Improvement in Lung Clearance Index and Chest Computed Tomography Scores with Elexacaftor/Tezacaftor/Ivacaftor Treatment in People with Cystic Fibrosis Aged 12 Years and Older - The RECOVER Trial

Advances in the treatment of cystic fibrosis: CFTR modulators

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

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.

Guidance for chest-CT in children and adults with cystic fibrosis: A European perspective

The European Cystic Fibrosis Society-Clinical Trials Network (ECFS-CTN) herein proposes guidance for the use of chest CT-scans for the regular monitoring of lung disease in CF. Statements were completed in a 3-step process: the questions were identified via an anonymous online survey, followed by a comprehensive literature search, and a final Delphi process. The guidance recommends the use of ultra-low dose CT scans (effective radiation dose, 0.08 mSv; equivalent to 2 to 4 chest X-rays), tracking of patients' cumulative radiation and effective communication strategies using "de-medicalized" information for shared decision making. Chest CT scans (with lung volume monitoring) are not recommended systematically in both children and adults. Ultimate responsibility for justifying a chest CT scan lies with the individual professionals directly involved, the final decision being influenced by indications, costs, expertise, available material, resources and/or the patient's values, as well as possible impact on treatment modalities.

CCR2+ monocytes are dispensable to resolve acute pulmonary Pseudomonas aeruginosa infections in WT and cystic fibrosis mice

Extravasation of CCR2-positive monocytes into tissue and to the site of injury is a fundamental immunological response to infections. Nevertheless, exuberant recruitment and/or activity of these monocytes and monocyte-derived macrophages can propagate tissue damage, especially in chronic inflammatory disease conditions. We have previously shown that inhibiting the recruitment of CCR2-positive monocytes ameliorates lung tissue damage caused by chronic neutrophilic inflammation in cystic fibrosis mouse models. A potential concern with targeting monocyte recruitment for therapeutic benefit in cystic fibrosis, however, is whether they are essential for eradicating infections such as Pseudomonas aeruginosa, a pathogen that commonly colonizes and damages the lungs of patients with cystic fibrosis. In this study, we investigated the role of CCR2-positive monocytes in the immune response to acute pulmonary P. aeruginosa infection. Our data show that the altered host immune response caused by the lack of monocyte recruitment to the lungs does not impact P. aeruginosa lung colonization, clearance, and the severity of the infection. These results also hold up in a cystic fibrosis mouse background, which has a hyperinflammatory immune response yet exhibits reduced bactericidal activity. Thus, we lay the groundwork for future studies to investigate the use of CCR2 inhibitors as a potential therapy to ameliorate lung tissue damage in cystic fibrosis. This could be given alone or as an adjunct therapy with CFTR modulators that significantly improve clinical outcomes for eligible patients but do not completely resolve the persistent infection and inflammation that drive lung tissue damage.

Aspergillus in Children and Young People with Cystic Fibrosis: A Narrative Review

Cystic fibrosis is a severe, inherited, life-limiting disorder, and over half of those living with CF are children. Persistent airway infection and inflammation, resulting in progressive lung function decline, is the hallmark of this disorder. Aspergillus colonization and infection is a well-known complication in people with CF and can evolve in a range of Aspergillus disease phenotypes, including Aspergillus bronchitis, fungal sensitization, and allergic bronchopulmonary aspergillosis (ABPA). Management strategies for children with CF are primarily aimed at preventing lung damage and lung function decline caused by bacterial infections. The role of Aspergillus infections is less understood, especially during childhood, and therefore evidence-based diagnostic and treatment guidelines are lacking. This narrative review summarizes our current understanding of the impact of Aspergillus on the airways of children and young people with CF.

Vanzacaftor-tezacaftor-deutivacaftor versus elexacaftor-tezacaftor-ivacaftor in individuals with cystic fibrosis aged 12 years and older (SKYLINE Trials VX20-121-102 and VX20-121-103): results from two randomised, active-controlled, phase 3 trials

BACKGROUND

The goal of cystic fibrosis transmembrane conductance regulator (CFTR) modulators is to reach normal CFTR function in people with cystic fibrosis. Vanzacaftor-tezacaftor-deutivacaftor restored CFTR function in vitro and in phase 2 trials in participants aged 18 years and older resulting in improvements in CFTR function, as measured by sweat chloride concentrations and lung function as measured by spirometry. We aimed to evaluate the efficacy and safety of vanzacaftor-tezacaftor-deutivacaftor compared with standard of care elexacaftor-tezacaftor-ivacaftor in individuals with cystic fibrosis aged 12 years and older.

METHODS

In two randomised, active-controlled, double-blind, phase 3 trials, individuals aged 12 years and older with stable cystic fibrosis with F508del-minimal function (SKYLINE Trial VX20-121-102) or with F508del-F508del, F508del-residual function, F508del-gating, or elexacaftor-tezacaftor-ivacaftor-responsive-non-F508del genotypes (SKYLINE Trial VX20-121-103) were enrolled at 126 and 159 international sites, respectively. Eligible individuals were entered into a 4-week run-in period, during which they received elexacaftor (200 mg once daily), tezacaftor (100 mg once daily), and ivacaftor (150 mg once every 12 h) as two fixed-dose combination tablets in the morning and one ivacaftor tablet in the evening. They were then randomly assigned (1:1) to either elexacaftor (200 mg once daily), tezacaftor (100 mg once daily), and ivacaftor (150 mg once every 12 h) as two fixed-dose combination tablets in the morning and one ivacaftor tablet in the evening, or vanzacaftor (20 mg once daily), tezacaftor (100 mg once daily), and deutivacaftor (250 mg once daily) as two fixed-dose combination tablets in the morning, for the 52-week treatment period. All participants received matching placebo tablets to maintain the treatment blinding. Randomisation was done using an interactive web-response system and stratified by age, FEV1 % predicted, sweat chloride concentration, and previous CFTR modulator use, and also by genotype for Trial VX20-121-103. The primary endpoint for both trials was absolute change in FEV1 % predicted from baseline (most recent value before treatment on day 1) through week 24 (with non-inferiority of vanzacaftor-tezacaftor-deutivacaftor shown if the lower bound of the 95% CI for the primary endpoint was -3·0 or higher). Efficacy was assessed in all participants with the intended CFTR genotype who were randomly assigned to treatment and received at least one dose of study treatment during the treatment period. Safety was assessed in all participants who received at least one dose of study drug during the treatment period. These trials are registered with ClinicalTrials.gov, NCT05033080 (Trial VX20-121-102) and NCT05076149 (Trial VX20-121-103), and are now complete.

FINDINGS

In Trial VX20-121-102 between Sept 14, 2021, and Oct 18, 2022, 488 individuals were screened, of whom 435 entered the 4-week run-in period, and subsequently 398 were randomly assigned and received at least one dose of elexacaftor-tezacaftor-ivacaftor (n=202) or vanzacaftor-tezacaftor-deutivacaftor (n=196). Median age was 31·0 years (IQR 22·6-38·5), 163 (41%) of 398 participants were female, 235 (59%) were male, and 388 (97%) were White. In Trial VX20-121-103, between Oct 27, 2021, and Oct 26, 2022, 699 individuals were screened, of whom 597 entered the 4-week run-in period, and subsequently 573 participants were randomly assigned and received at least one dose of elexacaftor-tezacaftor-ivacaftor (n=289) or vanzacaftor-tezacaftor-deutivacaftor (n=284). Median age was 33·1 years (IQR 24·5-42·2), 280 (49%) of 573 participants were female, 293 (51%) were male, and 532 (93%) were White. The absolute change in least squares mean FEV1 % predicted from baseline through week 24 for Trial VX20-121-102 was 0·5 (SE 0·3) percentage points in the vanzacaftor-tezacaftor-deutivacaftor group versus 0·3 (0·3) percentage points in the elexacaftor-tezacaftor-ivacaftor group (least squares mean treatment difference of 0·2 percentage points [95% CI -0·7 to 1·1]; p<0·0001), and for Trial VX20-121-103, was 0·2 (SE 0·3) percentage points in the vanzacaftor-tezacaftor-deutivacaftor group versus 0·0 (0·2) percentage points in the elexacaftor-tezacaftor-ivacaftor group (least squares mean treatment difference 0·2 percentage points [95% CI -0·5 to 0·9]; p<0·0001). Most adverse events were mild or moderate, with the most common being infective pulmonary exacerbation (133 [28%] of 480 participants in the pooled vanzacaftor-tezacaftor-deutivacaftor group vs 158 [32%] of 491 in the pooled elexacaftor-tezacaftor-ivacaftor group), cough (108 [23%] vs 101 [21%]), COVID-19 (107 [22%] vs 127 [26%]), and nasopharyngitis (102 [21%] vs 95 [19%]).

INTERPRETATION

Vanzacaftor-tezacaftor-deutivacaftor is non-inferior to elexacaftor-tezacaftor-ivacaftor in terms of FEV1 % predicted, and is safe and well tolerated. Once daily dosing with vanzacaftor-tezacaftor-deutivacaftor reduces treatment burden, potentially improving adherence, compared with the twice daily regimen of the current standard of care. The restoration of CFTR function and the potential variants treated are also considerations that should be compared with currently available CFTR modulators.

FUNDING

Vertex Pharmaceuticals.

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.

Longitudinal Study on Clinical Predictors for Allergic Bronchopulmonary Aspergillosis in Children and Young People with Cystic Fibrosis Highlights the Impact of Infection with Aspergillus and Pseudomonas and Ivacaftor Treatment

Allergic bronchopulmonary aspergillosis (ABPA) is a well-known complication in children and young people with cystic fibrosis (CF) and without treatment causes structural lung damage. We performed a longitudinal observational study to identify clinical risk factors for ABPA in a cohort of children and young people with CF aged 8 to 17 years at baseline. Anonymised annual review UK CF Registry data from 2009 to 2019 for patients aged 8-17 years in 2009 were collected, with lung transplant recipients excluded. Baseline characteristics are presented for the whole group and cross-sectional comparisons made according to the presence of ABPA or not in 2009. Longitudinal analysis from 2009 to 2019 was completed on the group without ABPA in 2009 to identify predictors for the subsequent development of ABPA using a complementary log-log regression model. In 2009, there were 1612 patients, of which 1420 were ABPA-negative and 192 ABPA-positive. Aspergillus colonisation (p = 0.01) and IV antibiotic use (p < 0.0001) were associated with having ABPA in 2009. Longitudinal analysis of the group without ABPA in 2009 identified male gender, younger age, lower lung function, Pseudomonas aeruginosa infection, and Aspergillus colonisation to be significantly associated with the development of ABPA (p < 0.0001). Ivacaftor was significantly associated with reduced ABPA (OR 0.46, p = 0.01) but not lumacaftor/ivacaftor (OR 0.64, p = 0.28). Chronic oral macrolide use was significantly associated with increased risk of development of ABPA (OR 1.30, p < 0.0001). This study shows that lower lung function, Aspergillus colonisation, and Pseudomonas aeruginosa infection in children with CF were associated with the development of ABPA, highlighting the need for enhanced surveillance in these patients. This is the first study to show a protective association of ivacaftor and ABPA.

Comparing Midline and Peripherally Inserted Central Catheters: A Randomized Feasibility Trial

OBJECTIVES

The most effective use of midline catheters in children is not understood. We aimed to (1) test the feasibility of a trial comparing peripherally inserted central catheters (PICCs) to midline catheters in hospitalized children in need of durable vascular access and (2) collect preliminary effectiveness data of the 2 devices.

METHODS

Our study combined a single site, randomized controlled feasibility trial (RCT, primary study) and a prospective observational study (alternative study) comparing PICCs to midline catheters. Hospitalized children aged 2 to 17 years in need of noncentral, medium-term vascular access (5-14 days) were enrolled for 1 year. The primary outcome of the RCT was a 4-measure feasibility outcome, and we had an enrollment goal of 30 participants/arm. Effectiveness outcomes (both studies) included time-to-device removal and all-cause failure.

RESULTS

Between August 2022 and August 2023, only 43 of 260 screened patients met eligibility criteria because of a decrease in eligible PICCs. A total of 35 patients were enrolled: 8 out of 10 in the RCT (4/arm) and 27 out of 33 in the alternative study (21 midline catheters, 6 PICCs). The RCT eligibility goal was not met. The other feasibility measures were met: (1) 80% of eligible patients enrolled, (2) 100% of eligible patients received the assigned intervention, (3) 96% of inserters found the study acceptable, and (4) there were no missing data.

CONCLUSIONS

Because of a decrease in PICC use for noncentral, medium-term vascular access needs, a trial comparing devices may not be practical for assessing the effective use of midline catheters in hospitalized children. Next steps may include a hybrid effectiveness-implementation study evaluating an intravenous catheter selection algorithm that incorporates midline catheters.

Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency

Alpha 1 antitrypsin deficiency (AATD) is a genetic disorder that alters the functionality and/or serum levels of alpha 1 antitrypsin (AAT). Dysfunctional forms of AAT, or low levels of serum AAT, predispose affected individuals to pulmonary complications. When AATD-associated lung disease develops, the most common pulmonary pathology is emphysema. The development of emphysema and decline in lung function varies by AATD genotype and is accelerated by risk factors, such as smoking. To improve the understanding and treatment of AATD, emerging knowledge and unresolved questions need to be discussed. Here we focus on developments in the areas of disease pathogenesis, biomarkers, and clinical endpoints for trials in AATD, as well as barriers to treatment. The clinical impact of AATD on lung function is highly variable and highlights the complexity of AATD pathogenesis, in which multiple underlying processes are involved. Reduced levels of functional AAT disrupt the protease-antiprotease homeostasis, leading to a loss of neutrophil elastase inhibition and the breakdown of elastin within the lung interstitium. Inflammatory processes also play a critical role in the development of AATD-associated lung disease, which is not yet fully understood. Biomarkers associated with the disease and its complications may have an important role in helping to address AATD underdiagnosis and evaluating response to treatment. To improve access to treatment, the problem of underdiagnosis needs to be addressed and the provision of therapeutic options needs to become uniform. Patients should also be empowered to play a key role in the self-management of the disease. Advancing our understanding of the disease will ultimately improve the life expectancy and quality of life for patients affected by AATD.

Cystic fibrosis: new challenges and perspectives beyond elexacaftor/tezacaftor/ivacaftor

Over the past decade, major clinical advances have been made in the healthcare and therapeutic development for cystic fibrosis (CF), a lethal genetic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein. CFTR modulators represent innovative treatments that directly target the primary defects in the mutated CFTR protein and have demonstrated significant clinical benefits for many people with CF (pwCF) who are eligible for these treatments. In particular, the triple combination therapy composed of elexacaftor, tezacaftor, and ivacaftor (ETI) has changed the CF therapeutic landscape by significantly improving lung function, quality of life, and predicted survival rates. Here, we provided a comprehensive summary of the impact of ETI on clinical outcomes and the need for further research on long-term efficacy, side effects, pregnancy, possible drug-drug interactions, and extra-pulmonary manifestations. Moreover, a significant number of pwCF are unresponsive to these drugs or cannot afford their high costs. We, therefore, discussed health inequity issues and alternative therapeutic strategies under development aiming to obtain effective therapies for all pwCF.

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.

Cystic fibrosis-related chronic rhinosinusitis: the key role of a comprehensive evaluation in the era of highly effective modulator therapy

BACKGROUND

Chronic rhinosinusitis (CRS) is prevalent in cystic fibrosis (CF), significantly affecting quality of life. The introduction of CFTR modulators, including elexacaftor-tezacaftor-ivacaftor (ETI), offers promise for improving sinonasal outcomes.

METHODS

We conducted a retrospective cohort multicenter study analyzing electronic medical records of 45 adult CF patients with CRS, predominantly heterozygous for the ΔF508 mutation, treated with ETI between January 2018 and December 2023. Assessments included Sinonasal Outcome Test 22 (SNOT-22), Nasal Polyp Score (NPS), modified Lund-Kennedy Score (mLKS), Lund-Mackay Score (LMS), and olfactory function using smell loss visual analog scale (VAS) and Sniffin' Sticks identification test (SSIT).

RESULTS

After 12 months of ETI therapy, significant improvements were observed in pulmonary function parameters (FEV1, FVC), CRS severity scores (SNOT-22, NPS, mLKS), radiological findings (LMS), and olfactory function. Subgroup analysis suggested enhanced efficacy in patients with prior endoscopic sinonasal surgery.

CONCLUSIONS

ETI therapy demonstrates comprehensive improvements in CRS and olfactory function in CF patients, highlighting the potential of CFTR modulators in managing sinonasal manifestations.

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.

Reported Adverse Events in a Multicenter Cohort of Patients Ages 6-18 Years with Cystic Fibrosis and at Least One F508del Allele Receiving Elexacaftor/Tezacaftor/Ivacaftor

OBJECTIVE

The objective of this study was to describe reported adverse events (AEs) associated with elexacaftor/tezacaftor/ivacaftor (ETI) in a pediatric sample with cystic fibrosis (CF) aged 6-18 years, with at least one F508del variant, followed at multiple Italian CF centers.

STUDY DESIGN

This was a retrospective, multicenter, observational study. All children receiving ETI therapy from October 2019 to December 2023 were included. We assessed the prevalence and type of any reported potential drug-related AEs, regardless of discontinuation necessity. Persistent AEs were defined as those continuing at the end of the observation period.

RESULTS

Among 608 patients on ETI, 109 (17.9%) reported at least 1 AE. The majority (n = 85, 77.9%) were temporary, with a median duration of 11 days (range 1-441 days). Only 7 (1.1%) patients permanently discontinued treatment, suggesting good overall safety of ETI. The most common AEs leading to discontinuation were transaminase elevations (temporary 14.1%, persistent 25.9%) and urticaria (temporary 41.2%, persistent 7.4%). Creatinine phosphokinase elevation was uncommon. No significant differences in AEs were observed based on sex, age groups (6-11 vs 12-18 years), or genotype. Pre-existing CF-related liver disease was associated with an increased risk of transaminase elevations. We identified significant variability in the percentage of reported AEs (ANOVA P value .026).

CONCLUSIONS

This real-world study highlights significant variability in reported AEs. Our findings suggest that ETI is a safe and well-tolerated therapy in children and adolescents with CF. However, further long-term safety and effectiveness investigations are warranted.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Current landscape of cystic fibrosis gene therapy

Cystic fibrosis is a life-threatening disease that is caused by mutations in CFTR, a gene which encodes an ion channel that supports proper function of several epithelial tissues, most critically the lung. Without CFTR, airway barrier mechanisms are impaired, allowing for chronic, recurrent infections that result in airway remodeling and deterioration of lung structure and function. Small molecule modulators can rescue existing, defective CFTR protein; however, they still leave a subset of people with CF with no current disease modifying treatments, aside from lung transplantation. Gene therapy directed to the lung is a promising strategy to modify CF disease in the organ most associated with morbidity and mortality. It is accomplished through delivery of a CFTR transgene with an airway permissive vector. Despite more than three decades of research in this area, a lung directed gene therapy has yet to be realized. There is hope that with improved delivery vectors, sufficient transduction of airway cells can achieve therapeutic levels of functional CFTR. In order to do this, preclinical programs need to meet a certain level of CFTR protein expression in vitro and in vivo through improved transduction, particularly in relevant airway cell types. Furthermore, clinical programs must be designed with sensitive methods to detect CFTR expression and function as well as methods to measure meaningful endpoints for lung structure, function and disease. Here, we discuss the current understanding of how much and where CFTR needs to be expressed, the most advanced vectors for CFTR delivery and clinical considerations for detecting CFTR protein and function in different patient subsets.

Impact of elexacaftor/tezacaftor/ivacaftor therapy on lung clearance index and magnetic resonance imaging in children with cystic fibrosis and one or two F508del alleles

BACKGROUND

We recently demonstrated that elexacaftor/tezacaftor/ivacaftor (ETI) improves the lung clearance index (LCI) and abnormalities in lung morphology detected by magnetic resonance imaging (MRI) in adolescent and adult patients with cystic fibrosis (CF). However, real-world data on the effect of ETI on these sensitive outcomes of lung structure and function in school-age children with CF have not been reported. The aim of this study was therefore to examine the effect of ETI on the LCI and the lung MRI score in children aged 6-11 years with CF and one or two F508del alleles.

METHODS

This prospective, observational, multicentre, post-approval study assessed the longitudinal LCI up to 12 months and the lung MRI score before and 3 months after initiation of ETI.

RESULTS

A total of 107 children with CF including 40 heterozygous for F508del and a minimal function mutation (F/MF) and 67 homozygous for F508del (F/F) were enrolled in this study. Treatment with ETI improved the median (interquartile range (IQR)) LCI in F/MF (-1.0 (-2.0- -0.1); p<0.01) and F/F children (-0.8 (-1.9- -0.2); p<0.001) from 3 months onwards. Further, ETI improved the median (IQR) MRI global score in F/MF (-4.0 (-9.0-0.0); p<0.01) and F/F children (-3.5 (-7.3- -0.8); p<0.001).

CONCLUSIONS

ETI improves early abnormalities in lung ventilation and morphology in school-age children with CF and at least one F508del allele in a real-world setting. Our results support early initiation of ETI to reduce or even prevent lung disease progression in school-age children with CF.

Relationship Between Lung Volumes and Heterogeneity in the Response to Elexacaftor/Tezacaftor/Ivacaftor in Patients With Cystic Fibrosis and Advanced Lung Disease

BACKGROUND

The effects of elexacaftor/tezacaftor/ivacaftor (ETI) on respiratory outcomes for people with cystic fibrosis (CF) were demonstrated by several clinical trials, mainly based on simple spirometry. However, gains in lung function may vary greatly between patients, and predictors of FEV1 change after treatment have yet to be defined.

RESEARCH QUESTION

Which ventilatory parameters are involved in the heterogeneity of FEV1 change after 12-month ETI treatment in people with CF and advanced lung disease?

STUDY DESIGN AND METHODS

This was a multicenter, observational, prospective cohort study at two major CF centers in Italy. We enrolled 47 adults with CF and advanced lung disease (FEV1 < 40% or actively listed for lung transplant) who started ETI treatment between December 2019 and December 2021. At treatment initiation and after 12 months, patients underwent body plethysmography. Values were compared at the two time points. To assess the relationship between baseline plethysmography measurements and treatment-induced changes in FEV1, we used the Spearman rank correlation coefficient (rs) and median quantile regressions.

RESULTS

After 12 months of ETI treatment, there was a significant increase in FEV1 % predicted from a median value of 36.0 (25th-75th percentile, 33-39) to 52 (25th-75th percentile, 43-61) (P < .001). Inspiratory capacity/total lung capacity (TLC) ratio also increased from 32.0 (25th-75th percentile, 28.6-36.9) to 36.3 (25th-75th percentile, 33.4-41.3) (P < .001). Specific airway resistance decreased from 263 (25th-75th percentile, 182-405) to 207 (25th-75th percentile, 120-258) (P < .001). Functional residual capacity/TLC ratio decreased from 68.2 (25th-75th percentile, 63.3-71.9) to 63.9 (25th-75th percentile, 58.8-67.1) (P < .001), and residual volume/TLC ratio decreased from 53.1 (25th-75th percentile, 48.3-59.4) to 45.6 (25th-75th percentile, 39.4-49.8) (P < .001). Changes in FEV1 % predicted negatively correlated with baseline functional residual capacity/TLC ratio (rs = -0.38, P = .009) and residual volume/TLC ratio (rs = -0.42, P = .004). After adjustment for age at treatment initiation and cystic fibrosis transmembrane conductance regulator genotype, we estimated that for each 10-unit increase in baseline residual volume/TLC ratio, the expected median change in FEV1 decreased by 2.3 (95% CI, -5.8 to -0.8).

INTERPRETATION

ETI was associated with improvements in both static and dynamic volumes in people with CF and advanced lung disease. Heterogeneity in FEV1 % predicted change after 12 months of treatment may be predicted by the severity of hyperinflation at baseline.

Advances in Care and Outcomes for Children with Cystic Fibrosis

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

Cystic fibrosis

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

The impact of elexacaftor/tezacaftor/ivacaftor on cystic fibrosis health-related quality of life and decision-making about daily treatment regimens: a mixed methods exploratory study

Background

Elexacaftor/tezacaftor/ivacaftor (ETI) has reduced many symptoms of cystic fibrosis (CF).

Objectives

We sought to identify the impact of ETI on both symptoms and treatment decisions among adults with CF.

Design

Participants were enrolled in a cross-sectional study. Surveys were sent via a RedCap link. Semistructured interviews were administered remotely via Microsoft Teams. Interviews were audio recorded and professionally transcribed.

Methods

We assessed Cystic Fibrosis Questionnaire-Revised (CFQ-R) subscales for physical, respiratory, emotion, and treatment, and analyzed semistructured interviews covering CF treatment regimens and daily living. Quantitative and qualitative results were analyzed separately and via a mixed-methods convergence coding matrix.

Results

Twenty-four adults with CF taking ETI were included. CFQ-R subscale scores (mean scores/standard deviation) were physical (82.1/22.8), respiratory (83.7/11.2), emotion (65.3/14.2), and treatment (57.5/20.1). Three themes about decision-making for non-ETI-treatments emerged: (1) How I'm feeling, (2) Not noticing a difference, and (3) Uncertainty about long-term impact of modifying treatment regimens, and we found participants weighed each of these factors in their treatment decisions. Key findings from mixed-methods analysis show that among individuals experiencing higher CFQ-R scores for physical and respiratory compared to emotion and treatment, there were statements indicating that while those participants were experiencing better physical health, many continued their burdensome treatment regimens.

Conclusion

With little long-term data on the impact of reducing non-ETI treatments, participants weighed how they were feeling, treatment efficacy beliefs, and risk tolerance when making treatment decisions.

Update on advances in cystic fibrosis towards a cure and implications for primary care clinicians

During the past quarter century, the diagnosis and treatment of cystic fibrosis (CF) have been transformed by molecular sciences that initiated a new era with discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The knowledge gained from that breakthrough has had dramatic clinical impact. Although once a diagnostic dilemma with long delays, preventable deaths, and irreversible pathology, CF can now be routinely diagnosed shortly after birth through newborn screening programs. This strategy of pre-symptomatic identification has eliminated the common diagnostic "odyssey" that was a failure of the healthcare delivery system causing psychologically traumatic experiences for parents. Therapeutic advances of many kinds have culminated in CFTR modulator treatment that can reduce the effects of or even correct the molecular defect in the chloride channel -the basic cause of CF. This astonishing advance has transformed CF care as described fully herein. Despite this impressive progress, there are challenges and controversies in the delivery of care. Issues include how best to achieve high sensitivity newborn screening with acceptable specificity; what course of action is appropriate for children who are identified through the unavoidable incidental findings of screening tests (CFSPID/CRMS cases and heterozygote carriers); how best to ensure genetic counseling; when to initiate the very expensive but life-saving CFTR modulator drugs; how to identify new CFTR modulator drugs for patients with non-responsive CFTR variants; how to adjust other therapeutic modalities; and how to best partner with primary care clinicians. Progress always brings new challenges, and this has been evident worldwide for CF. Consequently, this article summarizes the major advances of recent years along with controversies and describes their implications with an international perspective.

Anti-inflammatory effects of elexacaftor/tezacaftor/ivacaftor in adults with cystic fibrosis heterozygous for F508del

Inflammation is a key driver in the pathogenesis of cystic fibrosis (CF). We assessed the effectiveness of elexacaftor/tezacaftor/ivacaftor (ETI) therapy on downregulating systemic and immune cell-derived inflammatory cytokines. We also monitored the impact of ETI therapy on clinical outcome. Adults with CF, heterozygous for F508del (n = 19), were assessed at baseline, one month and three months following ETI therapy, and clinical outcomes were measured, including sweat chloride, lung function, weight, neutrophil count and C-reactive protein (CRP). Cytokine quantifications were measured in serum and following stimulation of peripheral blood mononuclear cells (PBMCs) with lipopolysaccharide (LPS) and adenosine triphosphate and analysed using LEGEND plex™ Human Inflammation Panel 1 by flow cytometry (n = 19). ASC specks were measured in serum and caspase-1 activity and mRNA levels determined from stimulated PBMCs were determined. Patients remained stable over the study period. ETI therapy resulted in decreased sweat chloride concentrations (p < 0.0001), CRP (p = 0.0112) and neutrophil count (p = 0.0216) and increased percent predicted forced expiratory volume (ppFEV1) (p = 0.0399) from baseline to three months, alongside a trend increase in weight. Three months of ETI significantly decreased IL-18 (p< 0.0011, p < 0.0001), IL-1β (p<0.0013, p = 0.0476), IL-6 (p = 0.0109, p = 0.0216) and TNF (p = 0.0028, p = 0.0033) levels in CF serum and following PBMCs stimulation respectively. The corresponding mRNA levels were also found to be reduced in stimulated PBMCs, as well as reduced ASC specks and caspase-1 levels, indicative of NLRP3-mediated production of pro-inflammatory cytokines, IL-1β and IL-18. While ETI therapy is highly effective at reducing sweat chloride and improving lung function, it also displays potent anti-inflammatory properties, which are likely to contribute to improved long-term clinical outcomes.

Year in review 2023 - Back to the future

This review synthesizes articles published in 2023, focusing on the impact of elexacaftor-tezacaftor-ivacaftor (ETI) in cystic fibrosis (CF) care. Real-world data highlights sustained benefits of ETI across age groups, while challenges like neuropsychological side effects persist. Beyond CFTR modulators, research explores telemedicine and novel therapies. Prioritizing equitable access and addressing unmet needs remain crucial for comprehensive CF management.

Reversal of cylindrical bronchial dilatations in a subset of adults with cystic fibrosis treated with elexacaftor/tezacaftor/ivacaftor

BACKGROUND

This study sought to evaluate the impact of elexacaftor/tezacaftor/ivacaftor (ETI) on lung structural abnormalities in adults with cystic fibrosis (awCF) with a specific focus on the reversal of bronchial dilatations.

METHODS

Chest computed tomography (CT) scans performed prior to and 12 months after initiation of ETI were visually reviewed for possible reversal of bronchial dilatations. AwCF with and without reversal of bronchial dilatations (the latter served as controls, with three controls per case) were selected. Visual Brody score, bronchial and arterial diameters, and lung volume were measured on CT.

RESULTS

Reversal of bronchial dilatations was found in 12/235 (5%) awCF treated with ETI. 12 awCF with and 36 without reversal of bronchial dilatations were further analysed (male 56%, mean±sd age 31.6±8.5 years, F508del/F508del CFTR 54% and mean forced expiratory volume in 1 s 58.8±22.3% predicted). The Brody score improved overall from 79.4±29.8 to 54.8±32.3 (p<0.001). Reversal of bronchial dilatations was confirmed by a decrease in bronchial lumen diameter in cases from 3.9±0.9 to 3.2±1.1 mm (p<0.001), whereas it increased in awCF without reversal of bronchial dilatations (from 3.5±1.1 to 3.6±1.2 mm; p=0.002). Reversal of bronchial dilatations occurred in cylindrical (not varicose or saccular) bronchial dilatations. Lung volumes decreased by -6.6±10.7% in awCF with reversal of bronchial dilatations but increased by +2.3±9.6% in controls (p=0.007).

CONCLUSIONS

Although bronchial dilatations are generally considered irreversible, ETI was associated with reversal, which was limited to the cylindrical bronchial dilatation subtype, and occurred in a small subset of awCF. Initiating ETI earlier in life may reverse early bronchial dilatations.