Impact of elexacaftor/tezacaftor/ivacaftor on lung function, nutritional status, pulmonary exacerbation frequency and sweat chloride in people with cystic fibrosis: real-world evidence from the German CF Registry

Progress of personalized medicine of cystic fibrosis in the times of efficient CFTR modulators

BACKGROUND

Cystic fibrosis (CF) is a systemic disorder of exocrine glands that is caused by mutations in the CFTR gene.

MAIN BODY

The basic defect in people with CF (pwCF) leads to impaired epithelial transport of chloride and bicarbonate that can be assessed by CFTR biomarkers, i.e. the β-adrenergic sweat rate and sweat chloride concentration (SCC), chloride conductance of the nasal respiratory epithelium (NPD), urine secretion of bicarbonate, intestinal current measurements (ICM) of chloride secretory responses in rectal biopsies and in bioassays of chloride transport in organoids or cell cultures. CFTR modulators are a novel class of drugs that improve defective posttranslational processing, trafficking and function of mutant CFTR. By April 2025, triple combination therapy with the CFTR potentiator ivacaftor (IVA) and the CFTR correctors elexacaftor (ELX) and tezacaftor (TEZ) has been approved in Europe for the treatment of all pwCF who do not carry two minimal function CFTR mutations. Previous phase 3 and post-approval phase 4 studies in pwCF who harbour one or two alleles of the major mutation F508del consistently reported significant improvements of lung function and anthropometry upon initiation of ELX/TEZ/IVA compared to baseline. Normalization of SCC, NPD and ICM correlated with clinical outcomes on the population level, but the restoration of CFTR function was diverse and not predictive for clinical outcome in the individual patient. Theratyping of non-F508del CF genotypes in patient-derived organoids and cell cultures revealed for most cases clinically meaningful increases of CFTR activity upon exposure to ELX/TEZ/IVA. Likewise, every second CF patient with non-F508del genotypes improved in SCC and clinical outcome upon exposure to ELX/TEZ/IVA indicating that triple CFTR modulator therapy is potentially beneficial for all pwCF who do not carry two minimal function CFTR mutations. This group who is not eligible for CFTR modulators may opt for gene addition therapy in the future, as the first-in-human trial with a recombinant lentiviral vector is underway.

FUTURE DIRECTIONS

The upcoming generation of pwCF will probably experience a rather normal life in childhood and adolescence. To classify the upcoming personal signatures of CF disease in the times of efficient modulators, we need more sensitive CFTR biomarkers that address the long-term course of airway and gut microbiome, host defense, epithelial homeostasis and multiorgan metabolism.

[Rare diseases: the role of internal medicine]

Rare diseases, defined in the European Union as conditions affecting fewer than five per 10,000 inhabitants, often manifest themselves in childhood, but are playing an increasingly important role in internal medicine due to the significantly improved long-term prognosis and a number of diseases that primarily occur in adulthood. Although noteworthy structures already exist nationally and internationally (networks, registers, databases, self-help groups), awareness of these diseases in daily routine and knowledge of the partly divergent care structures must be improved. There are no specific treatments for many of these diseases, but drugs are increasingly being developed-particularly in oncology-that are subject to special orphan drug status.

Cystic fibrosis-related bone disease: an update on screening, diagnosis, and treatment

Cystic fibrosis-related bone disease (CFBD) is a common endocrinopathy in people living with cystic fibrosis (CF) that is complex and multifactorial in origin. People with CF experience high rates of progressive bone density loss and increased fracture risk. Focus on prevention and treatment of CFBD is of increasing importance in a now aging CF population. This review will discuss current practices in CFBD, gaps in knowledge, and potential future studies with the goal of advancing the clinical care of patients with CFBD.

Same-Day Repeatability and 28-Day Reproducibility of Xenon MRI Ventilation in Children With Cystic Fibrosis in a Multi-Site Trial

BACKGROUND

MRI with xenon-129 gas (Xe MRI) can assess airflow obstruction and heterogeneity in lung diseases. Specifically, Xe MRI may represent a sensitive modality for future therapeutic trials of cystic fibrosis (CF) therapies. The reproducibility of Xe MRI has not yet been assessed in the context of a multi-site study.

PURPOSE

To determine the same-day repeatability and 28-day reproducibility of Xe MRI in children with CF.

STUDY TYPE

Four-center prospective, longitudinal.

POPULATION

Thirty-eight children (18 females, 47%), median interquartile range (IQR) age 12 (9-14) years old, with mild CF (forced expiratory volume in 1 second (FEV1) ≥85% predicted).

FIELD STRENGTH/SEQUENCE

3-T, two-dimensional (2D) gradient-echo (GRE) sequence.

ASSESSMENT

Xe MRI, FEV1, and nitrogen multiple-breath wash-out for lung-clearance index (LCI2.5) were performed. To assess same-day reproducibility, Xe MRI was performed twice within the first visit, and procedures were repeated at 28 days. Xe hypoventilation was quantified using ventilation-defect percentage (VDP) and reader-defect volume (RDV). For VDP, hypoventilated voxels from segmented images were identified using a threshold of <60% mean whole-lung signal and expressed as a percentage of the lung volume. For RDV, hypoventilation was identified by two trained readers and expressed as a percentage.

STATISTICAL TESTS

Inter-site comparisons were conducted using Kruskal-Wallis nonparametric tests with Dunn's multiple-comparisons tests. Differences for individuals were assessed using Wilcoxon matched-pairs tests. Bland-Altman tests were used to evaluate same-day repeatability, 28-day reproducibility, and inter-reader agreement. A P-value ≤0.05 was considered significant.

RESULTS

Median FEV1 %-predicted was 96.8% (86%-106%), and median LCI2.5 was 6.6 (6.3-7.4). Xe MRI had high same-day reproducibility (mean VDP difference 0.12%, 95% limits of agreement [-3.2, 3.4]; mean RDV difference 0.42% [-2.5, 3.3]). At 28 days, 26/31 participants (84%) fell within the same-day 95% limits of agreement.

DATA CONCLUSION

Xe MRI may offer excellent same-day and short-term reproducibility.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Changing Epidemiology of Pediatric Pulmonary Exacerbations in Cystic Fibrosis

RATIONALE

The introduction of elexacaftor/tezacaftor/ivacaftor (ETI), a highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy, to younger ages and the COVID-19 pandemic have significantly reduced pulmonary exacerbations requiring hospitalization among children with CF.

OBJECTIVE

To assess demographic and clinical characteristics of children and young adults with CF hospitalized for pulmonary exacerbations before and after pediatric ETI approval.

METHODS

A retrospective chart review was conducted at five United States CF Foundation-accredited care centers. Hospitalization data from children and young adults with CF in 2018 and 2022 were analyzed.

RESULTS

Hospitalizations decreased from 471 cases (241 individuals) in 2018 to 163 cases (110 individuals) in 2022. The racial distribution shifted, with more hospitalized patients identifying as people of color in 2022 (28% vs. 14%; p = 0.018). A greater proportion of hospitalized children in 2022 had two non-F508del mutations compared with children hospitalized in 2018 (38% vs. 19%) and were less likely to be infected with methicillin-resistant Staphylococcus aureus (MRSA). Comparing 2022-2018, children on CFTR modulator therapy, including ETI (76%), showed reduced infections with Pseudomonas aeruginosa and Achromobacter xylosoxidans.

CONCLUSIONS

The decline in hospitalizations for pulmonary exacerbations likely reflects the benefits of ETI therapy, as a higher proportion of children and young adults hospitalized in 2022 had two non-F508del mutations and were not eligible for ETI. A greater percentage of those hospitalized in 2022 identified as belonging to minority racial groups, highlighting ongoing health disparities in the ETI era. Additionally, there were notable changes in the microbiological characteristics between 2018 and 2022.

Evaluation of the Impact of Elexacaftor/Tezacaftor/Ivacaftor on Aerobic Capacity in Children With Cystic Fibrosis Aged 6-11 Years: Actual Observations and Clinical Perspectives

BACKGROUND

Cystic fibrosis causes exercise limitation due to impaired lung function and other complications, which in turn increases the chance of mortality. CFTR modulators, particularly the elexacaftor/tezacaftor/ivacaftor (ETI) combination, improve lung function in children older than 6 years in real-life studies.

OBJECTIVE

This study aimed to assess the impact of ETI on aerobic capacity in children with CF aged 6-11 years under real-life conditions and to evaluate whether prior CFTR modulator treatment affects these outcomes.

METHODS

A multicenter, prospective cohort study was conducted with pediatric CF patients. Participants underwent evaluations 6-8 months before ETI (T1), at the start of ETI (T2), and 6-8 months post-treatment (T3). Primary outcomes included cardiorespiratory fitness assessed via peak oxygen consumption (VO2peak) during a cardiopulmonary exercise test (CPET), and secondary outcomes encompassed lung function, quality of life, physical activity, and functional mobility.

RESULTS

Of the 28 patients (mean age 9.02±1.59 years), 19 were ETI-naive, and 9 had prior CFTR modulator treatment. Significant improvements were observed in FEV1 (p<0.001), and several functional mobility tests (30CST, Stair Climb Test, 10MWT). However, VO2peak showed no significant changes between T1 and T3. Quality of life scores improved notably in emotional, eating, and respiratory domains, and a slight improvement was noted in physical activity levels (p=0.037).

CONCLUSIONS

ETI treatment significantly enhances lung function and certain aspects of quality of life and physical fitness in pediatric CF patients. However, it does not significantly alter aerobic capacity (VO2peak) within the observed period.

Unveiling the psychosocial impact of Elexacaftor/Tezacaftor/Ivacaftor therapy in Cystic Fibrosis patients

BACKGROUND

This study aimed to assess how Elexacaftor/Tezacaftor/Ivacaftor (ETI) influences lung function, Body Mass Index (BMI), Sweat Test (ST) and mental health of Cystic Fibrosis (CF) patients, emphasizing on depression and anxiety.

METHODS

We conducted an observational, prospective, multicentre study including 108 patients over 18 years old who initiated ETI therapy between December 2019 and December 2023. Patients underwent regular evaluations, including clinical, functional, and microbiological assessments, alongside completion of quality of life, anxiety, and depression questionnaires. We evaluated whether there was a difference in anxiety and depression levels over time.

RESULTS

After 12 months of treatment, significant improvements were noted in BMI, lung function (FEV1%), ST and various aspects of quality of life (CFQ-R). However, anxiety and depression levels did not differ significantly during the follow-up. When we stratified our sample by key groups, we observed that younger patients (under 28 years) and those with homozygous Phe508del mutations experienced significant higher anxiety with no differences on depression. Furthermore, anxiety and depression demonstrated a moderate correlation, strengthening over time.

CONCLUSIONS

Treatment with ETI establishes significant improvements in lung function, BMI, ST and quality of life in patients with CF. However, despite these positive outcomes, there were no significant changes observed in levels of anxiety and depression, except for individuals with homozygous mutation type and those younger than 28 years old, who exhibited significant higher levels of anxiety.

Linking volatile metabolites from bacterial pathogens to exhaled breath condensate of people with cystic fibrosis

Obtaining sputum samples from people with cystic fibrosis (pwCF) for microbiology has become challenging due to the positive clinical effects of the cystic fibrosis transmembrane conductance regulator modulator therapy, elexacaftor-tezacaftor-ivacaftor (ETI). Although ETI improves lung function and reduces sputum production, recent data shows that bacterial pathogens persist, making continued monitoring of infection important. As an alternative to sputum sampling, this study developed a non-invasive technique called 'Cough Breath' (CB) to identify volatile organic compounds (VOCs) in exhaled breath condensate (EBC) and link them to cystic fibrosis (CF) bacterial pathogens using purge and trap GC-MS. The CB culturing approach was able to isolate pathogens from expectorated particulates simultaneously with EBC collection; however, culturing positivity was low, with 6% of samples collected (n=47) positive for either Pseudomonas aeruginosa or Staphylococcus aureus. From EBC, we identified VOCs matching those uniquely produced by P. aeruginosa (7), S. aureus (12), Achromobacter xylosoxidans (8) and Granulicatella adiacens (2); however, the overall detection rate was also low. Expanding to VOCs produced across multiple pathogens identified 30 frequently detected in the EBC of pwCF, including 2,3-pentanedione, propyl pyruvate, oxalic acid diallyl ester, methyl isobutyl ketone, methyl nitrate, 2-propenal, acetonitrile, acetoin and 2,3-butanedione. Comparing isolate volatilomes and EBC samples from the same pwCF enhanced detection rates with key VOCs, such as 2,3-pentanedione (86%) and propyl pyruvate (83%), in P. aeruginosa isolates. Further investigation showed that VOC production differed across strains and at different growth phases, creating variability that may explain the overall low EBC detection rate. Although this study successfully cultured CF pathogens from cough particulates and matched their unique VOCs in EBC samples, our results indicate that microbial volatiles more generally indicative of infection, such as 2,3-pentanedione, may have the most utility in aiding diagnostics in pwCF on ETI who have reduced sputum production in the clinic.

Real-world impact of Elexacaftor-Tezacaftor-Ivacaftor treatment in young people with Cystic Fibrosis: A longitudinal study

BACKGROUND

Elexacaftor, Tezacaftor, Ivacaftor (ETI) became available in the UK in August 2020 to treat people with Cystic Fibrosis (CF) aged >12 years. We report a real-world study of clinical outcomes in young people treated with ETI at our CF centre within the first two years of its availability.

METHODS

Participants aged 12-17 were identified within our clinic, with demographic data supplemented by the UK CF registry. Comprehensive outcome data spanning two years pre- and two years post-initiation of CFTR modulators were compiled from various local sources, including patient records, medication delivery logs, and clinical notes.

RESULTS

Of the 62 patients started on ETI (32 male, mean age 13.3 years), most (76 %) were homozygous for the F508del mutation. Three discontinuations occurred: one pregnancy, two related to side effects. Adherence was high (Proportion of Days covered >90 % both years). Following ETI initiation there was a significant increase in mean FEV1% (+11.7 units; 95 % CI 7.4-15.6), sustained throughout the two-year treatment period. There was no association between baseline lung function and the degree of improvement or rate of decline post-treatment. Improvements were similar for all treatable genotypes. BMI z-score increased by 0.25 units after four months of treatment, returning to baseline by 24 months. Intravenous antibiotic use decreased by 88 % (median IV days/year reduced from 32 to 4 days, p < 0.01).

CONCLUSIONS

ETI use in adolescents in a real-world setting led to sustained improvements in health outcomes, consistent with those seen in open trial extension studies.

Success of the German Cystic Fibrosis Registry

The German Cystic Fibrosis (CF) Registry (GCFR) is a national General Data Protection Regulation-compliant centralised database sponsored by the German Cystic Fibrosis Association (Mukoviszidose e.V.) and based on informed consent for each participating patient, ethical approval, and data protection votes. The aims of the GCFR are to optimise quality of care for CF at the centres, generate epidemiologic overviews, address research questions related to improved CF care, and inform caregivers, patients (aimed at patient empowerment), and health authorities and industry (aimed at care planning and pharmacovigilance). Established in 1995, the Registry has captured data on > 9600 individuals with a combined total of more than 140 000 annual assessments with an estimated coverage rate of > 90%. Patient data are collected after informed consent and confirmed diagnosis of CF, or a CFTR-related disorder, or a screening-positive inconclusive diagnosis of CF (i.e., CFSPID). The registry collects core, encounter, and annual health data. Data include demographics, anthropometrics, lung function, microbiology, CF-specific complications and chronic medications, hospitalisations, demand-oriented antibiotic therapies, and outcomes (death and transplants). Real world and pharmacovigilance studies have been published and additional research underway; there is a formal process for requesting access to the GCFR.

Nasal Epithelium Transcriptomics Predict Clinical Response to Elexacaftor/Tezacaftor/Ivacaftor

Elexacaftor/tezacaftor/ivacaftor (ETI) has had a substantial positive impact for people living with cystic fibrosis (pwCF). However, there can be substantial variability in efficacy, and we lack adequate biomarkers to predict individual response. We thus aimed to identify transcriptomic profiles in nasal respiratory epithelium that predict clinical response to ETI treatment. We obtained nasal epithelial samples from pwCF before ETI initiation and performed a transcriptome-wide analysis of baseline gene expression to predict changes in forced expiratory volume in 1 second (ΔFEV1), year's best FEV1 (ΔybFEV1), and body mass index (ΔBMI). Using the top differentially expressed genes, we generated transcriptomic risk scores (TRSs) and evaluated their predictive performance. The study included 40 pwCF ≥6 years of age (mean, 27.7 [SD, 15.1] years; 40% female). After ETI initiation, FEV1 improved by ≥5% in 22 (61.1%) participants, and ybFEV1 improved by ≥5% in 19 (50%). TRSs were constructed using top overexpressed and underexpressed genes for each outcome. Adding the ΔFEV1 TRS to a model with age, sex, and baseline FEV1 increased the area under the receiver operating characteristic curve (AUC) from 0.41 to 0.88, the ΔybFEV1 TRS increased the AUC from 0.51 to 0.88, and the ΔBMI TRS increased the AUC from 0.46 to 0.92. Average accuracy was thus ∼85% in predicting the response to the three outcomes. Results were similar in models further adjusted for F508del zygosity and previous CFTR modulator use. In conclusion, we identified nasal epithelial transcriptomic profiles that help accurately predict changes in FEV1 and BMI with ETI treatment. These novel TRSs could serve as predictive biomarkers for clinical response to modulator treatment in pwCF.

Effects on growth, weight and body composition after CFTR modulators in children with cystic fibrosis

BACKGROUND

Cystic Fibrosis (CF) is associated with compromised nutrition status, which is responsible for morbidity and mortality along with lung function decline. This study was designed to examine changes in anthropometric markers and body composition parameters by bioelectrical impedance analysis after CFTR modulator (CFTRm) treatment.

METHODS

We compared anthropometric parameters and body composition before and after 6 and 12 months of CFTRm treatment. Results are stratified into subgroups according to the modulator used with dual therapy with lumacaftor + ivacaftor or tezacaftor + ivacaftor (LUMA/TEZ + IVA) or triple therapy with elexacaftor + tezacaftor + ivacaftor (ELE + TEZ + IVA). Body composition data are available in patients treated with ELE + TEZ + IVA.

RESULTS

Two hundred and thirty-four children (55.1% male) were recruited. The median age was 13.6 years (inter-quartile range [IQR] 10.7-16.1). We can observe a statistically significant increase in the weight Z score and BMI Z score after CFTRm. In terms of changes in body composition, we observe a significant increase in fat mass (FM) expressed both in kilograms and as a percentage at 6 months (p < .05; Wilcoxon-test), with no such differences found at 12 months. We also observe a statistically significant increase in fat-free-mass (FFM), expressed in kilograms at 6 and 12 months (p < .05; Wilcoxon-test).

CONCLUSION

Weight status improved and changes in body composition occurred in children after CFTRm therapy, including an increase of fat mass. Further studies are needed to confirm these changes in body composition and their impact on disease progression.

Lung Clearance Index Improves in People with Cystic Fibrosis not Achieving a Clinical Important Difference in Forced Expiratory Volume in One Second After Elexacaftor/Tezacaftor/Ivacaftor Therapy

PURPOSE

In people with cystic fibrosis (pwCF), elexacaftor/tezacaftor/ivacaftor (ETI) therapy is associated with an average improvement in FEV1 of 10-14%. However, a subset of individuals fails to achieve a clinically meaningful increase in spirometric indicators. In this study, we aimed to assess whether the lung clearance index (LCI2.5), a more sensitive indicator of lung involvement, improves following ETI initiation in this population.

METHODS

We conducted a prospective observational study in a specialized CF center in Italy. PwCF performed a spirometry and a multiple breath nitrogen washout test the day they initiated ETI therapy and after 6 and 12 months. They were grouped according to the 12-month change in FEV1 into two groups: Individuals who experienced a change in FEV1 ≥ a minimal clinically important difference (MCID) of 3% and those who did not. Mean changes in LCI2.5 were estimated using generalized estimating equations.

RESULTS

The study included 129 pwCF who initiated ETI at our center (Age Range: 12-36 years). In 20 subjects (15.5%), the FEV1 change was < MCID. These individuals had better baseline pulmonary function than those with FEV1 changes ≥ MCID (Median FEV1: 102.5 vs 87.0%), with the majority (90%) having FEV1 values ≥ 90%. Mean changes in LCI2.5 at 12-month follow-up visit were - 1.44 units (95% CI: - 2.12; - 0.75) in individuals with changes in FEV1 < MCID and - 2.64 units (95% CI: -3.05; -2.23) in those with values ≥ MCID.

CONCLUSION

LCI2.5 is a useful measure to monitor the effectiveness of ETI in pwCF with normal spirometry and limited FEV1 change following treatment initiation.

Lung function improvement on triple modulators: high-resolution, nationwide data from the Danish Cystic Fibrosis Cohort

Background

People living with cystic fibrosis in Denmark had early, universal access to triple modulator treatment with elexacaftor/tezacaftor/ivacaftor. Close monitoring allowed us to assess the impact of treatment on lung function and progression of lung disease in an unselected nationwide cystic fibrosis population from 6 years of age.

Methods

Data were analysed using linear mixed-effect models to assess changes in levels and annual rates of change (slopes) in percent predicted (pp) forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and forced expiratory flow at 25-75% of FVC (ppFEF25-75%) between the 12 months pre-treatment and treatment periods. Subgroup analyses assessed the impact of elexacaftor/tezacaftor/ivacaftor among those with/without previous modulator treatment, normal/mild/moderate/severe lung disease at treatment initiation, children/adults and birth cohorts.

Results

We included 392 people living with cystic fibrosis with a median (interquartile range) 12 (nine to 15) spirometry measurements per person. The mean (95% CI) improvement in ppFEV1 was 13.0 (11.3-14.6) 12 months after initiation of elexacaftor/tezacaftor/ivacaftor treatment. The annual rate of change improved from -1.4 (-2.1 - -0.6) ppFEV1 in the pre-treatment year to 2.7 (1.8-3.5) ppFEV1 per year during treatment. Similarly, ppFVC increased by 8.0 (7.1-8.9) and FEF25--75% by 19.5 (17.0-21.9).

Conclusions

Using high-resolution data from a nationwide real-world setting, our study documents the impact of elexacaftor/tezacaftor/ivacaftor on lung function across subgroups based on age, disease severity and treatment history. These findings point towards a new period of consistent lung function improvement among people living with cystic fibrosis on elexacaftor/tezacaftor/ivacaftor.

Comparison of clinical features of cystic fibrosis patients eligible but not on CFTR modulators to ineligible for CFTR modulators

INTRODUCTION

Cystic fibrosis transmembrane conductance regulator (CFTR) modulator drugs target the underlying defect and improve CFTR function. They are a part of standard care in many countries, but not all patients are eligible for these drugs due to age and genotype. Here, we aimed to determine the characteristics of non-eligible patients for CFTR modulators in the CF registry of Turkey (CFRT) to highlight their clinical needs.

METHODS

This retrospective cohort study included CF patient data from the CFRT in 2021. The decision of eligibility for the CFTR modulator was determined according to the 'Vertex treatment-Finder' on the Vertex® website. Demographic and clinical characteristics of patients were compared between eligible (group 1) and ineligible (group 2) groups for CFTR modulators.

RESULTS

Among the study population (N = 1527), 873 (57.2%) were in group 1 and 654 (42.8%) were in group 2. There was no statistical difference between groups regarding sex, meconium ileus history, diagnoses via newborn screening, FEV1 z-score, CF-associated complications, organ transplant history, and death. Patients in group 2 had a higher incidence of pancreatic insufficiency (87.7% vs. 83.2%, p = .010), lower median height z-scores (-0.87 vs. -0.55, p < .001), lower median body mass index z-scores (-0.65 vs. -0.50, p < .001), longer days receiving antibiotics due to pulmonary exacerbation (0 [interquartile range, IQR: 0-2] vs. 0 [IQR: 0-7], p = 0.001), and more non-invasive ventilation support (2.6% vs. 0.9%, p = 0.008) than patients in group 1.

CONCLUSION

The ineligible group had worse clinical outcomes than the eligible group. This highlights their need for life-changing drugs to improve clinical outcomes.

Changing profile of bacterial infection and microbiome in cystic fibrosis: when to use antibiotics in the era of CFTR-modulator therapy

The advent of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy, especially the triple therapy combining the drugs elexacaftor, tezacaftor, ivacaftor (ETI), has significantly changed the course of the disease in people with cystic fibrosis (pwCF). ETI, which is approved for the majority (80-90%) of pwCF, partially restores CFTR channel function, resulting in improved mucociliary clearance and, consequently, improved lung function, respiratory symptoms and pulmonary exacerbations. The bacterial burden of classical CF pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus is reduced without reaching eradication in the majority of infected patients. Limited data is available on less common or emerging bacterial pathogens. ETI has a positive effect on the lung microbiome but does not fully restore it to a healthy state. Due to the significant reduction in sputum production under ETI, respiratory samples such as deep-throat swabs are commonly taken, despite their inadequate representation of lower respiratory tract pathogens. Currently, there are still unanswered questions related to this new therapy, such as the clinical impact of infection with cystic fibrosis (CF) pathogens, the value of molecular diagnostic tests, the durability of the effects on respiratory infection and the role of fungal and viral infections. This article reviews the changes in bacterial lung infections and the microbiome in CF to provide evidence for the use of antibiotics in the era of ETI.

Kidney effects of triple CFTR modulator therapy in people with cystic fibrosis

Background

Elexacaftor/tezacaftor/ivacaftor (ETI) is a new cystic fibrosis transmembrane conductance regulator (CFTR) modulator that has transformed the respiratory prognosis of people with cystic fibrosis (pwCF). However, its impact on other organs such as the kidneys, where CFTR is expressed, remains unclear. Since pwCF are risk of both kidney disease and urolithiasis, we aimed to study the potential effects of ETI on renal function, volume status, and risk factors for urolithiasis.

Methods

This prospective, observational, single-center, before-after cohort study, involved adult pwCF eligible for ETI. The changes in plasma and urinary profiles were assessed by comparing renal function (using 2021 CKD-EPIcreatinine and 2021 CKD-EPIcreatinine-cystatin C formulas), volume status (using aldosterone/renin ratio and blood pressure), and risk factors for urolithiasis, at the time of ETI introduction (M0) and 7 months after (M7).

Results

Nineteen pwCF were included. No significant change in renal function was observed between M0 and M7 (2021 CKD-EPIcreatinine: 105.5 ml/min/1.73 m² at M0 vs. 103.3 ml/min/1.73 m² at M7; P = .17). There was a significant reduction in aldosterone level (370.3 pmol/l at M0 vs. 232.4 pmol/l at M7; P = .02) and aldosterone/renin ratio (33.6 at M0 vs. 21.8 at M7; P = .03). Among the risk factors for urolithiasis, a significant reduction in magnesuria level was found (4.6 mmol/d at M0 vs. 3.8 mmol/d at M7; P = .01).

Conclusion

These findings suggest that ETI seem to have no short-term impact on the renal function of adult pwCF and appears to correct secondary hyperaldosteronism due to excessive sweat losses. Further investigations are needed to determine the potential impact of decreased magnesuria observed under ETI therapy on the risk of urolithiasis.

Is Obesity a Problem in New Cystic Fibrosis Treatments?

INTRODUCTION

Malnutrition has always been a problem in CF (cystic fibrosis) patients; however, new treatments with CFTR (cystic fibrosis transmembrane conductance regulator protein) modulators have led to weight gain, with some patients at risk of overweight and obesity.

OBJECTIVE

Our study aimed to analyze the evolution of BMI (body mass index) after one year of treatment with triple therapy and the factors associated with weight gain in CF patients undergoing treatment with triple therapy with CFTR protein modulators (ETI) (elexacaftor/tezacaftor/ivacaftor).

METHODS

We conducted a prospective, observational, longitudinal, multicenter study in patients diagnosed with cystic fibrosis, aged 18 years or older, with at least one F508del allele and who underwent ETI therapy for at least one year, from 2020 to 2023. One hundred and eight patients from two cystic fibrosis units in Spain, Princess University Hospital of Madrid (74 patients) and Central University Hospital of Asturias (HUCA) (34 patients), were included. Demographic data, anthropometric data, lung function, and exacerbations were collected, comparing the data in the previous year to the start of therapy with the results after one year of treatment. Multivariant models were developed to account for repeated weight and BMI measurements, using a mixed effects model approach and accounting for possible modifying factors Results: One hundred and eight patients were included in the study, 58 men (53.7%) and 50 women (46.3%) with a mean age of 29.5 ± 9.4 years (18-59). Patient weight and BMI were recorded at baseline and at 3-month intervals during the study period. The weight increased from 59.6 kg to 62.6 kg and BMI increased from 21.9 kg/m2 to 23.0 kg/m2 after one year of treatment (p < 0.0001 for both). The proportion of underweight individuals decreased after one year of ETI therapy, from 9.3% to 1.9%, while the proportion of overweight or obese individuals increased from 8.3% to 22.9 % at the same time (p < 0.001). In relation to exacerbations, there is a significant increase in the number of patients who did not have any exacerbations after one year of treatment, which increased from 10.2% to 46.2% (p < 0.001), while the number of patients who had >4 exacerbations decreased significantly, from 40.7% to 1.9% (p < 0.001). FEV1% (forced expiratory volume) increased from 63.9 ± 20.9 to 76.8 ± 21.4 (p < 0.001) and the VR/TLC (residual volume/total lung capacity) value decreased from 45.1 ± 10.9 to 34.9 ± 6.2 (p < 0.001). The proportion with FEV1% > 80% increased from 23.1% before ETI therapy to 49.1% one year after ETI therapy. We performed multivariate mixed models to evaluate the evolution of BMI changes with time, accounting for repeated measures and for possible modifying factors. After the introduction of the triple therapy, patients included in the study had significant weight gain during the 12 months, and when including different covariates in the multivariate mixed model, we found that lower baseline BMI, lower baseline FEV1 and FVC (forced vital capacity), and higher VR/TLC value and higher number of exacerbations were associated with higher BMI changes over the study period.

CONCLUSIONS

CF patients treated with triple therapy experience significant weight gain, increasing the proportion of overweight patients. CF patients who experienced greater weight gain were those with worse BMI at the start of treatment, as well as patients with worse lung function and a greater number of exacerbations in the year before starting ETI therapy.

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.

CFTR Modulators Therapy Efficacy in Reducing Cystic Fibrosis (CF) Exacerbation and Improving Selected Spirometry Parameters: A Real-Life Study in a Single-Centre Polish Population

Background/Objectives: Cystic fibrosis is a genetically determined disease that significantly influences and shortens life. Treatment with CFTR modulators (CFTR-T) is a new hope for patients. It can change the predictive values of a poor prognosis (e.g., exacerbation rate and FEV1 value). The aim of the study was to analyse exacerbation incidence and spirometry data before and after one year (+/- 2 weeks) of CFTR-T in 85 CF patients at the CF Centre in Poznań. To our knowledge, this is the first analysis of CFTR-T efficiency in the Central-Eastern Europe population. Methods: We retrospectively analysed the spirometry and exacerbation data of 85 CF adult patients (both men and women), who in the middle of 2022 began treatment with CFTR modulators. Results: The one-year ratio of hospitalisation caused by severe exacerbations lowered from 1.25 to 0.21 per patient per year. We also saw a 66% decline in ambulatory exacerbations. The median FEV1% increased by 9.60% in absolute values and by 460 mL. Even in the group with very severe obstruction (FEV1 < 35%), there was an increase in median FEV1% of 5.9 in absolute values. We also proved the increase in FVC% (median 17.10% in absolute value and 600 mL) in the study group. Conclusions: After one year of treatment, an impressive improvement was observed in two important predictive values of poor prognosis: exacerbation rate and FEV1 values. Further observation is needed to determine how long the improvement will be present and its influence on quality of life and life expectancy.

Nutritional Trends in Cystic Fibrosis: Insights from the Italian Cystic Fibrosis Patient Registry

Background: Over the past decades, efforts have been made to improve the nutritional well-being of people with cystic fibrosis (pwCF). Due to the correlation observed between nutritional indices and lung function, prevailing recommendations consistently advocate for BMI percentile goals at or above the 50th percentile in pwCF. Recent global trends show a notable increase in overweight and obese statuses among pwCF. This study aims to explore the nutritional status of Italian pwCF. Methods: Data from the Italian CF Patient's Registry were analysed to assess the proportion of individuals categorized as underweight, target weight, overweight, and obese from 2010 to 2021. Patient-level comparison data from 2021 were also examined to identify the potential determinants of overweight and obesity. Results: Analysis spanning 2010 to 2021 reveals a decrease of approximately 40% in underweight status among adults, while the proportion of malnourished patients younger than 18 years remained stable. Conversely, there was a substantial increase of over 70% in overweight status and over 85% in obesity among adults, with minor fluctuations observed among children and adolescents. Patient factors associated with increased obesity incidence included age older than 45 years, male gender, pancreatic sufficiency, possession of at least one CFTR variant conferring residual function, ppFEV1 > 90, and lower prevalence of Pseudomonas aeruginosa colonization. Conclusions: Our study confirms the evolving nutritional status landscape among Italian adult pwCF, with a significant shift towards overweight and obesity over the past decade. These trends highlight the need for proactive measures within CF standards of care to adapt and address the changing needs of patients.