Ivacaftor treatment of cystic fibrosis in children aged 12 to <24 months and with a CFTR gating mutation (ARRIVAL): a phase 3 single-arm study

Advances in the treatment of cystic fibrosis: CFTR modulators

Cystic fibrosis is a severe genetic disease caused by variants in the CFTR gene. Although it is a multisystem disease, respiratory involvement is the main cause of morbidity and mortality. Cystic fibrosis transmembrane conductance regulator modulator (CFTRm) therapies have advanced the treatment of this disease by improving function of this protein. Ivacaftor, the first CFTRm, has been found to significantly improve lung function and quality of life in patients with certain gating variants. However, only a small percentage of patients in Spain are eligible for this treatment. Combinations of correctors and potentiators, such as lumacaftor-ivacaftor or tezacaftor-ivacaftor, have been developed for treatment of patients with the most frequent variant (F508del), although with limited benefits. Triple therapy with elexacaftor-tezacaftor-ivacaftor has been found to significantly improve respiratory, gastrointestinal and nutritional outcomes as well as quality of life, thus changing the management of CF in eligible patients. The impact of triple therapy is also reflected in an increase in life expectancy and a decrease in mortality and lung transplantation. As regards hepatic and pancreatic involvement, while CFTR modulators have exhibited promising effects, further research is required. The use of CFTR modulators has also shifted nutritional status trends in patients with CF, reducing the risk of undernutrition but increasing the risk of obesity. The use of these drugs for treatment of less frequent variants and for potential antenatal treatment is currently being investigated. Despite these advances, there is still a subset of patients who are ineligible for treatment with modulators or highly effective therapy.

Sex disparities in cystic fibrosis in the era of highly effective modulator treatment

Cystic fibrosis (CF) is a genetic disorder characterized by progressive lung disease and extra-pulmonary manifestations with notable sex disparities in disease outcomes. In this review we summarize the underlying mechanisms driving this sex disparity, with a particular focus on the role of sex hormones on CF lung disease pathophysiology. We explore how the introduction of highly effective modulator therapies (HEMT) may impact sex differences in outcomes and assess whether they have the potential to close the sex gap. While treatment with HEMT has led to better outcomes in the CF population as a whole, females with CF continue to experience worse pulmonary morbidity than males. There is a need for continued research in this area, particularly into the influence and therapeutic potential of sex hormones.

A Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantification of Cystic Fibrosis Drugs (Caftors) in Plasma and Its Application for Therapeutic Monitoring

Cystic fibrosis (CF) is a life-threatening disorder caused by mutations in the CFTR gene, leading to defective chloride ion transport and thickened mucus in the respiratory and gastrointestinal systems. CFTR modulators, including ivacaftor, lumacaftor, tezacaftor, and elexacaftor, have improved patient outcomes, but interindividual pharmacokinetic variability and potential drug-drug interactions require therapeutic drug monitoring (TDM) for optimal efficacy and safety. In this context, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous quantification of CFTR modulators and their major active metabolites in human plasma to support pharmacokinetic studies and routine TDM. The multiplex LC-MS/MS assay was established using plasma protein precipitation, followed by chromatographic separation on an Xselect HSS T3 (Waters®) column and positive electrospray ionization mode detection. The method was validated based on FDA and EMA guidelines for specificity, linearity, accuracy (89.8-107.8%), repeatability (1.1-8.1%), intermediate fidelity (1.3-10.9%), matrix effects, and stability, demonstrating a robust performance with excellent precision and accuracy. International interlaboratory comparisons confirmed the reliability of the assay. The developed method can be applied for the clinical monitoring of caftors' plasma concentrations and preliminary data suggest that it can also be applied to alternative matrices, such as breast milk. This method will serve to characterize caftors' pharmacokinetic variability and monitor drug-drug interactions to further refine personalized dosing strategies and enhance precision medicine treatments for patients with CF.

Resolution of portal hypertension in a patient with cystic fibrosis after treatment with CFTR modulator: A case report

Portal hypertension (pH) secondary to cystic fibrosis liver disease (CFLD) is the fourth most common cause for mortality (after respiratory/cardiorespiratory, transplant-related, and cancer-related) in adults with cystic fibrosis (CF) and more often occurs in the absence of cirrhosis (i.e. non-cirrhotic pH, NCPH). Here, we describe a patient with NCPH secondary to CFLD, with resolution of pH after starting a cystic fibrosis transmembrane conductance regulator (CFTR) modulator. As demonstrated in this patient, CFTR modulators may provide extra-pulmonary benefits including reversal of NCPH. Long-term use of CFTR modulators could potentially result in reductions in mortality from pH and need for future liver or combined lung-liver transplantation in patients with CFLD.

Serum Trypsin Is a Reliable Biomarker of Pancreas Function

ABSTRACT

Pancreatic diseases pose significant diagnostic and therapeutic challenges necessitating robust biomarkers for accurate diagnosis, management, and monitoring of pancreas function.Pancreas function can be measured with direct (invasive) and indirect tests. However, neither approach allows for continuous disease monitoring to identify disease progression or therapeutic response. We demonstrate literature evidence suggesting that trypsin, an important pancreatic digestive enzyme, holds promise as a continuous biomarker. On one hand, assessment of trypsin concentration in the serum sensitively and specifically detects pancreas inflammation; whereas on the other hand, declining trypsin levels in serum show good correlation with direct pancreatic function tests to identify exocrine pancreatic insufficiency. With this comprehensive review, we aimed to evaluate the existing evidence on the utility of trypsin as a continuous biomarker, spanning from acute to chronic pancreatitis and pancreas function, highlighting its potential in monitoring disease evolution on an individual patient level.

Challenges to Optimizing Nutrition in Children With Cystic Fibrosis

PURPOSE OF REVIEW

Cystic fibrosis is a chronic condition that has significant effects on the nutritional status of pediatric patients. Malnutrition is frequently encountered in this population and has been shown to contribute to poor pulmonary and overall disease outcomes. This article will provide an overview of the physiologic and psychosocial challenges toward attaining optimal nutrition in pediatric cystic fibrosis patients.

RECENT FINDINGS

Newer therapies such as CFTR modulators have played significant roles in improving the nutritional status of patients with cystic fibrosis. There is also a greater focus on becoming more aware of psychosocial and cultural barriers in the care of cystic fibrosis patients. Many challenges exist in optimizing nutritional support including but not limited to the patient's clinical manifestations and disease severity, caregiver ability, and access to care. Both gastrointestinal and non-gastrointestinal disorders lead to insufficient caloric intake, increased loss and metabolic needs, and micronutrient and macronutrient deficiency. Social factors including stressful patient and caregiver relationships and altered body image also contribute to poor nutritional status.

Cystic Fibrosis Treatment Landscape: Progress, Challenges, and Future Directions

Cystic fibrosis (CF) is a monogenic autosomal recessive disorder that primarily affects the respiratory and gastrointestinal systems. It results from variants in the CFTR gene, leading to dysfunctional chloride channels, thickened mucus secretion, and subsequent multisystem complications. Significant advances have been made in CF treatment, particularly with the development of CFTR modulators, which are unique to genotypes and have improved clinical outcomes in many people with CF. However, the benefits of these therapies are not universal, with a considerable portion of the CF population-especially those with rare mutations-still without access to effective treatment options. This review provides a comprehensive overview of the pathophysiology and genetic basis of CF, explores current and emerging treatments, and discusses the ongoing challenges in the field.

Unraveling the Mechanism of Action, Binding Sites, and Therapeutic Advances of CFTR Modulators: A Narrative Review

Cystic fibrosis (CF) is a recessive genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride and bicarbonate channel localized on the plasma membrane of epithelial cells. Over the last three decades, high-throughput screening assays have been extensively employed in identifying drugs that target specific defects arising from CFTR mutations. The two main categories of such compounds are potentiators, which enhance CFTR gating by increasing the channel's open probability, and correctors, which improve CFTR protein folding and trafficking to the plasma membrane. In addition to these, other investigational molecules include amplifiers and stabilizers, which enhance the levels and the stability of CFTR on the cell surface, and read-through agents that promote the insertion of correct amino acids at premature termination codons. Currently, four CFTR modulators are clinically approved: the potentiator ivacaftor (VX-770), either as monotherapy or in combination with the correctors lumacaftor (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). Among these, the triple combination VX-445/VX-661/VX-770 (marketed as Trikafta® in the US and Kaftrio® in Europe) has emerged as the most effective CFTR modulator therapy to date, demonstrating significant clinical benefits in phase III trials for patients with at least one F508del CFTR allele. Despite these advancements, the mechanisms of action and binding sites of these modulators on CFTR have only recently begun to be elucidated. A deeper understanding of these mechanisms could provide essential insights for developing more potent and effective modulators, particularly in combination therapies. This narrative review delves into the mechanism of action, binding sites, and combinatorial effects of approved and investigational CFTR modulators, highlighting ongoing efforts to broaden therapeutic options for individuals with CF.

A review of proton pump inhibitor use in cystic fibrosis and considerations for deprescribing

Use of proton-pump inhibitors (PPIs) is common among people with cystic fibrosis (pwCF) both for the management of suspected GERD, as well as pancreatic enzyme replacement therapy augmentation. Despite their use, limited data exist to demonstrate a clinically significant impact of PPIs on key endpoints in pwCF. Furthermore, the advent of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy may modify the need for use. These notions, coupled with the potential for adverse outcomes associated with long-term PPI use in pwCF, should facilitate re-evaluation of long-term PPI use in pwCF and promote potential deprescribing. Despite limited data on PPI deprescribing in pwCF, it intuitively mirrors the existing guidance in adults in the general population, but with added consideration given to tapering strategy, and monitoring for CF-specific outcomes such as nutritional and respiratory status. The development of a monitoring and re-initiation plan is key to reducing deprescribing inertia. This review aims to summarize the evidence that details the concern for long-term use of PPIs and provide CF clinicians with rationale and guidance on how to approach deprescribing in their practice.

Allergic Bronchopulmonary Aspergillosis (ABPA) in the Era of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Modulators

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity disease caused by Aspergillus fumigatus (Af), prevalent in persons with cystic fibrosis (CF) or asthma. In ABPA, Af proteases drive a T-helper cell-2 (Th2)-mediated allergic immune response leading to inflammation that contributes to permanent lung damage. Corticosteroids and antifungals are the mainstays of therapies for ABPA. However, their long-term use has negative sequelae. The treatment of patients with CF (pwCF) has been revolutionized by the efficacy of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy. Pharmacological improvement in CFTR function with highly effective elexacaftor/tezacaftor/ivacaftor (ETI) provides unprecedented improvements in lung function and other clinical outcomes of pwCF. The mechanism behind the improvement in patient outcomes is a continued topic of investigation as our understanding of the role of CFTR function evolves. As ETI therapy gains traction in CF management, understanding its potential impact on ABPA, especially on the allergic immune response pathways and Af infection becomes increasingly crucial for optimizing patient outcomes. This literature review aims to examine the extent of these findings and expand our understanding of the already published research focusing on the intersection between ABPA therapeutic approaches in CF and the rapid impact of the evolving CFTR modulator landscape. While our literature search yielded limited reports specifically focusing on the role of CFTR modulator therapy on CF-ABPA, findings from epidemiologic and retrospective studies suggest the potential for CFTR modulator therapies to positively influence pulmonary outcomes by addressing the underlying pathophysiology of CF-ABPA, especially by decreasing inflammatory response and Af colonization. Thus, this review highlights the promising scope of CFTR modulator therapy in decreasing the overall prevalence and incidence of CF-ABPA.

Impact of age at ivacaftor initiation on pulmonary outcomes among people with cystic fibrosis

BACKGROUND

Ivacaftor (IVA) improves lung function and other extrapulmonary outcomes in people with cystic fibrosis (CF). However, the effect of initiating IVA at earlier versus later ages has not been studied.

METHODS

We conducted an observational cohort study of people in the US CF Foundation Patient Registry aged ≥6 years with ≥1 CF transmembrane conductance regulator-gating mutation to compare the effects of initiating IVA at earlier ages on per cent predicted forced expiratory volume in 1 s (ppFEV1) and pulmonary exacerbation (PEx) outcomes. People with CF were grouped by age at IVA initiation (ages 6-10, 11-15, 16-20 and 21-25 years) to perform three analyses of younger versus older IVA initiation (6-10 vs 11-15, 11-15 vs 16-20 and 16-20 vs 21-25 years). For each analysis, baseline characteristics assessed over 1-year periods at the same age prior to IVA initiation were balanced by standardised mortality/morbidity ratio (SMR) weighting. For each analysis, outcomes were compared over a 5-year outcome assessment period when both groups were in the same age range and receiving IVA.

FINDINGS

Baseline characteristics were well balanced between younger and older IVA initiator groups after SMR weighting. In the outcome assessment period, younger IVA initiators had significantly higher mean ppFEV1 than older initiators across all comparisons, and those initiating IVA between ages 6-10 and 11-15 years had significantly lower PEx rates.

INTERPRETATION

Study findings showed the importance of early IVA initiation in people with CF.

Nutritional status in the era of highly effective CFTR modulators

Advances in cystic fibrosis (CF) diagnostics and therapeutics have led to improved health and longevity, including increased body weight and decreased malnutrition in people with CF. Highly effective CFTR modulator therapies (HEMT) are associated with increased weight through a variety of mechanisms, accelerating trends of overweight and obesity in the CF population. Higher body mass index (BMI) is associated with improved pulmonary function in CF, yet the incremental improvement at overweight and obese BMIs is not clear. Improvements in pulmonary health with increasing BMI are largely driven by increases in fat-free mass (FFM), and impact of HEMT on FFM is uncertain. While trends toward higher weight and BMI are generally seen as favorable in CF, the increased prevalence of overweight and obesity has raised concern for potential risk of traditional age- and obesity-related comorbidities. Such comorbidities, including impaired glucose tolerance, hypertension, cardiac disease, hyperlipidemia, fatty liver, colon cancer, and obstructive sleep apnea, may occur on top of pre-existing CF-related comorbidities. CF nutrition recommendations are evolving in the post-modulator era to more individualized approaches, in contrast to prior blanket high-fat, high-calorie prescriptions for all. Ultimately, it will be essential to redefine goals for optimal weight and nutritional status to allow for holistic health and aging in people with CF.

Advances in Care and Outcomes for Children with Cystic Fibrosis

The landscape of care for children with cystic fibrosis (CF), a genetic disorder of chloride transport with multisystem manifestations including inspissated mucus, recurrent sinopulmonary infections, obstructive lung disease, and exocrine pancreatic insufficiency, is rapidly changing. Early diagnosis via newborn screening enabling timely nutritional support, chronic therapies to improve mucociliary clearance, and prompt treatment of pulmonary infections have improved overall outcomes in children with CF. More widespread availability of novel cystic fibrosis transmembrane conductance regulator modulator therapies for children continues to revolutionize pediatric CF care.However, significant challenges exist to optimize care and outcomes for all children with CF.

Cystic fibrosis

Cystic fibrosis is a rare genetic disease caused by mutations in CFTR, the gene encoding cystic fibrosis transmembrane conductance regulator (CFTR). The discovery of CFTR in 1989 has enabled the unravelling of disease mechanisms and, more recently, the development of CFTR-directed therapeutics that target the underlying molecular defect. The CFTR protein functions as an ion channel that is crucial for correct ion and fluid transport across epithelial cells lining the airways and other organs. Consequently, CFTR dysfunction causes a complex multi-organ disease but, to date, most of the morbidity and mortality in people with cystic fibrosis is due to muco-obstructive lung disease. Cystic fibrosis care has long been limited to treating symptoms using nutritional support, airway clearance techniques and antibiotics to suppress airway infection. The widespread implementation of newborn screening for cystic fibrosis and the introduction of a highly effective triple combination CFTR modulator therapy that has unprecedented clinical benefits in up to 90% of genetically eligible people with cystic fibrosis has fundamentally changed the therapeutic landscape and improved prognosis. However, people with cystic fibrosis who are not eligible based on their CFTR genotype or who live in countries where they do not have access to this breakthrough therapy remain with a high unmet medical need.

Cystic fibrosis hepatobiliary involvement: an update on imaging in diagnosis and monitoring

Analysis of the liver using imaging for persons with cystic fibrosis (CF) continues to evolve as new medical therapies are developed improving and extending life. In the 2010s, therapies targeted at modulating protein folding became available to those with CF. Therapeutic options have continued to expand, now providing both correction of protein folding and stabilization for most gene mutations that code for the CF transmembrane receptor protein (CFTR). Today, approximately 80% of persons with CF are eligible for highly effective modulator therapy. With these advancements, the impact of CF on the liver has become more complex, adding metabolism of CFTR modulators to intrinsic CF hepatobiliary involvement (CFHBI) and adding not previously appreciated vascular changes within the liver due to increased longevity in persons with CF. A combination of serum biomarkers and imaging is needed to add clarity to the diagnosis and monitoring of the severity of liver disease. A substantial portion of persons with CF will develop at least CFHBI and a subset will develop advanced cystic fibrosis-associated liver disease (aCFLD); therefore, diagnosis and monitoring need to begin in childhood. In this review, we cover the use of and need for imaging, including elastography, ultrasound, and magnetic resonance imaging (MRI), in diagnosing and monitoring CFHBI and its associated complications.

Cystic fibrosis patient characteristics and healthcare resource utilization in Finland using linked registries

Background

Knowledge of prevalence and epidemiology of cystic fibrosis (CF) and healthcare resource use among Finnish people with CF is incomplete.

Methods

We conducted a population-based matched cohort study using retrospective real-world data from linked Finnish national registries. Electronic healthcare data and drug purchases of 102 people with CF were analyzed between January 2015 and December 2019 (follow-up). A 5-fold control population was matched by sex, age, and place of residence. Comorbidities and medication use that occurred at any time during follow-up were assessed; annual rates of hospital service use were adjusted for follow-up.

Results

The prevalence of CF in Finland was 1.85 per 100,000. Median age at diagnosis was 1 year, with 60 % diagnosed at age <2 years and 80 % at age <10 years. Median age at death in people with CF was 31.4 years (n < 5); no controls died. The most common comorbidities included chronic sinusitis (39.2 %), pneumonia (38.2 %), diabetes (20.6 %), and nasal polyps (18.6 %). The most purchased medications were antibiotics (99.0 %) and pancreatic enzymes (84.3 %). The annualized rate of hospital visits was higher in people with CF vs controls (outpatient: mean [SD], 17.4 [14.5] vs 0.9 [3.3]; median, 13.6 vs 0.4, respectively; inpatient: mean [SD], 1.0 [1.66] vs 0.03 [0.14]; median, 0.34 vs 0, respectively).

Conclusions

The prevalence of CF in Finland is remarkably low, likely reflecting unique population characteristics and, in part, delayed diagnosis. Antibiotic use is frequent among Finnish people with CF. Inpatient hospital visits are >30 times higher in people with CF than matched controls.

New drugs, new challenges in cystic fibrosis care

Cystic fibrosis (CF) is a genetic disease caused by variants in the gene encoding for the CF transmembrane conductance regulator (CFTR) protein, a chloride and bicarbonate channel. CFTR dysfunction results in a multiorgan disease with the main clinical features being exocrine pancreatic insufficiency and diffuse bronchiectasis with chronic airway infection leading to respiratory failure and premature death. Over the past decades, major progress has been made by implementing multidisciplinary care, including nutritional support, airway clearance techniques and antibiotics in specialised CF centres. The past decade has further seen the progressive development of oral medications, called CFTR modulators, for which around 80% of people with CF are genetically eligible in Europe. CFTR modulators partially restore ion transport and lead to a rapid and major improvement in clinical manifestations and lung function, presumably resulting in longer survival. CFTR modulators have been game-changing in the care of people with CF. However, many questions remain unanswered, such as the long-term effects of CFTR modulators, especially when treatment is started very early in life, or the new CF-related disease emerging due to CFTR modulators. Moreover, severe complications of CF, such as diabetes or cirrhosis, are not reversed on CFTR modulators and around 20% of people with CF bear CFTR variants leading to a CFTR protein that is unresponsive to CFTR modulators. Challenges also arise in adapting CF care to a changing disease. In this review article, we highlight the new questions and challenges emerging from this revolution in CF care.

Improved early growth in Danish children with cystic fibrosis from 2000-2022

BACKGROUND

Improved growth in children with CF may have resulted from advances in treatment for cystic fibrosis (CF) over the past two decades, including the implementation of newborn screening in Denmark in 2016. This observational cohort study focuses on changes in early growth in Danish children with CF born between 2000 and January 2022.

METHODS

Age, length/height, and weight data of children 0-5 years old were obtained from the Danish CF Cohort. Data were stratified to four birth cohorts born between 2000 and 2022. Weight-for-age (WAZ), length-for-age (LAZ), height-for-age (HAZ) and body-mass-index (BMZ) z-scores were computed using WHO growth curves. Cubic spline mixed effects models were used to evaluate growth over 5 years between birth cohorts.

RESULTS

We included 255 children in the analyses. Cubic spline mixed effects models show that catch-up growth improved in birth cohorts over time, with the 2016-2022 birth cohort achieving growth reference curve values in WAZ, LAZ/HAZ and BMZ the earliest. The proportion of underweight and stunting observations among children born 2000-2004 decreased by the 2016-2022 birth cohort, while the proportion of overweight, low BMZ and high BMZ observations increased.

CONCLUSION

Advances in care for young children with CF have led to improvements in growth - with the 2016-2022 birth cohort approaching potential for overweight. Nonetheless, low BMZ remains. Immediate, individualized nutrition care throughout early childhood remain crucial in mitigating malnutrition.

Current and future therapeutic approaches of CFTR and airway dysbiosis in an era of personalized medicine

Cystic fibrosis (CF) is a life-threatening genetic disorder caused by mutations in the CFTR gene. This leads to a defective protein that impairs chloride transport, resulting in thick mucus buildup and chronic inflammation in the airways. The review discusses current and future therapeutic approaches for CFTR dysfunction and airway dysbiosis in the era of personalized medicine. Personalized medicine has revolutionized CF treatment with the advent of CFTR modulator therapies that target specific genetic mutations. These therapies have significantly improved patient outcomes, slowing disease progression, and enhancing quality of life. It also highlights the growing recognition of the airway microbiome's role in CF pathogenesis and discusses strategies to modulate the microbiome to further improve patient outcomes. This review discusses various therapeutic approaches for cystic fibrosis (CFTR) mutations, including adenovirus gene treatments, nonviral vectors, CRISPR/cas9 methods, RNA replacement, antisense-oligonucleotide-mediated DNA-based therapies, and cell-based therapies. It also introduces airway dysbiosis with CF and how microbes influence the lungs. The review highlights the importance of understanding the cellular and molecular causes of CF and the development of personalized medicine to improve quality of life and health outcomes.

Evolution of nutritional management in children with cystic fibrosis - a narrative review

Nutrition has played a central role in the management and outcomes of people with cystic fibrosis (pwCF) since the 1970s. Advances in therapies and practices in recent decades have led to a significant change in the patient landscape with dramatic improvements in life expectancy, as well as quality of life, bringing with it new issues. Historically, cystic fibrosis was a condition associated with childhood and malnutrition; however, changes in patient demographics, nutritional assessment and fundamental nutritional management have evolved, and it has become an increasingly prevalent adult disease with new nutritional challenges, including obesity. This paper aims to describe these changes and the impact and challenges they bring for those working in this field. Nutritional professionals will need to evolve, adapt and remain agile to the wider range of situations and support required for a new generation of pwCF. Specialised nutrition support will continue to be required, and it will be additionally important to improve and optimise quality of life and long-term health.

SHIFTing goals in cystic fibrosis-managing extrapulmonary disease in the era of CFTR modulator therapy; Proceedings of the International Shaping Initiatives and Future Trends (SHIFT) Symposium

BACKGROUND

Cystic fibrosis (CF) is a life-shortening multisystem genetic disease. Although progressive pulmonary disease is the predominant cause of morbidity and mortality, improvements in treatment for CF-related lung disease, with associated increase in longevity, have increased the prevalence of extrapulmonary manifestations1.

METHODS

To discuss these issues, a multidisciplinary meeting of international leaders and experts in the field was convened in November 2021 at the Shaping Initiatives and Future Trends  Symposium with the goal of highlighting shifting management paradigms in CF. The main topics covered were: (1) nutrition and obesity, (2) exocrine pancreas, (3) CF-related diabetes, (4) CF liver disease, (5) CF-related bone disease, and (6) post-lung transplant care. This document summarizes the proceedings, highlighting the key priorities and important research questions that were discussed.

RESULTS

Improved life expectancy, the advent of cystic fibrosis transmembrane conductance regulator modulators, and the increasing appreciation of the heterogeneity or spectrum of disease are leading to a shift in management for patients with cystic fibrosis. Care should be individualized to ensure that increased longevity is accompanied by improved extra-pulmonary care and reduced morbidity.

Levelling the playing field through the London Network of the UK clinical trials accelerator platform

Cystic fibrosis (CF) is a multisystem, genetic disease with a significantly reduced life expectancy. Despite substantial progress in therapies in the last 10-15 years, there is still no cure. There are dozens of drugs in the development pipeline and multiple clinical trials are being conducted across the globe. The UK Cystic Fibrosis Trust's (CFT) Clinical Trials Accelerator Platform (CTAP) is a national initiative bringing together 25 UK based CF centres to support the CF community in accessing and participating in CF clinical trials. CTAP enables more CF centres to run a broader portfolio of trials and increases the range of CF studies available for UK patients. There are four large specialist CF centres based in London, all within a small geographical region as well as two smaller centres which deliver CF care. At the launch of CTAP, these centres formed a sub-network in a consortium-style collaboration. The purpose of the network was to ensure equity of access to trials for patients across the UK's capital, and to share experience and knowledge. Four years into the programme we have reviewed our practices through working group meetings and an online survey. We sought to identify strengths and areas for improvement. We share our findings here, as we believe they are relevant to others delivering research in regions outside of London and in other chronic diseases.

Cystic fibrosis management in pediatric population-from clinical features to personalized therapy

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). In 1949, it's been identified as a monogenic disease and was thought to primarily affect individuals of Northern European descent. It was the most prevalent autosomal recessive disease that shortens life. With the availability of multiple testing methodologies nowadays, there is a chance to create novel and enhanced treatment options. Even in the absence of a high sweat chloride test (SCT) result, the discovery of two causal mutations is diagnostic for cystic fibrosis (CF). For a CF diagnosis, however, at least two positive E sweat chloride tests are still required. In order to achieve early and active intervention to manage cystic fibrosis (CF) and its comorbidities, treatment regimens for pediatric patients should be evaluated, improved, and closely monitored. New developments in the treatment of cystic fibrosis (CF) have led to the development of medications derived from molecules that target the pathogenetic pathway of the illness. These options are very efficient and allow pediatric patients to receive individualized care. However, in order to better direct patient care and enhance patient outcomes, it is crucial to research uncommon CF mutations, which can provide crucial information about the prognosis of the disease and the relationships between genotype and phenotype. To ensure the success of creating novel, safer, and more efficient treatment approaches, a deeper understanding of the pathogeny of the illness is required. In the age of customized medicine, genetic research will be essential to improving patient care and quality of life for those with uncommon mutations.

Safety and efficacy of ivacaftor in infants aged 1 to less than 4 months with cystic fibrosis

BACKGROUND

Ivacaftor (IVA) has been shown to be safe and efficacious in children aged ≥4 months with cystic fibrosis (CF) and CFTR gating variants. We evaluated safety, pharmacokinetics (PK), and efficacy of IVA in a small cohort of infants aged 1 to <4 months with CF.

METHODS

In this phase 3, open-label study, infants 1 to <4 months with CF and an IVA-responsive CFTR variant received an initial low dose of IVA based on age and weight. Because IVA is a sensitive CYP3A substrate and CYP3A maturation is uncertain in infants, doses were adjusted at day 15 to better match median adult exposures based on individual PK measurements taken on day 4. Primary endpoints were safety and PK measurements.

RESULTS

Seven infants (residual function CFTR variants [n=5]; minimal function CFTR variants [n=2]) received ≥1 dose of IVA. Six infants had doses adjusted at day 15 and one infant did not require dose adjustment; subsequent PK analyses showed mean trough concentrations for IVA and metabolites were within range of prior clinical experience. Four infants (57.1%) had adverse events (AEs); no serious AEs were noted. One infant discontinued study drug due to a non-serious AE of elevated alanine aminotransferase >8x the upper limit of normal. Mean sweat chloride concentration decreased (-40.3 mmol/L [SD: 29.2]) through week 24. Improvements in biomarkers of pancreatic function and intestinal inflammation, as well as growth parameters, were observed.

CONCLUSIONS

In this small, open-label study, IVA dosing in infants achieved exposures previously shown to be safe and efficacious. Because PK was predictable, a dosing regimen based on age and weight is proposed. IVA was generally safe and well tolerated, and led to improvements in CFTR function, markers of pancreatic function and intestinal inflammation, and growth parameters, supporting use in infants as young as 1 month of age.

CFTR function is impaired in a subset of patients with pancreatitis carrying rare CFTR variants

BACKGROUND

Many affected by pancreatitis harbor rare variants of the cystic fibrosis (CF) gene, CFTR, which encodes an epithelial chloride/bicarbonate channel. We investigated CFTR function and the effect of CFTR modulator drugs in pancreatitis patients carrying CFTR variants.

METHODS

Next-generation sequencing was performed to identify CFTR variants. Sweat tests and nasal potential difference (NPD) assays were performed to assess CFTR function in vivo. Intestinal current measurement (ICM) was performed on rectal biopsies. Patient-derived intestinal epithelial monolayers were used to evaluate chloride and bicarbonate transport and the effects of a CFTR modulator combination: elexacaftor, tezacaftor and ivacaftor (ETI).

RESULTS

Of 32 pancreatitis patients carrying CFTR variants, three had CF-causing mutations on both alleles and yielded CF-typical sweat test, NPD and ICM results. Fourteen subjects showed a more modest elevation in sweat chloride levels, including three that were provisionally diagnosed with CF. ICM indicated impaired CFTR function in nine out of 17 non-CF subjects tested. This group of nine included five carrying a wild type CFTR allele. In epithelial monolayers, a reduction in CFTR-dependent chloride transport was found in six out of 14 subjects tested, whereas bicarbonate secretion was reduced in only one individual. In epithelial monolayers of four of these six subjects, ETI improved CFTR function.

CONCLUSIONS

CFTR function is impaired in a subset of pancreatitis patients carrying CFTR variants. Mutations outside the CFTR locus may contribute to the anion transport defect. Bioassays on patient-derived intestinal tissue and organoids can be used to detect such defects and to assess the effect of CFTR modulators.

Reduction in abdominal symptoms (CFAbd-Score), faecal M2-pyruvate-kinase and Calprotectin over one year of treatment with Elexacaftor-Tezacaftor-Ivacaftor in people with CF aged ≥12 years - The RECOVER study

BACKGROUND

RECOVER is a multicentre post-approval study of Elexacaftor/Tezacaftor/Ivacaftor (ETI) in pwCF in Ireland and the UK. The CFAbd-Score is the first validated CF-specific patient reported outcome measure (PROM) focusing on gastrointestinal symptoms; it comprises 28 items in 5 domains. In a preliminary study, we previously reported reductions in abdominal symptoms (AS) in pwCF after 26 weeks of ETI-therapy using the CFAbd-Score.

AIM

to assess changes in AS in a second, large cohort and explore novel GI-biomarkers of gut inflammation and cell-proliferation in pwCF over one year of ETI-therapy.

METHODS

Participants were recruited as part of the RECOVER study at 8 sites (Ireland&UK). The CFAbd-Score was administered prior to ETI-initiation, and subsequently at 1,2,6 and 12 months on treatment. Faecal M2-pyruvate kinase (M2-PK) and calprotectin (FC) were quantified in samples collected at baseline, 1 and 6 months.

RESULTS

108 CFAbd-Scores and 73 stool samples were collected at baseline. After 12 months of ETI-therapy, total CFAbd-Scores had significantly declined (15.0±1.4→9.8±1.2pts/p<0.001), and so had all its five domains of "pain" (16.9±2.0pts→9.9±1.8pts/p<0.01), "GERD" (14.4±1.8→9.9±1.6/p<0.05), "disorders of bowel movements" (19.2±1.4→14.1±1.5/p<0.01), "appetite" (7.0±1.1→4.6±1.2/p<0.01) and "impaired-QoL" (13.3±1.9→7.5±1.5/p<0.001). Levels of M2-PK and FC significantly decreased during ETI-therapy.

DISCUSSION

In-depth analysis of AS with the CFAbd-Score reveals a statistically significant, clinically relevant and sustained improvement with ETI. We attribute this to high sensitivity of the implemented CF-specific PROM, developed and validated following FDA-guidelines. Furthermore, for the first time during ETI-therapy a significant decline in faecal M2-PK, a marker of inflammation and cell-proliferation, was found, in parallel to FC.

Improved Nutritional Outcomes and Gastrointestinal Symptoms in Adult Cystic Fibrosis Patients Treated with Elexacaftor/Tezacaftor/Ivacaftor

INTRODUCTION

Cystic fibrosis transmembrane conductance regulator modulator therapy improves nutritional status and quality of life. Clinical trials have shown pancreatic insufficiency conversion, mostly in pediatric patients treated with ivacaftor. Studies with elexacaftor/tezacaftor/ivacaftor (ETI) in older patients have not suggested restoration of exocrine pancreas function, but quality data in adults are lacking. Our aim was to show the effect of ETI in adults with cystic fibrosis (CF) on nutritional status and digestive function. We hypothesized improvement of nutritional parameters and gastrointestinal symptoms, reduction of pancreatic enzyme replacement therapy, but uncertain improvement in exocrine pancreatic function.

METHODS

We prospectively enrolled adults with CF treated with ETI from August 2021 to June 2022. We measured anthropometric parameters, laboratory nutritional markers, change of fecal elastase, pancreatic enzymes replacement therapy needs, and gastrointestinal symptoms.

RESULTS

In the cohort of 29 patients (mean age 29.1 years), 82.8% suffered exocrine pancreatic insufficiency. After ETI, mean BMI increased by 1.20 kg/m2 (p < 0.001), mean body weight by 3.51 kg (p < 0.001), albumin by 2.81 g/L, and prealbumin by 0.06 (both p < 0.001). Only 1 patient, initially pancreatic insufficient (4.5%, p < 0.001), developed pancreatic sufficiency, indicated by increased fecal elastase from 45 μg/g to 442.1 μg/g. Mean change in lipase substitution decreased by 1,969 units/kg/day (p < 0.001) and stools frequency by 1.18 per day (p < 0.001).

CONCLUSION

Our data suggest increased nutritional parameters, lower pancreatic substitution requirements, and improved defecation in adult CF patients on ETI. Improvement in exocrine pancreatic function might be mutation-specific and needs further study.

Diagnosing Cystic Fibrosis in the 21st Century-A Complex and Challenging Task

Cystic fibrosis (CF) is a chronic and potentially life-threatening condition, wherein timely diagnosis assumes paramount significance for the prompt initiation of therapeutic interventions, thereby ameliorating pulmonary function, addressing nutritional deficits, averting complications, mitigating morbidity, and ultimately enhancing the quality of life and extending longevity. This review aims to amalgamate existing knowledge to provide a comprehensive appraisal of contemporary diagnostic modalities pertinent to CF in the 21st century. Deliberations encompass discrete delineations of each diagnostic modality and the elucidation of potential diagnostic quandaries encountered in select instances, as well as the delineation of genotype-phenotype correlations germane to genetic counseling endeavors. The synthesis underscores that, notwithstanding the availability and strides in diagnostic methodologies, including genetic assays, the sweat test (ST) retains its position as the preeminent diagnostic standard for CF, serving as a robust surrogate for CFTR functionality. Prospective clinical investigations in the realm of CF should be orchestrated with the objective of discerning novel diagnostic modalities endowed with heightened specificity and sensitivity.

Cystic fibrosis and fat malabsorption: Pathophysiology of the cystic fibrosis gastrointestinal tract and the impact of highly effective CFTR modulator therapy

Cystic fibrosis (CF) is a progressive, genetic, multi-organ disease affecting the respiratory, digestive, endocrine, and reproductive systems. CF can affect any aspect of the gastrointestinal (GI) tract, including the esophagus, stomach, small intestine, colon, pancreas, liver, and gall bladder. GI pathophysiology associated with CF results from CF membrane conductance regulator (CFTR) dysfunction. The majority of people with CF (pwCF) experience exocrine pancreatic insufficiency resulting in malabsorption of nutrients and malnutrition. Additionally, other factors can cause or worsen fat malabsorption, including the potential for short gut syndrome with a history of meconium ileus, hepatobiliary diseases, and disrupted intraluminal factors, such as inadequate bile salts, abnormal pH, intestinal microbiome changes, and small intestinal bacterial overgrowth. Signs and symptoms associated with fat malabsorption, such as abdominal pain, bloating, malodorous flatus, gastroesophageal reflux, nausea, anorexia, steatorrhea, constipation, and distal intestinal obstruction syndrome, are seen in pwCF despite the use of pancreatic enzyme replacement therapy. Given the association of poor nutrition status with lung function decline and increased mortality, aggressive nutrition support is essential in CF care to optimize growth in children and to achieve and maintain a healthy body mass index in adults. The introduction of highly effective CFTR modulator therapy and other advances in CF care have profoundly changed the course of CF management. However, GI symptoms in some pwCF may persist. The use of current knowledge of the pathophysiology of the CF GI tract as well as appropriate, individualized management of GI symptoms continue to be integral components of care for pwCF.

A randomised crossover trial of tezacaftor-ivacaftor for gut dysfunction in cystic fibrosis with magnetic resonance imaging (MRI) outcomes: a pilot study

Background

People with cystic fibrosis (CF) can experience recurrent chest infections, pancreatic exocrine insufficiency and gastrointestinal symptoms. New cystic fibrosis transmembrane conductance regulator (CFTR) modulator drugs improve lung function but gastrointestinal effects are unclear. We aimed to see if a CFTR modulator (tezacaftor-ivacaftor,TEZ/IVA) improves gastrointestinal outcomes in CF.

Methods

We conducted a randomised, double-blind, placebo-controlled, two-period crossover trial (2019-2020) at Nottingham University Hospitals. The effects of TEZ/IVA on gut physiology were measured using MRI. Participants were randomly assigned to treatment sequences AB or BA (A:TEZ/IVA, B:placebo, each 28 days), with a 28-day washout period. Participants had serial MRI scans at baseline and after 19-23 days of each treatment. Due to the COVID-19 pandemic, a protocol amendment allowed for observer-blind comparisons prior to and during TEZ/IVA. In such cases, participants were not blind to the treatment but researchers remained blind. The primary outcome was oro-caecal transit time (OCTT). Secondary outcomes included MRI metrics, symptoms and stool biomarkers.

Results

We randomised 13 participants. Before the COVID-19 pandemic 8 participants completed the full protocol and 1 dropped out. The remaining 4 participants followed the amended protocol. There were no significant differences between placebo and TEZ/IVA for OCTT (TEZ/IVA >360minutes [225,>360] vs. placebo 330minutes [285,>360], p=0.8) or secondary outcomes. There were no adverse events.

Conclusions

Our data contribute to a research gap in the extra-pulmonary effects of CFTR modulators. We found no effect after TEZ/IVA on MRI metrics of gut function, GI symptoms or stool calprotectin. Effects might be detectable with larger studies, longer treatment or more effective CFTR modulators.

ClinicalTrialsgov registration

NCT04006873 (02/07/2019).

Unmet challenges in cystic fibrosis treatment with modulators

INTRODUCTION

'Highly effective' modulator therapies (HEMTs) have radically changed the Cystic Fibrosis (CF) therapeutic landscape.

AREAS COVERED

A comprehensive search strategy was undertaken to assess impact of HEMT in life of pwCF, treatment challenges in specific populations such as very young children, and current knowledge gaps.

EXPERT OPINION

HEMTs are prescribed for pwCF with definite genotypes. The heterogeneity of variants complicates treatment possibilities and around 10% of pwCF worldwide remains ineligible. Genotype-specific treatments are prompting theratyping and personalized medicine strategies. Improvement in lung function and quality of life increase survival rates, shifting CF from a pediatric to an adult disease. This implies new studies addressing long-term efficacy, side effects, emergence of adult co-morbidities and possible drug-drug interactions. More sensitive and predictive biomarkers for both efficacy and toxicity are warranted. As HEMTs cross the placenta and are found in breast milk, studies addressing the potential consequences of treatment during pregnancy and breastfeeding are urgently needed. Finally, although the treatment and expected outcomes of CF have improved dramatically in high- and middle-income countries, lack of access in low-income countries to these life-changing medicines highlights inequity of care worldwide.

Small molecule modulators of cystic fibrosis transmembrane conductance regulator (CFTR): Structure, classification, and mechanisms

The advent of small molecule modulators targeting the cystic fibrosis transmembrane conductance regulator (CFTR) has revolutionized the treatment of persons with cystic fibrosis (CF) (pwCF). Presently, these small molecule CFTR modulators have gained approval for usage in approximately 90 % of adult pwCF. Ongoing drug development endeavors are focused on optimizing the therapeutic benefits while mitigating potential adverse effects associated with this treatment approach. Based on their mode of interaction with CFTR, these drugs can be classified into two distinct categories: specific CFTR modulators and non-specific CFTR modulators. Specific CFTR modulators encompass potentiators and correctors, whereas non-specific CFTR modulators encompass activators, proteostasis modulators, stabilizers, reader-through agents, and amplifiers. Currently, four small molecule modulators, all classified as potentiators and correctors, have obtained marketing approval. Furthermore, numerous novel small molecule modulators, exhibiting diverse mechanisms of action, are currently undergoing development. This review aims to explore the classification, mechanisms of action, molecular structures, developmental processes, and interrelationships among small molecule CFTR modulators.

ESPEN-ESPGHAN-ECFS guideline on nutrition care for cystic fibrosis

BACKGROUND

Nutritional status is paramount in Cystic Fibrosis (CF) and is directly correlated with morbidity and mortality. The first ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with CF were published in 2016. An update to these guidelines is presented.

METHODS

The study was developed by an international multidisciplinary working group in accordance with officially accepted standards. Literature since 2016 was reviewed, PICO questions were discussed and the GRADE system was utilized. Statements were discussed and submitted for on-line voting by the Working Group and by all ESPEN members.

RESULTS

The Working Group updated the nutritional guidelines including assessment and management at all ages. Supplementation of vitamins and pancreatic enzymes remains largely the same. There are expanded chapters on pregnancy, CF-related liver disease, and CF-related diabetes, bone disease, nutritional and mineral supplements, and probiotics. There are new chapters on nutrition with highly effective modulator therapies and nutrition after organ transplantation.

Pro-inflammatory cytokines stimulate CFTR-dependent anion secretion in pancreatic ductal epithelium

BACKGROUND

Loss of CFTR-dependent anion and fluid secretion in the ducts of the exocrine pancreas is thought to contribute to the development of pancreatitis, but little is known about the impact of inflammation on ductal CFTR function. Here we used adult stem cell-derived cell cultures (organoids) obtained from porcine pancreas to evaluate the effects of pro-inflammatory cytokines on CFTR function.

METHODS

Organoids were cultured from porcine pancreas and used to prepare ductal epithelial monolayers. Monolayers were characterized by immunocytochemistry. Epithelial bicarbonate and chloride secretion, and the effect of IL-1β, IL-6, IFN-γ, and TNF-α on CFTR function was assessed by electrophysiology.

RESULTS

Immunolocalization of ductal markers, including CFTR, keratin 7, and zonula occludens 1, demonstrated that organoid-derived cells formed a highly polarized epithelium. Stimulation by secretin or VIP triggered CFTR-dependent anion secretion across epithelial monolayers, whereas purinergic receptor stimulation by UTP, elicited CFTR-independent anion secretion. Most of the anion secretory response was attributable to bicarbonate transport. The combination of IL-1β, IL-6, IFN-γ, and TNF-α markedly enhanced CFTR expression and anion secretion across ductal epithelial monolayers, whereas these cytokines had little effect when tested separately. Although TNF-α triggered apoptotic signaling, epithelial barrier function was not significantly affected by cytokine exposure.

CONCLUSIONS

Pro-inflammatory cytokines enhance CFTR-dependent anion secretion across pancreatic ductal epithelium. We propose that up-regulation of CFTR in the early stages of the inflammatory response, may serve to promote the removal of pathogenic stimuli from the ductal tree, and limit tissue injury.

Diagnosis and Management of Gastrointestinal Manifestations in Children with Cystic Fibrosis

Cystic fibrosis (CF) is primarily known for its pulmonary consequences, which are extensively explored in the existing literature. However, it is noteworthy that individuals with CF commonly display gastrointestinal (G-I) manifestations due to the substantial presence of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in the intestinal tract. Recognized as pivotal nonpulmonary aspects of CF, G-I manifestations exhibit a diverse spectrum. Identifying and effectively managing these manifestations are crucial for sustaining health and influencing the overall quality of life for CF patients. This review aims to synthesize existing knowledge, providing a comprehensive overview of the G-I manifestations associated with CF. Each specific G-I manifestation, along with the diagnostic methodologies and therapeutic approaches, is delineated, encompassing the impact of innovative treatments targeting the fundamental effects of CF on the G-I tract. The findings underscore the imperative for prompt diagnosis and meticulous management of G-I manifestations, necessitating a multidisciplinary team approach for optimal care and enhancement of the quality of life for affected individuals. In conclusion, the authors emphasize the urgency for further clinical studies to establish a more robust evidence base for managing G-I symptoms within the context of this chronic disease. Such endeavors are deemed essential for advancing understanding and refining the clinical care of CF patients with G-I manifestations.

Standards for the care of people with cystic fibrosis; establishing and maintaining health

This is the second in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy.

A Cross-Sectional Study of Pediatric Feeding Disorder in Children with Cystic Fibrosis

BACKGROUND

The exact prevalence of feeding problems in children with cystic fibrosis (CF) is unknown. Pediatric feeding disorder (PFD) encompasses poor oral intake with associated medical, nutrition, psychosocial, or feeding skill dysfunction. We hypothesized that PFD is common in CF and aimed to categorize feeding dysfunction across various domains in children with CF.

METHODS

An observational cross-sectional study was conducted in children with CF. Data collected included anthropometrics, nutrition data (including need for tube feeding/enteral nutrition [EN] or high-energy beverages, dietary diversity), feeding skills (Pediatric version of the Eating Assessment tool [pEAT]), and psychosocial function (About Your Child's Eating questionnaire [AYCE] in children 2-17 years of age/Behavioral Pediatric Feeding Assessment Scale [BPFAS] in children 12-23 months of age). PFD was defined as poor oral intake with: (a) pEAT score > 5; and/or (b) AYCE or BPFAS score > 2 standard deviation of normative controls; and/or (c) nutrition dysfunction (body mass index/weight-for-length z score < -1 and/or preference of oral high energy beverages or dependence on EN and/or decreased dietary diversity).

RESULTS

Of 103 children in the study, 62 (60.1%) had PFD, 7 children (6.8%) were malnourished, 10 needed EN (9.7%), and 30 (29.1%) needed oral high-energy beverages. Dietary diversity was decreased in 42 children (41.5%), 1 child had feeding skill dysfunction, and 11 (10.8%) met criteria for psychosocial dysfunction.

CONCLUSION

Almost 2/3rd of children with CF have PFD and many have poor dietary diversity. A significant percentage of children rely on EN and oral supplements, but psychosocial dysfunction is less prevalent.

Trials and tribulations of highly effective modulator therapies in cystic fibrosis

Highly effective modulator therapies (HEMTs) have revolutionised the management approach of most patients living with cystic fibrosis (CF) who have access to these therapies. Clinical trials have reported significant improvements across multiorgan systems, with patients surviving longer. However, there are accumulating case reports and observational data describing various adverse events following initiation of HEMTs including drug-to-drug interactions, drug induced liver injury, Stevens-Johnson syndrome, and neurocognitive symptoms including psychosis and depression, which have required discontinuation of therapy. Current clinical trials are assessing efficacy in younger patients with CF, yet long-term studies are also required to better understand the safety profile in the real-world setting across all ages and the impact of HEMT dose alteration or discontinuation.

[Cystic fibrosis: Epidemiology, clinical manifestations, diagnosis and treatment]

Cystic fibrosis is a genetic and multisystemic disease. The main comorbidity in adulthood is respiratory involvement, with the presence of bronchiectasis, chronic bronchial infection and airflow obstruction. Until a decade ago, treatments were aimed at favoring secretion drainage, reducing respiratory exacerbations, controlling chronic bronchial infection and slowing functional deterioration, but with the advent of cystic fibrosis transmembrane conductance regulator (CFTR) modulators, the cystic fibrosis paradigm has changed. This novel treatment goes a step further in the management of this disease, it is able to improve the production of defective CFTR protein and increase its expression on the cell surface, thus achieving a better functioning of ion exchange, fluidizing respiratory secretions and reducing airflow obstruction. In addition, there are currently different lines of research aimed at correcting the genetic defect that causes cystic fibrosis.

Improvement of lipid and lipoprotein profiles in children and adolescents with cystic fibrosis on CFTR modulator therapy

BACKGROUND

Association of a high-fat diet with increased risks of cardiovascular disease (CVD) and type 2 diabetes, has prompted evaluation of lipids in people with CF (pwCF). However, most evidence on dyslipidemia was published before CF transmembrane conductance regulator (CFTR) modulators became a standard of care. The main goal of this study was to investigate the effect of CFTR modulator therapies on lipid and lipoprotein profiles in children and adolescents with CF.

METHODS

Blood samples were collected from 153 pwCF (10.1 ± 4.7 years of age) and 60 age-matched controls. Most pwCF were pancreatic insufficient on pancreatic enzyme replacement therapy. By the end of the study, 65% of CF participants were on CFTR modulator therapy for >1 month. The results of traditional and advanced lipid testing in pwCF were correlated with clinical and dietary information.

RESULTS

Total cholesterol and low-density lipoprotein (LDL) cholesterol were significantly lower in pwCF compared to non-CF participants. Those not receiving CFTR modulators also had significantly lower high-density lipoprotein (HDL) cholesterol and HDL particle number than controls. Individuals with CF on modulator therapy had significantly higher concentrations of anti-atherogenic HDL cholesterol and HDL particles along with lower levels of atherogenic large very-low density lipoprotein (VLDL) particles, total and small LDL particles, and triglycerides compared to those without CFTR modulator therapy.

CONCLUSION

CFTR modulator therapy has a beneficial effect on dyslipidemia in CF. It remains to be seen if these positive changes translate into decreased CVD risk later in life given the increasing life expectancy in CF.

Update on Cystic Fibrosis in Pediatric Patients

PURPOSE OF REVIEW

Cystic fibrosis is an inherited, multisystem disease that affects the gastrointestinal system in numerous ways. This article reviews the nutritional, gastrointestinal, and hepatobiliary manifestations of cystic fibrosis with an emphasis on the effects of CFTR modulator therapy.

RECENT FINDINGS

The life expectancy of individuals with cystic fibrosis has increased substantially in recent years. CFTR modulator therapy improves pulmonary function and results in weight gain. An individualized approach to nutrition is encouraged. Pancreatic exocrine function may improve with intervention early in life. The use of non-invasive methods to screen for hepatobiliary involvement is recommended. Highly effective CFTR modulators lead to increased survival and improved quality of life for many individuals. Their effects on gastrointestinal symptoms and hepatobiliary disease are not fully understood. Patient-reported outcome measures and biomarkers are important clinical endpoints for studying the effects of modulators.

Chronic daily respiratory care needs in people with cystic fibrosis treated with highly effective cystic fibrosis transmembrane conductance regulator modulators

PURPOSE OF REVIEW

Cystic fibrosis is a genetic disease that increases risk of death from respiratory failure because of impairment in mucociliary clearance. Complex daily care regimens including medications and airway clearance techniques (ACTs) aim to preserve lung function and alleviate symptoms for people with cystic fibrosis (pwCF). The success of highly effective modulator therapy (HEMT) permits evaluation of treatment simplification. In this review, we evaluate adjustments made in daily respiratory care among pwCF taking HEMT and the feasibility of treatment simplification.

RECENT FINDINGS

Treatment simplification has been identified as a top priority among pwCF, with recent studies showing pwCF are willing to sacrifice mild to moderate amounts of lung function and longevity to reduce treatment burden. Retrospective studies have shown that patients taking HEMT with better baseline lung function have lower adherence to and prescription of inhaled medications. A randomized, controlled trial found that short-term discontinuation of dornase alfa or hypertonic saline was clinically noninferior to continuation of these medications. Major knowledge gaps remain about withdrawing ACTs.

SUMMARY

This review highlights trials evaluating the feasibility of treatment simplification among pwCF taking HEMT. More data is needed to evaluate approaches to simplification in this phenotypically diverse patient population.

Changes in fecal elastase-1 following initiation of CFTR modulator therapy in pediatric patients with cystic fibrosis

BACKGROUND

Improvement in exocrine pancreatic function in persons with CF (pwCF) on cystic fibrosis transmembrane conductance regulator (CFTR) modulators has been documented in clinical trials using fecal pancreatic elastase-1 (FE-1). Our group endeavored to evaluate real-world data on FE-1 in children on CFTR modulator therapy at three pediatric cystic fibrosis (CF) centers.

METHODS

Pediatric pwCF were offered FE-1 testing if they were on pancreatic enzyme replacement therapy (PERT) and on CFTR modulator therapy according to their center's guideline. FE-1 data were collected retrospectively. The primary outcome was absolute change in FE-1.

RESULTS

70 pwCF were included for analysis. 53 had baseline and post-modulator FE-1 values. There was a significant increase in FE-1 from median 25 mcg/g (IQR 25-60) at baseline to 57 mcg/g (IQR 20-228) post-modulator (p<0.001 by Wilcoxon matched pairs), with an absolute change in FE-1 of median 28 mcg/g (IQR -5-161) and mean 93.5 ± 146.8 mcg/g. Age was negatively correlated with change in FE-1 (Spearman r=-0.48, p<0.001). 15 pwCF (21%) had post-modulator FE-1 values ≥200 mcg/g, consistent with pancreatic sufficiency (PS). The PS group was significant for younger age at initiation of first CFTR modulator and a higher baseline FE-1.

CONCLUSIONS

Most pwCF experienced an increase in FE-1 while receiving CFTR modulator treatment and a small percentage demonstrated values reflective of PS. These data suggest that PS may be attained in those that initiated modulator therapy at a younger age or had a higher baseline FE-1. FE-1 testing is suggested for children on any CFTR modulator therapy.

The impact of elexacaftor/tezacaftor/ivacaftor on fat-soluble vitamin levels in people with cystic fibrosis

BACKGROUND

While elexacaftor/tezacaftor/ivacaftor (ETI) has improved the pulmonary health of many people with cystic fibrosis (PwCF), less is known about ETI effectiveness for extra-pulmonary manifestations, including fat-soluble vitamin malabsorption. This study aims to evaluate ETI's impact on vitamin A, D, E, and international normalized ratio (INR, an indirect marker for Vitamin K) serum levels.

METHODS

Retrospective cohort study of PwCF ≥12 years receiving ETI. Vitamin levels up to four years preceding and up to two years following ETI initiation were collected. Pairwise comparisons of vitamin levels pre/post-ETI initiation were made using Wilcoxon signed rank and McNemar's tests. Linear mixed effect models were used to regress vitamin levels on time since starting ETI, ETI use (yes/no), the interaction between time and ETI use, and age.

RESULTS

Two hundred and sixty-four participants met study inclusion, and 169 (64%) had post-ETI initiation vitamin levels. Median vitamin A levels increased from 422.0 to 471.0 mcg/L (p < 0.001), median vitamin D levels increased from 28.5 to 30.8 ng/mL (p = 0.003), and there were no significant changes in median vitamin E or INR. Vitamin A levels rose at a rate of 40.7 mcg/L/year (CI 11.3, 70.2) after ETI start.

CONCLUSIONS

ETI initiation is associated with increased median vitamin A and vitamin D levels, but no change in median vitamin E or INR levels. Ongoing monitoring of vitamin levels after ETI initiation is needed to screen for potential deficiencies and toxicities, particularly in light of case reports of hypervitaminosis A following ETI initiation.

Advancements in small molecule drug design: A structural perspective

In this review, we outline recent advancements in small molecule drug design from a structural perspective. We compare protein structure prediction methods and explore the role of the ligand binding pocket in structure-based drug design. We examine various structural features used to optimize drug candidates, including functional groups, stereochemistry, and molecular weight. Computational tools such as molecular docking and virtual screening are discussed for predicting and optimizing drug candidate structures. We present examples of drug candidates designed based on their molecular structure and discuss future directions in the field. By effectively integrating structural information with other valuable data sources, we can improve the drug discovery process, leading to the identification of novel therapeutics with improved efficacy, specificity, and safety profiles.

Nutritional management of people living with cystic fibrosis throughout life and disease continuum: Changing times, new challenges

Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding for the ion channel cystic fibrosis transmembrane conductance regulator (CFTR). The management of CF disease has evolved in recent decades from treating downstream disease manifestations affecting the airways, the lungs and the gastrointestinal system to addressing the CFTR gene defect. The advent of CFTR modulators, which correct the functionality of the defective CFTR, contributes to reshaping the landscape of CF demographics, prognosis and therapies, including nutritional management. A spectrum of clinical manifestations is emerging within the same patient population where undernutrition and nutritional deficiencies coexist with excessive weight gain and metabolic derangements. Such contrasting presentations challenge current practices, require adjustments to traditional approaches, and involve more individualised interventions. This narrative review examines the current state of knowledge on the nutritional management of people living with cystic fibrosis from early life to adulthood in the era of CFTR modulation.