Elexacaftor-Tezacaftor-Ivacaftor Treatment Reduces Abdominal Symptoms in Cystic Fibrosis-Early results Obtained With the CF-Specific CFAbd-Score

Effectiveness and safety of elexacaftor/tezacaftor/ivacaftor treatment in children aged 6-11 years with cystic fibrosis in a real-world setting

BACKGROUND

Elexacaftor-tezacaftor-ivacaftor (ETI) is a highly effective cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulating therapy for people with CF and at least one F508del variant. However, there is limited data about the safety and efficacy of this therapy in pediatric populations and in real-world settings. This study aimed at evaluating the effectiveness, tolerability, and safety of ETI in children with CF.

METHODS

This was a prospective observational study including all children aged 6-11 years who initiated ETI therapy between October 2022 and March 2023 at the Pediatric CF Center of Milan (Italy). Study outcomes included changes in sweat chloride concentration, FEV1, LCI2.5, body mass index (BMI), tolerance, and safety. Mean changes in study outcomes from baseline through 24 weeks were estimated using mixed-effects regression models.

RESULTS

The study included 34 children with CF (median age: 8.3 years). At Week 12, we observed an average decrease in LCI2.5 of 2.3 units (95% confidence interval [CI]: -3.1; -1.5). At Week 24, sweat chloride concentration decreased by 63 mEq/L (95% CI: -69; -58), FEV1 increased by 8.8 percentage point (95% CI: 3.7; 13.9) and BMI increased by 0.15 standard deviation scores (95% CI: 0.04; 0.25). Skin rashes appeared in 6 patients which spontaneously resolved within a few days. One month after treatment initiation, one patient experienced an elevation in liver function test results, which subsequently decreased during follow-up visits without necessitating discontinuation of therapy.

CONCLUSIONS

Our data indicate that ETI therapy is well tolerated by children with CF and is effective in improving signs of lung function abnormalities from early childhood.

Impact of highly effective modulator therapy on gastrointestinal symptoms and features in people with cystic fibrosis

Highly effective modulator therapy (HEMT), particularly the triple combination elexacaftor-tezacaftor-ivacaftor (ETI), significantly improved clinical outcomes and quality of life in people with Cystic Fibrosis (pwCF). This review analyzes current knowledge on the impact of HEMTs on gastrointestinal (GI) symptoms and features in pwCF. A descriptive review of English literature until February 29, 2024, was conducted using medical databases. Observational studies and clinical trials addressing GI reflux disease (GERD), lower GI symptoms and pancreatic disease were considered. Studies report positive effects of HEMTs on pH levels and bicarbonate secretion as well as improvement on intestinal inflammation. HEMTs also demonstrated positive effects on GERD and lower GI symptoms or conditions CF related such as dysbiosis. Taking ETI during pregnancy could also allow resolution of meconium ileus in fetuses with CF. The best benefits were observed in pancreatic function, potentially delaying CF-related diabetes and recovering pancreatic function in some children on ETI. Larger trials, particularly in pediatric populations, need to confirm these findings and explore long-term effects.

The foregut in cystic fibrosis

The aerodigestive organs share a kindred embryologic origin that allows for a more complete explanation as to how the foregut can remain a barrier to normalcy in people with cystic fibrosis (pwCF). The structures of the aerodigestive tract include the nasopharynx, the oropharynx, the hypopharynx, the esophagus, the stomach, as well as the supraglottic, glottic, and subglottic tubular airways (including the trachea). Additional gastrointestinal (GI) luminal/alimentary organs of the foregut include the duodenum. Extraluminal foregut structures include the liver, the gall bladder, the biliary tree, and the pancreas. There are a variety of neurologic controls within these complicated anatomic compartments to separate the transit of food and liquid from air. These structures share the same origin from the primitive foregut/mesenchyme. The vagus nerve is a critical structure that unites respiratory and digestive functions. This article comments on the interconnected nature of cystic fibrosis and the GI tract. As it relates to the foregut, this has been typically treated as simple "reflux" as the cause of worsened lung function in pwCF. That terms like gastroesophageal reflux (GER), gastroesophageal reflux disease (GERD), heartburn, and regurgitation are used interchangeably to reflect pathology further complicates matters; we offer a more physiologically accurate term called "GI-related aspiration" or "GRASP." Broadly, this term reflects that aspiration of foregut contents from the duodenum through the stomach to the esophagus, into the pharynx and the respiratory tree in pwCF. As a barrier to normalcy in pwCF, GRASP is fundamentally two disease processes-GERD and gastroparesis-that likely contribute most to the deterioration of lung disease in pwCF. In the modulator era, successful GRASP management will be critical, particularly in those post-lung transplantation (LTx), only through successful management of both GERD and gastroparesis. Standardization of clinical management algorithms for GRASP in CF-related GRASP is a key clinical and research gap preventing normalcy in pwCF; what exists nearly exclusively addresses surgical evaluations or offers guidance for the management of GI symptoms alone (with unclear parameters for respiratory disease considerations). We begin first by describing the result of GRASP damage to the lung in various stages of lung disease. This is followed by a discussion of the mechanisms by which the digestive tract can injure the lungs. We summarize what we anticipate future research directions will be to reduce the impact of GRASP as a barrier to normalcy in pwCF.

A longitudinal study assessing the impact of elexacaftor/tezacaftor/ivacaftor on gut transit and function in people with cystic fibrosis using magnetic resonance imaging (MRI)

BACKGROUND

Gastrointestinal (GI) symptoms in cystic fibrosis (CF) are common and disruptive. The effect of cystic fibrosis transmembrane conductance regulator (CFTR) modulators on the GI tract is not fully understood. The aim was to use magnetic resonance imaging (MRI) to determine if elexacaftor/tezacaftor/ivacaftor (ETI) changed GI function and transit.

METHODS

This was an 18 month prospective, longitudinal, observational study. We enrolled 24 people with CF aged 12 years or older to undergo MRI scans before starting ETI and 3, 6, and 18 months after starting ETI. The primary outcome measure was change in oro-caecal transit time (OCTT) at 6 and 18 months. Secondary outcome measures included change in small bowel water content (SBWC), change in the reduction in small bowel water content following a meal (DeltaSBWC) and change in total colonic volume (TCV).

RESULTS

A total of 21 participants completed MRI scans at 6 months and 11 completed at 18 months. After 18 months of ETI, median OCTT significantly reduced, from >360 min [IQR 240->360] to 240 min [IQR 180-300] (p = 0.02, Wilcoxon signed-rank). Both SBWC and DeltaSBWC increased after starting ETI. TCV reduced significantly after 18 months (p = 0.005, Friedman).

CONCLUSIONS

Our findings suggest an improvement in small bowel transit, small bowel response to food and a reduction in colonic volume after starting ETI. These effects may relate to CFTR activation in the small bowel. To our knowledge this is the first study to show a physiological change in GI transit and function in response to CFTR modulator use through imaging studies.

The gastrointestinal microbiome, small bowel bacterial overgrowth, and microbiome modulators in cystic fibrosis

People with cystic fibrosis (pwCF) have an altered gastrointestinal microbiome. These individuals also demonstrate propensity toward developing small intestinal bacterial overgrowth (SIBO). The dysbiosis present has intestinal and extraintestinal implications, including potential links with the higher rates of gastrointestinal malignancies described in CF. Given these implications, there is growing interest in therapeutic options for microbiome modulation. Alternative therapies, including probiotics and prebiotics, and current CF transmembrane conductance regulator gene modulators are promising interventions for ameliorating gut microbiome dysfunction in pwCF. This article will characterize and discuss the current state of knowledge and expert opinions on gut dysbiosis and SIBO in the context of CF, before reviewing the current evidence supporting gut microbial modulating therapies in 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.

Impaired intestinal free fatty acid transport followed by chylomicron malformation, not pancreatic insufficiency, cause metabolic defects in cystic fibrosis

Intestinal disease is one of the earliest manifestations of cystic fibrosis (CF) in children and is closely tied to deficits in growth and nutrition, both of which are directly linked to future mortality. Patients are treated aggressively with pancreatic enzyme replacement therapy and a high-fat diet to circumvent fat malabsorption, but this does not reverse growth and nutritional defects. We hypothesized that defects in chylomicron production could explain why CF body weights and nutrition are so resistant to clinical treatments. We used gold standard intestinal lipid absorption and metabolism approaches, including mouse mesenteric lymph cannulation, in vivo chylomicron secretion kinetics, transmission electron microscopy, small intestinal organoids, and chylomicron metabolism assays to test this hypothesis. In mice expressing the G542X mutation in cystic fibrosis transmembrane conductance regulator (CFTR-/- mice), we find that defective FFA trafficking across the epithelium into enterocytes drives a chylomicron formation defect. Furthermore, G542X mice secrete small, triglyceride-poor chylomicrons into the lymph and blood. These defective chylomicrons are cleared into extraintestinal tissues at ∼10-fold faster than WT chylomicrons. This defect in FFA absorption resulting in dysfunctional chylomicrons cannot be explained by steatorrhea or pancreatic insufficiency and is maintained in primary small intestinal organoids treated with micellar lipids. These studies suggest that the ultrahigh-fat diet that most people with CF are counselled to follow may instead make steatorrhea and malabsorption defects worse by overloading the absorptive capacity of the CF small intestine.

Cystic fibrosis liver disease in the new era of cystic fibrosis transmembrane conductance regulator (CFTR) modulators

Cystic fibrosis liver disease (CFLD) is characterised by a wide heterogenity of manifestations and severity. It represents a major cause of morbidity in people with cystic fibrosis (PwCF), which will be of increasing relevance as survival increases in the new era of cystic fibrosis care. No medical therapy currently available has evidence to treat or prevent progression of liver disease. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators may be transformative on pulmonary, nutritional and quality of life, but direct effect on long term liver disease outcomes is not yet established. Drug-associated hepatic adverse effects may be common, and clinician familiarity with drug-monitoring recommendations is essential. Longitudinal studies are required to understand the effect of CFTR modulators on the incidence and natural history of CFLD, including with early treatment initiation, in established advanced liver disease, and post liver transplantation.

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.

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).

[Chronic rhinosinusitis in people with cystic fibrosis-an up-to-date review from the perspective of otorhinolaryngology]

BACKGROUND

Cystic fibrosis (CF) is a complex systemic disease involving numerous organ systems. With improved treatment options and increasing life expectancy of persons with CF (PwCF), extrapulmonary manifestations are coming increasingly into the focus. From birth, almost all PwCF have radiologically detectable pathologies in the upper airways attributable to CF-associated chronic rhinosinusitis (CF-CRS).

OBJECTIVE

The aim of this work is to provide an up-to-date overview of CF-CRS from the otorhinolaryngology perspective and to provide the reader with background knowledge and current developments.

PATHOPHYSIOLOGY

The cystic fibrosis transmembrane conductance regulator (CFTR) gene defect leads to increased viscosity of sinonasal secretions and reduced mucociliary clearance, causing chronic infection and inflammation in the upper airway segment and, consequently, to CF-CRS.

CLINICAL PICTURE AND DIAGNOSTICS

The clinical picture of CF-CRS comprises a wide spectrum from asymptomatic to symptomatic courses. CF-CRS is diagnosed clinically and radiologically.

THERAPY

Sinonasal saline irrigation is recommended as a conservative treatment measure. Topical corticosteroids are also commonly used. Surgical therapy is reserved for highly symptomatic treatment-refractory patients without a sufficient response to conservative treatment including CFTR modulator (CFTRm) therapies. Depending on the CFTR mutation, CFTRm therapies are the treatment of choice. They not only improve the pulmonary and gastrointestinal manifestations in PwCF, but also have positive effects on CF-CRS.

CONCLUSION

The ENT specialist is part of the interdisciplinary team caring for PwCF. Depending on symptom burden and treatment responsiveness, CF-CRS should be treated conservatively and/or surgically. Modern CFTRm have a positive effect on the clinical course of CF-CRS.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

Gastroenterology services for patients with Cystic Fibrosis across Australia and New Zealand: a multi-stakeholder assessment of patients' and professionals' perspectives

Introduction

Gastrointestinal (GI) symptoms are common in individuals with Cystic Fibrosis (CF). International research has highlighted that GI care for this group of patients is lacking. Gastroenterology services to CF clinics across Australasia are yet to be examined. This study aimed to describe the current service delivery model and identify areas for improvement that may lead to positive patient outcomes.

Materials and methods

CF clinicians (dietitians, clinical nurse consultants, respiratory consultants), gastroenterologists (GE), and patients or their carers from Australia and New Zealand (NZ) were surveyed online to gather their opinions on CF gastroenterology services provided in their region. Data were analysed using descriptive statistics (frequencies and percentages). Likert scale questions were analysed by grouping responses 1-5 and 6-10, presented alongside the median and interquartile range (IQR). Mann-Whitney U and chi-square tests were used to look at differences between stakeholder groups.

Results

One hundred and fifty-six health professionals and 172 patients or their carers completed the survey. Results showed that the current GI model of care is predominantly a publicly funded service delivered outside of CF clinic time. GE are largely not integrated into the CF team and report a lack of training opportunities. There is a higher level of dissatisfaction with the current service model in NZ than Australia.

Discussion

No stakeholder group deemed the current CF gastroenterology service model as adequate, leaving opportunity for transformations in this field. Ideally this study will invigorate the need for promotion and integration of GI services that would ultimately benefit the whole CF community.

Efficacy and safety profile of elexacaftor-tezacaftor-ivacaftor triple therapy on cystic fibrosis: a systematic review and single arm meta-analysis

Background: Elexacaftor-Tezacaftor-Ivacaftor (ELE/TEZ/IVA) is believed to be an effective and well-tolerated treatment for cystic fibrosis (CF), but the exact efficacy and safety profile are still unknown. Objective: This study aimed to clarify the extent of functional restoration when patients are given with triple combination treatment and demonstrate the prevalence of adverse events, to evaluate the overall profile of ELE/TEZ/IVA on CF. Methods: A literature search was conducted in PubMed, Web of Science and Cochrane Library. Random effects single-arm meta-analysis was performed to decipher the basal characteristics of CF, the improvement and safety profile after ELE/TEZ/IVA treatment. Results: A total 53 studies were included in this analysis. For all the patients in included studies. 4 weeks after ELE/TEZ/IVA treatment, the increasement of percentage of predicted Forced Expiratory Volume in the first second (ppFEV1) was 9.23% (95%CI, 7.77%-10.70%), the change of percentage of predicted Forced Vital Capacity (ppFVC) was 7.67% (95%CI, 2.15%-13.20%), and the absolute change of Cystic Fibrosis Questionnaire-Revised (CFQ-R) score was 21.46 points (95%CI, 18.26-24.67 points). The Sweat chloride (SwCl) was significantly decreased with the absolute change of -41.82 mmol/L (95%CI, -44.38 to -39.25 mmol/L). 24 weeks after treatment, the increasement of ppFEV1 was 12.57% (95%CI, 11.24%-13.90%), the increasement of ppFVC was 10.44% (95%CI, 7.26%-13.63%), and the absolute change of CFQ-R score was 19.29 points (95%CI, 17.19-21.39 points). The SwCl was significantly decreased with the absolute change of -51.53 mmol/L (95%CI, -56.12 to -46.94 mmol/L). The lung clearance index2.5 (LCI2.5) was also decreased by 1.74 units (95%CI, -2.42 to -1.07 units). The body mass index increased by 1.23 kg/m2 (95%CI, 0.89-1.57 kg/m2). As for adverse events, 0.824 (95%CI, 0.769-0.879) occurred during ELE/TEZ/IVA period, while the incidence of severe adverse events was 0.066 (95%CI, 0.028-0.104). Conclusion: ELE/TEZ/IVA is a highly effective strategy and relatively safe for CF patients and needs to be sustained to achieve better efficacy. Systematic Review Registration: Identifier: CRD42023441840.

Dynamics of abdominal symptoms during the start of a new therapy with elexacaftor/tezacaftor/ivacaftor using the novel CFAbd-day2day questionnaire

Background: Elexacaftor-tezacaftor-ivacaftor (ETI) is a novel, highly effective CFTR modulator combination proven to enhance lung function and body weight in people with cystic fibrosis (pwCF) carrying a F508del mutation. Recently, we revealed significant reductions in abdominal symptoms (AS) in German, British, and Irish pwCF after 24-26 weeks of ETI using the CFAbd-Score, the first patient-reported outcome measure (PROM) specifically developed and validated for pwCF following FDA guidelines. Notably, many pwCF reported marked changes in their AS during the first days of the new treatment. To capture these immediate effects, we developed the CFAbd-day2day, a CF-specific GI-diary, following FDA and COSMIN guidelines. Aim: To prospectively capture the immediate dynamics of AS using the CFAbd-day2day 14 days before and 14-28 days after ETI initiation. In addition, we aim to provide validation steps of the novel PROM concerning sensitivity to changes. Methods: To develop the CFAbd-day2day, focus groups (community voice = pwCF and their proxies and CF specialists from different fields) were repeatedly consulted. Before and during the new ETI therapy, pwCF prospectively scored AS on a daily basis with the CFAbd-day2day. Results: Altogether, 45 pwCF attended in five CF centers prospectively completed the CFAbd-day2day before (mean ± sd:14 ± 7 days) and after (mean ± sd: 28 ± 23 days) ETI initiation. On the one hand, cumulative scores significantly decreased during the 3-4-week time frame after ETI initiation, compared to 2 weeks prior to therapy. On the other hand, many patients who revealed a relatively stable level of AS before ETI reported changes during the first days of treatment with the highly effective CFTR modulators. Factors like pain and flatulence increased in up to 21% of patients during the first 14 days of therapy, but they improved during days 15-27. Conclusion: The CFAbd-day2day, specifically developed and in the process of validation to prospectively capture GI symptoms in pwCF, provides new substantial insights into the dynamics of AS in pwCF receiving a new treatment with ETI. This novel tool is also helpful in prospectively monitoring patients with specific GI problems. International implementation and further validation steps of the diary are ongoing.

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.

Prebiotics for people with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multisystem disease; the importance of growth and nutritional status is well established given their implications for lung function and overall survivability. Furthermore, it has been established that intestinal microbial imbalance and inflammation are present in people with CF. Oral prebiotics are commercially available substrates that are selectively utilised by host intestinal micro-organisms and may improve both intestinal and overall health.

OBJECTIVES

To evaluate the benefits and harms of prebiotics for improving health outcomes in children and adults with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Date of last search: 19 October 2022. We also searched PubMed and online trials registries. Date of last search: 13 January 2023.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the efficacy of prebiotics in children and adults with CF. We planned to only include the first treatment period from cross-over RCTs, regardless of washout period.

DATA COLLECTION AND ANALYSIS

We did not identify any relevant trials.

MAIN RESULTS

We did not identify any relevant trials for inclusion in this review.

AUTHORS' CONCLUSIONS

This review did not find any evidence for the use of prebiotics in people with CF. Until such evidence is available, it is reasonable for clinicians to follow any local guidelines and to discuss the use of dietary prebiotics with their patients. Large and robust RCTs assessing the dietary prebiotics of inulin or galacto-oligosaccharides or fructo-oligosaccharides, or any combination of these, are needed. Such studies should be of at least 12 months in duration and assess outcomes such as growth and nutrition, gastrointestinal symptoms, pulmonary exacerbations, lung function, inflammatory biomarkers, hospitalisations, intestinal microbial profiling, and faecal short-chain fatty acids. Trials should include both children and adults and aim to be adequately powered to allow for subgroup analysis by age.

Therapeutic potential of phytochemicals for cystic fibrosis

The aim of this review was to review and discuss various phytochemicals that exhibit beneficial effects on mutated membrane channels, and hence, improve transmembrane conductance. These therapeutic phytochemicals may have the potential to decrease mortality and morbidity of CF patients. Four databases were searched using keywords. Relevant studies were identified, and related articles were separated. Google Scholar, as well as gray literature (i.e., information that is not produced by commercial publishers), were also checked for related articles to locate/identify additional studies. The relevant databases were searched a second time to ensure that recent studies were included. In conclusion, while curcumin, genistein, and resveratrol have demonstrated effectiveness in this regard, it should be emphasized that coumarins, quercetin, and other herbal medicines also have beneficial effects on transporter function, transmembrane conductivity, and overall channel activity. Additional in vitro and in vivo studies should be conducted on mutant CFTR to unequivocally define the mechanism by which phytochemicals alter transmembrane channel function/activity, since the results of the studies evaluated in this review have a high degree of heterogenicity and discrepancy. Finally, continued research be undertaken to clearly define the mechanism(s) of action and the therapeutic effects that therapeutic phytochemicals have on the symptoms observed in CF patients in an effort to reduce mortality and morbidity.

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

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

Thinking outside the box: a review of gastrointestinal symptoms and complications in cystic fibrosis

INTRODUCTION

Gastrointestinal (GI)-related symptoms, complications, and comorbidities in cystic fibrosis (CF) are common and research to reduce their burden is a priority for the CF community. To enable future research, this review aimed to summarize the range of GI symptoms, complications and comorbidities seen in CF, the underlying pathophysiology, and treatments.

AREAS COVERED

This was a rapid systematic review undertaken using the recommendations from the Cochrane Rapid Reviews Methods Group. We searched databases including PubMed, Embase, Medline and the Cochrane database and identified those studies reporting GI-related symptoms, complications, or comorbidities in CF or their treatment. Our searches identified 2,930 studies and a total 119 studies met our inclusion criteria. Where a prevalence could be determined, GI symptoms were reported in 33.7% of study participants. The range of symptoms reported was broad and the highest median prevalence included flatulence (43.5%), bloating and abdominal distension (36%), and fatty stool (36%). Meconium ileus was reported in 12% and distal intestinal obstruction syndrome in 8.5.

EXPERT OPINION

GI-related symptoms, complications, and comorbidities in CF are common. More consistent characterization and recording of these symptoms in clinical studies may help achieve the priority of reducing the burden of GI disease in CF.

Identifying the need for a UK colorectal cancer screening programme for patients with cystic fibrosis (CF): 10-year retrospective review of colonoscopy and colorectal cancer outcomes at a single CF centre

OBJECTIVE

Patients with cystic fibrosis (pwCF) have a high incidence of early colorectal cancer (CRC). In the absence of a UK CRC screening programme for pwCF, we evaluated the utility and outcomes of colonoscopy and CRC at a large UK CF centre.

DESIGN

In a retrospective study of colonoscopy and CRC outcomes between 2010 and 2020 in pwCF aged≥30 years at a large CF centre, data were collected on colonoscopy indications and findings, polyp detection rates, bowel preparation regimens and outcomes, colonoscopy completion rates, and patient outcomes.

RESULTS

We identified 361 pwCF aged ≥30 years, of whom 135 were ≥40 years old. In the absence of a UK CRC screening guideline only 33 (9%)/361 pwCF aged ≥30 years (mean age: 44.8±11.0 years) had a colonoscopy between 2010 and 2020. Colonoscopy completion rate was 94.9%, with a 33% polyp detection rate, 93.8% of the polyps retrieved were premalignant. During the study period no patients developed postcolonoscopy CRC. However, of the patients aged ≥40 years who did not have a colonoscopy (111/135, 82.2%), four (3.6%) patients developed CRC and three pwCF died from complications of CRC.

CONCLUSION

In this 10-year experience from a large CF centre, colonoscopy uptake for symptomatic indications was low, yet of high yield for premalignant lesions in pwCF >40 years. These data highlight the risk of potentially preventable, early CRC, and therefore support the need for prospective, large-scale nationwide studies which may inform the need for UK CRC screening guidelines for pwCF.

Clinical change 2 years from start of elexacaftor-tezacaftor-ivacaftor in severe cystic fibrosis

RATIONALE

Limited published research is available on the impact of elexacaftor/tezacaftor/ivacaftor (ETI) beyond the initial few months postdrug initiation, especially for those who initiated therapy via individual investigational new drug application. The experiences of patients with cystic fibrosis (CF) experiencing severe lung disease were reviewed for significant improvements in clinical symptoms and quality of life.

OBJECTIVES

To examine clinical outcomes 2 years post-ETI in patients with CF and advanced lung disease.

METHODS

This single center institutional review board-approved, retrospective chart review assessed clinical markers (percent predicted forced expiratory volume in 1 s, weight, sweat chloride), quality of life and computed tomography scans in patients with advanced lung disease who met criteria for compassionate use/expanded access program due to high risk of death or transplant need within 2 years.

RESULTS

Eighteen identified patients (ages 15-49 years) initiated drug between July and September 2019. Clinical markers indicated that therapy was well tolerated, not discontinued by any participant, and lab values did not indicate medical concern or discontinuation. Monitoring results indicated the safety of modulator therapy as there were no adverse clinical occurrences and all patients presented universal stabilization. There were no deaths and no transplants by the end of the study.

CONCLUSIONS

This study focused on patients with CF eligible for modulator therapy and were initiated due to advanced lung disease. Initiation of modulator therapy was deemed safe and resulted in objective positive changes in nutrition, cough, FEV₁ , subjective reports of clinical status, level of activity, and a reduction in burden of treatment.

Post-approval studies with the CFTR modulators Elexacaftor-Tezacaftor-Ivacaftor

Triple combination therapy with the CFTR modulators elexacaftor (ELX), tezacaftor (TEZ) and ivacaftor (IVA) has been qualified as a game changer in cystic fibrosis (CF). We provide an overview of the body of literature on ELX/TEZ/IVA published between November 2019 and February 2023 after approval by the regulators. Recombinant ELX/TEZ/IVA-bound Phe508del CFTR exhibits a wild type conformation in vitro, but in patient's tissue a CFTR glyoisoform is synthesized that is distinct from the wild type and Phe508del isoforms. ELX/TEZ/IVA therapy improved the quality of life of people with CF in the real-life setting irrespective of their anthropometry and lung function at baseline. ELX/TEZ/IVA improved sinonasal and abdominal disease, lung function and morphology, airway microbiology and the basic defect of impaired epithelial chloride and bicarbonate transport. Pregnancy rates were increasing in women with CF. Side effects of mental status changes deserve particular attention in the future.

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

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

Elexacaftor-Tezacaftor-Ivacaftor: A Life-Changing Triple Combination of CFTR Modulator Drugs for Cystic Fibrosis

Cystic fibrosis (CF) is a potentially fatal monogenic disease that causes a progressive multisystemic pathology. Over the last decade, the introduction of CF transmembrane conductance regulator (CFTR) modulator drugs into clinical practice has profoundly modified the lives of many people with CF (PwCF) by targeting the fundamental cause of the disease. These drugs consist of the potentiator ivacaftor (VX-770) and the correctors lumacaftor (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). In particular, the triple combination of CFTR modulators composed of elexacaftor, tezacaftor, and ivacaftor (ETI) represents a life-changing therapy for the majority of PwCF worldwide. A growing number of clinical studies have demonstrated the safety and efficacy of ETI therapy in both short- and long-term (up to two years of follow-up to date) and its ability to significantly reduce pulmonary and gastrointestinal manifestations, sweat chloride concentration, exocrine pancreatic dysfunction, and infertility/subfertility, among other disease signs and symptoms. Nevertheless, ETI therapy-related adverse effects have also been reported, and close monitoring by a multidisciplinary healthcare team remains vital. This review aims to address and discuss the major therapeutic benefits and adverse effects reported by the clinical use of ETI therapy for PwCF.

Elexacaftor/tezacaftor/ivacaftor and gastrointestinal outcomes in cystic fibrosis: Report of promise-GI

BACKGROUND

Elexacaftor/tezacaftor/ivacaftor (ETI) improves pulmonary disease in people with cystic fibrosis (PwCF), but its effect on gastrointestinal symptoms, which also affect quality of life, is not clear.

METHODS

PROMISE is a 56-center prospective, observational study of ETI in PwCF >12 years and at least one F508del allele. Gastrointestinal symptoms, evaluated by validated questionnaires: Patient Assessment of Upper Gastrointestinal Disorders-Symptom (PAGI-SYM), Patient Assessment of Constipation-Symptom (PAC-SYM), Patient Assessment of Constipation-Quality of Life (PAC-QOL)), fecal calprotectin, steatocrit and elastase-1 were measured before and 6 months after ETI initiation. Mean difference and 95% confidence intervals were obtained from linear regression with adjustment for age and sex.

RESULTS

438 participants fully completed at least 1 questionnaire. Mean (SD) for baseline PAGI-SYM, PAC-SYM, and PAC-QOL total scores were 0.56 (0.59), 0.47 (0.45), and 0.69 (0.53) out of maximum 5, 4, and 5, respectively (higher score indicates greater severity). Corresponding age- and sex-adjusted 6 months mean changes (95% CI) in total scores were -0.15 (-0.21, -0.09) for PAGI-SYM, -0.14 (-0.19, -0.09) for PAC-SYM, and -0.15 (-0.21, -0.10) for PAC-QOL. While statistically significant, changes were small and unlikely to be of clinical importance. Fecal calprotectin showed a change (95% CI) from baseline of -66.2 µg/g (-86.1, -46.2) at 6 months, while fecal elastase and steatocrit did not meaningfully change.

CONCLUSIONS

After 6 months of ETI, fecal markers of inflammation decreased. Gastrointestinal symptoms improved, but the effect size was small. Pancreatic insufficiency did not improve.

Need to study simplification of gastrointestinal medication regimen in cystic fibrosis in the era of highly effective modulators

INTRODUCTION

The success of highly effective modulator therapy (HEMT) has led to consideration of simpler regimens for people with CF (PwCF) with opportunities to modify burdensome regimens. Despite the intuitive appeal of discontinuing chronic therapies no longer necessary, this process should be pursued systematically to ensure safety, adherence, and validate patient-centered preferences. We designed a questionnaire to determine the state of use of acid-suppressive medications (ASM) and pancreatic enzyme therapy (PERT), current self-withdrawal and provider-directed withdrawal practices, and interest in a standardized withdrawal study.

METHODS

In collaboration with CF Foundation (CFF), a questionnaire was developed and distributed to members of Community Voice (CV, comprised of PwCF and their loved ones), and CF providers regarding the need to study simplifying the gastrointestinal (GI) regimen for PwCF on HEMT.

RESULTS

Approximately 20-40% of CV or CF providers have decreased or stopped ASM for those on HEMT. For PERT, CV and CF providers have decreased dose (34%-48% and approximately 25%, respectively) more often than having stopped it altogether (13%-24% and 3%-12%, respectively). Cumulatively, there is interest in pursuing research in this area (86% CV and 89% CF providers) and willingness to enroll in such a study (80% CV and 89% CF providers).

CONCLUSION

Systematically studying the withdrawal of common GI medications, ASM and PERT, is important to CV and CF providers. Decreases in dosing and withdrawal are already taking place without evidence to support this practice. This questionnaire is the first step in designing a GI medication simplification study in PwCF on HEMT.

Diabetes is associated with increased burden of gastrointestinal symptoms in adults with cystic fibrosis

BACKGROUND

Individuals with diabetes mellitus (DM) are known to frequently experience gastrointestinal (GI) symptoms. In contrast, the impact of cystic fibrosis-related diabetes (CFRD) on accentuating GI symptoms in people with cystic fibrosis (pwCF) is unknown. We sought to examine this.

METHODS

Abdominal symptoms were measured using the validated CF-specific GI symptom questionnaire - CFAbd-Score© - as part of a multicentre cohort study in pancreatic insufficient adults with CF, not on cystic fibrosis transmembrane conductance regulator (CFTR) modulators. The CFAbd-Score total score (0-100pts), its 5 domains, alongside nine specific GI symptoms associated with DM, were compared between the CFRD and non-CFRD groups.

RESULTS

27 (31%) and 61 (69%) participants with CF were recruited in the CFRD and non-CFRD groups respectively. Total CFAbd-Score and the two domains: gastroesophageal reflux disease and disorders of appetite were significantly higher in the CFRD group compared to the non-CFRD group (p<0.05), with the mean total CFAbd-Score being 25.4 ± 2.5 and 18.4 ± 1.5 in the CFRD and non-CFRD groups respectively. Among the nine GI symptoms commonly reported as elevated in DM, bloating and nausea were significantly more common in individuals with CFRD compared to those without (p<0.05).

CONCLUSIONS

Individuals with CFRD overall, have a higher GI symptom burden, according to CFAbd-Scores. Specifically, they experience significantly more bloating and nausea. Close monitoring and further research is needed to better understand and manage GI symptoms in this group.

Prebiotics for people with cystic fibrosis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To evaluate the benefits and harms of prebiotics for improving health outcomes in children and adults with CF.

Nutritional and metabolic management for cystic fibrosis in a post-cystic fibrosis transmembrane conductance modulator era

PURPOSE OF REVIEW

The introduction of highly effective cystic fibrosis transmembrane conductance regulator modulators has resulted in a paradigm shift towards treating underlying cause of cystic fibrosis (CF) rather than the ensuing complications. In this review, we will describe the impact of these small molecules on growth, nutrition, and metabolic status in people with CF (pwCF).

RECENT FINDING

Results of clinical trials and real world data demonstrate that these small molecules are having a significant impact of on augmenting body weight, improving nutritional status and reducing gastrointestinal symptom burden. Early treatment can also positively impact on pancreatic endocrine and exocrine function.

SUMMARY

Nutritional and metabolic management of pwCF needs to change in order to maximize long term health and avoid future complications relating to obesity and increased cardiovascular risk. Longitudinal registry studies will be key to improve our understanding of the longer-term outcome of these new therapies.