An Observational Study of Outcomes and Tolerances in Patients with Cystic Fibrosis Initiated on Lumacaftor/Ivacaftor

Nanoparticle-based platforms for targeted drug delivery to the pulmonary system as therapeutics to curb cystic fibrosis: A review

Cystic fibrosis (CF) is a genetic disorder of the respiratory system caused by mutation of the Cystic Fibrosis Trans-Membrane Conductance Regulator (CFTR) gene that affects a huge number of people worldwide. It results in difficulty breathing due to a large accumulation of mucus in the respiratory tract, resulting in serious bacterial infections, and subsequent death. Traditional drug-based treatments face hindered penetration at the site of action due to the thick mucus layer. Nanotechnology offers possibilities for developing advanced and effective treatment platforms by focusing on drugs that can penetrate the dense mucus layer, fighting against the underlying bacterial infections, and targeting the genetic cause of the disease. In this review, current nanoparticle-mediated drug delivery platforms for CF, challenges in therapeutics, and future prospects have been highlighted. The effectiveness of the different types of nano-based systems conjugated with various drugs to combat the symptoms and the challenges of treating CF are brought into focus. The toxic effects of these nano-medicines and the various factors that are responsible for their effectiveness are also highlighted.

The gut-lung axis in the CFTR modulator era

The advent of CFTR modulators represents a turning point in the history of cystic fibrosis (CF) management, changing profoundly the disease's clinical course by improving mucosal hydration. Assessing changes in airway and digestive tract microbiomes is of great interest to better understand the mechanisms and to predict disease evolution. Bacterial and fungal dysbiosis have been well documented in patients with CF; yet the impact of CFTR modulators on microbial communities has only been partially deciphered to date. In this review, we aim to summarize the current state of knowledge regarding the impact of CFTR modulators on both pulmonary and digestive microbiomes. Our analysis also covers the inter-organ connections between lung and gut communities, in order to highlight the gut-lung axis involvement in CF pathophysiology and its evolution in the era of novel modulators therapies.

Modulation of Plasmatic Matrix Metalloprotease 9: A Promising New Tool for Understanding the Variable Clinical Responses of Patients with Cystic Fibrosis to Cystic Fibrosis Transmembrane Conductance Regulator Modulators

BACKGROUND

The most recent modulator combination, elexacaftor/tezacaftor/ivacaftor (Trikafta®), has been shown to improve clinical outcomes in most patients with cystic fibrosis (PwCF). Unfortunately, the clinical benefits are sometimes variable; thus, improving our knowledge of the possible causes of this variability can help reduce it.

METHODS

Circulating mononuclear cells (CMCs) and plasma were collected from 16 PwCF (including those on Trikafta® therapy) and 4 non-CF subjects. Cystic fibrosis transmembrane conductance regulator (CFTR) activity and matrix metalloprotease 9 (MMP9) expression were monitored before and after therapy, together with some clinical parameters. The relationship between MMP9 expression and the modulation of the extracellular-regulated 1/2 (ERK1/2) and nuclear factor-kB (NF-kB) pathways was also analyzed.

RESULTS

MMP9, markedly expressed in the CMCs and plasma of all the patients included in the study, was downregulated in the clinically responsive PwCF. In the non-responder, the MMP9 levels remained high. The modulation of MMP9 following treatment with Trikafta® may be controlled by the NF-kB pathway.

CONCLUSIONS

These data strongly suggest that MMP9 downregulation is a potential biomarker of therapy efficacy and that it could be useful in understanding the molecular events underlying the variable clinical responses of patients to Trikafta®. This knowledge could be helpful for future studies of personalized medicine and thereby ensure improvements in individual responses to therapies.

Tezacaftor-ivacaftor use in routine care of adults with cystic fibrosis: a medicine use evaluation

OBJECTIVES

Cystic fibrosis is a devastating life-limiting genetic condition characterised by a progressive decline in lung function, respiratory infections and premature death. Tezacaftor-ivacaftor is a combined cystic fibrosis transmembrane conductance regulator (CFTR) modulator that targets the underlying cause of the disease. This study aimed to assess the impact of tezacaftor-ivacaftor use in routine clinical practice for adults with cystic fibrosis.

METHODS

A retrospective observational longitudinal cohort study design was applied to examine the clinical effect of tezacaftor-ivacaftor in routine practice in the West of Scotland Adult Cystic Fibrosis Unit. Adults receiving tezacaftor-ivacaftor for at least 4 weeks were included in this medicine use evaluation.A standardised data form was used to collect patient-level data: demographics, genotype, complications of cystic fibrosis, medicine access process. Fifty-two weeks pre and post tezacaftor-ivacaftor initiation data: lung function, body mass index (BMI), days spent in hospital, days receiving antibiotic treatment for respiratory exacerbations. Anonymised data were collated and analysed using SPSS V.26.

RESULTS

Of 121 potential patients, 45 received treatment with tezacaftor-ivacaftor; median age 30 years (range 17-64) at initiation, 56% were male, 76% were deemed to be homozygote and 41 patients continued treatment for at least 52 weeks. There was no significant change in % predicted FEV1; median difference 0 (IQR -3 to 6). There was a significant improvement in BMI, mean 0.6 kg/m2 (95% CI 0.2 to 1.0), as well as a median 4 (IQR -17 to 0) day reduction in days in hospital and 21 (IQR -42 to 0) day reduction in days receiving antibiotics.

CONCLUSIONS

The use of tezacaftor-ivacaftor in routine practice for people with cystic fibrosis was associated with improvements in weight, as well as reducing the number of days people needed to spend in hospital and receive antibiotics.

Respiratory Infection and Inflammation in Cystic Fibrosis: A Dynamic Interplay among the Host, Microbes, and Environment for the Ages

The interplay between airway inflammation and infection is now recognized as a major factor in the pathobiology in cystic fibrosis (CF). A proinflammatory environment is seen throughout the CF airway resulting in classic marked and enduring neutrophilic infiltrations, irreversibly damaging the lung. Although this is seen to occur early, independent of infection, respiratory microbes arising at different timepoints in life and the world environment perpetuate this hyperinflammatory state. Several selective pressures have allowed for the CF gene to persist until today despite an early mortality. Comprehensive care systems, which have been a cornerstone of therapy for the past few decades, are now revolutionized by CF transmembrane conductance regulator (CTFR) modulators. The effects of these small-molecule agents cannot be overstated and can be seen as early as in utero. For an understanding of the future, this review looks into CF studies spanning the historical and present period.

Brazilian guidelines for the pharmacological treatment of the pulmonary symptoms of cystic fibrosis. Official document of the Sociedade Brasileira de Pneumologia e Tisiologia (SBPT, Brazilian Thoracic Association)

Cystic fibrosis (CF) is a genetic disease that results in dysfunction of the CF transmembrane conductance regulator (CFTR) protein, which is a chloride and bicarbonate channel expressed in the apical portion of epithelial cells of various organs. Dysfunction of that protein results in diverse clinical manifestations, primarily involving the respiratory and gastrointestinal systems, impairing quality of life and reducing life expectancy. Although CF is still an incurable pathology, the therapeutic and prognostic perspectives are now totally different and much more favorable. The purpose of these guidelines is to define evidence-based recommendations regarding the use of pharmacological agents in the treatment of the pulmonary symptoms of CF in Brazil. Questions in the Patients of interest, Intervention to be studied, Comparison of interventions, and Outcome of interest (PICO) format were employed to address aspects related to the use of modulators of this protein (ivacaftor, lumacaftor+ivacaftor, and tezacaftor+ivacaftor), use of dornase alfa, eradication therapy and chronic suppression of Pseudomonas aeruginosa, and eradication of methicillin-resistant Staphylococcus aureus and Burkholderia cepacia complex. To formulate the PICO questions, a group of Brazilian specialists was assembled and a systematic review was carried out on the themes, with meta-analysis when applicable. The results obtained were analyzed in terms of the strength of the evidence compiled, the recommendations being devised by employing the GRADE approach. We believe that these guidelines represent a major advance to be incorporated into the approach to patients with CF, mainly aiming to favor the management of the disease, and could become an auxiliary tool in the definition of public policies related to CF.

Modifier Factors of Cystic Fibrosis Phenotypes: A Focus on Modifier Genes

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 various CF phenotypes as well as the response to the recent CFTR modulator therapies.

An Update on CFTR Modulators as New Therapies for Cystic Fibrosis

Over the past decade there have been significant developments in the field of Cystic Fibrosis Transmembrane Regulator modulator drugs. Following treatment in patients with cystic fibrosis with common gating mutations using the potentiator drug ivacaftor, successive development of corrector drugs used in combination has led to highly effective modulator therapy being available to more than 85% of the cystic fibrosis population over 12 years of age in the form of elexacaftor/tezacaftor/ivacaftor. In this article, we review the evidence from clinical trials and mounting real-world observational and registry data that demonstrates the impact highly effective modulators have on both pulmonary and extra-pulmonary manifestations of cystic fibrosis. As clinical trials progress to younger patient groups, we discuss the challenges to demonstrating drug efficacy in early life, and also consider practicalities of drug development in an ever-shrinking modulator-naïve population. Drug-drug interactions are an important consideration in people with cystic fibrosis, where polypharmacy is commonplace, but also as the modulated population look to remain healthier for longer, we identify trials that aim to address treatment burden too. Inequity of care, through drug cost or ineligibility for modulators by genotype, is widening without apparent strategies to address this; however, we present evidence of hopeful early-stage drug development for non-modulatable genes and summarise the current state of gene-therapy development.

Proteostasis Regulators in Cystic Fibrosis: Current Development and Future Perspectives

In cystic fibrosis (CF), the deletion of phenylalanine 508 (F508del) in the CF transmembrane conductance regulator (CFTR) leads to misfolding and premature degradation of the mutant protein. These defects can be targeted with pharmacological agents named potentiators and correctors. During the past years, several efforts have been devoted to develop and approve new effective molecules. However, their clinical use remains limited, as they fail to fully restore F508del-CFTR biological function. Indeed, the search for CFTR correctors with different and additive mechanisms has recently increased. Among them, drugs that modulate the CFTR proteostasis environment are particularly attractive to enhance therapy effectiveness further. This Perspective focuses on reviewing the recent progress in discovering CFTR proteostasis regulators, mainly describing the design, chemical structure, and structure-activity relationships. The opportunities, challenges, and future directions in this emerging and promising field of research are discussed, as well.

Cystic fibrosis: candidate selection and impact of the cystic fibrosis transmembrane conductance regulator therapy

PURPOSE OF REVIEW

Over the past decade, the development of highly effective cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulators has dramatically ameliorated the manifestations of CF for most patients. Perhaps most importantly, CFTR modulators impact the development and progression of advanced lung disease (ALD) and are changing the CF population accessing lung transplant.

RECENT FINDINGS

A recent phase 3 trial of elexacaftor/tezacaftor/ivacaftor (ETI) demonstrated efficacy for individuals with at least one copy of the most common CF mutation, F508del. Studies of CFTR modulator therapy in patients with ALD have demonstrated similar improvements in lung function, nutrition, and pulmonary exacerbation frequency as seen in individuals with higher lung function. Due to improvements with ETI, rates of lung transplant for CF have declined and individuals are achieving stability in lung function. Nevertheless, the Cystic Fibrosis Foundation guidelines for lung transplant referral should be used to guide referral decisions for all individuals with CF, including those on CFTR modulator therapy, to allow remediation of modifiable barriers to transplant. ETI may be used in the posttransplant setting but for selected individuals and with close monitoring.

SUMMARY

Increasing access to highly effective CFTR modulators has changed the trajectory of lung disease in CF for many, but not all, individuals and there remain individuals who cannot access therapy or whose mutations do not respond to modulators. Lung transplant remains an important treatment option for individuals with advanced CF lung disease. Increasing attention will be required to optimize decisions of when to list for transplant.

Factors Predisposing the Response to Lumacaftor/Ivacaftor in People with Cystic Fibrosis

Lumacaftor/ivacaftor (LUMA-IVA) therapy is prescribed to people with cystic fibrosis (pwCF) homozygous for the Phe508del-CFTR variant to restore CFTR protein function. There is, however, large inter-individual variability in treatment response. Here, we seek to identify clinical and/or genetic factors that may modulate the response to this CFTR modulator therapy. A total of 765 pwCF older than 12 years under LUMA-IVA therapy and with lung function and nutritional measurements available before and after treatment initiation were included. Response to treatment was determined by the change in lung function and nutritional status, from baseline and over the first two years after initiation, and it was assessed by weighted generalized estimating equation models. Gains in lung function and nutritional status were observed after 6 months of treatment (on average 2.11 ± 7.81% for percent predicted FEV₁ and 0.44 ± 0.77 kg/m² for BMI) and sustained over the 2 years. We observed that the more severe patients gained the most in lung function and nutritional status. While females started with a nutritional status more impaired than males, they had a larger response and regained BMI Z-score values similar to men after 2 years of treatment. We observed no association between variants in solute carrier (SLC) genes and the respiratory function response to LUMA-IVA, but the SLC6A14 rs12839137 variant was associated with the nutritional response. Further investigations, including other genomic regions, will be needed to fully explore the inter-individual variability of the response to LUMA-IVA.

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

Revisiting the Role of Leukocytes in Cystic Fibrosis

Cystic fibrosis in characterized by pulmonary bacterial colonization and hyperinflammation. Lymphocytes, monocytes/macrophages, neutrophils, and dendritic cells of patients with CF express functional CFTR and are directly affected by altered CFTR expression/function, impairing their ability to resolve infections and inflammation. However, the mechanism behind and the contribution of leukocytes in the pathogenesis of CF are still poorly characterized. The recent clinical introduction of specific CFTR modulators added an important tool not only for the clinical management of the disease but also to the investigation of the pathophysiological mechanisms related to CFTR dysfunction and dysregulated immunity. These drugs treat the basic defect in cystic fibrosis (CF) by increasing CFTR function with improvement of lung function and quality of life, and may improve clinical outcomes also by correcting the dysregulated immune function that characterizes CF. Measure of CFTR function, protein expression profiling and several omics methods were used to identify molecular changes in freshly isolated leukocytes of CF patients, highlighting two roles of leukocytes in CF: one more generally related to the mechanism(s) causing immune dysregulation in CF and unresolved inflammation, and another more applicative role, which identifies in myeloid cells, an important tool predictive of the therapeutic response of CF patients. In this review we will summarize available data on CFTR expression and function in leukocyte populations and will discuss potential clinical applications based on available data.

The Intestinal Microbiome and Cystic Fibrosis Transmembrane Conductance Regulator Modulators: Emerging Themes in the Management of Gastrointestinal Manifestations of Cystic Fibrosis

PURPOSE OF REVIEW

While commonly associated with pulmonary manifestations, cystic fibrosis (CF) is a systemic disease with wide-ranging effects on the gastrointestinal (GI) tract. This article reviews major recent updates in gastroenterological CF care and research.

RECENT FINDINGS

The high burden of GI symptoms in CF has led to recent studies assessing GI-specific symptom questionnaires and scoring systems. Intestinal dysbiosis potentially contributes to gastrointestinal symptoms in patients with CF and an increased risk of gastrointestinal cancers in CF. An increased incidence of colorectal cancer (CRC) has led to CF-specific CRC screening and surveillance recommendations. Pharmacologic therapies targeting specific cystic fibrosis transmembrane conductance regulator (CFTR) mutations have shown promise in treating GI manifestations of CF. New research has highlighted the importance of intestinal dysbiosis in CF. Future studies should assess whether CFTR modulators affect the gut microbiome and whether altering the gut microbiome will impact GI symptoms and GI cancer risk.

Quantitative Method for the Analysis of Ivacaftor, Hydroxymethyl Ivacaftor, Ivacaftor Carboxylate, Lumacaftor, and Tezacaftor in Plasma and Sputum Using Liquid Chromatography With Tandem Mass Spectrometry and Its Clinical Applicability

BACKGROUND

The novel cystic fibrosis transmembrane conductance regulator (CFTR) modulators, ivacaftor, lumacaftor, and tezacaftor, are the first drugs directly targeting the underlying pathophysiological mechanism in cystic fibrosis (CF); however, independent studies describing their pharmacokinetics are lacking. The aim of this study was to develop a quantification method for ivacaftor and its 2 main metabolites, lumacaftor and tezacaftor, in plasma and sputum using liquid chromatography with tandem mass spectrometry.

METHODS

The developed method used a small sample volume (20 µL) and simple pretreatment method; protein precipitation solution and internal standard were added in one step to each sample. Liquid chromatography with tandem mass spectrometry was performed for a total run time of 6 minutes. The method was validated by assessing selectivity, carryover, linearity, accuracy and precision, dilution, matrix effects, and stability.

RESULTS

The selectivity was good as no interference from matrices was observed. In the concentration range from 0.01 to 10.0 mg/L, calibration curves were linear with a correlation coefficient >0.9997 for all compounds. The within-run and between-run accuracy were between 99.7% and 116% at the lower limit of quantitation (LLOQ) and between 95.8% and 112.9% for all concentrations above LLOQ for all analytes in plasma and sputum. Within-run and between-run precisions were <12.7% for LLOQ and <6.7% for the higher limit of quantitation. Samples were stable, with no significant degradation at examined temperatures and time points. Clinical applicability was revealed by analyzing samples from 2 patients with CF.

CONCLUSIONS

The presented method enables simultaneous quantification of ivacaftor, lumacaftor, and tezacaftor in plasma and sputum and is an improvement over previous methods because it uses smaller sample volumes, a simple pretreatment protocol, and includes tezacaftor. In future studies, it can be applied for examining pharmacokinetics characteristics of new CF transmembrane conductance regulator modulators.

Identification of Potential Leukocyte Biomarkers Related to Drug Recovery of CFTR: Clinical Applications in Cystic Fibrosis

The aim of this study was the identification of specific proteomic profiles, related to a restored cystic fibrosis transmembrane conductance regulator (CFTR) activity in cystic fibrosis (CF) leukocytes before and after ex vivo treatment with the potentiator VX770. We used leukocytes, isolated from CF patients carrying residual function mutations and eligible for Ivacaftor therapy, and performed CFTR activity together with proteomic analyses through micro-LC–MS. Bioinformatic analyses of the results obtained revealed the downregulation of proteins belonging to the leukocyte transendothelial migration and regulation of actin cytoskeleton pathways when CFTR activity was rescued by VX770 treatment. In particular, we focused our attention on matrix metalloproteinase 9 (MMP9), because the high expression of this protease potentially contributes to parenchyma lung destruction and dysfunction in CF. Thus, the downregulation of MMP9 could represent one of the possible positive effects of VX770 in decreasing the disease progression, and a potential biomarker for the prediction of the efficacy of therapies targeting the defect of Cl⁻ transport in CF.

Modulators of CFTR. Updates on clinical development and future directions

Cystic fibrosis (CF) is the most frequent life-limiting autosomal recessive disorder in the Caucasian population. It is due to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Current symptomatic CF therapies, which treat the downstream consequences of CFTR mutations, have increased survival. Better knowledge of the CFTR protein has enabled pharmacologic therapy aiming to restore mutated CFTR expression and function. These CFTR "modulators" have revolutionised the CF therapeutic landscape, with the potential to transform prognosis for a considerable number of patients. This review provides a brief summary of their mechanism of action and presents a thorough review of the results obtained from clinical trials of CFTR modulators.

VO2max as an exercise tolerance endpoint in people with cystic fibrosis: Lessons from a lumacaftor/ivacaftor trial

BACKGROUND

The impact of lumacaftor/ivacaftor on exercise tolerance in people with cystic fibrosis (CF) has not been thoroughly studied.

METHODS

We conducted a multisite Phase 4 trial comparing the impact of lumacaftor/ivacaftor on exercise tolerance with that of placebo in participants ≥ 12 years of age with CF homozygous for F508del-CFTR. The primary endpoint was relative change from baseline in maximum oxygen consumption (VO_2max) during cardiopulmonary exercise testing (CPET) at Week 24. The key secondary endpoint was relative change from baseline in exercise duration during CPET at Week 24. Other secondary endpoints included changes in other indices of exercise tolerance and changes in CF assessments; safety and tolerability were assessed as an endpoint.

RESULTS

Seventy participants were randomized to receive lumacaftor/ivacaftor (n = 34) or placebo (n = 36). The least-squares mean difference for lumacaftor/ivacaftor versus placebo in relative change in VO_2max from baseline at Week 24 was -3.2% (95% CI: -9.2, 2.9; P=0.3021); the least-squares mean difference in relative change from baseline in exercise duration at Week 24 was -3.2% (95% CI: -8.0, 1.6). Safety results were consistent with the known lumacaftor/ivacaftor safety profile.

CONCLUSIONS

Definitive conclusions regarding the impact of lumacaftor/ivacaftor on exercise tolerance cannot be drawn from these results; however, multicenter studies using CPETs can be reliably performed with multiple time points and conventional methods, provided that calibration can be achieved. Future studies of exercise tolerance may benefit from lessons learned from this study. NCT02875366.

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.

Practitioner Due Diligence: Real-World Lumacaftor/Ivacaftor Use

OBJECTIVE

Previous trials evaluated the efficacy of lumacaftor/ivacaftor in Phe508del homozygotes. These trials are limited by manufacturer sponsorship and were conducted under strict protocol. Additionally, this therapy is costly and does not allow for reduction in daily cystic fibrosis therapies. This study assessed the efficacy of lumacaftor/ivacaftor therapy and its effect on health care utilization in a real-world setting.

METHODS

Retrospective chart review comparing the first 12 months of therapy to the 24 months prior was conducted to evaluate the impact of lumacaftor/ivacaftor on pulmonary function following a streamlined process for therapy introduction. The impact on body mass index and healthcare utilization were also evaluated. The following measurements were assessed: percent predicted forced expiratory volume in 1 second, body mass index and z-scores, number of admissions, length of stay, number of emergency department visits.

RESULTS

Mean ppFEV₁ was improved for the first 12 months on lumacaftor/ivacaftor treatment when compared with the 24 months prior: 78.8 (95% CI: 72.6, 84.9) vs 76.2 (95% CI: 70.1, 82.3) (p = 0.03). Body mass index significantly improved (patients ≥20 years), but improvement in BMI z-score (patients <20 years) was not significant. Number of admissions and LOS were significantly decreased, but ED visits were not.

CONCLUSIONS

Lumacaftor/ivacaftor is effective for improving ppFEV1 and BMI and for reducing health care utilization. However, this small reduction does not overcome the financial cost of treatment. Long-term outcomes and use must be studied to determine the overall effect of this therapy on cystic fibrosis interventions and their costs.

Epithelial vectorial ion transport in cystic fibrosis: Dysfunction, measurement, and pharmacotherapy to target the primary deficit

Cystic fibrosis patients display multi-organ system dysfunction (e.g. pancreas, gastrointestinal tract, and lung) with pathogenesis linked to a failure of Cl^- secretion from the epithelial surfaces of these organs. If unmanaged, organ dysfunction starts early and patients experience chronic respiratory infection with reduced lung function and a failure to thrive due to gastrointestinal malabsorption. Early mortality is typically caused by respiratory failure. In the past 40 years of newborn screening and improved disease management have driven the median survival up from the mid-teens to 43-53, with most of that improvement coming from earlier and more aggressive management of the symptoms. In the last decade, promising pharmacotherapies have been developed for the correction of the underlying epithelial dysfunction, namely, Cl^- secretion. A new generation of systemic drugs target the mutated Cl^- channels in cystic fibrosis patients and allow trafficking of the immature mutated protein to the cell membrane (correctors), restore function to the channel once in situ (potentiators), or increase protein levels in the cells (amplifiers). Restoration of channel function prior to symptom development has the potential to significantly change the trajectory of disease progression and their evidence suggests that a modest restoration of Cl^- secretion may delay disease progression by decades. In this article, we review epithelial vectorial ion and fluid transport, its quantification and measurement as a marker for cystic fibrosis ion transport dysfunction, and highlight some of the recent therapies targeted at the dysfunctional ion transport of cystic fibrosis.

Re-imagining cystic fibrosis care: next generation thinking

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 and earlier in life, it is likely that general CF care will increasingly pivot around these specific therapies, although it is also likely that effects other than those identified in the initial trials will be discovered and need to be managed. Despite great excitement for modulator therapies, they are unlikely to be suitable or available for all; whether this is due to a lack of availability for specific CFTR mutations, drug-reactions or the health economic set-up in certain countries. Nevertheless, the CF community must be applauded for its ongoing focus on research and development for this life-limiting disease. With time, personalised individualised therapy would ideally be the mainstay of CF care.

The preclinical discovery and development of the combination of ivacaftor + tezacaftor used to treat cystic fibrosis

INTRODUCTION

Cystic Fibrosis (CF) is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. The most common mutation, F508del, induces protein misprocessing and loss of CFTR function. The discovery through in vitro studies of the CFTR correctors (i.e. lumacaftor, tezacaftor) that partially rescue the misprocessing of F508del-CFTR with the potentiator ivacaftor is promising in giving an unprecedented clinical benefit in affected patients.

AREAS COVERED

Online databases were searched using key phrases for CF and CFTR modulators. Tezacaftor-ivacaftor treatment has proved to be safer than lumacaftor-ivacaftor, although clinical efficacy is similar. Further clinical efficacy has ensued with the introduction of triple therapy, i.e. applying second-generation correctors, such as VX-569 and VX-445 (elexacaftor) to tezacaftor-ivacaftor. The triple combinations will herald the availability of etiologic therapies for patients for whom no CFTR modulators are currently applied (i.e. F508del/minimal function mutations) and enhance CFTR modulator therapy for patients homozygous for F508del.

EXPERT OPINION

CF patient-derived tissue models are being explored to determine donor-specific response to current approved and future novel CFTR modulators for F508del and other rare mutations. The discovery and validation of biomarkers of CFTR modulation will complement these studies in the long term and in real-life world.

Treatment of Cystic Fibrosis Patients Homozygous for F508del with Lumacaftor-Ivacaftor (Orkambi®) Restores Defective CFTR Channel Function in Circulating Mononuclear Cells

The treatment of cystic fibrosis (CF) patients homozygous for the F508del mutation with Orkambi^®, a combination of a corrector (lumacaftor) and a potentiator (ivacaftor) of the mutated CFTR protein, resulted in some amelioration of the respiratory function. However, a great variability in the clinical response was also observed. The aim of this study was to evaluate the response to Orkambi^® in a small cohort of F508del/F508del patients (n = 14) in terms of clinical and laboratory parameters, including ex vivo CFTR activity in mononuclear cells (MNCs), during a 12-month treatment. Patients responded with an increase in percent predicted forced expiratory volume in 1 s (FEV₁%) and body mass index (BMI) as well as with a decrease in white blood cell (WBC) total counts and serum C-reactive protein (CRP) levels, although not significantly. Sweat chloride and CFTR-dependent chloride efflux were found to decrease and increase, respectively, as compared with pre-therapy values. CFTR and BMI showed a statistically significant correlation during Orkambi^® treatment. Clustering analysis showed that CFTR, BMI, sweat chloride, FEV₁%, and WBC were strongly associated. These data support the notion that CFTR-dependent chloride efflux in MNCs should be investigated as a sensitive outcome measure of Orkambi^® treatment in CF patients.

Impact of CFTR modulator use on outcomes in people with severe cystic fibrosis lung disease

Drug compounds that augment the production and activity of the cystic fibrosis (CF) transmembrane regulator (CFTR) have revolutionised CF care. Many adults and some children with CF suffer advanced and severe lung disease or await lung transplantation. While the hope is that these drug compounds will prevent lung damage when started early in life, there is an ongoing need to care for people with advanced lung disease. The focus of this review is the accumulating data from clinical trials and case series regarding the benefits of CFTR modulator therapy in people with advanced pulmonary disease. We address the impact of treatment with ivacaftor, lumacaftor/ivacaftor, tezacaftor/ivacaftor and elexacaftor/tezacaftor/ivacaftor on lung function, pulmonary exacerbations, nutrition and quality of life. Adverse events of the different CFTR modulators, as well as the potential for drug–drug interactions, are discussed.

CFTR modulators are efficacious in improving lung function and exacerbations, even in advanced CF. However, adverse drug reactions and drug interactions are frequent.http://bit.ly/37aN81E

Biological Characterization of F508delCFTR Protein Processing by the CFTR Corrector ABBV-2222/GLPG2222

Cystic fibrosis (CF) is the most common monogenic autosomal recessive disease in Caucasians caused by pathogenic mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (CFTR). Significant small molecule therapeutic advances over the past two decades have been made to target the defective CFTR protein and enhance its function. To address the most prevalent defect of the defective CFTR protein (i.e., F508del mutation) in CF, two biomolecular activities are required, namely, correctors to increase the amount of properly folded F508delCFTR levels at the cell surface and potentiators to allow the effective opening, i.e., function of the F508delCFTR channel. Combined, these activities enhance chloride ion transport yielding improved hydration of the lung surface and subsequent restoration of mucociliary clearance. To enhance clinical benefits to CF patients, a complementary triple combination therapy consisting of two corrector molecules, type 1 (C1) and type 2, with additive mechanisms along with a potentiator are being investigated in the clinic for maximum restoration of mutated CFTR function. We report the identification and in vitro biologic characterization of ABBV-2222/GLPG2222 (4-[(2R,4R)-4-({[1-(2,2-difluoro-1,3-benzodioxol-5-yl)cyclopropyl]carbonyl}amino)-7-(difluoromethoxy)-3,4-dihydro-2H-chromen-2-yl]benzoic acid),-a novel, potent, and orally bioavailable C1 corrector developed by AbbVie-Galapagos and currently in clinical trials-which exhibits substantial improvements over the existing C1 correctors. This includes improvements in potency and drug-drug interaction (DDI) compared with 3-(6-(1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-3-methylpyridin-2-yl)benzoic acid (VX-809, Lumacaftor) and improvements in potency and efficacy compared with 1-(2,2-difluoro-1,3-benzodioxol-5-yl)-N-[1-[(2R)-2,3-dihydroxypropyl]-6-fluoro-2-(1-hydroxy-2-methylpropan-2-yl)indol-5-yl]cyclopropane-1-carboxamide (VX-661, Tezacaftor). ABBV-2222/GLPG2222 exhibits potent in vitro functional activity in primary patient cells harboring F508del/F508del CFTR with an EC50 value <10 nM. SIGNIFICANCE STATEMENT: To address the most prevalent defect of the defective CFTR protein (i.e., F508del mutation) in cystic fibrosis, AbbVie-Galapagos has developed ABBV-2222/GLPG2222, a novel, potent, and orally bioavailable C1 corrector of this protein. ABBV-2222/GLPG2222, which is currently in clinical trials, exhibits potent in vitro functional activity in primary patient cells harboring F508del/F508del CFTR and substantial improvements over the existing C1 correctors.

Cystic Fibrosis: Translating Molecular Mechanisms into Effective Therapies

Cystic fibrosis is a genetic disease that affects approximately 75,000 individuals around the world. Long regarded as a lethal and life-limiting disease, with the most severe manifestations expressed in the progressive decline of lung function, treatment advances focusing on airway clearance and management of chronic lung infection have resulted in improved outcomes for individuals with cystic fibrosis. These advances have been realized in conjunction with an improved understanding of the genetic basis of this disease, dating back to the discovery of the cystic fibrosis gene in 1989. The identification of the cystic fibrosis gene and the advancement of our understanding of the resultant cystic fibrosis transmembrane conductance regulator protein have led to the development of a new class of cystic fibrosis therapies designed to directly impact the function of this protein. These therapeutic developments have progressed, targeting the various mutations that can cause cystic fibrosis. These new medications, known as cystic fibrosis transmembrane conductance regulator modulators, have changed the landscape of cystic fibrosis care and cystic fibrosis research. Their demonstrated effect in patients with specific cystic fibrosis mutations has ignited the hope that such therapies will soon be available to more individuals with this disease, moving the cystic fibrosis community significantly closer to the ultimate goal of curing this disease.

Effect of Lumacaftor/Ivacaftor on Pulmonary Exacerbation Rates in Members with Cystic Fibrosis in a Medicaid Population

BACKGROUND

Lumacaftor/ivacaftor (LUM/IVA) is indicated for patients with cystic fibrosis (CF) homozygous for the F508del mutation in the CFTR gene. In clinical trials, LUM/IVA decreased pulmonary exacerbation rates. To our knowledge, there is no published data evaluating real-world outcomes for Medicaid patients receiving LUM/IVA.

OBJECTIVE

To compare CF pulmonary exacerbation rates before and after initiation of LUM/IVA in 1 state's Medicaid program.

METHODS

This pre-post claims analysis screened fee-for-service and managed Medicaid members who had ≥ 1 pharmacy claim for LUM/IVA between July 2, 2015, and September 30, 2016. Members were included if they were aged ≥ 6 years with a CF diagnosis and homozygous for the F508del mutation, consistent with the indication at study initiation. Exclusion criteria included Medicaid as a secondary payer or any break in coverage during the study. The index date was defined as the first claim for LUM/IVA. Demographics and outcomes were derived from pharmacy and medical claims. Outcomes included overall rate of pulmonary exacerbations (reported as the total events for the study population 6 months before and after the index date and average annualized rate). Pulmonary exacerbation was defined as any combination of medical claims for an emergency room (ER) visit or inpatient hospitalization with a CF pulmonary exacerbation or respiratory infection (ICD-9/10-CM codes) or pharmacy claims for an oral or intravenous antibiotic (excluding macrolides). A gap of > 7 days was considered a new pulmonary exacerbation. Paired t-test was used to test significance.

RESULTS

21 patients met inclusion criteria with an average age at treatment initiation of 20.1 years. Average proportion of days covered (SD) was 0.62 (0.29). The number of pulmonary exacerbations increased from 45 to 48 during the 6 months before and after the index date, respectively, and the annualized rate increased from 4.37 to 4.66 (P = 0.69). While the number of pulmonary exacerbations associated with antibiotics alone increased (23 to 33; P = 0.08), those associated with at least 1 ER visit or inpatient hospitalization decreased (22 to 15; P = 0.08).

CONCLUSIONS

This analysis did not find a decrease in pulmonary exacerbation rate for Medicaid members receiving LUM/IVA; however, adherence was low. Further study of similar populations is needed to better understand the long-term effect of treatment.

DISCLOSURES

No outside funding supported this study. The authors have nothing to disclose. A poster of this project was presented at the Academy of Managed Care Pharmacy Managed Care & Specialty Pharmacy Annual Meeting 2018 in Boston, MA, on April 23-26, 2018.

Whole-blood transcriptomic responses to lumacaftor/ivacaftor therapy in cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) remains without a definitive cure. Novel therapeutics targeting the causative defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are in clinical use. Lumacaftor/ivacaftor is a CFTR modulator approved for patients homozygous for the CFTR variant p.Phe508del, but there are wide variations in treatment responses preventing prediction of patient responses. We aimed to determine changes in gene expression related to treatment initiation and response.

METHODS

Whole-blood transcriptomics was performed using RNA-Seq in 20 patients with CF pre- and 6 months post-lumacaftor/ivacaftor (drug) initiation and 20 non-CF healthy controls. Correlation of gene expression with clinical variables was performed by stratification via clinical responses.

RESULTS

We identified 491 genes that were differentially expressed in CF patients (pre-drug) compared with non-CF controls and 36 genes when comparing pre-drug to post-drug profiles. Both pre- and post-drug CF profiles were associated with marked overexpression of inflammation-related genes and apoptosis genes, and significant under-expression of T cell and NK cell-related genes compared to non-CF. CF patients post-drug demonstrated normalized protein synthesis expression, and decreased expression of cell-death genes compared to pre-drug profiles, irrespective of clinical response. However, CF clinical responders demonstrated changes in eIF2 signaling, oxidative phosphorylation, IL-17 signaling, and mitochondrial function compared to non-responders. Top overexpressed genes (MMP9 and SOCS3) that decreased post-drug were validated by qRT-PCR. Functional assays demonstrated that CF monocytes normalized calcium (increases MMP9 expression) concentrations post-drug.

CONCLUSIONS

Transcriptomics revealed differentially regulated pathways in CF patients at baseline compared to non-CF, and in clinical responders to lumacaftor/ivacaftor.

RNA delivery biomaterials for the treatment of genetic and rare diseases

Genetic and rare diseases (GARDs) affect more than 350 million patients worldwide and remain a significant challenge in the clinic. Hence, continuous efforts have been made to bridge the significant gap between the supply and demand of effective treatments for GARDs. Recent decades have witnessed the impressive progress in the fight against GARDs, with an improved understanding of the genetic origins of rare diseases and the rapid development in gene therapy providing a new avenue for GARD therapy. RNA-based therapeutics, such as RNA interference (RNAi), messenger RNA (mRNA) and RNA-involved genome editing technologies, demonstrate great potential as a therapy tool for treating genetic associated rare diseases. In the meantime, a variety of RNA delivery vehicles were established for boosting the widespread applications of RNA therapeutics. Among all the RNA delivery platforms which enable the systemic applications of RNAs, non-viral RNA delivery biomaterials display superior properties and a few biomaterials have been successfully exploited for achieving the RNA-based gene therapies on GARDs. In this review article, we focus on recent advances in the development of novel biomaterials for delivery of RNA-based therapeutics and highlight their applications to treat GARDs.

A Systematic Review of the Clinical Efficacy and Safety of CFTR Modulators in Cystic Fibrosis

Several placebo-controlled trials have been recently published evaluating novel therapies targeting the defective CFTR protein. This systematic review examines the clinical efficacy and safety of CFTR modulators in individuals with cystic fibrosis (CF) with specific genetic mutations. Online sources were searched for placebo-controlled, parallel-design clinical trials investigating CFTR modulators from January 1, 2005 to March 31, 2018. The primary outcome of interest was FEV₁% predicted (ppFEV₁). Fourteen RCTs met our eligibility criteria. The largest improvement in ppFEV₁ favouring treatment was observed for ivacaftor (IVA) in G551D individuals (≥6 years old). Both tezacaftor-ivacaftor (TEZ-IVA) and lumacaftor-ivacaftor (LUM-IVA) also improved ppFEV₁ in F508del homozygous individuals but there was increased reporting of respiratory adverse events with LUM-IVA compared to placebo. IVA also significantly improved ppFEV₁ in a sub-group of individuals ≥18 years old with an R117H mutation. No significant improvements in ppFEV₁ were observed for IVA, LUM, or TEZ in F508del homozygous individuals, LUM or LUM-IVA in F508del heterozygous individuals, or ataluren in individuals with a nonsense mutation. Significant improvements in ppFEV₁ and other clinical outcomes were observed for IVA in G551D individuals, TEV-IVA and LUM-IVA in F508del homozygous individuals, and IVA in adults with a R117H mutation.

CFTR activity is enhanced by the novel corrector GLPG2222, given with and without ivacaftor in two randomized trials

BACKGROUND

Several treatment approaches in cystic fibrosis (CF) aim to correct CF transmembrane conductance regulator (CFTR) function; the efficacy of each approach is dependent on the mutation(s) present. A need remains for more effective treatments to correct functional deficits caused by the F508del mutation.

METHODS

Two placebo-controlled, phase 2a studies evaluated GLPG2222, given orally once daily for 29 days, in subjects homozygous for F508del (FLAMINGO) or heterozygous for F508del and a gating mutation, receiving ivacaftor (ALBATROSS). The primary objective of both studies was to assess safety and tolerability. Secondary objectives included assessment of pharmacokinetics, and of the effect of GLPG2222 on sweat chloride concentrations, pulmonary function and respiratory symptoms.

RESULTS

Fifty-nine and 37 subjects were enrolled into FLAMINGO and ALBATROSS, respectively. Treatment-related treatment-emergent adverse events (TEAEs) were reported by 29.2% (14/48) of subjects in FLAMINGO and 40.0% (12/30) in ALBATROSS; most were mild to moderate in severity and comprised primarily respiratory, gastrointestinal, and infection events. There were no deaths or discontinuations due to TEAEs. Dose-dependent decreases in sweat chloride concentrations were seen in GLPG2222-treated subjects (maximum decrease in FLAMINGO: -17.6 mmol/L [GLPG2222 200 mg], p < 0.0001; ALBATROSS: -7.4 mmol/L [GLPG2222 300 mg], p < 0.05). No significant effects on pulmonary function or respiratory symptoms were reported. Plasma GLPG2222 concentrations in CF subjects were consistent with previous studies in healthy volunteers and CF subjects.

CONCLUSIONS

GLPG2222 was well tolerated. Sweat chloride reductions support on-target enhancement of CFTR activity in subjects with F508del mutation(s). Significant improvements in clinical endpoints were not demonstrated. Observed safety results support further evaluation of GLPG2222, including in combination with other CFTR modulators.

FUNDING

Galapagos NV. Clinical trial registration numbers FLAMINGO, NCT03119649; ALBATROSS, NCT03045523.

Tezacaftor/Ivacaftor in Subjects with Cystic Fibrosis and F508del/F508del-CFTR or F508del/G551D-CFTR

RATIONALE

Tezacaftor (formerly VX-661) is an investigational small molecule that improves processing and trafficking of the cystic fibrosis transmembrane conductance regulator (CFTR) in vitro, and improves CFTR function alone and in combination with ivacaftor.

OBJECTIVES

To evaluate the safety and efficacy of tezacaftor monotherapy and of tezacaftor/ivacaftor combination therapy in subjects with cystic fibrosis homozygous for F508del or compound heterozygous for F508del and G551D.

METHODS

This was a randomized, placebo-controlled, double-blind, multicenter, phase 2 study (NCT01531673). Subjects homozygous for F508del received tezacaftor (10 to 150 mg) every day alone or in combination with ivacaftor (150 mg every 12 h) in a dose escalation phase, as well as in a dosage regimen testing phase. Subjects compound heterozygous for F508del and G551D, taking physician-prescribed ivacaftor, received tezacaftor (100 mg every day).

MEASUREMENTS AND MAIN RESULTS

Primary endpoints were safety through Day 56 and change in sweat chloride from baseline through Day 28. Secondary endpoints included change in percent predicted FEV₁ (ppFEV₁) from baseline through Day 28 and pharmacokinetics. The incidence of adverse events was similar across treatment arms. Tezacaftor (100 mg every day)/ivacaftor (150 mg every 12 h) resulted in a 6.04 mmol/L decrease in sweat chloride and 3.75 percentage point increase in ppFEV₁ in subjects homozygous for F508del, and a 7.02 mmol/L decrease in sweat chloride and 4.60 percentage point increase in ppFEV₁ in subjects compound heterozygous for F508del and G551D from baseline through Day 28 (P < 0.05 for all).

CONCLUSIONS

These results support continued clinical development of tezacaftor (100 mg every day) in combination with ivacaftor (150 mg every 12 h) in subjects with cystic fibrosis. Clinical trial registered with www.clinicaltrials.gov (NCT01531673).

Safety and efficacy of treatment with lumacaftor in combination with ivacaftor in younger patients with cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is the most common autosomal recessive disorder among Caucasians affecting ~70,000 people worldwide. The lack of functional cystic fibrosis transmembrane conductance regulator (CFTR) causes dysregulation of epithelial fluid transport in the lungs, gastrointestinal tract, and sweat glands. Areas covered: The most common disease-causing CFTR mutation, F508del, is present in over 75% of those affected;. therapies targeting F508del function have the promise to reduce morbidity and mortality in the majority of patients with CF. The combination of lumacaftor, which corrects the aberrant intracellular trafficking of F508del, and ivacaftor, which potentiates CFTR function, is known as Orkambi^TM, and is the first drug approved for the treatment of CF in patients who are F508del-homozygotes. Orkambi^TM is currently approved for use in children aged 2 and older based on recent data from open-label Phase 3 clinical safety studies. Expert opinion: Orkambi^TM modestly improves clinical outcomes for people with CF who are F508del-homozygotes, and does so with a reasonable safety profile. This is a major advance in therapy for CF, but further advances are needed, perhaps with the addition of a third agent to this combination small molecule therapy, in order to expand both the targeted population and beneficial effects.

Efficacy and Safety of CFTR Corrector and Potentiator Combination Therapy in Patients with Cystic Fibrosis for the F508del-CFTR Homozygous Mutation: A Systematic Review and Meta-analysis

INTRODUCTION

Cystic fibrosis (CF) is a progressive, genetic disease that causes persistent lung infections and limits the ability to breathe over time. The combination of a cystic fibrosis transmembrane conductance regulator (CFTR) corrector and potentiator has provided a benefit by decreasing sweat chloride concentration in CF for the F508del-CFTR homozygous mutation, but it remains controversial in lung function, nutritional status, clinical score and safety.

METHODS

The authors performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of combination therapy on lung function, nutritional status, clinical score and safety in CF for the F508del-CFTR homozygous mutation. Web of Science, Cochrane Central Register of Controlled Trials, Medline, and Embase were searched. The registered PROSPERO number was CRD42018085875.

RESULTS

Five RCTs, including a total of 1637 participants with the F508del-CFTR homozygous mutation who accepted CFTR corrector and potentiator combination therapy along with basic treatment were enrolled in this analysis. Primary analysis revealed that combination therapy improved the percent of predicted FEV₁ (ppFEV₁) (MD 2.38, 1.62-3.15, P < 0.00001), Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain score (MD 2.59, 0.96-4.22, P = 0.002) and body-mass index (BMI) (MD 0.21, 0.03-0.39, P = 0.02). In the secondary analysis, combination therapy had no impact on the number of participants reporting adverse events (OR 0.88, 0.58-1.33, P = 0.53), but increased the proportion of discontinued treatments due to adverse events (OR 2.71, 1.3-5.63, P = 0.008).

CONCLUSIONS

CFTR corrector and potentiator combination therapy effectively improves lung function, nutritional status and clinical score in CF patients with the F508del-CFTR homozygous mutation, and has an acceptable safety profile.

Clinical and microbiological characteristics of cystic fibrosis adults never colonized by Pseudomonas aeruginosa: Analysis of the French CF registry

Pseudomonas aeruginosa is the main cause of chronic airway infection in cystic fibrosis (CF). However, for unclear reasons some patients are never colonized by P. aeruginosa. The objectives of this study were to better define the clinical, genetic, and microbiological characteristics of such a subpopulation and to identify predictive factors of non-colonization with P. aeruginosa. The French CF patient registry 2013–2014 was used to identify CF patients aged ≥ 20 years. The clinical outcomes, CF Transmembrane conductance Regulator (CFTR) genotypes, and microbiological data of patients reported positive at least once for P. aeruginosa (“Pyo” group, n = 1,827) were compared to those of patients with no history of P. aeruginosa isolation (“Never” group, n = 303). Predictive factors of non-colonization by P. aeruginosa were identified by multivariate logistic regression model with backward selection. Absence of aspergillosis (odds ratio (OR) [95% CI] = 1.64 [1.01–2.66]), absence of diabetes (2.25 [1.21–4.18]), pancreatic sufficiency (1.81 [1.30–2.52]), forced expiratory volume 1 (FEV1) ≥ 80% (3.03 [2.28–4.03]), older age at CF diagnosis (1.03 [1.02–1.04]), and absence of F508del/F508del genotype (2.17 [1.48–3.19]) were predictive clinical factors associated with absence of infection (“Never” group). Microbiologically, this same group was associated with more frequent detection of Haemophilus influenzae and lower rates of Stenotrophomonas maltophilia, Achromobacter xylosoxidans and Aspergillus spp. (all p<0.01) in sputum. This study strongly suggests that the absence of pulmonary colonization by P. aeruginosa in a minority of CF adults (14.2%) is associated with a milder form of the disease. Recent progress in the development of drugs to correct CFTR deficiency thus may be decisive in the control of P. aeruginosa lung infection.

Predictive factors for lumacaftor/ivacaftor clinical response

BACKGROUND

Ivacaftor-lumacaftor combination therapy corrects the F508 del-CFTR mutated protein which causes Cystic Fibrosis. The clinical response of the patients treated with the combination therapy is highly variable. This study aimed to determine factors involved in the individual's response to lumacaftor-ivacaftor therapy.

METHODS

Sweat test was assessed at baseline and after 6 months of ivacaftor-lumacaftor treatment in 41 homozygous F508del children and young adults. β-adrenergic peak sweat secretion, nasal potential difference (NPD) and intestinal current measurements (ICM) were performed in patients accepting these tests. Seric level of lumacaftor and ivacaftor were determined and additional CFTR variant were searched.

RESULTS

Sweat chloride concentration significantly decreased after treatment, whereas the β-adrenergic peak sweat response did not vary in 9 patients who underwent these tests. The average level of F508del-CFTR activity rescue reached up to 15% of the normal level in intestinal epithelium, as studied by ICM in 12 patients (p = .03) and 20% of normal in the nasal epithelium in NPD tests performed in 21 patients (NS). There was no significant correlation between these changes and improvements in FEV₁ at 6 months. Serum drug levels did not correlate with changes in FEV₁, BMI-Zscore or other CFTR activity biomarkers. Additional exonic variants were identified in 4 patients. The F87L-I1027T-F508del-CFTR complex allele abolished the lumacaftor corrector effect.

CONCLUSION

This observational study investigates a number of potential factors linked to the clinical response of F508del homozygous patients treated with lumacaftor-ivacaftor combination therapy. Lumacaftor and ivacaftor blood levels are not associated with the clinical response. Additional exonic variants may influence protein correction.

Corticosteroid use and increased CXCR2 levels on leukocytes are associated with lumacaftor/ivacaftor discontinuation in cystic fibrosis patients homozygous for the F508del CFTR mutation

Cystic fibrosis (CF) is the most common life-shortening genetic disease and is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Several current therapies aim at improving availability and/or function of the mutant CFTR proteins. The combination therapeutic lumacaftor/ivacaftor (Orkambi, luma/iva) partially corrects folding and potentiates CFTR function impaired by the F508del mutation. Despite the potential for clinical benefit, a substantial number of patients discontinue treatment due to intolerable adverse effects. The aim of the present study is to identify differences between individuals who continued treatment and those who discontinued due to adverse respiratory effects to potentially inform treatment decisions. Clinical data from the year prior to treatment initiation were analyzed from 82 patients homozygous for the F508del mutation treated at the Colorado Adult CF Program. Blood samples were collected from 30 of these subjects before initiation of treatment to examine expression of circulating leukocyte surface antigens and cytokines. Clinical and demographic characteristics were analyzed along with inflammatory markers to determine biomarkers of drug discontinuation. The use of oral prednisone and/or nasal budesonide in the year prior to luma/iva initiation was more prevalent in CF subjects who did not tolerate luma/iva (82% vs. 43%). Increased age, but not gender or initial lung function, was associated with higher probability of discontinuing treatment due to side effects overall. Worse lung function (lower ppFEV₁, ppFEF_25-75 ≤ 60%) was associated with higher incidence of discontinuing treatment due to pulmonary adverse effects. In a nested cohort of patients, increased surface levels of CXCR2 on CD14+CD16- monocytes were associated with discontinuation. Overall, the patients who tolerated luma/iva were distinguishable from those who did not tolerate the drug based on clinical and cellular markers obtained prior to treatment initiation.

Cost-effectiveness analysis of lumacaftor and ivacaftor combination for the treatment of patients with cystic fibrosis in the United States

Background

Lumacaftor/ivacaftor was approved by the Food and Drug Administration (FDA) as a combination treatment for Cystic Fibrosis (CF) patients who are homozygous for the F508del mutation. The objective of this study was to assess the cost-effectiveness of lumacaftor/ivacaftor combination for the treatment of CF homozygous for F508del CF Transmembrane Conductance Regulator (CFTR) mutation.

Methods

A Markov-state transition model following a cohort of 12 year-old CF patients homozygous for F508del CFTR mutation in the United States (US) over two, four, six, eight and ten years from a payer’s perspective was developed using TreeAge Pro 2016. Markov states included: mild (percentage of predicted forced expiratory volume in 1 s or FEV1 > 70%), moderate (FEV1 40–70%), severe (FEV1 < 40%) disease, post-transplant, and death. Pulmonary exacerbation and lung transplant were included as transition states. All the input parameters were estimated from the literature. A 1-year cycle length and 3% discount rate were applied. To assess uncertainty in long-term treatment effects, several scenarios were modelled: 100% long-term effectiveness (base-case), defined as improvement in FEV1 in the first year followed by no annual FEV1 decline and a constant reduction in pulmonary exacerbations throughout, 75%, 50%, 25% and 0% (worst case) long-term effectiveness, where treatment effects were intermediate from the second year of treatment until the end of the time horizon. Other scenarios included changing the starting age of the cohort to 6 and 25 years. Primary outcome included incremental cost-effectiveness ratio (ICER) in terms of cost per quality adjusted life year (QALY) gained. One-way and probabilistic sensitivity analyses were performed to determine uncertainty.

Results

Under the base-case, Lumacaftor/ivacaftor resulted in higher QALYs (7.29 vs 6.84) but at a very high cost ($1,778,920.88) compared to usual care ($116,155.76) over a 10-year period. The ICER for base-case and worst-case scenarios were $3,655,352 / QALY, and $8,480,265/QALY gained, respectively. In the base-case, lumacaftor/ivacaftor was cost-effective at a threshold of $150,000/QALY-gained when annual drug costs were lower than $4153. The results were not substantially affected by the sensitivity analyses.

Conclusions

The intervention produces large QALY gains but at an extremely high cost, resulting in an ICER that would not typically be covered by any insurer. Lumacaftor/ivacaftor’s status as an orphan drug complicates coverage decisions.

Cystic Fibrosis Newborn Screening in Portugal: PAP Value in Populations with Stringent Rules for Genetic Studies

Newborn screening (NBS) for cystic fibrosis (CF) has been shown to be advantageous for children with CF, and has thus been included in most NBS programs using various algorithms. With this study, we intend to establish the most appropriate algorithm for CF-NBS in the Portuguese population, to determine the incidence, and to contribute to elucidating the genetic epidemiology of CF in Portugal. This was a nationwide three-year pilot study including 255,000 newborns (NB) that were also screened for congenital hypothyroidism (CH) and 24 other metabolic disorders included in the Portuguese screening program. Most samples were collected in local health centers spread all over the country, between the 3rd and 6th days of life. The algorithm tested includes immunoreactive trypsinogen (IRT) determination, pancreatitis associated protein (PAP) as a second tier, and genetic study for cases referred to specialized clinical centers. Thirty-four CF cases were confirmed positive, thus indicating an incidence of 1:7500 NB. The p.F508del mutation was found in 79% of the alleles. According to the results presented here, CF-NBS is recommended to be included in the Portuguese NBS panel with a small adjustment regarding the PAP cut-off, which we expect to contribute to the improvement of the CF-NBS performance. According to our results, this algorithm is a valuable alternative for CF-NBS in populations with stringent rules for genetic studies.

Prolonged co-treatment with HGF sustains epithelial integrity and improves pharmacological rescue of Phe508del-CFTR

Cystic fibrosis (CF), the most common inherited disease in Caucasians, is caused by mutations in the CFTR chloride channel, the most frequent of which is Phe508del. Phe508del causes not only intracellular retention and premature degradation of the mutant CFTR protein, but also defective channel gating and decreased half-life when experimentally rescued to the plasma membrane (PM). Despite recent successes in the functional rescue of several CFTR mutations with small-molecule drugs, the folding-corrector/gating-potentiator drug combinations approved for Phe508del-CFTR homozygous patients have shown only modest benefit. Several factors have been shown to contribute to this outcome, including an unexpected intensification of corrector-rescued Phe508del-CFTR PM instability after persistent co-treatment with potentiator drugs. We have previously shown that acute co-treatment with hepatocyte growth factor (HGF) can significantly enhance the chemical correction of Phe508del-CFTR. HGF coaxes the anchoring of rescued channels to the actin cytoskeleton via induction of RAC1 GTPase signalling. Here, we demonstrate that a prolonged, 15-day HGF treatment also significantly improves the functional rescue of Phe508del-CFTR by the VX-809 corrector/VX-770 potentiator combination, in polarized bronchial epithelial monolayers. Importantly, we found that HGF treatment also prevented VX-770-mediated destabilization of rescued Phe508del-CFTR and enabled further potentiation of the rescued channels. Most strikingly, prolonged HGF treatment prevented previously unrecognized epithelial dedifferentiation effects of sustained exposure to VX-809. This was observed in epithelium-like monolayers from both lung and intestinal origin, representing the two systems most affected by adverse symptoms in patients treated with VX-809 or the VX-809/VX-770 combination. Taken together, our findings strongly suggest that co-administration of HGF with corrector/potentiator drugs could be beneficial for CF patients.

Tezacaftor for the treatment of cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is the most common, life-limiting autosomal recessive disease in Caucasians, and is caused by defects in production of the CFTR ion channel. Until recently, there were no available treatments targeting the disease-causing defects in CFTR but newly developed CFTR modulators are changing the course of disease in CF. The newest modulator, tezacaftor, is a CFTR corrector that was recently approved by the FDA to be used in combination with the first approved CFTR potentiator, ivacaftor. Areas covered: A detailed review of the clinical trials and published literature, focusing on safety and efficacy, leading to the approval of tezacaftor in CF. Expert commentary: Recent trials have demonstrated that the combination of tezacaftor-ivacaftor is a slightly superior combination to its predecessor, lumacaftor-ivacaftor, with respect to an increase in FEV1, adverse event profile, and drug-drug interactions. It is also approved for a large number of non-F508del, residual function mutations that are predicted to respond based on in vitro testing. The horizon for continued improvements in CFTR-targeted treatments is promising, with three-drug combinations currently in Phase 3 clinical trials, and other drugs with novel mechanisms of action being studied. Within the next 5 years, the vast majority of patients with CF are expected to have a modulator approved for their genotype.

Lipid Nanoparticle-Delivered Chemically Modified mRNA Restores Chloride Secretion in Cystic Fibrosis

The promise of gene therapy for the treatment of cystic fibrosis has yet to be fully clinically realized despite years of effort toward correcting the underlying genetic defect in the cystic fibrosis transmembrane conductance regulator (CFTR). mRNA therapy via nanoparticle delivery represents a powerful technology for the transfer of genetic material to cells with large, widespread populations, such as airway epithelia. We deployed a clinically relevant lipid-based nanoparticle (LNP) for packaging and delivery of large chemically modified CFTR mRNA (cmCFTR) to patient-derived bronchial epithelial cells, resulting in an increase in membrane-localized CFTR and rescue of its primary function as a chloride channel. Furthermore, nasal application of LNP-cmCFTR restored CFTR-mediated chloride secretion to conductive airway epithelia in CFTR knockout mice for at least 14 days. On day 3 post-transfection, CFTR activity peaked, recovering up to 55% of the net chloride efflux characteristic of healthy mice. This magnitude of response is superior to liposomal CFTR DNA delivery and is comparable with outcomes observed in the currently approved drug ivacaftor. LNP-cmRNA-based systems represent a powerful platform technology for correction of cystic fibrosis and other monogenic disorders.

Cystic fibrosis transmembrane conductance regulator modulators: precision medicine in cystic fibrosis

PURPOSE OF REVIEW

The aim of this study was to describe the newest development in cystic fibrosis (CF) care, CF transmembrane conductance regulator (CFTR) modulator therapies.

RECENT FINDINGS

Phase II results showing CFTR modulator triple therapies are more effective than current CFTR modulators.

SUMMARY

CFTR modulator therapy targets the protein defective in CF and boosts its function, but the drug must match mutation pathobiology. Ivacaftor, a CFTR potentiator, was the first modulator approved in 2012, with impressive improvement in lung function and other measures of disease in patients with gating and other residual function mutations (∼10% of CF patients). In 2015, the combination of lumacaftor, a CFTR corrector, and ivacaftor was approved for patients homozygous for the F508del mutation (∼40-50% of the CF population) with positive but less impressive clinical response and 10-20% incidence of intolerance. A next-generation CFTR corrector, tezacaftor, with ivacaftor equally effective and better tolerated than lumacaftor, has also received US Food and Drug Administration approval. Novel CFTR correctors, entering Phase 3 trials in triple modulator combination with tezacaftor-ivacaftor, appear substantially more effective for patients who are homozygous for the F508del mutation and can provide benefit for patients with a single F508del mutation. This offers promise of effective CFTR modulator therapy for nearly 90% of CF patients.