cystic fibrosis (CF) is an inherited, rare autosomal recessive disease that results in chronically debilitating morbidities and high premature mortality. We evaluated how ivacaftor treatment affected CF symptoms, functioning, and well-being, as measured by the Cystic Fibrosis Questionnaire-Revised (CFQ-R), a widely-used patient-reported outcome (PRO) measure. Methods: STRIVE, a double-blind, placebo-controlled randomized trial, evaluated ivacaftor (150 mg) in CF patients aged 12+ with the G551D-CFTR mutation for 48 weeks. Treatment effect analysis used a mixed-effects repeated measures model. Treatment benefit analyses applied the cumulative distribution function and a categorical analysis of change scores ("improvement," "no change," or "decline"). Content-based interpretation examined treatment effect on specific item responses. Results: Data from 152 patients with a baseline CFQ-R assessment were analyzed. The treatment effect analysis favored treatment with ivacaftor over placebo on the Body Image, Eating, Health Perceptions, Physical Functioning, Respiratory, Social Functioning, Treatment Burden, and Vitality scales. Findings were supported by the analysis of categorical change. On all CFQ-R scales, the percentage of patients who improved was greater for ivacaftor. In the content-based analysis, the treatment benefit was characterized by better scores across a broad range of domains. Conclusions: Results illustrate broad benefits of ivacaftor treatment across many domains: respiratory symptoms, physical and social functioning, health perceptions, and vitality, as measured by the CFQ-R. The breadth of improvements reflects the systemic mechanism of action of ivacaftor compared to other therapies. Findings support the patient-reported value of ivacaftor treatment in this patient population.
The Pulmonary Microbiome in Cystic Fibrosis
Cystic Fibrosis - Heterogeneity and Personalized Treatment, 2020
The chronic colonisation of the lower airways by bacterial pathogens is the leading cause of morbidity and mortality in patients with cystic fibrosis (CF). The use of novel culture-independent techniques such as next-generation sequencing (NGS) to analyse the lungs has allowed us to further understand the diversity, the complexity, the effects of acute exacerbations and the use of antibiotics on the bacterial communities. The understanding of the CF microbiome to airway disease remains a fascinating area of research; it presents new opportunities for disease management in CF and has the potential to explore the effects of cystic fibrosis transmembrane conductance regulator (CFTR) modulators. It also allows further appreciation regarding the roles played by anaerobic organisms within the CF airways. It is also of interest that a number of studies have demonstrated that the fluctuations of microbiome are not necessarily associated with the patient's clinical status. Despite the available evidence, there remain many challenges that must be overcome if microbiome profiling is going to influence future clinical practice. The effects of fungus and the emergence of nontuberculous mycobacteria in CF are also briefly discussed in this chapter.
F1000Research, 2018
Background: Forced expiratory volume in one second (FEV1) is an important cystic fibrosis (CF) prognostic marker and an established endpoint for CF clinical trials. FEV1 is also used in observation studies, e.g. to compare different centre’s outcomes. We wished to evaluate whether different methods of processing FEV1 data can impact on centre outcome. Methods: This is a single-centre retrospective analysis of routinely collected data from 2013-2016 among 208 adults. Year-to-year %FEV1 change was calculated by subtracting best %FEV1 at Year 1 from Year 2 (i.e. negative values indicate fall in %FEV1), and compared using Friedman test. Three methods were used to process %FEV1 data. First, %FEV1 calculated with Knudson equation was extracted directly from spirometer machines. Second, FEV1 volume were extracted then converted to %FEV1 using clean height data and Knudson equation. Third, FEV1 volume were extracted then converted to %FEV1 using clean height data and GLI equation. In additi...
CFTR Modulators: Does One Dose Fit All?
Journal of Personalized Medicine, 2021
For many people with cystic fibrosis (pwCF), CFTR modulators will be the cornerstone of their treatment. These modulators show robust treatment effects at group level in pwCF with specific mutations. The individual effect however, is variable. In this review we will explain reasons for reconsideration of dosing regimens of CFTR modulating therapy in order to improve treatment response and prevent side effects. Since the effect of a drug depends on pharmacodynamics and pharmacokinetics, pharmacodynamics and pharmacokinetic properties of CFTR modulators will be discussed. Pharmacokinetic-pharmacodynamic relationships will be used to gain insight in dosage response and exposure response relationships. To understand the cause of variation in drug exposure, pharmacokinetic properties that may change due to CF disease will be explained. We show that with current insight, there are conceivable situations that give reason for reconsideration of dosing regimens, however many questions need t...
Psuedomonas aeruginosa-Associated Acute and Chronic Pulmonary Infections
Pathogenic Bacteria, 2020
Pseudomonas aeruginosa is highly successful in colonizing in all types of environments. P. aeruginosa colonizing in adverse environment due to the presence of its virulence factors include production of toxins, proteases hemolysins, and formation of biofilms. In man, the most common opportunist pathogen is P. aeruginosa. Metabolically P. aeruginosa is versatile. Most of the antibiotics targeted metabolically active cells and bacteria could contribute to decrease in biofilm susceptibility to the antimicrobial agents. Scientists suggested about Pseudomonas that it can be catabolized any hydrocarbon in specific time along with availability of oxygen and nitrite. If bacteria are not susceptible to one agent in three or more, it is called as multidrug-resistance strains. The antimicrobial treatments were not suitable when microorganism presented in vitro microorganism resistance to antimicrobials used for treatment of the patient which lack of treatment for 24 h after diagnosis of microb...
Evaporimeter and Bubble-Imaging Measures of Sweat Gland Secretion Rates
PLOS ONE, 2016
Beta-adrenergically-stimulated sweat rates determined by evaporimetry or by sweat bubble imaging are useful for measuring CFTR function because they provide a near-linear readout across almost the full range of CFTR function. They differentiate cystic fibrosis (CF) subjects from CF carriers and carriers from controls. However, evaporimetry, unlike bubble imaging, appears to be unable to detect improved levels of CFTR function in G551D subjects taking the CFTR modulator ivacaftor. Here, we quantify the sensitivity of evaporimetry and bubble imaging methods for assessing low levels of CFTR-dependent sweat rates. To establish sensitivity, we did dose-ranging studies using intradermally injected [cAMP] i-elevating cocktails. We reduced isoproterenol/aminophylline levels while maintaining a high level of atropine to block muscarinic elevation of [Ca 2+ ] i. We stimulated the same sets of glands for both assays and recorded responses for 20 min. In response to a 3-log dilution of the stimulating cocktail (0.1%), bubble responses were detected in 12/12 tests (100%), with 49% ± 3% of glands secreting to produce an aggregate volume of 598 nl across the 12, 20min tests. This was~5% of the response to full cocktail. Evaporimetry detected responses in 3/12 (25%) tests with an aggregate secretion volume of 175 nl. After stimulation with a still more dilute cocktail (0.03%), bubble imaging detected 15 ± 13% of glands secreting at a rate~0.9% of the response to full cocktail, while zero responding was seen with evaporimetry. The bubble imaging method detected secretion down to aggregate rates of <0.2 nl/ (cm 2 Ámin), or~1/30 th of the average basal transepithelial water loss (TEWL) in the test subject of 4 g/m 2 Áhr or 6.7 nl/(cm 2 Ámin). The increased sensitivity of bubble imaging may be required to detect small but physiologically important increases in secretion rates produced by CFTR modulators.
International Journal of Environmental Research and Public Health
Background: Modulator therapy represents a significant step forward in CF care and is expected to have a significant impact on the health and mortality of many individuals with CF. Studies have predominantly explored the physiological effects of modulator therapy on clinical outcomes, with little consideration of the individual lived experience of modulator therapy among adults with Cystic Fibrosis. Methods: To explore this, semi-structured interviews were conducted with 12 individuals currently taking Kaftrio, which were subsequently thematically analysed. Results: Three overarching themes were identified: (i) positive perception of Kaftrio, (ii) negative perception of Kaftrio, and (iii) the relationships with the clinical team. The experience of modulator therapy should be recognised as being unique to the individual, with perceptions of illness, self-identity, and outcomes strongly dictating the lived experience. Conclusions: There is a consensus that, while for many, the quality...
Nouvelles thérapeutiques ciblant le canal chlorure dans la mucoviscidose
Archives de Pédiatrie, 2016
Depuis la découverte du fonctionnement du canal chlorure CFTR (Cystic Fibrosis Transport Regulator) en 1983, puis du gène CFTR en 1989, la compréhension des mécanismes physiologiques de sa synthèse, son transfert intracellulaire et son fonctionnement à la membrane apicale cellulaire a considérablement évolué. Ces découvertes ont permis de distinguer 6 classes de mutations responsables de la mucoviscidose ayant 6 mécanismes physiopathologiques de l'atteinte de CFTR différents. Nous allons explorer dans cet article, l'état actuel des connaissances concernant la synthèse et le fonctionnement physiologique de CFTR. Puis nous verrons les différentes conséquences des 6 classes de mutations sur le fonctionnement de la protéine CFTR et ferons le point sur les avancées thérapeutiques ciblant ces différents mécanismes.
Re-imagining cystic fibrosis care: next generation thinking
European Respiratory Journal, 2020
Cystic fibrosis (CF) is a common multi-system genetically inherited condition, predominately found in individuals of Caucasian decent. Since the identification of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene in 1989, and the subsequent improvement in understanding of CF pathophysiology, significant increases in life-expectancy have followed. Initially this was related to improvements in the management and systems of care for treating the various affected organ systems. These cornerstone treatments are still essential for CF patients born today. However, over the last decade, the major advance has been in therapies that target the resultant genetic defect: the dysfunctional CFTR protein. Small molecule agents that target this dysfunctional protein via a variety of mechanisms have led to lung function improvements, reductions in pulmonary exacerbation rates and increases in weight and quality-of-life indices. As more patients receive these agents earlier an...
Supporting medication adherence for adults with cystic fibrosis: a randomised feasibility study
BMC Pulmonary Medicine, 2019
Background: Preventative medication reduces hospitalisations in people with cystic fibrosis (PWCF) but adherence is poor. We assessed the feasibility of a randomised controlled trial of a complex intervention, which combines display of real time adherence data and behaviour change techniques. Methods: Design: Pilot, open-label, parallel-group RCT with concurrent semi-structured interviews. Participants: PWCF at two Cystic Fibrosis (CF) units. Eligible: aged 16 or older; on the CF registry. Ineligible: post-lung transplant or on the active list; unable to consent; using dry powder inhalers. Interventions: Central randomisation on a 1:1 allocation to: (1) intervention, linking nebuliser use with data recording and transfer capability to a software platform, and behavioural strategies to support self-management delivered by trained interventionists (n = 32); or, (2) control, typically face-to-face meetings every 3 months with CF team (n = 32). Outcomes: RCT feasibility defined as: recruitment of ≥ 48 participants (75% of target) in four months (pilot primary outcome); valid exacerbation data available for ≥ 85% of those randomised (future RCT primary outcome); change in % medication adherence; FEV 1 percent predicted (key secondaries in future RCT); and perceptions of trial procedures, in semi-structured interviews with intervention (n = 14) and control (n = 5) participants, interventionists (n = 3) and CF team members (n = 5). Results: The pilot trial recruited to target, randomising 33 to intervention and 31 to control in the four-month period, June-September 2016. At study completion (30th April 2017), 60 (94%; Intervention = 32, Control =28) participants contributed good quality exacerbation data (intervention: 35 exacerbations; control: 25 exacerbation). The mean change in adherence and baseline-adjusted FEV 1 percent predicted were higher in the intervention arm by 10% (95% CI:-5.2 to 25.2) and 5% (95% CI-2 to 12%) respectively. Five serious adverse events occurred, none related to the intervention. The mean change in adherence was 10% (95% CI:-5.2 to 25.2), greater in the intervention arm. Interventionists delivered insufficient numbers of review sessions due to concentration on participant recruitment. This left interventionists insufficient time for key intervention procedures. A total of 10 key changes that were made to RCT procedures are summarised. Conclusions: With improved research processes and lower monthly participant recruitment targets, a full-scale trial is feasible.
BMJ Open
ObjectivesTo undertake a process evaluation of an adherence support intervention for people with cystic fibrosis (PWCF), to assess its feasibility and acceptability.SettingTwo UK cystic fibrosis (CF) units.ParticipantsFourteen adult PWCF; three professionals delivering adherence support (‘interventionists’); five multi-disciplinary CF team members.InterventionsNebuliser with data recording and transfer capability, linked to a software platform, and strategies to support adherence to nebulised treatments facilitated by interventionists over 5 months (± 1 month).Primary and secondary measuresFeasibility and acceptability of the intervention, assessed through semistructured interviews, questionnaires, fidelity assessments and click analytics.ResultsInterventionists were complimentary about the intervention and training. Key barriers to intervention feasibility and acceptability were identified. Interventionists had difficulty finding clinic space and time in normal working hours to con...
Nanomedicine Approaches for the Pulmonary Treatment of Cystic Fibrosis
Frontiers in Bioengineering and Biotechnology, 2019
Cystic fibrosis (CF) is a genetic disease affecting today nearly 70,000 patients worldwide and characterized by a hypersecretion of thick mucus difficult to clear arising from the defective CFTR protein. The overproduction of the mucus secreted in the lungs, along with its altered composition and consistency, results in airway obstruction that makes the lungs susceptible to recurrent and persistent bacterial infections and endobronchial chronic inflammation, which are considered the primary cause of bronchiectasis, respiratory failure, and consequent death of patients. Despite the difficulty of treating the continuous infections caused by pathogens in CF patients, various strategies focused on the symptomatic therapy have been developed during the last few decades, showing significant positive impact on prognosis. Moreover, nowadays, the discovery of CFTR modulators as well as the development of gene therapy have provided new opportunity to treat CF. However, the lack of effective methods for delivery and especially targeted delivery of therapeutics specifically to lung tissues and cells limits the efficiency of the treatments. Nanomedicine represents an extraordinary opportunity for the improvement of current therapies and for the development of innovative treatment options for CF previously considered hard or impossible to treat. Due to the peculiar environment in which the therapies have to operate characterized by several biological barriers (pulmonary tract, mucus, epithelia, bacterial biofilm) the use of nanotechnologies to improve and enhance drug delivery or gene therapies is an extremely promising way to be pursued. The aim of this review is to revise the currently used treatments and to outline the most recent progresses about the use of nanotechnology for the management of CF.
International Journal of Molecular Sciences, 2020
Many heritable genetic disorders arise from nonsense mutations, which generate premature termination codons (PTCs) in transcribed mRNA. PTCs ablate protein synthesis by prematurely terminating the translation of mutant mRNA, as well as reducing mutant mRNA quantity through targeted degradation by nonsense-mediated decay (NMD) mechanisms. Therapeutic strategies for nonsense mutations include facilitating ribosomal readthrough of the PTC and/or inhibiting NMD to restore protein function. However, the efficacy of combining readthrough agents and NMD inhibitors has not been thoroughly explored. In this study, we examined combinations of known NMD inhibitors and readthrough agents using functional analysis of the CFTR protein in primary cells from a mouse model carrying a G542X nonsense mutation in Cftr. We observed synergy between an inhibitor of the NMD component SMG-1 (SMG1i) and the readthrough agents G418, gentamicin, and paromomycin, but did not observe synergy with readthrough cau...
JIMD Reports, 2021
Due to advances in sequencing technologies, identification of genetic variants is rapid. However, the functional consequences of most genomic variants remain unknown. Consequently, variants of uncertain significance (VUS) that appear in clinical DNA diagnostic reports lack sufficient data for interpretation. Algorithms exist to aid prediction of a variant's likelihood of pathogenicity, but these predictions usually lack empiric evidence. To examine the feasibility of generating functional evidence in vitro for a given variant's role in disease, a panel of 29 coding sequence variants in the G6PC gene was assessed. G6PC encodes glucose‐6 phosphatase enzyme, and reduction in its function causes the rare metabolic disease glycogen storage disease type 1a (GSD1a). Variants were heterologously expressed as fusion proteins in a hepatocyte‐derived cell line and examined for effects on steady‐state protein levels, biosynthetic processing, and intracellular distribution. The screen re...
Investigation of the effects of the CFTR potentiator ivacaftor on human P-glycoprotein (ABCB1)
Scientific Reports, 2017
Ivacaftor is a potentiator of the CFTR chloride channel and is in worldwide clinical use for the chronic treatment of cystic fibrosis in patients. There is evidence that the bioavailability of ivacaftor in the body may be influenced by the multi-drug exporter P-glycoprotein. Here we have employed purified and reconstituted P-glycoprotein to study its interaction with ivacaftor as well as the ability of the drug to compete with a known transported substrate of the protein. We find that ivacaftor stimulates the ATPase activity of the purified protein and can compete with the transport of the fluorescent substrate Hoechst 33342. These findings lead us to conclude that ivacaftor is very likely an efficiently transported substrate of P-glycoprotein. Evidence for state-dependent binding of ivacaftor was obtained using a fluorescent, cysteine-reactive reporter dye. The quiescent, nucleotide-free state in the P-glycoprotein transport cycle appears to bind ivacaftor strongly.
Pseudomonas eradication and clinical effectivness of Ivacaftor in four Hispanic patients with S549N
Pediatric Pulmonology, 2017
Ivacaftor was approved for rarer class-III CFTR mutations including S549N in 2014. Since these mutations are uncommon, ongoing reports of patient experiences with Ivacaftor and these mutations are important. This case series describes the clinical effectiveness (including airway infection status, lung function, and growth) of Ivacaftor therapy in four pediatric Hispanic patients with S549N and F508del over 24 months. In these patients, Ivacaftor was highly efficacious with no further Pseudomonas-positive cultures despite prior chronic colonization in three patients as well as notable improvements in lung function and growth. The remarkable improvements in lung function and growth were similar to G551D patients with more striking changes in airway infection status. Pediatr Pulmonol.
Airway Inflammation and Host Responses in the Era of CFTR Modulators
International Journal of Molecular Sciences, 2020
The arrival of cystic fibrosis transmembrane conductance regulator (CFTR) modulators as a new class of treatment for cystic fibrosis (CF) in 2012 represented a pivotal advance in disease management, as these small molecules directly target the upstream underlying protein defect. Further advancements in the development and scope of these genotype-specific therapies have been transformative for an increasing number of people with CF (PWCF). Despite clear improvements in CFTR function and clinical endpoints such as lung function, body mass index (BMI), and frequency of pulmonary exacerbations, current evidence suggests that CFTR modulators do not prevent continued decline in lung function, halt disease progression, or ameliorate pathogenic organisms in those with established lung disease. Furthermore, it remains unknown whether their restorative effects extend to dysfunctional CFTR expressed in phagocytes and other immune cells, which could modulate airway inflammation. In this review,...
European Respiratory Journal, 2014
TheCFTRgene displays a tightly regulated tissue-specific and temporal expression. Mutations in this gene cause cystic fibrosis (CF). In this study we wanted to identifytrans-regulatory elements responsible forCFTRdifferential expression in fetal and adult lung, and to determine the importance of inhibitory motifs in theCFTR-3′UTR with the aim of developing new tools for the correction of disease-causing mutations withinCFTR.We show that lung development-specific transcription factors (FOXA, C/EBP) and microRNAs (miR-101, miR-145, miR-384) regulate the switch from strong fetal to very lowCFTRexpression after birth. By using miRNome profiling and gene reporter assays, we found that miR-101 and miR-145 are specifically upregulated in adult lung and that miR-101 directly acts on its cognate site in theCFTR-3′UTR in combination with an overlapping AU-rich element. We then designed miRNA-binding blocker oligonucleotides (MBBOs) to prevent binding of several miRNAs to theCFTR-3′UTR and tes...
Pharmaceuticals
Cystic fibrosis (CF) is a potentially fatal monogenic disease that causes a progressive multisystemic pathology. Over the last decade, the introduction of CF transmembrane conductance regulator (CFTR) modulator drugs into clinical practice has profoundly modified the lives of many people with CF (PwCF) by targeting the fundamental cause of the disease. These drugs consist of the potentiator ivacaftor (VX-770) and the correctors lumacaftor (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). In particular, the triple combination of CFTR modulators composed of elexacaftor, tezacaftor, and ivacaftor (ETI) represents a life-changing therapy for the majority of PwCF worldwide. A growing number of clinical studies have demonstrated the safety and efficacy of ETI therapy in both short- and long-term (up to two years of follow-up to date) and its ability to significantly reduce pulmonary and gastrointestinal manifestations, sweat chloride concentration, exocrine pancreatic dysfunction, ...
PloS one, 2017
Abdominal symptoms (AS) are a hallmark of the multiorgan-disease cystic fibrosis (CF). However, the abdominal involvement in CF is insufficiently understood and, compared to the pulmonary manifestation, still receives little scientific attention. Aims were to assess and quantify AS and to relate them to laboratory parameters, clinical findings, and medical history. A total of 131 patients with CF of all ages were assessed with a new CF-specific questionnaire (JenAbdomen-CF score 1.0) on abdominal pain and non-pain symptoms, disorders of appetite, eating, and bowel movements as well as symptom-related quality of life. Results were metrically dimensioned and related to abdominal manifestations, history of surgery, P. aeruginosa and S. aureus colonization, genotype, liver enzymes, antibiotic therapy, lung function, and nutritional status. AS during the preceding 3 months were reported by all of our patients. Most common were lack of appetite (130/131) and loss of taste (119/131) follow...
Is cellular senescence involved in cystic fibrosis?
Respiratory Research, 2019
Pulmonary disease is the main cause of the morbidity and mortality of patients affected by cystic fibrosis (CF). The lung pathology is dominated by excessive recruitment of neutrophils followed by an exaggerated inflammatory process that has also been reported to occur in the absence of apparent pathogenic infections. Airway surface dehydration and mucus accumulation are the driving forces of this process. The continuous release of reactive oxygen species and proteases by neutrophils contributes to tissue damage, which eventually leads to respiratory insufficiency. CF has been considered a paediatric problem for several decades. Nevertheless, during the last 40 years, therapeutic options for CF have been greatly improved, turning CF into a chronic disease and extending the life expectancy of patients. Unfortunately, chronic inflammatory processes, which are characterized by a substantial release of cytokines and chemokines, along with ROS and proteases, can accelerate cellular senescence, leading to further complications in adulthood. The alterations and mechanisms downstream of CFTR functional defects that can stimulate cellular senescence remain unclear. However, while there are correlative data suggesting that cellular senescence may be implicated in CF, a causal or consequential relationship between cellular senescence and CF is still far from being established. Senescence can be both beneficial and detrimental. Senescence may suppress bacterial infections and cooperate with tissue repair. Additionally, it may act as an effective anticancer mechanism. However, it may also promote a pro-inflammatory environment, thereby damaging tissues and leading to chronic age-related diseases. In this review, we present the most current knowledge on cellular senescence and contextualize its possible involvement in CF.
CFTR Modulators in People with Cystic Fibrosis: Real-World Evidence in France
Cells
Cystic fibrosis (CF) is a rare genetic multisystemic disease, the manifestations of which are due to mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein and can lead to respiratory insufficiency and premature death. CFTR modulators, which were developed in the past decade, partially restore CFTR protein function. Their clinical efficacy has been demonstrated in phase 3 clinical trials, particularly in terms of lung function and pulmonary exacerbations, nutritional status, and quality of life in people with gating mutations (ivacaftor), homozygous for the F508del mutation (lumacaftor/ivacaftor and tezacaftor/ivacaftor), and in those with at least one F508del mutation (elexacaftor/tezacaftor/ivacaftor). However, many questions remain regarding their long-term safety and effectiveness, particularly in patients with advanced lung disease, liver disease, renal insufficiency, or problematic bacterial colonization. The impact of CFTR modulators on other...
European Journal of Drug Metabolism and Pharmacokinetics
Background and Objective Elexacaftor/tezacaftor/ivacaftor is highly effective in treating people with cystic fibrosis (pwCF) who have ≥ 1 responsive mutation. Liver disease occurs in approximately 10%-20% of pwCF. The objective of this study was to assess the safety and pharmacokinetics of elexacaftor/tezacaftor/ivacaftor in people with moderate hepatic impairment, which is necessary to inform on its use and guide dosing recommendations. Methods The safety and pharmacokinetics of elexacaftor/tezacaftor/ivacaftor were evaluated in subjects without CF with moderate hepatic impairment versus matched healthy controls. Twenty-two subjects (11 with moderate hepatic impairment and 11 healthy subjects) received half the standard adult daily dose of elexacaftor/tezacaftor/ivacaftor (elexacaftor 100 mg/ tezacaftor 50 mg/ivacaftor 150 mg) orally for 10 days. Results Elexacaftor/tezacaftor/ivacaftor was safe and well tolerated in subjects with moderate hepatic impairment and healthy controls. On day 10, the mean values of the area under the curve during the dosing interval (AUC τ) for total (bound and unbound) elexacaftor and its major active metabolite M23-elexacaftor were increased 1.25-fold (95% CI 1.01, 1.54) and 1.73-fold (95% CI 1.27, 2.35), respectively, in subjects with moderate hepatic impairment compared with matched healthy subjects. The mean values of AUC τ for ivacaftor and tezacaftor were increased 1.50-fold (95% CI 1.09, 2.06) and 1.20-fold (95% CI 1.00, 1.43), respectively, while the mean value of AUC τ for the active metabolite M1-tezacaftor was 1.29-fold lower [ratio of moderate hepatic impairment to healthy subjects (95% CI): 0.778 (0.655, 0.924)] in subjects with moderate hepatic impairment. Conclusions A dose reduction of elexacaftor/tezacaftor/ivacaftor is warranted in people with moderate hepatic impairment. (Trial registry number 2018-002570-40; registered 2 July 2018.) Plain Language Summary Elexacaftor/tezacaftor/ivacaftor is a combination product (made up of the three drugs elexacaftor, tezacaftor, and ivacaftor) that can effectively treat cystic fibrosis (CF). About 10%-20% of people with CF have liver disease, and the liver plays an important role in breaking down these drugs. Thus, it is important to understand how liver disease or reduced liver function affects the amounts of these drugs in the body over time. This can help determine how much of the drug (i.e., what dose) people should take.
The era of CFTR modulators: improvements made and remaining challenges
Breathe, 2020
The entry into the clinic of CFTR modulators such as TRIKAFTA has significantly improved life for ∼90% CF patients carrying one or two F508del mutations but challenges remain for rare CFTR mutations and the management of lung infections @SaraOcana1 https://bit.ly/3aRafQF
Journal of Personalized Medicine
Previous studies reported the influence of cis variants in F508del cystic fibrosis (CF) patients in their responses to CFTR modulators. The current study is a prospective, observational study involving three patients with CF and pancreatic insufficiency, carrying a complex allele including F508del with A238V, I1027T, or L467F. We report clinical data before and after 4 weeks of treatment with tezacaftor (TEZ)/ivacaftor (IVA), elexacaftor (ELX)/TEZ/IVA, and lumacaftor (LUM)/IVA for patients with complex alleles A238V, I1027T, and L467F, respectively. The 50-year-old patient bearing F508del;A238V/D1152H showed a normal sweat test (13 mEq/L) and improvements in forced expiratory volume in the first second (FEV1) (+7 points), body mass index (BMI) (+0.85), and respiratory CF Questionnaire-Revised (CFQ-R) domain (+22.2 points). The 12-year-old patient bearing F508del;I1027T/R709X showed an improvement in a sweat test (−40 mEq/l), FEV1 (+9 points) and the respiratory CFQ-R domain (+16.7 p...
BioMed research international, 2015
Lipoxin A4 has been described as a major signal for the resolution of inflammation and is abnormally produced in the lungs of patients with cystic fibrosis (CF). In CF, the loss of chloride transport caused by the mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel gene results in dehydration, mucus plugging, and reduction of the airway surface liquid layer (ASL) height which favour chronic lung infection and neutrophil based inflammation leading to progressive lung destruction and early death of people with CF. This review highlights the unique ability of LXA4 to restore airway surface hydration, to stimulate airway epithelial repair, and to antagonise the proinflammatory program of the CF airway, circumventing some of the most difficult aspects of CF pathophysiology. The report points out novel aspects of the cellular mechanism involved in the physiological response to LXA4, including release of ATP from airway epithelial cell via pannexin chan...
Essential Fatty Acid Deficiency in Cystic Fibrosis Disease Progression: Role of Genotype and Sex
Nutrients
Adequate intake of nutrients such as essential fatty acids (EFA) are critical in cystic fibrosis (CF). The clinical course of deterioration of lung function in people with CF has been shown to relate to nutrition. Independent of the higher energy consumption and malabsorption due to pancreatic insufficiency, EFA deficiency is closely associated with the risk of pulmonary infection, the most significant pathology in CF. This review will focus on the EFA deficiency identified in people with CF, as well as the limited progress made in deciphering the exact metabolic pathways that are dysfunctional in CF. Specifically, people with CF are deficient in linoleic acid, an omega 6 fatty acid, and the ratio of arachidonic acid (omega 6 metabolite) and docosahexaenoic acid (omega 3 metabolite) is increased. Analysis of the molecular pathways in bronchial cells has identified changes in the enzymes that metabolise EFA. However, fatty acid metabolism primarily occurs in the liver, with EFA metab...
Fixing cystic fibrosis by correcting CFTR domain assembly
Journal of Cell Biology, 2012
For cystic fibrosis (CF) patients most therapies focus on alleviating the disease symptoms. Yet the cellular basis of the disease has been well studied; mutations in the CF gene can impair folding, secretion, cell surface stability, and/or function of the CFTR chloride channel. Correction of these basic defects has been a challenge, but indicates that a deeper understanding of the molecular and cellular mechanism of mutations is a prerequisite for developing more efficient therapies.
Drug-drug plasma protein binding interactions of ivacaftor
Journal of molecular recognition : JMR, 2015
Ivacaftor is a novel cystic fibrosis (CF) transmembrane conductance regulator (CFTR) potentiator that improves the pulmonary function for patients with CF bearing a G551D CFTR-protein mutation. Because ivacaftor is highly bound (>97%) to plasma proteins, there is the strong possibility that co-administered CF drugs may compete for the same plasma protein binding sites and impact the free drug concentration. This, in turn, could lead to drastic changes in the in vivo efficacy of ivacaftor and therapeutic outcomes. This biochemical study compares the binding affinity of ivacaftor and co-administered CF drugs for human serum albumin (HSA) and α1 -acid glycoprotein (AGP) using surface plasmon resonance and fluorimetric binding assays that measure the displacement of site-selective probes. Because of their ability to strongly compete for the ivacaftor binding sites on HSA and AGP, drug-drug interactions between ivacaftor are to be expected with ducosate, montelukast, ibuprofen, diclox...
Modifier Factors of Cystic Fibrosis Phenotypes: A Focus on Modifier Genes
International Journal of Molecular Sciences
Although cystic fibrosis (CF) is recognized as a monogenic disease, due to variants within the CFTR (Cystic Fibrosis Transmembrane Regulator) gene, an extreme clinical heterogeneity is described among people with CF (pwCF). Apart from the exocrine pancreatic status, most studies agree that there is little association between CFTR variants and disease phenotypes. Environmental factors have been shown to contribute to this heterogeneity, accounting for almost 50% of the variability of the lung function of pwCF. Nevertheless, pwCF with similar CFTR variants and sharing the same environment (such as in siblings) may have highly variable clinical manifestations not explained by CFTR variants, and only partly explained by environmental factors. It is recognized that genetic variants located outside the CFTR locus, named “modifier genes”, influence the clinical expression of the disease. This short review discusses the latest studies that have described modifier factors associated with the...
Different CFTR modulator combinations downregulate inflammation differently in cystic fibrosis
eLife, 2020
Previously, we showed that serum and monocytes from patients with CF exhibit an enhanced NLRP3-inflammasome signature with increased IL-18, IL-1β, caspase-1 activity and ASC speck release (Scambler et al. eLife 2019). Here we show that CFTR modulators down regulate this exaggerated proinflammatory response following LPS/ATP stimulation. In vitro application of ivacaftor/lumacaftor or ivacaftor/tezacaftor to CF monocytes showed a significant reduction in IL-18, whereas IL-1β was only reduced with ivacaftor/tezacaftor. Thirteen adults starting ivacaftor/lumacaftor and eight starting ivacaftor/tezacaftor were assessed over three months. Serum IL-18 and TNF decreased significantly with treatments, but IL-1β only declined following ivacaftor/tezacaftor. In (LPS/ATP-stimulated) PBMCs, IL-18/TNF/caspase-1 were all significantly decreased and IL-10 was increased with both combinations. Ivacaftor/tezacaftor alone showed a significant reduction in IL-1β and pro-IL-1β mRNA. This study demonstr...
Dysregulated signalling pathways in innate immune cells with cystic fibrosis mutations
Cellular and Molecular Life Sciences, 2020
Cystic fibrosis (CF) is one of the most common life-limiting recessive genetic disorders in Caucasians, caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). CF is a multi-organ disease that involves the lungs, pancreas, sweat glands, digestive and reproductive systems and several other tissues. This debilitating condition is associated with recurrent lower respiratory tract bacterial and viral infections, as well as inflammatory complications that may eventually lead to pulmonary failure. Immune cells play a crucial role in protecting the organs against opportunistic infections and also in the regulation of tissue homeostasis. Innate immune cells are generally affected by CFTR mutations in patients with CF, leading to dysregulation of several cellular signalling pathways that are in continuous use by these cells to elicit a proper immune response. There is substantial evidence to show that airway epithelial cells, neutrophils, monocytes and macropha...
Repurposing therapies for the personalised treatment of cystic fibrosis
Expert Opinion on Orphan Drugs, 2018
Introduction: Cystic Fibrosis (CF) is an inherited, lethal and expensive rare disease affecting more than 85,000 people worldwide. CF is caused by more than 2000 loss-of-function mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR). Personalized interventions on individual CF patients probably constitute the future of CF management. Areas covered: The molecular genetics exploration of CF has led in the last years to the development of mutation-specific therapies that aim at directly targeting the mutant CFTR to reverse disease phenotype. Here, we will summarize the strategies of drug repositioning, i.e. the use of 'old drugs' for 'new purposes' in the perspective of a personalized approach to CF treatment. Expert opinion: Rare diseases like CF may well enter the era of precision medicine. A personalized/ repositioning medicine in CF could help to provide the right drug to the right patient and potentially reduce the costs of developing disease-modifying drugs.
Defective proteostasis in celiac disease as a new therapeutic target
Cell Death & Disease, 2019
Cystic fibrosis (CF) is a disease caused by loss-of-function mutations affecting the CF transmembrane conductance regulator (CFTR), a chloride channel. Recent evidence indicates that CFTR is inhibited by a gluten/gliadin-derived peptide (P31-43), causing an acquired state of CFTR inhibition within the gut that contributes to the pathogenesis of celiac disease (CD). Of note, CFTR inhibition does not only cause intra- and extracellular ion imbalances but also affects proteostasis by activating transglutaminase-2 (TGM2) and by disabling autophagy. These three phenomena (CFTR inhibition, TGM2 activation, and autophagy impairment) engage in multiple self-amplifying circuitries, thus forming an “infernal trio”. The trio hinders enterocytes from returning to homeostasis and instead locks them in an irreversible pro-inflammatory state that ultimately facilitates T lymphocyte-mediated immune responses against another gluten/gliadin-derived peptide (P57–68), which,upon deamidation by activate...
Maintaining mental health and function for the long run in cystic fibrosis
Pediatric pulmonology, 2016
Research shows that individuals with cystic fibrosis (CF) and their families experience significant emotional morbidity. In addition to distress, worry, and grief, high rates of clinically significant symptoms of depression and anxiety have been found in both individuals with CF and parents. These disorders have a major impact on the person's functioning, and that of their family, and adversely impact the capacity to cope with the burden of CF and adhere to prescribed treatments. Despite growing recognition that mental health care is an essential component of comprehensive CF care, evidence suggests many patients and their families do not receive needed support and mental health interventions. Clinical practice guidelines for screening and treating depression and anxiety in individuals with CF have been developed by The Cystic Fibrosis Foundation and the European Cystic Fibrosis Society in response to this need. This review highlights that the optimum care for individuals with C...
Vnitřní lékařství, 2017
Souhrn Cystická fibróza (CF) je vrozené onemocnění vyvolané mutacemi genu pro transmembránový regulátor vodivosti (CFTR). Onemocnění vede k dysfunkci žláz s vnitřní sekrecí s vysokou koncentrací chloridů v potu a s tvorbou ab normálně vazkého hlenu v dýchacím, trávicím a rozmnožovacím ústrojí. Klinicky se projevuje především chronic kým sinopulmonálním onemocněním, insuficiencí zevní sekrece pankreatu, hepatopatií, poruchami střevní pasáže a výživy, syndromem ztráty solí a mužskou neplodností. V diagnostice se k průkazu dysfunkce CFTR proteinu vy užívá vyšetření koncentrace chloridů v potu a mutací genu CFTR. V léčbě se uplatňuje především respirační fyzio terapie s inhalacemi mukolytik, agresivní antibiotická léčba a vysokokalorická strava spolu s adekvátní substitucí pankreatickými enzymy. Zcela zásadní je prevence infekce dýchacích cest rezistentními bakteriálními patogeny, ze jména Pseudomonas aeruginosa. Mezi významné pokroky posledních let pak můžeme zahrnout využití novoroze neckého screeningu CF a léků cílených na jednotlivé mutace genu CFTR v klinické praxi. S využitím moderních lé čebných metod a centrové péče se podařilo zlepšit prognózu nemocných tak, že v současnosti narozené děti s CF mají předpokládané přežití 40-50 let. Klíčová slova: cystická fibróza-diagnostika-dospělý věk-léčba Cystic fibrosis in adults Summary Cystic fibrosis (CF) is an inherited disease caused by mutations in the transmembrane conductance regulator (CFTR) gene. The disease leads to dysfunction of the exocrine glands with high concentration of chloride in the sweat and formation of abnormally viscous mucus in the respiratory, digestive and reproductive tract. Chronic sinopulmonary disease, exocrine pancreatic insufficiency, liver disease, intestinal obstruction, impaired nutritional status, salt loss syndrome and male infertility dominates in the clinical presentation. The examination of sweat chloride concentra tion and mutations in the CFTR gene is used in CF diagnostics for detection of CFTR protein dysfunction. The treat ment comprises especially respiratory physiotherapy with mucolytics inhalations, aggressive antibiotic thera py and highcalorie diet together with adequate pancreatic enzymes substitution. The prevention of airway infection with resistant bacterial pathogens, particularly Pseudomonas aeruginosa, is a fundamental measure. Significant recent progress include the use of newborn screening of CF and drugs targeted to individual CFTR gene mutations in the clinical practise. The prognosis of patients has improved due to using of modern therapeutic methods in CF treat ment centres. Children born at present time have survival probability 40-50 years.
CFTR: A New Horizon in the Pathomechanism and Treatment of Pancreatitis
Reviews of physiology, biochemistry and pharmacology, 2016
Cystic fibrosis transmembrane conductance regulator (CFTR) is an ion channel that conducts chloride and bicarbonate ions across epithelial cell membranes. Mutations in the CFTR gene diminish the ion channel function and lead to impaired epithelial fluid transport in multiple organs such as the lung and the pancreas resulting in cystic fibrosis. Heterozygous carriers of CFTR mutations do not develop cystic fibrosis but exhibit increased risk for pancreatitis and associated pancreatic damage characterized by elevated mucus levels, fibrosis, and cyst formation. Importantly, recent studies demonstrated that pancreatitis causing insults, such as alcohol, smoking, or bile acids, strongly inhibit CFTR function. Furthermore, human studies showed reduced levels of CFTR expression and function in all forms of pancreatitis. These findings indicate that impairment of CFTR is critical in the development of pancreatitis; therefore, correcting CFTR function could be the first specific therapy in p...
Sweat rate analysis of ivacaftor potentiation of CFTR in non-CF adults
Scientific reports, 2018
To determine if ivacaftor (Kalydeco) influences non-CF human CFTR function in vivo, we measured CFTR-dependent (C-sweat) and CFTR-independent (M-sweat) rates from multiple identified sweat glands in 8 non-CF adults. The two types of sweating were stimulated sequentially with intradermal injections of appropriate reagents; each gland served as its own control via alternating off-on drug tests on both arms, given at weekly intervals with 3 off and 3 on tests per subject. We compared drug effects on C-sweating stimulated by either high or low concentrations of β-adrenergic cocktail, and on methacholine-stimulated M-sweating. For each subject we measured ~700 sweat volumes from ~75 glands per arm (maximum 12 readings per gland), and sweat volumes were log-transformed for statistical analysis. T-tests derived from linear mixed models (LMMs) were more conservative than the familiar paired sample t-tests, and show that ivacaftor significantly increased C-sweating stimulated by both levels ...
F1000Research, 2018
Forced expiratory volume in one second (FEV) is an important Background: cystic fibrosis (CF) prognostic marker and an established endpoint for CF clinical trials. FEV is also used in observation studies, e.g. to compare different centre's outcomes. We wished to evaluate whether different methods of processing FEV data can impact on a centre's outcome. This is a single-centre retrospective analysis of routinely collected Methods: data from 2013-2016 which included 208 adults with CF. Year-to-year %FEV change was calculated by subtracting best %FEV at Year 1 from Year 2 (i.e. negative values indicate %FEV decline), and compared using Friedman test. Three methods were used to process %FEV data. First, %FEV calculated with Knudson equation was extracted directly from spirometer machines. Second, FEV volume were extracted then converted to %FEV using clean height data and Knudson equation. Third, FEV volume were extracted then converted to %FEV using clean height data and GLI equation. In addition, %FEV decline calculated using GLI equation was adjusted for baseline %FEV to understand the impact of case-mix adjustment. There was a trend of reduction in %FEV decline with all three data Results: processing methods but the magnitude of %FEV decline differed. Median change in %FEV for 2013-2014, 2014-2015 and 2015-2016 was-2.0,-1.0 and 0.0 respectively using %FEV in Knudson equation whereas the median change was-1.1,-0.9 and-0.3 respectively using %FEV in the GLI equation. A statistically significant p-value (0.016) was only obtained when using %FEV in Knudson equation extracted directly from spirometer machines. Although the trend of reduction in %FEV decline was robust, Conclusions: different data processing methods yielded varying results when %FEV decline was compared using a standard related group non-parametric statistical test.
Longitudinal Cystic Fibrosis Care
Clinical Pharmacology & Therapeutics, 2012
state art nature publishing group Cystic fibrosis, also referred as mucoviscidosis, is a lifethreatening autosomal recessive genetic disorder affecting multiple organs, most critically the respiratory and digestive systems. The prognosis for cystic fibrosis has significantly improved as a result of earlier diagnosis, better treatment, and expanded access to specialized care. Modern cystic fibrosis care incorporates a longitudinal strategy that includes early prenatal detection, management of disease manifestations during infancy and childhood, and chronic treatment in the adult. Decoding the pathogenesis of cystic fibrosis has advanced personalized treatment algorithms. Most notable is the realization that cystic fibrosis is a generalized exocrinopathy with reduced chloride ion transport across cell membranes as a consequence of a primary genetic disorder within the long arm of chromosome 7 encoding the transmembrane conductance regulating protein (CFTR). In healthy duct epithelia, chloride is transported by plasma membrane channels. Opening of chloride channels is mediated by an agonist-induced increase in cyclic adenosine monophosphate, followed by activation of protein kinase A, which phosphorylates channel proteins. 1 The impact of defective chloride transport differs in various tissues. In sweat gland ducts, it leads to decreased reabsorption of sodium chloride from the lumen, resulting in an increased concentration of sweat chloride, the basis for clinical diagnosis of cystic fibrosis. In other epithelia, especially the respiratory and intestinal epithelia, as well as in the biliary and pancreatic ducts, chloride channel defects result in loss or reduction of chloride secretion. Active sodium absorption is also increased, and these concomitant ionic changes increase water reabsorption from the lumen. As a consequence, dehydration of the mucus layer leads to viscid secretions, resulting in lumen obstruction and predisposing over time to recurrent infection, inflammation, fibrosis, and organ failure. The pronounced improvement in life expectancy for patients with cystic fibrosis, which is experienced across global health systems, particularly in developed countries, is a result of early diagnosis and improved symptomatic treatment based on control of airway infections, intestinal function, mobilization of secretions, reduction of inflammation, and improved nutrition. 2 Treating the fundamental defect underlying cystic fibrosis through a gene-modifying therapy offers the prospect of potential cures. In this regard, encouraging results from early clinical trials with mutation-correcting drug and gene therapy pave the way to more efficient management in the future. 3 Prenatal Diagnosis Cystic fibrosis is a hereditary, autosomal recessive disease, passed on from parents to offspring, with the highest prevalences of 1 in 3,000 Caucasian children of northern European descent and from North America and 1 in 2,300 in the Ashkenazi Jewish population. Other ethnic and racial groups are less commonly affected, reflected in the prevalences of 1 in 10,000 in the Latino American population and 1 in 15,000 in African Americans. The disease is uncommon in Africa and Asia, with reported frequencies ranging from 1 in 35,000 to 1 in 350,000. The earliest manifestation of cystic fibrosis may be associated with bowel lesions identified at prenatal ultrasonography, especially
Journal of Magnetic Resonance Imaging, 2020
BackgroundMRI has been suggested as a radiation‐free imaging modality to investigate early structural alterations and regional functional impairment in cystic fibrosis (CF) lung disease.Purpose/HypothesisTo compare functional and morphological MRI changes over the course of the disease to changes in spirometry.Study TypeLongitudinal retrospective study.PopulationTwenty patients with CF lung disease (at baseline, age = 16.5 (13.3–20.6) years, forced expiratory volume in 1 second (as % of predicted [%pred]) FEV1 = 71 (59–87) %pred, forced expiratory flow at 25–75% of forced vital capacity FEF25‐75 = 39 (25–63) %pred.Field Strength/Sequence1.5T / T2‐weighted HASTE; T2‐weighted TSE‐PROPELLER; T2‐weighted bSSFP; T1‐weighted 3D GRE.AssessmentNonenhanced chest MRI and spirometry were retrospectively collected over a 3‐year period from the initial recruitment visit. Images acquired at end‐inspiration and end‐expiration were registered by software using the optical flow method to measure exp...
The Journal of biological chemistry, 2017
Cystic fibrosis (CF) is caused by mutations that disrupt the plasma membrane expression, stability, and function of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. Two small molecules, the CFTR corrector lumacaftor and the potentiator ivacaftor, are now used clinically to treat CF, although some studies suggest that they have counteracting effects on CFTR stability. Here, we investigated the impact of these compounds on the instability of F508del-CFTR, the most common CF mutation. To study individual CFTR Cl- channels, we performed single-channel recording, whereas to assess entire CFTR populations, we used purified CFTR proteins and macroscopic CFTR Cl- currents. At 37 degC, low temperature-rescued F508del-CFTR more rapidly lost function in cell-free membrane patches, and showed altered channel gating and current flow through open channels. Compared with purified wild-type CFTR, the full-length F508del-CFTR was about 10 degC less thermo-stable. Lumacafto...
BMC Pulmonary Medicine, 2019
Background: Clinical studies demonstrate that ivacaftor (IVA) improves health-related quality of life (HRQoL) in patients aged ≥6 years with cystic fibrosis (CF). The real-world impact of IVA and standard of care (SOC) in groups of patients with G551D and F508del mutations, respectively, was assessed using a survey comprising disease-specific and generic HRQoL measures. Methods: Patients with CF aged ≥12 years, or aged 6-11 years with caregiver support, with either (1) a G551D mutation and receiving IVA (G551D/IVA) for ≥3 months, or (2) homozygous for F508del and receiving SOC before lumacaftor/IVA availability (F508del/SOC), were eligible to participate in a cross-sectional survey. Demographic and clinical characteristics, and HRQoL measures were compared between patient groups, and multiple regression analyses were conducted. Results: After differences in patient demographic and clinical characteristics were controlled for, significantly better scores were observed in the G551D/IVA group than in the F508del/SOC group on multiple domains of the validated Cystic Fibrosis Questionnaire-Revised and the EuroQol 5-dimensions 5-level questionnaire. Conclusions: G551D/IVA patients reported better HRQoL than F508del/SOC patients on generic and disease-specific measures in a real-world setting.
Acta Médica Portuguesa
A fibrose quística é a doença genética letal mais comum na população branca, afetando aproximadamente 80 000 pessoas em todo o mundo. É uma doença autossómica recessiva, monogenética e multissistémica, estando descritas mais de 2000 mutações no gene da proteína CFTR. A disfunção desta proteína leva à diminuição da secreção de cloro e de bicarbonato, hiperabsorção de sódio e consequentemente de água, resultando no espessamento das secreções e acumulação de agentes patogénicos. Estas alterações culminam em inflamação, infeção pulmonar crónica e agudizações recorrentes, sendo a doença pulmonar a principal causa de morbilidade e mortalidade. Nas fases iniciais da doença, o Staphylococcus aureus é, geralmente, o agente responsável pela infeção crónica. Com o tempo, a Pseudomonas aeruginosa vai adquirindo um papel mais preponderante, sendo a bactéria mais frequente nos adultos. Contudo, em até 70% dos doentes, a colonização é polimicrobiana, sendo frequente o isolamento de S. aureus e P. ...
On the Corner of Models and Cure: Gene Editing in Cystic Fibrosis
Frontiers in Pharmacology, 2021
Cystic fibrosis (CF) is a severe genetic disease for which curative treatment is still lacking. Next generation biotechnologies and more efficient cell-based and in vivo disease models are accelerating the development of novel therapies for CF. Gene editing tools, like CRISPR-based systems, can be used to make targeted modifications in the genome, allowing to correct mutations directly in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. Alternatively, with these tools more relevant disease models can be generated, which in turn will be invaluable to evaluate novel gene editing-based therapies for CF. This critical review offers a comprehensive description of currently available tools for genome editing, and the cell and animal models which are available to evaluate them. Next, we will give an extensive overview of proof-of-concept applications of gene editing in the field of CF. Finally, we will touch upon the challenges that need to be addressed before these pro...
Journal of the Academy of Nutrition and Dietetics, 2021
There is a strong positive association between nutrition status and lung function in cystic fibrosis (CF). Improvements in clinical care have increased longevity for individuals with CF, and it is unknown how cystic fibrosis transmembrane regulator (CFTR) modulation therapy affects nutrition status over time. The objective of this systematic review of the literature was to examine anthropometric (height, weight, and body mass index [BMI; calculated as kg/m 2 ]) and body composition outcomes of CFTR modulation therapy. A literature search of Medline (Ovid), Embase, and CINAHL (EBSCO) databases was conducted for randomized controlled trials examining the effect of CFTR modulation therapy on anthropometric and body composition parameters, published in peer-reviewed journals from January 2002 until May 2018. Articles were screened, data were synthesized qualitatively, and evidence quality was graded by a team of content experts and systematic review methodologists. Significant weight gain with ivacaftor was noted in children and adults with at least 1 copy of G551D mutation. In adults with at least 1 copy of R117H the effect of ivacaftor on BMI was not significant. Effects on BMI were mixed in adults with class II mutations taking ivacaftor with lumacaftor. There was no significant change in BMI in children homozygous for F508del who took ivacaftor with tezacaftor. Elexacaftortezacaftor-ivacaftor increased BMI and body weight in individuals 12 years of age and older who were hetero-or homozygous for the F508del mutation. The effect of CFTR modulation therapy on anthropometric parameters depends on the genetic mutation and the type of modulation therapy used. More research is needed to understand the long-term clinical impact of these drugs on nutritional status, including body composition and the role of dietary intake.
Cystic fibrosis: a comprehensive review
Reviews in Biological and Biomedical Sciences, 2022
With almost 100 000 people affected worldwide, cystic fibrosis (CF) represents one of the most fatal inherited conditions found in Caucasian individuals, being clinically characterized by a progressive pulmonary dysfunction, pancreatic insufficiency, and male infertility. Alterations in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein has been found to be the sole responsible for the disease, with over 2000 defects being identified since 1989. Here we present, at a basic descriptive level, the current understanding of the clinical and genetic traits of CF gene modifications, the challenges associated with the early diagnosis and management strategies but also new emerging therapies that can improve the individual's life expectancy by enabling patient-specific treatment.
Precision medicine in united airways disease: A “treatable traits” approach
Allergy, 2018
United airways disease (UAD) is the concept that the upper and lower airways, which are anatomically and immunologically related, form a single organ. According to this concept, upper and lower airway diseases are frequently comorbid because they reflect manifestations of a single underlying disease at different sites of the respiratory tract. Allergic asthma‐allergic rhinitis is the archetypal UAD, but emerging data indicate that UAD is a heterogeneous condition and consists of multiple phenotypes (observable clinical characteristics) and endotypes (pathobiologic mechanisms). The UAD paradigm also extends to myriad sinonasal diseases (eg, chronic rhinosinusitis with or without nasal polyps) and lower airway diseases (eg, bronchiectasis, chronic obstructive pulmonary disease). Here, we review currently known phenoendotypes of UAD and propose a “treatable traits” approach for the classification and management of UAD, wherein pathophysiological mechanisms and factors contributing to d...
PLOS ONE
Objectives Cystic fibrosis (CF) is a rare genetic disease characterized by life-shortening lung function decline. Ivacaftor, a CF transmembrane conductance regulator modulator (CFTRm), was approved in 2012 for people with CF with specific gene mutations. We used real-world evidence of 5-year mortality impacts of ivacaftor in a US registry population to validate a CF disease-progression model that estimates the impact of ivacaftor on survival. Methods The model projects the impact of ivacaftor vs. standard care in people with CF aged ≥6 years with CFTR gating mutations by combining parametric equations fitted to historical registry survival data, with mortality hazards adjusted for fixed and time-varying person-level characteristics. Disease progression with standard care was derived from published registry studies and the expected impact of ivacaftor on clinical characteristics was derived from clinical trials. Individual-level baseline characteristics of the registry ivacaftor-trea...
Effectivenesss of ivacaftor in severe cystic fibrosis patients and non‐G551D gating mutations
Pediatric Pulmonology, 2019
Background: Ivacaftor is a significant innovation in the treatment of cystic fibrosis (CF) with gating mutations. A substantial percentage of patients with CF have severe lung involvement, but these patients are usually excluded from phase III clinical trials. Thus, the effectiveness of ivacaftor in this population has not been fully determined. Methods: Data were collected from Italian CF centers with patients enrolled in an ivacaftor compassionate use programme (percent predicted [pp] forced expiratory volume in 1 second [FEV 1 ] < 40%, or on lung transplant waiting list, or with a fast worsening trend of lung function). Data were collected for 1 year before and 1 year after ivacaftor commencement. Results: Thirteen patients received ivacaftor for a median of 320 days. Mean (SD) ppFEV 1 increased from 35.1% (14.3%) before treatment to 46.6% (18.8%) after 12 months of treatment (absolute increase 11.5%, relative increase 32.8%). Mean distance of the 6-minute walking test improved significantly, from 535.1 m before to 611.6 m after 12 months of treatment (P = .002). The number of pulmonary exacerbations decreased significantly, from 57 during the year before ivacaftor to 28 in the year following ivacaftor (P = .0048). Five of the 13 patients (38.5%) had no exacerbations during the 12 months after starting ivacaftor. Median weight increased significantly, from 52.7 kg to 55.6 kg (P = .0031). Mean (SD) sweat chloride concentration decreased significantly, from 99.5 (22.8) mmol/L to 39.3 (15.8) mmol/ L (P < .0001). No safety concerns were registered. Conclusions: Ivacaftor was safe and effective in patients with CF with severe lung disease and non-G551D gating mutations.
PloS one, 2017
We optically measured effects of orally available ivacaftor (Kalydeco®) on sweat rates of identified glands in 3 R117H subjects, each having a unique set of additional mutations, and compared them with 5 healthy control subjects tested contemporaneously. We injected β-adrenergic agonists intradermally to stimulate CFTR-dependent 'C-sweat' and methacholine to stimulate 'M-sweat', which persists in CF subjects. We focused on an R117H-7T/F508del subject who produced quantifiable C-sweat off ivacaftor and was available for 1 blinded, 3 off ivacaftor, and 3 on ivacaftor tests, allowing us to estimate in vivo fold-increase in sweat rates produced by ivacaftor's effect on the open probability (PO) of R117H-CFTR. Measured sweat rates must be corrected for sweat losses. With estimated sweat losses of 0.023 to 0.08 nl·gland-1·min-1, ivacaftor increased the average C-sweat rates 3-7 fold, and estimated function as % of WT were 4.1-12% off ivacaftor and 21.9-32% on ivacaftor...
Therapeutic Advances in Respiratory Disease, 2019
Background: Lumacaftor/ivacaftor combination therapy is efficacious and generally safe for patients with cystic fibrosis (CF) homozygous for the F508del-CF transmembrane conductance regulator (CFTR) mutation. However, long-term survival benefits of lumacaftor/ivacaftor (LUM/IVA) cannot yet be quantified. Simulation models can provide predictions about long-term health outcomes. In this study, we aimed to project long-term health outcomes of LUM/IVA plus standard care (SC) in patients with CF homozygous for F508del-CFTR. Methods: This modeling study was an individual patient simulation in US patients aged ⩾6 years with CF, homozygous for F508del-CFTR. The primary outcome was projected survival among (a) a cohort of patients who ever initiated LUM/IVA, accounting for treatment discontinuations, and (b) a cohort of patients who remain on continuous LUM/IVA. Patient characteristics and model parameters were derived from clinical trials: VX14-809-109, VX13-809-011B, TRAFFIC/TRANSPORT, an...
Synthesis and Therapeutic Applications of Iminosugars in Cystic Fibrosis
International Journal of Molecular Sciences, 2020
Iminosugars are sugar analogues endowed with a high pharmacological potential. The wide range of biological activities exhibited by these glycomimetics associated with their excellent drug profile make them attractive therapeutic candidates for several medical interventions. The ability of iminosugars to act as inhibitors or enhancers of carbohydrate-processing enzymes suggests their potential use as therapeutics for the treatment of cystic fibrosis (CF). Herein we review the most relevant advances in the field, paying attention to both the chemical synthesis of the iminosugars and their biological evaluations, resulting from in vitro and in vivo assays. Starting from the example of the marketed drug NBDNJ (N-butyl deoxynojirimycin), a variety of iminosugars have exhibited the capacity to rescue the trafficking of F508del-CFTR (deletion of F508 residue in the CF transmembrane conductance regulator), either alone or in combination with other correctors. Interesting results have also ...
Nature Reviews Disease Primers, 2015
Cystic fibrosis is an autosomal-recessive, monogenetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The gene defect was first described 25 years ago and much progress has been made since then in our understanding on how CFTR mutations cause disease and how this can be addressed therapeutically. CFTR is a transmembrane protein that transports ions across the surface of epithelial cells. CFTR dysfunction affects many organs; however, lung disease is responsible for the vast majority of morbidity and mortality in patients with cystic fibrosis. Prenatal diagnostics, newborn screening and new treatment algorithms are changing the incidence and prevalence of the disease. Until recently, the standard of care in cystic fibrosis treatment focused on preventing and treating complications of the disease; now, novel treatment strategies targeting the ion channel abnormality directly are becoming available and it will be important to evaluate how these treatments affect disease progression and quality of life of patients. In this Primer, we summarize the current knowledge and provide an outlook on how cystic fibrosis clinical care and research will be affected by new knowledge and therapeutic options in the near future. Cystic fibrosis is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Close to 2,000 mutations in this gene have been described to date (), although fewer than 150 are known to be disease causing (). Although cystic fibrosis is a monogenetic
Journal of Cystic Fibrosis
Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was shown to be safe and efficacious in people with cystic fibrosis (CF) heterozygous for F508del and a minimal function mutation ( F /MF) or homozygous for F508del ( F / F ) in two pivotal Phase 3 trials, significantly improving percentage predicted forced expiratory volume in 1 second, Cystic Fibrosis Questionnaire-Revised, Respiratory Domain (CFQ-R RD) scores, and sweat chloride concentration. Here, we analyzed the 11 non-respiratory domains (non-RDs) of the CFQ-R, which assess general health-related quality of life (i.e., Physical Functioning, Role Functioning, Vitality, Health Perceptions, Emotional Functioning, and Social Functioning) and quality of life impacted by CF (i.e., Body Image, Eating Problems, Treatment Burden, Weight, and Digestive Symptoms), for participants in these two Phase 3 trials. ELX/TEZ/IVA treatment led to higher scores in all CFQ-R non-RDs, with improvements in most domains compared with control treatments. These findings demonstrate that ELX/TEZ/IVA improves a range of CF-specific symptoms and general functioning and well-being.
Discovery of a picomolar potency pharmacological corrector of the mutant CFTR chloride channel
Science Advances, 2020
F508del, the most frequent mutation causing cystic fibrosis (CF), results in mistrafficking and premature degradation of the CFTR chloride channel. Small molecules named correctors may rescue F508del-CFTR and therefore represent promising drugs to target the basic defect in CF. We screened a carefully designed chemical library to find F508del-CFTR correctors. The initial active compound resulting from the primary screening underwent extensive chemical optimization. The final compound, ARN23765, showed an extremely high potency in bronchial epithelial cells from F508del homozygous patients, with an EC 50 of 38 picomolar, which is more than 5000-fold lower compared to presently available corrector drugs. ARN23765 also showed high efficacy, synergy with other types of correctors, and compatibility with chronic VX-770 potentiator. Besides being a promising drug, particularly suited for drug combinations, ARN23765 represents a high-affinity probe for CFTR structure-function studies.
Cell Death & Differentiation, 2016
We previously reported that the combination of two safe proteostasis regulators, cysteamine and epigallocatechin gallate (EGCG), can be used to improve deficient expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in patients homozygous for the CFTR Phe508del mutation. Here we provide the proof-of-concept that this combination treatment restored CFTR function and reduced lung inflammation (Po0.001) in Phe508del/Phe508del or Phe508del/null-Cftr (but not in Cftr-null mice), provided that such mice were autophagy-competent. Primary nasal cells from patients bearing different class II CFTR mutations, either in homozygous or compound heterozygous form, responded to the treatment in vitro. We assessed individual responses to cysteamine plus EGCG in a single-centre, open-label phase-2 trial. The combination treatment decreased sweat chloride from baseline, increased both CFTR protein and function in nasal cells, restored autophagy in such cells, decreased CXCL8 and TNF-α in the sputum, and tended to improve respiratory function. These positive effects were particularly strong in patients carrying Phe508del CFTR mutations in homozygosity or heterozygosity. However, a fraction of patients bearing other CFTR mutations failed to respond to therapy. Importantly, the same patients whose primary nasal brushed cells did not respond to cysteamine plus EGCG in vitro also exhibited deficient therapeutic responses in vivo. Altogether, these results suggest that the combination treatment of cysteamine plus EGCG acts 'on-target' because it can only rescue CFTR function when autophagy is functional (in mice) and improves CFTR function when a rescuable protein is expressed (in mice and men). These results should spur the further clinical development of the combination treatment.
Frontiers in Pharmacology, 2023
Introduction: Seminal clinical trials with the triple combination of elexacaftortezacaftor-ivacaftor (ETI) demonstrated clinical efficacy in people with cystic fibrosis (pwCF) who carry at least one F508del mutation. However, due to exclusion criteria of these clinical trials, the effect of ETI was not studied in a substantial number of pwCF. Thus, we ran a single center trial to evaluate a clinical efficacy of ETI treatment in adult pwCF who were ineligible for enrollment in registration studies. Methods: PwCF on ETI with prior lumacaftor-ivacaftor therapy, severe airway obstruction, well-preserved lung function, or with airway infection with pathogens at risk of more rapid decline in lung function formed the study group, while all the others on ETI formed the control group. Lung function, nutritional status and sweat chloride concentration were assessed before and after initialization of ETI therapy over a 6-month period. Results: Approximately a half of the ETI-treated pwCF at the adult Prague CF center (49 of 96) were assigned to the study group. Their mean changes in body mass index ( + 1.04 kg/m 2 ) and in sweat chloride concentration (-48.4 mmol/L) were similar to the control group ( + 1.02 kg/m 2 ; -49.7 mmol/L), while the mean change in percent predicted forced expiratory volume in 1 s (ppFEV 1 ; + 10.3 points) was significantly lower than in the control group ( + 15.8 points) (p = 0.0015). In the subgroup analysis, pwCF with severe airway obstruction (ppFEV 1 <40) and pwCF with well-preserved lung function (ppFEV 1 >90) showed a less potential for improvement in lung function during the ETI treatment than controls (median change in ppFEV 1 + 4.9 points and + 9.5 points, respectively). PwCF not eligible for inclusion in clinical trials demonstrated improvement in lung function and nutritional status following the initiation of treatment with the ETI combination. Moderate increase in ppFEV 1 was observed in those with severe airway obstruction or well-preserved lung function.
Italian Journal of Pediatrics, 2021
In this article, we describe the advances in the field of pediatrics that have been published in the Italian Journal of Pediatrics in 2020. We report progresses in understanding allergy, autoinflammatory disorders, critical care, endocrinology, genetics, infectious diseases, microbiota, neonatology, neurology, nutrition, orthopedics, respiratory tract illnesses, rheumatology in childhood.