From Ivacaftor to Triple Combination: A Systematic Review of Efficacy and Safety of CFTR Modulators in People with Cystic Fibrosis

Learning from cystic fibrosis: How can we start to personalise treatment of Children's Interstitial Lung Disease (chILD)?

Cystic fibrosis (CF) is a monogenic disorder cause by mutations in the CF Transmembrane Regulator (CFTR) gene. The prognosis of cystic fibrosis has been transformed by the discovery of highly effective modulator therapies (HEMT). Treatment has changed from reactive therapy dealing with complications of the disease to pro-active correction of the underlying molecular functional abnormality. This has come about by discovering the detailed biology of the different CF molecular sub-endotypes; the development of biomarkers to assess response even in mild disease or young children; the performance of definitive large randomised controlled trials in patients with a common mutation and the development of in vitro testing systems to test efficacy in those patients with rare CFTR mutations. As a result, CF is now an umbrella term, rather than a specific diagnostic label; we have moved from clinical phenotypes to molecular subendotypes. Children's Interstitial Lung Diseases (chILDs) comprise more than 200 entities, and are a diverse group of diseases, for an increasing number of which an underlying gene mutation has been discovered. Many of these entities are umbrella terms, such as pulmonary alveolar proteinosis or hypersensitivity pneumonitis, for each of which there are multiple and very different endotypes. Even those chILDs for which a specific gene mutation has been discovered comprise, as with CF, different molecular subendotypes likely mandating different therapies. For most chILDs, current treatment is non-specific (corticosteroids, azithromycin, hydroxychloroquine). The variability of the different entities means that there is little evidence for the efficacy of any treatment. This review considers how some of the lessons of the success story of CF are being applied to chILD, thus opening the opportunities for truly personalised medicine in these conditions. Advances in knowledge in the molecular biology of surfactant protein C and Adenosine triphosphate binding cassette subfamily A member 3 (ABCA3), and the possibilities of discovering novel therapies by in vitro studies will especially be highlighted.

Glutathione and bicarbonate nanoparticles improve mucociliary transport in cystic fibrosis epithelia

INTRODUCTION

Cystic fibrosis (CF) airway disease is characterized by thick mucus and impaired mucociliary transport (MCT). Loss of functional cystic fibrosis transmembrane receptor (CFTR) leads to acidification and oxidation of airway surface mucus. Replacing bicarbonate (HCO3 -) topically fails due to rapid reabsorption and neutralization, while the scavenging antioxidant, glutathione sulfhydryl (GSH), is also rapidly degraded. The objective of this study is to investigate GSH/NaHCO3 nanoparticles as novel strategy for CF airway disease.

METHODS

GSH/NaHCO3 poly (lactic-co-glycolic acid) nanoparticles were tested on primary CF (F508del/F508del) epithelial cultures to evaluate dose-release curves, surface pH, toxicity, and MCT indices using micro-optical coherence tomography. In vivo tests were performed in three rabbits to assess safety and toxicity. After 1 week of daily injections, histopathology, computed tomography (CT), and blood chemistries were performed and compared to three controls. Fluorescent nanoparticles were injected into a rabbit with maxillary sinusitis and explants visualized with confocal microscopy.

RESULTS

Sustained release of GSH and HCO3 - with no cellular toxicity was observed over 2 weeks. Apical surface pH gradually increased from 6.54 ± 0.13 (baseline) to 7.07 ± 0.10 (24 h) (p < 0.001) and 6.87 ± 0.05 at 14 days (p < 0.001). MCT, ciliary beat frequency, and periciliary liquid were significantly increased. When injected into the maxillary sinuses of rabbits, there were no changes to histology, CT, or blood chemistries. Nanoparticles penetrated rabbit sinusitis mucus on confocal microscopy.

CONCLUSION

Findings suggest that GSH/NaHCO3 - nanoparticles are a promising treatment option for viscous mucus in CF and other respiratory diseases of mucus obstruction such as chronic rhinosinusitis.

Heterogeneity in response to Elexacaftor/Tezacaftor/Ivacaftor in people with cystic fibrosis

BACKGROUND

Highly effective modulators of the CFTR channel have been demonstrated to dramatically impact disease progression and outcome. However, real-world data indicates that the magnitude of the clinical benefit is not equal among all patients receiving the treatment. We aimed to assess the variability in treatment response (as defined by the 6-month change in sweat chloride concentration, forced expiratory volume in one second [ppFEV1], body mass index [BMI], and CF Questionnaire-Revised [CFQ-R] respiratory domain score) and identify potential predictors in a group of patients receiving Elexacaftor-Tezacaftor-Ivacaftor (ETI) triple combination therapy.

METHODS

This was a single-center, prospective cohort study enrolling adults with CF at a major center in Italy. We used linear regression models to identify a set of potential predictors (including CFTR genotype, sex, age, and baseline clinical characteristics) and estimate the variability in treatment response.

RESULTS

The study included 211 patients (median age: 29 years, range: 12-58). Median changes (10-90th percentile) from baseline were: - 56 mEq/L (-76; -27) for sweat chloride concentration, +14.5 points (2.5; 32.0) for ppFEV1, +0.33 standard deviation scores (-0.13; 1.05) for BMI and +17 points (0; 39) for the CFQ-R respiratory domain score. The selected predictors explained 23 % of the variability in sweat chloride concentration changes, 18 % of the variability in ppFEV1 changes, 39 % of the variability in BMI changes, and 65 % of the variability in CFQ-R changes.

CONCLUSIONS

This study highlights a high level of heterogeneity in treatment response to ETI, which can only be partially explained by the baseline characteristics of the disease.

Monitoring of ECFS quality standards for the clinical management of adults with cystic fibrosis

BACKGROUND

Although cystic fibrosis (CF) standards of care have been produced and regularly updated, they are not specifically targeting at the adult population. The ECFS Standards of Care Project established an international task force of experts to identify quality standards for adults with CF and assess their adherence.

METHODS

This study was composed of two phases. In the first one, a task force of international experts derived from published guidelines and graded ten quality standards for adult CF care using a modified Delphi methodology. In the second phase, an international audit was conducted among adult CF centers to retrospectively validate the quality statements and monitor adherence.

RESULTS

The task force identified 10 quality standards specific to the care of adults with CF, mainly based on the 2018 ECFS standards of care. 14 adult CF centers participated in the audit, which showed that most quality standards for the management of CF in adults are met across Europe. Heterogeneity in adherence to standards was found across centers according to geographical setting and centers' characteristics.

CONCLUSIONS

The identification of quality standards is a valuable resource for the standardization and monitoring of care delivery across centers taking care of adults with CF.

Longitudinal changes in habitual physical activity in adult people with cystic fibrosis in the presence or absence of treatment with elexacaftor/tezacaftor/ivacaftor

Background

Habitual physical activity (PA) and exercise training are accepted as important aspects of care for people with cystic fibrosis (pwCF) to improve health-related measures of physical fitness, which in turn have a positive impact on quality of life and prognosis. In the last decade, effective CFTR modulator therapies have become a promising treatment for pwCF by targeting the underlying cause of CF. This highly effective therapy improves clinical outcomes and quality of life in people with specific CFTR mutations. Little is known about the longitudinal pattern of PA or the impact of the highly effective modulator therapy with Elexacaftor/Tezacaftor/Ivacaftor (ETI) on PA in adult pwCF. This study assessed the course of device-based PA measurement in adult pwCF and evaluated the effects of ETI on habitual physical activity in those who were eligible for ETI.

Methods

Data from adult pwCF (aged ≥18 years) were analysed at baseline and follow-up, using identical assessments at both time points. Outcome parameters were PA in steps/day and the intensity of PA. The group that received ETI was treated for an average of 33 weeks and not for the entire duration of the period. The data were collected between 2021 and 2022, following the removal of absolute pandemic restrictions/lockdowns.

Results

Follow-up duration was 5.6 years in pwCF with ETI (ETI group, n = 21) and 6.5 years in pwCF without ETI (non-ETI group, n = 6). From baseline to follow-up, pwCF treated with ETI had a significant increase in steps/day (+25%, p = 0.019) and a non-significant increase in moderate-to-vigorous intensity time (+5.6%, p = 0.352). Conversely, individuals in the non-ETI group showed a non-significant decrease in both steps/day -3.2%, p = 0.893) and moderate-to-vigorous intensity time (-25%, p = 0.207). The ETI group showed a significant decrease in percent predicted forced expiratory volume in 1 s (ppFEV1) and FEV1 z-score before the start of ETI treatment, both of which improved significantly after therapy initiation. Body weight and body mass index also improved significantly with ETI use.

Conclusions

These data suggest that ETI treatment has a positive effect on habitual physical activity behavior in the adult pwCF studied.

Treatable traits and challenges in the clinical management of non-tuberculous mycobacteria lung disease in people with cystic fibrosis

INTRODUCTION

Over the last ten years an increasing prevalence and incidence of non-tuberculous mycobacteria (NTM) has been reported among patients with cystic fibrosis (CF) Viviani (J Cyst Fibros, 15(5):619-623, 2016). NTM pulmonary disease has been associated with negative clinical outcomes and often requires pharmacological treatment. Although specific guidelines help clinicians in the process of diagnosis and clinical management, the focus on the multidimensional assessment of concomitant problems is still scarce.

MAIN BODY

This review aims to identify the treatable traits of NTM pulmonary disease in people with CF and discuss the importance of a multidisciplinary approach in order to detect and manage all the clinical and behavioral aspects of the disease. The multidisciplinary complexity of NTM pulmonary disease in CF requires careful management of respiratory and extra-respiratory, including control of comorbidities, drug interactions and behavioral factors as adherence to therapies.

CONCLUSIONS

The treatable trait strategy can help to optimize clinical management through systematic assessment of all the aspects of the disease, providing a holistic treatment for such a multi-systemic and complex condition.

The impact of elexacaftor/tezacaftor/ivacaftor therapy on the pulmonary management of adults with cystic fibrosis: An expert-based Delphi consensus

BACKGROUND

The advent of elexacaftor/tezacaftor/ivacaftor (ETI) resulted in unprecedented clinical benefits for eligible adults with CF. As a result, the question of whether chronic treatments can be safely stopped or adapted to this new situation has become a matter of great interest. Our objective was to derive a consensus among Italian experts on the impact of ETI on the current clinical management of CF lung disease.

METHODS

From December 2021 to April 2022 a panel of Italian experts endorsed by the national CF scientific society derived and graded a set of statements on the pulmonary management of adults with cystic fibrosis through a modified Delphi methodology.

RESULTS

The panel produced 13 statements exploring possible modifications in the fields of inhaled antibiotics and mucoactives; airway clearance and physical activity; chronic macrolides and bronchodilators; and lung transplant referral. The areas that the experts considered most urgent to explore were the impact of ETI on the role of inhaled antibiotics and lung transplant.

CONCLUSIONS

The list of priorities that emerged from this study could be useful to guide and inform clinical research on the most urgent area of impact of ETI on CF lung disease and its clinical management.

Novel small molecule-mediated restoration of the surface expression and anion exchange activity of mutated pendrin causing Pendred syndrome and DFNB4

Variants in SLC26A4 (pendrin) are the most common reasons for genetic hearing loss and vestibular dysfunction in East Asians. In patients with Pendred syndrome and DFNB4 (autosomal recessive type of genetic hearing loss 4), caused by variants in SLC26A4, the hearing function is residual at birth and deteriorates over several years, with no curative treatment for these disorders. In the present study, we revealed that a novel small molecule restores the expression and function of mutant pendrin. High-throughput screening of 54,000 small molecules was performed. We observed that pendrin corrector (PC2-1) increased the surface expression and anion exchange activity of p.H723R pendrin (H723R-PDS), the most prevalent genetic variant that causes Pendred syndrome and DFNB4. Furthermore, in endogenous H723R-PDS-expressing human nasal epithelial cells, PC2-1 significantly increased the surface expression of pendrin. PC2-1 exhibited high membrane permeability in vitro and high micromolar concentrations in the cochlear perilymph in vivo. In addition, neither inhibition of Kv11.1 activity in the human ether-a-go-go-related gene assay nor cell toxicity in the cell proliferation assay was observed at a high PC2-1 concentration (30 μM). These preclinical data support the hypothesis of the druggability of mutant pendrin using the novel corrector molecule PC2-1. In conclusion, PC2-1 may be a new therapeutic molecule for ameliorating hearing loss and treating vestibular disorders in patients with Pendred syndrome or DFNB4.

"It is like a pet in a way": The self-management experiences of people with cystic fibrosis diabetes

BACKGROUND

Cystic fibrosis diabetes (CFD) is a very common co-morbidity affecting the lives of people with cystic fibrosis. Surprisingly, minimal research has been undertaken to understand the experiences of people with CFD and how they self-mange this condition.

METHODS

Using interpretative phenomenological analysis, the present study examined the self-management experiences of people with CFD. In-depth semi-structure interviews were conducted with eight people who had CFD.

RESULTS

The following three superordinate themes were identified: forming a relationship with CFD, balancing the CFD self-management triad, and the unmet need for information and support.

CONCLUSIONS

The findings suggest that the management of CFD is challenging and, although people with CFD experience many adaptation and management processes similar to people with type 1 diabetes, they struggle with the additional complexity of balancing CF and CFD. The provision of appropriate education, support and person-centred care needs to be addressed.

Tezacaftor/Ivacaftor therapy has negligible effects on the cystic fibrosis gut microbiome

People with cystic fibrosis (pwCF) experience a range of persistent gastrointestinal symptoms throughout life. There is evidence indicating interaction between the microbiota and gut pathophysiology in CF. However, there is a paucity of knowledge on the potential effects of CF transmembrane conductance regulator (CFTR) modulator therapies on the gut microbiome. In a pilot study, we investigated the impact of Tezacaftor/Ivacaftor dual combination CFTR modulator therapy on the gut microbiota and metabolomic functioning in pwCF. Fecal samples from 12 pwCF taken at baseline and following placebo or Tezacaftor/Ivacaftor administration were subjected to microbiota sequencing and to targeted metabolomics to assess the short-chain fatty acid (SCFA) composition. Ten healthy matched controls were included as a comparison. Inflammatory calprotectin levels and patient symptoms were also investigated. No significant differences were observed in overall gut microbiota characteristics between any of the study stages, extended also across intestinal inflammation, gut symptoms, and SCFA-targeted metabolomics. However, microbiota and SCFA metabolomic compositions, in pwCF, were significantly different from controls in all study treatment stages. CFTR modulator therapy with Tezacaftor/Ivacaftor had negligible effects on both the gut microbiota and SCFA composition across the course of the study and did not alter toward compositions observed in healthy controls. Future longitudinal CFTR modulator studies will investigate more effective CFTR modulators and should use prolonged sampling periods, to determine whether longer-term changes occur in the CF gut microbiome. IMPORTANCE People with cystic fibrosis (pwCF) experience persistent gastrointestinal (GI) symptoms throughout life. The research question "how can we relieve gastrointestinal symptoms, such as stomach pain, bloating, and nausea?" remains a top priority for clinical research in CF. While CF transmembrane conductance regulator (CFTR) modulator therapies are understood to correct underlying issues of CF disease and increasing the numbers of pwCF are now receiving some form of CFTR modulator treatment. It is not known how these therapies affect the gut microbiome or GI system. In this pilot study, we investigated, for the first time, effects of the dual combination CFTR modulator medicine, Tezacaftor/Ivacaftor. We found it had negligible effects on patient GI symptoms, intestinal inflammation, or gut microbiome composition and functioning. Our findings are important as they fill important knowledge gaps on the relative effectiveness of these widely used treatments. We are now investigating triple combination CFTR modulators with prolonged sampling periods.

Elexacaftor Mediates the Rescue of F508del CFTR Functional Expression Interacting with MSD2

Cystic fibrosis (CF) is one of the most frequent lethal autosomal recessive diseases affecting the Caucasian population. It is caused by loss of function variants of the cystic fibrosis transmembrane conductance regulator (CFTR), a membrane protein located on the apical side of epithelial cells. The most prevalent CF-causing mutation, the deletion of phenylalanine at position 508 (F508del), is characterized by folding and trafficking defects, resulting in the decreased functional expression of the protein on the plasma membrane. Two classes of small-molecule modulators, termed potentiators and correctors, respectively, have been developed to rescue either the gating or the cellular processing of defective F508del CFTR. Kaftrio, a next-generation triple-combination drug, consisting of the potentiator ivacaftor (VX770) and the two correctors tezacaftor (VX661) and elexacaftor (VX445), has been demonstrated to be a life-changing therapeutic modality for the majority of people with CF worldwide. While the mechanism of action of VX770 and VX661 is almost known, the precise mechanism of action and binding site of VX445 have not been conclusively determined. We investigated the activity of VX445 on mutant F508del to identify the protein domains whose expression is mostly affected by this corrector and to disclose its mechanisms of action. Our biochemical analyses revealed that VX445 specifically improves the expression and the maturation of MSD2, heterologously expressed in HEK 293 cells, and confirmed that its effect on the functional expression of defective F508del CFTR is additive either with type I or type II CFTR correctors. We are confident that our study will help to make a step forward in the comprehension of the etiopathology of the CF disease, as well as to give new information for the development and testing of combinations of even more effective correctors able to target mutation-specific defects of the CFTR protein.

Therapeutic interventions alter ecological interactions among cystic fibrosis airway microbiota

The airways of people with cystic fibrosis (CF) often harbor a diverse microbiota and in recent years, much effort has been invested in cataloguing these. In spite of providing a wealth of insight, this cataloguing tells us little about how the organisms interact with one another in the CF airways. However, such relationships can be inferred using the theoretical framework of the Lotka-Volterra (LV) model. In the current work, we use a generalized Lotka-Volterra model to interrogate the nationwide data collected and curated by the UK CF Registry. This longitudinal dataset (covering the period 2008-2020) contains annual depositions that record the presence/absence of microbial taxa in each patient, their medication, and their CF genotype. Specifically, we wanted to identify trends in ecological relationships between the CF microbiota at a nationwide level, and whether these are potentially affected by medication. Our results show that some medications have a distinct influence on the microbial interactome, especially those that potentially influence the "gut-lung axis" or mucus viscosity. In particular, we found that patients treated with a combination of antimicrobial agents (targeting the airway microbiota), digestive enzymes (assisting in the assimilation of dietary fats and carbohydrates), and DNase (to reduce mucus viscosity) displayed a distinctly different airway interactome compared with patients treated separately with these medications.

A grumbling concern: an international survey of gastrointestinal symptoms in cystic fibrosis in the modulator era

Background

Gastrointestinal symptoms in cystic fibrosis (CF) are common and intrusive to daily life. Relieving gastrointestinal symptoms was identified as an important research priority and previously explored in an international survey in 2018. However, following the widespread introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulators in 2019, the landscape of CF treatment has changed. We repeated an online survey to further describe gastrointestinal symptoms and their effect on quality of life (QoL) in the CFTR modulator era.

Methods

An electronic survey consisting of closed questions and free text responses was distributed via social media and professional networks for a period of one month between March - April 2022. People with CF (pwCF), their family and friends, and healthcare professionals (HCPs) were invited to take part.

Results

There were 164 respondents: 88 pwCF (54%), 22 (13%) family, and 54 (33%) healthcare professionals (HCPs). A total of 89/110 (81%) pwCF or family members reported CFTR modulator treatment. The most commonly reported symptoms were wind / gas, rumbling stomach noises, loose motions (modulator) and bloating (no modulator). Abdominal pain and bloating had the greatest impact on QoL.For those on a CFTR modulator, the proportion of pwCF reporting "no change" or "worse" for all of the symptoms surveyed was greater than the proportion reporting an improvement. Following modulator introduction, dietary changes were recommended by 28/35 (80%) of HCPs and reported by 38/76 (50%) lay respondents. Changes in medication were recommended by 19/35 (54%) HCPs and reported by 44/76 (58%) of patients and family members.

Conclusion

This survey has shown that gastrointestinal symptoms remain prevalent in pwCF in the CFTR modulator era, though the nature of these symptoms may have changed. A better understanding of the underlying pathophysiology of these symptoms is essential. Future clinical studies should focus on improving symptoms and QoL.

Cystic fibrosis macrophage function and clinical outcomes after elexacaftor/tezacaftor/ivacaftor

BACKGROUND

Abnormal macrophage function caused by dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) is a critical contributor to chronic airway infections and inflammation in people with cystic fibrosis (PWCF). Elexacaftor/tezacaftor/ivacaftor (ETI) is a new CFTR modulator therapy for PWCF. Host-pathogen and clinical responses to CFTR modulators are poorly described. We sought to determine how ETI impacts macrophage CFTR function, resulting effector functions and relationships to clinical outcome changes.

METHODS

Clinical information and/or biospecimens were obtained at ETI initiation and 3, 6, 9 and 12 months post-ETI in 56 PWCF and compared with non-CF controls. Peripheral blood monocyte-derived macrophages (MDMs) were isolated and functional assays performed.

RESULTS

ETI treatment was associated with increased CF MDM CFTR expression, function and localisation to the plasma membrane. CF MDM phagocytosis, intracellular killing of CF pathogens and efferocytosis of apoptotic neutrophils were partially restored by ETI, but inflammatory cytokine production remained unchanged. Clinical outcomes including increased forced expiratory volume in 1 s (+10%) and body mass index (+1.0 kg·m-2) showed fluctuations over time and were highly individualised. Significant correlations between post-ETI MDM CFTR function and sweat chloride levels were observed. However, MDM CFTR function correlated with clinical outcomes better than sweat chloride.

CONCLUSION

ETI is associated with unique changes in innate immune function and clinical outcomes.

Cystic fibrosis and primary ciliary dyskinesia: Similarities and differences

Cystic fibrosis (CF) and Primary ciliary dyskinesia (PCD) are both rare chronic diseases, inherited disorders associated with multiple complications, namely respiratory complications, due to impaired mucociliary clearance that affect severely patients' lives. Although both are classified as rare diseases, PCD has a much lower prevalence than CF, particularly among Caucasians. As a result, CF is well studied, better recognized by clinicians, and with some therapeutic approaches already available. Whereas PCD is still largely unknown, and thus the approach is based on consensus guidelines, expert opinion, and extrapolation from the larger evidence base available for patients with CF. Both diseases have some clinical similarities but are very different, necessitating different treatment by specialists who are familiar with the complexities of each disease.This review aims to provide an overview of the knowledge about the two diseases with a focus on the similarities and differences between both in terms of disease mechanisms, common clinical manifestations, genetics and the most relevant therapeutic options. We hoped to raise clinical awareness about PCD, what it is, how it differs from CF, and how much information is still lacking. Furthermore, this review emphasises the fact that both diseases require ongoing research to find better treatments and, in particular for PCD, to fill the medical and scientific gaps.

Efficacy and Safety of Elexacaftor-Tezacaftor-Ivacaftor in the Treatment of Cystic Fibrosis: A Systematic Review

Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) is a new CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) modulator treatment, used over the last few years, which has shown an improvement in different clinical outcomes in patients with cystic fibrosis (CF). The objective of this study was a systematic research of the literature on the efficacy and safety of this CFTR modulator on patients with CF. A search of Pubmed was conducted for randomized clinical trials and observational studies published from 2012 to September 2022. The included full manuscripts comprised nine clinical trials and 16 observational studies, whose participants were aged ≥12 years or were children 6–11 years old with at least one Phe508del mutation and/or advanced lung disease (ALD). These studies reported that ELX/TEZ/IVA has a significant positive effect on the lung function of patients with CF, by ameliorating parameters such as FEV1, LCI, pulmonary exacerbations or sweat chloride concentration, increasing BMI and improving quality of their life. Its role in cystic fibrosis-related diabetes (CFRD) is not yet clear. It was found that this new CFTR modulator has an overall favorable safety profile, with mild to moderate adverse events. Further studies are needed for a deeper understanding of the impact of CFTR modulators on other CF manifestations, or the possibility of treating with ELX/TEZ/IVA CF patients with rare CFTR mutations.

Cystic Fibrosis Transmembrane Conductance Regulator Protein Modulators in Children and Adolescents with different CF Genotypes - Systematic Review and Meta-Analysis

OBJECTIVE

To determine the efficacy of the first triple CFTR protein modulators in children and adolescents with cystic fibrosis.

METHODS

Systematic review and meta-analysis were conducted, following PRISMA guidelines. The following databases were searched extensively: PubMed/Medline, Clinical trials.gov, Google Scholar, Scopus, Embase, and Europe PMC using the keywords: "Ivacaftor," "Elexacaftor," "Tezacaftor," VX_661", VX_770", "VX_445", "cystic fibrosis". A total of ten randomized clinical trials were included in our analysis. Primary outcomes included: Absolute change in predicted FEV1 from baseline, Absolute change in sweat chloride test from baseline, Absolute change in BMI from baseline, Absolute change in CF-QR from baseline, and Adverse Events.

RESULTS

Among primary findings, significant absolute change in predictive FEV1 from baseline through 4 weeks favoured the triple CFTR protein modulators. [MD=11.80,95%CI=8.47_15.12, p value=<0.00001]; as well as CF_QR score [MD=0.00,95%CI=-2.50_2.50, p value=1.00], and BMI kg/m² change [MD=16.90,95%CI=12.73_21.06, p value=<0.00001]. No significant change was noted for CFTR channels activity in the treatment group when compared to placebo or VX_770/VX_661 [MD= -12.57,95%CI=-94.46_69.32, p value=0.76].

CONCLUSION

In children aged ≥ 6 y old and adolescents with F508del_CFTR mutation, Elexacaftor-Tezacaftor-Ivacaftor tend to be more effective than first-generation therapy, demonstrating promising results by exhibiting significant improvement in lung function, body weight, and respiratory-related quality of life.

Cystic fibrosis: Infection prevention & control recommendations for universities, colleges and institutes of further and higher education - A practical guide

BACKGROUND

The avoidance of cross-infection remains of critical importance to prevent the transmission of cystic fibrosis (CF)-related microbial pathogens to persons/people with cystic fibrosis (PwCF). To date, there has been a paucity of infection prevention and control (IPC) guidance relating to infection risk at higher educational institutions. With improvements in treatments, more PwCF are now attending universities/colleges and educational institutions now seek CF-specific guidance on IPC from clinical CF teams/centres.

METHODS

Real world infection-related questions from university students, educators, university support staff and the CF multidisciplinary team were received and collated from various stakeholders, including individual consultations and focus group sessions with two local universities. Subsequently, evidence-based recommendations were compiled from existing peer-reviewed literature and from cystic fibrosis organisations. Glossaries were constructed relating to clinical, microbiological and educational/pedagogical terminology to aid with the understanding amongst these stakeholder groups.

RESULTS

This review addresses CF-related IPC recommendations across five areas of university/college life, including (i) on campus estate, (ii) teaching (lectures/tutorials/small study group work/group assignments), (iii) laboratory practicals, (iv) field trips/study visits/work placements and (v) residential accommodation and lists practical recommendations to help prevent the transmission of infections to PwCF students.

CONCLUSIONS

It is important that the educational institutional environment is safe permitting the PwCF student to enjoy their educational experience and journey through higher education, culminating in achievement of their educational goals, employment and independent living. The guidance presented in this review is intended to equip educational establishments in creating their own bespoke and robust IPC policies relating to PwCF students.

Current and Future Therapeutic Approaches of Exocrine Pancreatic Insufficiency in Children with Cystic Fibrosis in the Era of Personalized Medicine

This review presents current updates of pancreatic enzyme replacement therapy in children with cystic fibrosis based on literature published in the last decade and some special considerations regarding pancreatic enzyme replacement therapy in the era of new therapies, such as cystic fibrosis transmembrane conductance regulator modulator therapies. Few articles evaluate the efficacy of pancreatic enzyme replacement therapy in the pediatric population, and most studies also included children and adults with cystic fibrosis. Approximately 85% of cystic fibrosis patients have exocrine pancreatic insufficiency and need pancreatic enzyme replacement therapy. Fecal elastase is the most commonly used diagnostic test for exocrine pancreatic insufficiency, although this value can fluctuate over time. While it is used as a diagnostic test, it cannot be used for monitoring the effectiveness of pancreatic enzyme replacement therapy and for adjusting doses. Pancreatic enzyme replacement therapy, the actual treatment for exocrine pancreatic insufficiency, is essential in children with cystic fibrosis to prevent malabsorption and malnutrition and needs to be urgently initiated. This therapy presents many considerations for physicians, patients, and their families, including types and timing of administration, dose monitoring, and therapy failures. Based on clinical trials, pancreatic enzyme replacement therapy is considered effective and well-tolerated in children with cystic fibrosis. An important key point in cystic fibrosis treatment is the recent hypothesis that cystic fibrosis transmembrane conductance regulator modulators could improve pancreatic function, further studies being essential. Pancreatic enzyme replacement therapy is addressed a complication of the disease (exocrine pancreatic insufficiency), while modulators target the defective cystic fibrosis transmembrane conductance regulator protein. Exocrine pancreatic insufficiency in cystic fibrosis remains an active area of research in this era of cystic fibrosis transmembrane conductance regulator modulator therapies. This new therapy could represent an example of personalized medicine in cystic fibrosis patients, with each class of modulators being addressed to patients with specific genetic mutations.

Using the genome to correct the ion transport defect in cystic fibrosis

KEY POINTS

Human genome information can help finding drugs for human diseases. 'Omics' allow unbiased identification of novel drug targets. High-throughput (HT) approaches provide a global view on disease mechanisms. As a monogenic disease CF has led the way in multiple 'Omic' studies. 'Multi-omics' integration will generate maximal biological significance.

ABSTRACT

Today Biomedicine faces one of its greatest challenges, i.e. treating diseases through their causative dysfunctional processes and not just their symptoms. However, we still miss a global view of mechanisms and pathways involved in pathophysiology of most diseases. In fact, disease mechanisms and pathways can be achieved by holistic studies provided by 'Omic' approaches. Cystic Fibrosis (CF), caused by mutations in the CF transmembrane conductance regulator (CFTR) gene which encodes an anion channel, is paradigmatic for monogenic disorders, namely channelopathies. A high number of 'omics studies' have focussed on CF, namely several cell-based high-throughput (HT) approaches were developed and applied towards a global mechanistic characterization of CF pathophysiology and the identification of novel and 'unbiased' drug targets. Notwithstanding, it is likely that, through the integration of all these 'layers' of large datasets into comprehensive disease maps that biological significance can be extracted so that the enormous potential of these approaches to identifying dysfunctional mechanisms and novel drugs may become a reality. Abstract figure legend Schematic overview of the 3 main approaches to discovery of new drugs/drug targets. This article is protected by copyright. All rights reserved.

Mucins and CFTR: Their Close Relationship

Mucociliary clearance is a critical defense mechanism for the lungs governed by regionally coordinated epithelial cellular activities, including mucin secretion, cilia beating, and transepithelial ion transport. Cystic fibrosis (CF), an autosomal genetic disorder caused by the dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, is characterized by failed mucociliary clearance due to abnormal mucus biophysical properties. In recent years, with the development of highly effective modulator therapies, the quality of life of a significant number of people living with CF has greatly improved; however, further understanding the cellular biology relevant to CFTR and airway mucus biochemical interactions are necessary to develop novel therapies aimed at restoring CFTR gene expression in the lungs. In this article, we discuss recent advances of transcriptome analysis at single-cell levels that revealed a heretofore unanticipated close relationship between secretory MUC5AC and MUC5B mucins and CFTR in the lungs. In addition, we review recent findings on airway mucus biochemical and biophysical properties, focusing on how mucin secretion and CFTR-mediated ion transport are integrated to maintain airway mucus homeostasis in health and how CFTR dysfunction and restoration of function affect mucus properties.

Triangulating variation in the population to define mechanisms for precision management of genetic disease

To understand mechanistically how the protein fold is shaped by therapeutics to inform precision management of disease, we developed variation-capture (VarC) mapping. VarC triangulates sparse sequence variation information found in the population using Gaussian process regression (GPR)-based machine learning to define the combined pairwise-residue interactions contributing to dynamic protein function in the individual in response to therapeutics. Using VarC mapping, we now reveal the pairwise-residue covariant relationships across the entire protein fold of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) to define the molecular mechanisms of clinically approved CF chemical modulators. We discover an energetically destabilized covariant core containing a di-acidic YKDAD endoplasmic reticulum (ER) exit code that is only weakly corrected by current therapeutics. Our results illustrate that VarC provides a generalizable tool to triangulate information from genetic variation in the population to mechanistically discover therapeutic strategies that guide precision management of the individual.

Towards Innovative Antibacterial-Correctors for Cystic Fibrosis Targeting the Lung Microbiome with a Multifunctional Effect

Cystic Fibrosis (CF) is a genetic disease caused by loss-of-function mutations in the CFTR gene, which codes for a defective ion channel. This causes an electrolyte imbalance and results in a spiral of negative effects on multiple organs, most notably the accumulation of thick mucus in the lungs, chronic respiratory tract infections and inflammation leading to pulmonary exacerbation and premature death. Progressive decline of lung function is mainly linked to persistent or recurring infections, mostly caused by bacteria, which require treatments with antibiotics and represent one of the major life-limiting factors in subjects with CF. Treatment of such a complex disease require multiple drugs with a consequent therapeutic burden and complications caused by drug-drug interactions and rapid emergence of bacterial drug resistance. We report herein our recent efforts in developing innovative multifunctional antibiotics specifically tailored to CF by a direct action on bacterial topoisomerases and a potential indirect effect on the pulmonary mucociliary clearance mediated by ΔF508-CFTR correction. The obtained results may pave the way for the development of a simplified therapeutic approach with a single agent acting as multifunctional antibacterial-corrector.

CFTR Modulator Therapy in an Individual With Cystic Fibrosis Caused by a N1303K CFTR Variant and Infected With Mycobacterium abscessus

This report describes a case of a 15-year-old male with cystic fibrosis caused by N1303K and Q493X cystic fibrosis transmembrane conductance regulator (CFTR) protein variants. In this case, CFTR modulators including tezacaftor-ivacaftor and subsequently elexacaftor-tezacaftor-ivacaftor were used and resulted in clinical stability and improvement.

Efficacy and Safety of Triple Combination Cystic Fibrosis Transmembrane Conductance Regulator Modulators in Patients With Cystic Fibrosis: A Meta-Analysis of Randomized Controlled Trials

Background: Cystic fibrosis is a rare, recessive, progressive genetic disease caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Small molecules have recently been developed to treat the molecular consequences of CFTR mutations and restore CFTR protein function. However, the data on triple combination therapy (mainly from Vertex Pharmaceuticals, which is most tested in clinical trials) are limited. This meta-analysis was aimed to assess the efficacy and safety of this therapy according to different mutation genotypes and comparators. Methods: Relevant publications were identified through searching several medical databases before 31 December 2021. The primary outcomes of ppFEV₁, sweat chloride concentration and Cystic Fibrosis Questionnaire-Revised (CFQ-R) score were pooled and analyzed. The secondary outcomes were adverse events in triple combination therapy. Results: Six randomized controlled trials were eligible for analysis. The total outcome of the ppFEV1 change was higher with triple combination therapy than triple placebo or active control (mean difference, MD, 13.6% and 8.74%, respectively). The pooled result of sweat chloride concentrations with triple combination therapy was lower than that of triple placebo or active control (MD, -44.13 and -39.26, respectively). The pooled estimate of the CFQ-R score was higher with triple combination therapy than triple placebo or active control (MD, 19.8% and 14.63%, respectively). No clear differences in adverse events were found between triple combination therapy and the control (placebo or active control). Conclusion: CFTR modulators in triple combination achieve better clinical results than placebo and active control, and result in comparable adverse events. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021293402, identifier PROSPERO 2021 CRD42021293402.

Treatment of cystic fibrosis related bone disease

The advent of highly effective CFTR modulator therapies has slowed the progression of pulmonary complications in people with cystic fibrosis. There is increased interest in cystic fibrosis bone disease (CFBD) due to the increasing longevity of people with cystic fibrosis. CFBD is a complex and multifactorial disease. CFBD is a result of hypomineralized bone leading to poor strength, structure and quality leading to susceptibility to fractures. The development of CFBD spans different age groups. The management must be tailored to each group with nuance and based on available guidelines while balancing therapeutic benefits to risks of long-term use of bone-active medication. For now, the mainstay of treatment includes bisphosphonates. However, the long-term effects of bisphosphonate treatment in people with CF are not fully understood. We describe newer agents available for osteoporosis treatment. Still, the lack of data behooves trials of monoclonal antibodies treatments such as Denosumab and Romozosumab and anabolic bone therapy such as teriparatide and Abaloparatide. In this review, we also summarize screening and non-pharmacologic treatment of CFBD and describe the various options available for the pharmacotherapy of CFBD. We address the prospect of CFTR modulators on bone health while awaiting long-term trials to describe the effects of these medications on bone health.

Understanding Cystic Fibrosis Comorbidities and Their Impact on Nutritional Management

Cystic fibrosis (CF) is a chronic, multisystem disease with multiple comorbidities that can significantly affect nutrition and quality of life. Maintaining nutritional adequacy can be challenging in people with cystic fibrosis and has been directly associated with suboptimal clinical outcomes. Comorbidities of CF can result in significantly decreased nutritional intake and intestinal absorption, as well as increased metabolic demands. It is crucial to utilize a multidisciplinary team with expertise in CF to optimize growth and nutrition, where patients with CF and their loved ones are placed in the center of the care model. Additionally, with the advent of highly effective modulators (HEMs), CF providers have begun to identify previously unrecognized nutritional issues, such as obesity. Here, we will review and summarize commonly encountered comorbidities and their nutritional impact on this unique population.

Progress in precision medicine in cystic fibrosis: a focus on CFTR modulator therapy

The genetic multisystem condition cystic fibrosis (CF) has seen a paradigm shift in therapeutic approaches within the past decade. Since the first clinical descriptions in the 1930s, treatment advances had focused on the downstream consequences of a dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) chloride ion channel. The discovery of the gene that codes for CFTR and an understanding of the way in which different genetic mutations lead to disruption of normal CFTR function have led to the creation and subsequent licensing of drugs that target this process. This marks an important move towards precision medicine in CF and results from clinical trials and real-world clinical practice have been impressive. In this review we outline how CFTR modulator drugs restore function to the CFTR protein and the progress that is being made in this field. We also describe the real-world impact of CFTR modulators on both pulmonary and multisystem complications of CF and what this will mean for the future of CF care.

CFTR modulator drugs target the underlying cellular defect in cystic fibrosis. They have a range of pulmonary and multisystem effects and are leading to a transformation of care for a majority of people with cystic fibrosis.https://bit.ly/3nfEt8i

The Exocrine Pancreas in Cystic Fibrosis in the Era of CFTR Modulation: A Mini Review

Cystic fibrosis (CF) is a common disorder of autosomal recessive inheritance, that once conferred a life expectancy of only a few months. Over recent years, significant advances have been made to CF therapeutic approaches, changing the face of the disease, and facilitating the partial restoration of pancreatic function. This mini review summarizes the current landscape of exocrine pancreatic management in CF and explores areas for future direction and development.

Management of respiratory tract exacerbations in people with cystic fibrosis: Focus on imaging

Respiratory tract exacerbations play a crucial role in progressive lung damage of people with cystic fibrosis, representing a major determinant in the loss of functional lung tissue, quality of life and patient survival. Detection and monitoring of respiratory tract exacerbations are challenging for clinicians, since under- and over-treatment convey several risks for the patient. Although various diagnostic and monitoring tools are available, their implementation is hampered by the current definition of respiratory tract exacerbation, which lacks objective "cut-offs" for clinical and lung function parameters. In particular, the latter shows a large variability, making the current 10% change in spirometry outcomes an unreliable threshold to detect exacerbation. Moreover, spirometry cannot be reliably performed in preschool children and new emerging tools, such as the forced oscillation technique, are still complementary and need more validation. Therefore, lung imaging is a key in providing respiratory tract exacerbation-related structural and functional information. However, imaging encompasses several diagnostic options, each with different advantages and limitations; for instance, conventional chest radiography, the most used radiological technique, may lack sensitivity and specificity in respiratory tract exacerbations diagnosis. Other methods, including computed tomography, positron emission tomography and magnetic resonance imaging, are limited by either radiation safety issues or the need for anesthesia in uncooperative patients. Finally, lung ultrasound has been proposed as a safe bedside option but it is highly operator-dependent and there is no strong evidence of its possible use during respiratory tract exacerbation. This review summarizes the clinical challenges of respiratory tract exacerbations in patients with cystic fibrosis with a special focus on imaging. Firstly, the definition of respiratory tract exacerbation is examined, while diagnostic and monitoring tools are briefly described to set the scene. This is followed by advantages and disadvantages of each imaging technique, concluding with a diagnostic imaging algorithm for disease monitoring during respiratory tract exacerbation in the cystic fibrosis patient.

Effectiveness and Safety of Cystic Fibrosis Transmembrane Conductance Regulator Modulators in Children With Cystic Fibrosis: A Meta-Analysis

BACKGROUND AND AIM

Cystic fibrosis (CF) is a genetic disease that is difficult to treat and caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Small molecules have been used to treat the symptom caused by CFTR mutations by restoring CFTR protein function. However, the data on children with CF are scarce. This meta-analysis aimed to evaluate the effectiveness and safety of this therapy in children diagnosed with CF.

MATERIALS AND METHODS

Relevant studies were identified through searching medical databases before April 1, 2022. The primary outcomes of ppFEV₁, lung clearance index_2.5 (LCI_2.5), sweat chloride concentration (SwCI), and Cystic Fibrosis Questionnaire-Revised (CFQ-R) score were pooled and analyzed. The secondary outcomes were nutritional status (weight, BMI, stature, and their z-score) and adverse events under therapy.

RESULTS

A total of twelve studies were included. Compared with the placebo group, the pooled outcome of the ppFEV1, LCI_2.5, SwCI, and CFQ-R score were improved by 7.91 {[95% confidence interval (CI), 3.71-12.12], -1.00 (95% CI, -1.38 to -0.63), -35.22 (95% CI, -55.51 to -14.92), and 4.45 (95% CI, 2.31-6.59), respectively}. Compared with the placebo group, the pooled result of the change in weight was improved by 1.53 (95% CI, 0.42-2.63). All the aforementioned results were also improved in single-arm studies. No clear differences in adverse events were found between CFTR modulator therapy and the placebo group.

CONCLUSION

CFTR modulators could improve multiaspect function in children with CF and result in comparable adverse events.

Short-Term Effects of Elexacaftor/Tezacaftor/Ivacaftor Combination on Glucose Tolerance in Young People With Cystic Fibrosis-An Observational Pilot Study

BACKGROUND

The effect of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) on glucose tolerance and/or cystic-fibrosis-related diabetes (CFRD) is not well understood. We performed an observational study on the short-term effects of ELX/TEZ/IVA on glucose tolerance.

METHODS

Sixteen adolescents with CF performed oral glucose tolerance tests (OGTT) before and 4-6 weeks after initiating ELX/TEZ/IVA therapy. A continuous glucose monitoring (CGM) system was used 3 days before until 7 days after starting ELX/TEZ/IVA treatment.

RESULTS

OGTT categories improved after initiating ELX/TEZ/IVA therapy (p = 0.02). Glucose levels of OGTT improved at 60, 90, and 120 min (p < 0.05), whereas fasting glucose and CGM measures did not change.

CONCLUSION

Shortly after initiating ELX/TEZ/IVA therapy, glucose tolerance measured by OGTT improved in people with CF. This pilot study indicates that ELX/TEZ/IVA treatment has beneficial effects on the endocrine pancreatic function and might prevent or at least postpone future CFRD.

Obesity in cystic fibrosis

The prevalence of obesity in patients with cystic fibrosis (CF) is increasing and around one-third of adults with CF are now overweight or obese. The causes of excess weight gain in CF are likely multifactorial, including: adherence to the high-fat legacy diet, reduced exercise tolerance, therapeutic advances, and general population trends. Increased weight has generally been considered favorable in CF, correlating with improved pulmonary function and survival. While the optimal BMI for overall health in CF is unknown, most studies demonstrate minimal improvement in pulmonary function when BMI exceeds 30 kg/m2. Dyslipidemia and cardiovascular disease are important co-morbidities of obesity in the general population, but are uncommon in CF. In people with CF, obesity is associated with hypertension and higher cholesterol levels. With longer life expectancy and rising obesity rates, there may be an increase in cardiovascular disease among people with CF in coming years. Overweight CF patients are more likely to be insulin resistant, taking on features of type 2 diabetes. Treating obesity in people with CF requires carefully weighing the metabolic risks of overnutrition with the impact of low or falling BMI on lung function. This article describes current knowledge on the epidemiology, causes, consequence, and treatment of obesity in people with CF.

Emerging non-pulmonary complications for adults with cystic fibrosis

Improved treatments of cystic fibrosis (CF) related lung disease have resulted in increased longevity, but also increasing prevalence and severity of extrapulmonary manifestations of CF, treatment related complications, age-related conditions and psychosocial effects of longstanding chronic disease. Likewise, the recognition of mild CF phenotypes has changed the landscape of CF disease. This review outlines our current understanding of the common extrapulmonary complications of CF, as well as the changing landscape and future directions of the extrapulmonary complications experienced by patients with CF.

The short-term effects of ORKAMBI (lumacaftor/ivacaftor) on regional and distal lung structures using functional respiratory imaging

Background:

Lumacaftor/ivacaftor (LUM/IVA) has shown modest benefits in previous research, but the exact effects in the cystic fibrosis (CF) lung remain unclear. This study aims to offer novel information on the mode of action of the cystic fibrosis transmembrane conductance regulator (CFTR)-modulating drug by assessing lung structure and function using functional respiratory imaging (FRI).

Methods:

CF patients aged ⩾12 years homozygous for F508del were recruited in an open-label study. Before and after 12 weeks of treatment with LUM/IVA, FRI was used to visualize regional information, such as air trapping, lobar volume and airway wall volume. Secondary outcomes included the CF-CT scoring system, spirometry, the Cystic Fibrosis Questionnaire–Revised (CFQ-R) questionnaire, exercise tolerance and nutritional status.

Results:

Of the 12 patients enrolled in the study, 11 completed all study visits. Concerning the FRI parameters, hyperinflation of the lung decreased, indicated by a reduction in air trapping and lobar volume at expiration. Also, a decrease in airway wall volume and a redistribution of pulmonary blood volume were noted, which might be related to a decrease in mucus impaction. Airway resistance, airway volume, internal airflow distribution and aerosol deposition pattern did not show significant changes. No significant improvements were found in any of the CF-CT scores or in the spirometric parameters. Other secondary outcomes showed similar results compared with previous research. Correlations at baseline were found between FRI and conventional outcomes, including physical functioning, spirometry and CF-CT scores.

Conclusions:

LUM/IVA decreased lung hyperinflation in combination with a potential decrease in mucus impaction, which can be related to an improved mucociliary transport. These results indicate that several FRI parameters, reflecting regional and distal lung structures, are more sensitive to changes caused by LUM/IVA than conventional respiratory outcomes.

Human Growth and Growth Hormone: From Antiquity to the Recominant Age to the Future

Since antiquity Man has been fascinated by the variations in human (and animal) growth. Stories and art abound about giants and little people. Modern genetics have solved some of etiologies at both extremes of growth. Serious study began with the pathophysiology of acromegaly followed by early attempts at treatment culminating in modern endoscopic surgery and multiple pharmacologic agents. Virtually at the same time experiments with the removal of the pituitary from laboratory animals noted the slowing or stopping of linear growth and then over a few decades the extraction and purification of a protein within the anterior pituitary that restored, partially or in full, the animal's growth. Human growth hormone was purified decades after those from large animals and it was noted that it was species specific, that is, only primate growth hormone was metabolically active in primates. That was quite unlike the beef and pork insulins which revolutionized the care of children with diabetes mellitus. A number of studies included mild enzymatic digestion of beef growth hormone to determine if those "cores" had biologic activity in primates and man. Tantalizing data showed minimal but variable metabolic efficacy leading to the "active core" hypothesis, for these smaller peptides would be amenable to peptide synthesis in the time before recombinant DNA. Recombinant DNA changed the landscape remarkably promising nearly unlimited quantities of metabolically active hormone. Eight indications for therapeutic use have been approved by the Food and Drug Administration and a large number of clinical trials have been undertaken in multiple other conditions for which short stature in childhood is a sign. The future predicts other clinical indications for growth hormone therapy (and perhaps other components of the GH?IGF-1 axis), longer-acting analogues and perhaps a more physiologic method of administration as virtually all methods at present are far from physiologic.

Real-World Long-Term Ivacaftor for Cystic Fibrosis in France: Clinical Effectiveness and Healthcare Resource Utilization

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 (ppFEV₁); secondary objectives were evaluating the effect of ivacaftor on clinical effectiveness, healthcare resource utilization (HCRU), and safety.

Results

A total of 129 pwCF were enrolled; 58.9% were aged < 18 years; 64.3% had a G551D-CFTR allele. Mean age at ivacaftor initiation was 19.1 years (range, 2–64 years); ppFEV₁ increased by a least squares mean of 8.49 percentage points in the first 6 months and was sustained through 36 months of ivacaftor use. Growth metrics increased during the first 12 months post-ivacaftor and remained stable. The rate of pulmonary exacerbations (PEx) decreased during the 12 months post-ivacaftor compared with the 12 months pre-ivacaftor; estimated rate ratios (95% CI) were 0.57 (0.43–0.75) for PEx events and 0.25 (0.13–0.48) for PEx requiring hospitalization. No new safety concerns were identified; no deaths occurred.

Conclusions

The results from this real-world study of ivacaftor usage in France were consistent with prior clinical trial outcomes, confirming the clinical effectiveness of ivacaftor, as well as an associated reduction in HCRU.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00158-5.

Partial Rescue of F508del-CFTR Stability and Trafficking Defects by Double Corrector Treatment

Deletion of phenylalanine at position 508 (F508del) in the CFTR chloride channel is the most frequent mutation in cystic fibrosis (CF) patients. F508del impairs the stability and folding of the CFTR protein, thus resulting in mistrafficking and premature degradation. F508del-CFTR defects can be overcome with small molecules termed correctors. We investigated the efficacy and properties of VX-445, a newly developed corrector, which is one of the three active principles present in a drug (Trikafta^®/Kaftrio^®) recently approved for the treatment of CF patients with F508del mutation. We found that VX-445, particularly in combination with type I (VX-809, VX-661) and type II (corr-4a) correctors, elicits a large rescue of F508del-CFTR function. In particular, in primary bronchial epithelial cells of CF patients, the maximal rescue obtained with corrector combinations including VX-445 was close to 60–70% of CFTR function in non-CF cells. Despite this high efficacy, analysis of ubiquitylation, resistance to thermoaggregation, protein half-life, and subcellular localization revealed that corrector combinations did not fully normalize F508del-CFTR behavior. Our study indicates that it is still possible to further improve mutant CFTR rescue with the development of corrector combinations having maximal effects on mutant CFTR structural and functional properties.

Real-World Outcomes of Ivacaftor Treatment in People with Cystic Fibrosis: A Systematic Review

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 as early as 1 month following ivacaftor initiation and were sustained over long-term follow-up. Decreases in pulmonary exacerbations, Pseudomonas aeruginosa prevalence, and healthcare resource utilization also were reported for up to 66 months following ivacaftor initiation. In studies comparing ivacaftor treatment to modulator untreated comparator groups, clinical benefits similarly were reported as were decreases in mortality, organ-transplantation, and CF-related complications. The safety profile of ivacaftor observed in these real-world studies was consistent with the well-established safety profile based on clinical trial data. Our systematic review of real-world studies shows ivacaftor treatment in pwCF results in highly consistent and sustained clinical benefit in both pulmonary and non-pulmonary outcomes across various geographies, study designs, patient characteristics, and follow-up durations, confirming and expanding upon evidence from clinical trials.

Elexacaftor-tezacaftor-ivacaftor: The new paradigm to treat people with cystic fibrosis with at least one p.Phe508del mutation

Cystic fibrosis is the most common life-limiting genetic disease in the Caucasian population, with median predicted survival progressively improving up to 50 years, thanks to highly standardized multidisciplinary approach. Patients with p.Phe508del homozygosity usually have poorer lung function and higher mortality rates per year than other groups. By reason of that, this population has been among the most eligible target of the cystic fibrosis transmembrane conductance regulator (CFTR) modulators, a new class of drugs that can partially restore CFTR function by the correction of CFTR misfolding and trafficking to the cell surface. This narrative review summarizes the current preclinical and clinical evidence of the triple combination of elexacaftor-tezacaftor-ivacaftor, the new benchmark among highly effective CFTR modulators. It provides details on the efficacy and safety that led to drug regulation and approval and discusses future developments in clinical and translational research.

In silico drug repositioning on F508del-CFTR: A proof-of-concept study on the AIFA library

Computational drug repositioning is of growing interest to academia and industry, for its ability to rapidly screen a huge number of candidates in silico (exploiting comprehensive drug datasets) together with reduced development cost and time. The potential of drug repositioning has not been fully evaluated yet for cystic fibrosis (CF), a disease mainly caused by deletion of Phe 508 (F508del) of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. F508del-CFTR is thus withheld in the endoplasmic reticulum and rapidly degraded by the ubiquitin/proteasome system. CF is still a fatal disease. Nowadays, it is treatable by some CFTR-rescuing drugs, but new-generation drugs with stronger therapeutic benefits and fewer side effects are still awaited. In this manuscript we report about the results of a pilot computational drug repositioning screening in search of F508del-CFTR-targeted drugs performed on AIFA library by means of a dedicated computational pipeline and surface plasmon resonance binding assay to experimentally validate the computational findings.

Real-World Safety of CFTR Modulators in the Treatment of Cystic Fibrosis: A Systematic Review

Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies target the underlying cause of cystic fibrosis (CF), and are generally well-tolerated; however, real-world studies indicate the frequency of discontinuation and adverse events (AEs) may be higher than what was observed in clinical trials. The objectives of this systematic review were to summarize real-world AEs reported for market-available CFTR modulators (i.e., ivacaftor (IVA), lumacaftor/ivacaftor (LUM/IVA), tezacaftor/ivacaftor (TEZ/IVA), and elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA)), and to identify ways in which the pharmacist on CF healthcare teams may contribute to mitigating and managing these AEs. The MEDLINE, EMBASE, CINAHL, and Web of Science Core Collection online databases were searched from 2012 to 1 Aug 2020. Full manuscripts or conference abstracts of observational studies, case series, and case reports were eligible for inclusion. The included full manuscripts and conference abstracts comprised of 54 observational studies, 5 case series, and 9 case reports. The types of AEs reported generally aligned with what have been observed in clinical trials. LUM/IVA was associated with a higher frequency of respiratory-related AE and discontinuation in real-world studies. A signal for mental health and neurocognitive AEs was identified with all 4 CFTR modulators. A systematic approach to monitoring for AEs in people with CF on CFTR modulators in the real-world setting is necessary to help better understand potential AEs, as well as patient characteristics that may be associated with higher risk of certain AEs. Pharmacists play a key role in the safe initiation and monitoring of people with CF on CFTR modulator therapies.

Aerosolized lancovutide in adolescents (≥12 years) and adults with cystic fibrosis - a randomized trial

BACKGROUND

Lancovutide activates a chloride channel (TMEM-16A) other than the cystic fibrosis (CF) transmembrane conductance regulator protein and could benefit CF patients.

METHODS

In this randomized, multi-center, double-blind, placebo-controlled, parallel-group trial 161 patients ≥12 years with a confirmed diagnosis of CF were randomized to either placebo (saline) or active drug in 3 different dosing schemes of 2.5mg inhaled lancovutide (once daily, every other day or twice a week) for eight weeks. The primary endpoint was the change in the forced expiratory volume in 1 second (FEV1) percent predicted. Secondary endpoints included further lung function parameters (FEV1 (absolute), functional vital capacity percent predicted, forced expiratory flow percent predicted, pulse oximetry), quality of life assessment, pulmonary exacerbations, hospitalization due to pulmonary exacerbations, time to first pulmonary exacerbation, duration of anti-inflammatory, mucolytic or antibiotic treatment, and safety.

RESULTS

There was no significant difference in the change in FEV1 percent predicted, quality of life, other lung function parameters, pulmonary exacerbations or requirement of additional treatment between groups. Overall, the inhalation of lancovutide was safe although a higher rate of adverse events, especially related to the respiratory system, occurred as compared to placebo.

CONCLUSIONS

Lancovutide did not improve FEV1 percent predicted when compared to placebo (NCT00671736).