Elexacaftor-tezacaftor-ivacaftor Research Articles

Mental Health of Pediatric Patients with Cystic Fibrosis after 18 Months on Elexacaftor-Tezacaftor-Ivacaftor Therapy.

Research studies are conflicting regarding new highly effective modulators and the association with mental health symptoms for adults and adolescents with cystic fibrosis (CF). For younger children, small studies and case reports indicate a wide range of effects, ranging from improvement in mood to the development of neuropsychiatric symptoms. However, a large placebo-controlled study indicated no causal connection. This study evaluates the frequency and severity of mental health symptoms in children and adolescents while taking elexacaftor/tezacaftor/ivacaftor (ETI). The study includes 81 pediatric patients with CF followed at Nationwide Children's Hospital (NCH). Patient Reported Outcomes Measurement Information System (PROMIS)-Anxiety and Depression, Patient Health Questionnaire 8 (PHQ-8) and Generalized Anxiety Disorder Questionnaire (GAD-7) were used to screen for depression and anxiety. Age-appropriate questionnaires were completed over the first 18 months after initiating ETI. At baseline, majority of participants reported mental health symptoms within normal limits (WNL). For participants with elevated baseline measures, depressive and anxiety symptoms significantly decreased throughout the study period. Depending on the metric, patients experiencing depressive and anxiety symptoms dropped to 2-3% (n = 1, on each depressive measure) and 0% (n = 0, on either anxiety measures) respectively by 18 months. Most pediatric patients with CF did not endorse symptoms of depression or anxiety disorders at ETI initiation. Over the first 18 months of ETI usage, the percentage of patients with these symptoms decreased, suggesting that the percentage of patients experiencing severe symptoms of depression and anxiety may decrease with ongoing use of ETI.

Respiratory Outcomes of Interrupted Modulator Therapies in Children With Cystic Fibrosis.

Cystic fibrosis (CF) is a multisystemic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, resulting in defective synthesis or function of the CFTR protein. Historically, CF treatment focused on managing symptoms and complications. Fortunately, modulator drugs are now available to directly target the defective CFTR protein. However, in some countries, such as Turkey, these drugs are not covered by social insurance. Consequently, many CF patients face barriers to accessing modulatory therapies or must interrupt their treatment. This study demonstrates the impact of interrupting modulator therapy on pulmonary function, emphasizing the need for uninterrupted continuous treatment. In this study, 39 CF patients receiving elexacaftor-tezacaftor-ivacaftor (ETI) at our clinic were retrospectively analyzed. Among the patients, 18 experienced one or more interruptions, ranging from 15 to 210 days during ETI treatment. We analyzed pulmonary function test results from 27 interruption periods. At the beginning of the interruption, the mean percent predicted FEV1 (ppFEV1) was 69.59% ± 25.87%, which decreased to 64.96% ± 24.52% by the end of the interruption. There was a significant decrease with a mean change of 4.62 ± 8.49 (p = 0.008). However, no significant correlation was found between the interruption duration and FEV1 change. Our results demonstrate that pulmonary functions are adversely affected by interruption periods, regardless of their duration. Even short interruptions have a significant impact on pulmonary functions. This underscores the need for uninterrupted continuation of modulatory treatment and for improved policies to ensure equitable access to treatment.

Increased fat mass and obesity risk after elexacaftor–tezacaftor–ivacaftor therapy in young adults with cystic fibrosis

Increased fat mass and obesity risk after elexacaftor–tezacaftor–ivacaftor therapy in young adults with cystic fibrosis

Impact of sociodemographic status and sex on chronic rhinosinusitis and olfaction in people with cystic fibrosis.

Sociodemographic status (SDS) including race/ethnicity and socioeconomic status as approximated by education, income, and insurance status impact pulmonary disease in people with cystic fibrosis (PwCF). The relationship between SDS and chronic rhinosinusitis (CRS) remains understudied. In a prospective, multi-institutional study, adult PwCF completed the 22-Question SinoNasal Outcome Test (SNOT-22), Smell Identification Test (SIT), Questionnaire of Olfactory Disorder Negative Statements (QOD-NS), and Cystic Fibrosis Questionnaire-Revised (CFQ-R). Lund-Kennedy scores, sinus computed tomography, and clinical data were collected. Data were analyzed across race/ethnicity, sex, and socioeconomic factors using multivariate regression. Seventy-three PwCF participated with a mean age of 34.7±10.9 years and 49 (67.1%) were female. Linear regression identified that elexacaftor/tezacaftor/ivacaftor (ETI) use (β=‒4.09, 95% confidence interval [CI] [‒6.08, ‒2.11], p<0.001), female sex (β=‒2.14, 95% CI [‒4.11, ‒0.17], p=0.034), and increasing age (β=‒0.14, 95% CI [‒0.22, ‒0.05], p=0.003) were associated with lower/better endoscopy scores. Private health insurance (β=17.76, 95% CI [5.20, 30.32],p=0.006) and >16 educational years (β=13.50, 95% CI [2.21, 24.80], p=0.020) were associated with higher baseline percent predicted forced expiratory volume in one second (ppFEV1). Medicaid/Medicare insurance was associated with worse endoscopy scores, CFQ-R respiratory scores, and ppFEV1 (all p<0.017), and Hispanic/Latino ethnicity was associated with worse SNOT-22 scores (p=0.047), prior to adjustment for other cofactors. No other SDS factors were associated with SNOT-22, QOD-NS, or SIT scores. Differences in objective measures of CRS severity exist among PwCF related to sex, age, and ETI use. Variant status and race did not influence patient-reported CRS severity measures or olfaction in this study. Understanding how these factors impact response to treatment may improve care disparities among PwCF. NCT04469439.

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

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. 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. 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. 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 Discontinuing Both Hypertonic Saline and Dornase Alfa after Elexacaftor-Tezacaftor-Ivacaftor in Cystic Fibrosis.

Rationale: Evaluating approaches to reduce treatment burden is a research priority among people with cystic fibrosis on highly effective modulators, including elexacaftor-tezacaftor-ivacaftor (ETI). Objectives: We sought to evaluate the impact of discontinuing both hypertonic saline (HS) and dornase alfa (DA) versus continuing both therapies among a subgroup of participants in the SIMPLIFY study who sequentially participated in trials evaluating the independent clinical effects of discontinuing HS and DA. Methods: SIMPLIFY participants ≥12 years old on ETI and constituting a subgroup using both HS and DA at study entry were randomized to the HS or DA trial and then randomized 1:1 to continue or discontinue the applicable therapy for 6 weeks. After completion of the first trial, eligible participants could enroll in the second trial beginning with a 2-week run-in. Study outcomes were compared across the duration of SIMPLIFY participation between a cohort remaining on both therapies during SIMPLIFY and a cohort that sequentially discontinued both as a result of trial randomizations. Multivariable regression models were used to estimate treatment differences, adjusted for time between trials, trial order, baseline age, sex at birth, and percent predicted forced expiratory volume in 1 second (ppFEV1) at study entry. Results: Forty-three participants discontinued both therapies by the end of SIMPLIFY, and 63 remained on both, with overall average ppFEV1 of 96.7% at study entry and 3.9 months as the average duration of follow-up from beginning of the first trial to completion of the second trial, including time between trials. No clinically meaningful difference in the change in ppFEV1 from baseline to completion of the second trial was observed between those who discontinued and those who remained on both therapies (difference: 0.22% off-on; 95% confidence interval = -1.60, 2.03). Changes in lung clearance index at 2.5% starting concentration, patient-reported outcomes, and safety outcomes were also comparable. Patient-reported treatment burden, as measured by a Cystic Fibrosis Questionnaire-Revised subscale, significantly decreased in those who discontinued both therapies. Conclusions: SIMPLIFY participants who sequentially discontinued both HS and DA experienced no meaningful changes in clinical outcomes and reported decreased treatment burden as compared with those who remained on both therapies. These data continue to inform a new era of postmodulator care of people with cystic fibrosis.

The expanded French compassionate programme for elexacaftor–tezacaftor–ivacaftor use in people with cystic fibrosis without a F508del CFTR variant: a real-world study

Elexacaftor-tezacaftor-ivacaftor has been approved in Europe for people with cystic fibrosis with at least one F508del CFTR variant. Additionally, it is approved by the US Food and Drug Administration (FDA) for people with cystic fibrosis with at least one of 177 rare variants. The aims of this study were to describe the clinical response to elexacaftor-tezacaftor-ivacaftor for people with cystic fibrosis without a F508del CFTR variant in France and to determine CFTR variant responsiveness to elexacaftor-tezacaftor-ivacaftor based on the observed clinical response. The French compassionate programme expanded access to elexacaftor-tezacaftor-ivacaftor to people with cystic fibrosis, aged 6 years and older, without a F508del variant, excluding those with two variants previously characterised as non-responsive. Participants at France's 47 cystic fibrosis centres were given a 4-6 week trial of elexacaftor-tezacaftor-ivacaftor and response was determined by a centralised committee based on evolution of clinical data, lung function, and sweat chloride concentration. Responsiveness of individual CFTR variants was derived from observed clinical responses. The first compassionnate programme was launched on May 19, 2022; by March 8, 2024, 516 people with cystic fibrosis had been identified for inclusion in this real-word study: 37 were not included due to the presence of two variants previously characterised as non-responsive to elexacaftor-tezacaftor-ivacaftor, and 479 (229 females [48%] and 250 males [52%]) received elexacaftor-tezacaftor-ivacaftor for 4-6 weeks. Among 443 participants who received no CFTR modulator before elexacaftor-tezacaftor-ivacaftor, 83 had at least one FDA-approved variant, of whom 81 (98%) were responders and continued elexacaftor-tezacaftor-ivacaftor; in responders, mean absolute change in sweat chloride was -44·5 mmol/L (95% CI -39·1 to -49·8) and percentage of predicted FEV1 (ppFEV1) was 11·1 percentage points (95% CI 8·4 to 13·7; both comparisons p<0·0001). Among 360 participants with no FDA-approved variant and no previous CFTR modulator, 177 (49%) were responders; in responders, mean absolute change in sweat chloride was -20·5 mmol/L (-17·2 to -23·8) and ppFEV1 was 13·2 percentage points (11·4 to 15·0; both comparisons p<0·0001). Among 36 participants who were receiving ivacaftor before elexacaftor-tezacaftor-ivacaftor, 32 (89%) continued elexacaftor-tezacaftor-ivacaftor. Of 251 individual CFTR variants, 64 (28 FDA-approved) were classified as responsive or possibly responsive to elexacaftor-tezacaftor-ivacaftor, and 123 (two FDA-approved) as non-responsive or possibly non-responsive to elexacaftor-tezacaftor-ivacaftor. In France, over half of the population with cystic fibrosis without a F508del variant responded to elexacaftor-tezacaftor-ivacaftor, with most responders having no FDA-approved variant. The treatment period was relatively short and further research is warranted to describe the long-term safety and effectiveness of elexacaftor-tezacaftor-ivacaftor in this population. Association Vaincre la Mucoviscidose, Société Française de la Mucoviscidose, and Filière Maladies Rares MUCO-CFTR.

Impact of CFTR modulatory therapies on liver function and fibrosis indices in cystic fibrosis patients: a retrospective analysis from two Romanian medical centers

Background. Patients with cystic fibrosis (CF) frequently require modulatory therapies such as Lumacaftor/Ivacaftor (LI) and Elexacaftor/Tezacaftor/Ivacaftor (ETI) to manage their condition. Given the potential hepatic complications associated with CF, it is critical to understand the impact of these therapies on liver function and fibrosis indices. This study aimed to evaluate the changes in liver function markers and fibrosis indices in CF patients undergoing LI and ETI therapies, with a specific focus on the influence of underlying hepatic disease. Methods. In this retrospective analysis, liver function markers and fibrosis indices were assessed in CF patients receiving ETI (n=24), LI (n=4), or a combination of both (LI/ETI, n=8). Key liver function markers, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, platelet count, and fibrosis indices (APRI and FIB-4), were measured at baseline and at various time points up to 12 months. Results. In patients receiving LI therapy, ALT and AST levels demonstrated a slight but non-significant decrease over six months, accompanied by significant fluctuations in total bilirubin levels. Among those receiving ETI therapy, ALT and AST levels initially increased but stabilized over time, while total bilirubin levels significantly increased from baseline to 12 months. No significant differences were observed in liver function markers between patients with and without hepatic disease under ETI therapy. Trends in fibrosis indices (APRI and FIB-4) were modest and largely non-significant across both therapies. Conclusions. ETI therapy appears to be safe for CF patients, including those with pre-existing hepatic disease, with no significant deterioration in liver function over a 12-month period. However, the observed fluctuations in bilirubin levels underscore the necessity for ongoing monitoring. Further research is warranted to investigate the long-term hepatic effects of LI and ETI therapies.

Gene expression responses of CF airway epithelial cells exposed to elexacaftor/tezacaftor/ivacaftor (ETI) suggest benefits beyond improved CFTR channel function.

The combination of elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) reverses the primary defect in Cystic Fibrosis (CF) by improving CFTR mediated Cl- and HCO3- secretion by airway epithelial cells (AEC), leading to improved lung function and less frequent exacerbations and hospitalizations. However, studies have shown that CFTR modulators like ivacaftor, a component of ETI, has numerous effects on CF cells beyond improved CFTR channel function. Because little is known about the effect of ETI on CF AEC gene expression we exposed primary human AEC to ETI for 48 hours and interrogated the transcriptome by RNA-seq and qPCR. ETI increased CFTR Cl- secretion, and defensin gene expression (DEFB1) an observation consistent with reports of decreased bacterial burden in the lungs of people with CF (pwCF). ETI decreased MMP10 and MMP12 gene expression, suggesting that ETI may reduce proteolytic induced lung destruction in CF. ETI also reduced the expression of the stress response gene heme oxygenase (HMOX1). qPCR analysis confirmed DEFB1, HMOX1, MMP10 and MMP12 gene expression results observed by RNA-seq. Gene pathway analysis revealed that ETI decreased inflammatory signaling, cellular proliferation and MHC Class II antigen presentation. Collectively, these findings suggest that the clinical observation that ETI reduces lung infections in pwCF is related in part to drug induced increases in DEFB1, and that ETI may reduce lung damage by reducing MMP10 and MMP12 gene expression. Moreover, pathway analysis also identified several other genes responsible for the ETI induced reduction in inflammation observed in pwCF.

One-Year Effect of Elexacaftor/Tezacaftor/Ivacaftor Therapy on HbA1c Levels and Insulin Requirement in Patients with Insulin-Dependent Cystic Fibrosis-Related Diabetes: A Retrospective Observational Study.

The impact of ETI therapy on pulmonary function and nutritional status has been widely studied; the literature on the possible outcomes on glycemic control and insulin requirement in patients affected by CFRD is controversial. The main objective of our study was to evaluate HbA1c levels in patients with cystic fibrosis-related diabetes (CFRD) after one year of therapy with elexacaftor/tezacaftor/ivacaftor (ETI). The secondary objective was to study the changes in the total daily insulin dose (TDD), pulmonary function and metabolism in this population. A retrospective single-center observational study was conducted at the Regional Cystic Fibrosis Centre and Diabetology Centre of IRCCS Istituto Giannina Gaslini. The observation period was divided into four different time points: initiation (T0), 3 months (T3mo), 6 months (T6mo) and 12 months (T12mo) of ETI therapy. Demographic and clinical data were collected. The results were then stratified by genotype (homozygous or heterozygous F508del). Twenty-eight patients with CFRD undergoing insulin therapy were included. TDD (IU) significantly decreased at T3mo and T6mo, but not at T12mo, whereas HbA1c decreased significantly at all three times. The number of hospitalizations and pulmonary exacerbations decreased significantly. We demonstrated both improvement in glycemic control (by means of HbA1c) and insulin requirement in insulin-dependent CFRD patients after one year of ETI treatment.

Development of metabolic syndrome in people with Cystic Fibrosis one year after exposure to elexacaftor-tezacaftor-ivacaftor

BackgroundThe constellation of hypertension, truncal obesity, impaired fasting glucose, low high-density lipoprotein, and hypertriglyceridemia is known as metabolic syndrome (MetSyn) and is associated with cardiovascular and other diseases. Elexacaftor-tezacaftor-ivacaftor (ETI) in people with cystic fibrosis (pwCF) is associated with weight gain but effects on cardiovascular risk are unknown. This study sought to investigate ETI exposure and risk for development of MetSyn in pwCF. MethodsA prospective cohort study including pwCF ≥ 18 years old exposed to ETI was performed. All data for calculating MetSyn was collected from the electronic medical record at initiation and 1 year ± 3 months after starting ETI. A total of 152 pwCF exposed to ETI and 34 pwCF never exposed to CF transmembrane conductance regulator modulators were included in the analysis. Changes to hypertension classification was also examined over this period. ResultsAfter 1 year of ETI there was an increase in MetSyn from 13 to 30 pwCF, p < 0.0001. No new cases of MetSyn were seen in the group not exposed to ETI. After 1 year of ETI, more people met criteria for class 1 (BP 130–139/90–99 mm Hg) or class 2 hypertension (BP ≥140/≥90 mm Hg) regardless of prior modulator exposure, p < 0.0001. ConclusionsExposure to ETI for 1 year resulted in an increased number of cases of MetSyn. There was an increased incidence of hypertension associated with ETI exposure. Additional studies are needed to further examine this trend and to determine if these changes will translate to cardiovascular complications over time.

Heightened mitochondrial respiration in CF cells is normalised by triple CFTR modulator therapy through mechanisms involving calcium

BackgroundCystic fibrosis (CF) is associated with increased resting energy expenditure. However, the introduction of elexacaftor/tezacaftor/ivacaftor (ETI) has resulted in a paradigm shift in nutritional status for many people with CF, with increase body mass index and reduction in the need for nutritional support. While these changes are likely to reflect improved clinical status and an associated downregulation of energy expenditure, they may also reflect drug-induced alterations in metabolic perturbations within CF cells. We hypothesise that some of these changes relate to normalisation of mitochondrial respiration in CF. MethodsUsing wild-type (WT) and F508del/F508del CFTR human bronchial epithelial cell lines (HBE cell lines) and baby hamster kidney (BHK) cells we examined the impact of ETI on cellular metabolism. We monitored mitochondrial respiration, using Seahorse extracellular flux assays and monitored mitochondrial reactive oxygen species (mROS) and intracellular calcium levels by flow cytometry. ResultsIncreased mitochondrial respiration was found in HBE cell lines and BHK cells expressing CFTR F508del/F508del when assessing basal, maximal, spare respiratory capacities and ATP production, as well as increased mitochondrial ROS generated via forward electron transport. ETI significantly decreased basal, maximal, spare respiratory capacity and ATP production to WT levels or below. Calcium blocker, BAPTA-AM normalised mitochondrial respiration, suggesting a calcium-mediated mechanism. ETI decreased intracellular calcium levels in CF cells to the same extent as BAPTA-AM, highlighting the importance of calcium and chloride in mitochondrial respiration in CF. ConclusionsCF cell lines exhibit increased mitochondrial respiration, which can be downregulated by ETI therapy through mechanisms involving calcium.

Calibrating sweat chloride levels to CFTR activity via ETI effects on CF subjects with one or two F508DEL mutations

BackgroundIt is difficult to determine CFTR activity following highly effective CFTR modulator therapies (HEMT). The sweat gland provides two biomarkers of CFTR activity: a linear readout via the β-sweat rate and a logarithmic readout via sweat chloride concentration (SCC). In prior work, different logarithmic functions were generated to calibrate SCC with the percent of healthy control CFTR activity (HCCFTR). Two functions, A and B, were fit to SCC means from healthy controls set = 100 % and CF carriers measured as 50 % HCCFTR. A and B differ in the % HCCFTR activity assigned to SCC for minimal function mutations = 0.01 % for A and 1 % for B. MethodsHere, the functions are evaluated based on retrospective analysis of three multi-center studies of CF subjects with one or two F508del mutations treated with Elexacaftor/Tezacaftor/Ivacaftor (ETI). Predictions of the percent HCCFTR activity for one vs two mutations were compared for the two functions. The expectation is that after ETI treatment, subjects with two responsive mutations will have 2-fold higher HCCFTR activity than subjects with only one. The hypothesis is that the SCCHCCFTR function that most closely fits that expectation provides the more accurate prediction of CFTR activity. ResultsIn two separate comparisons, function B most accurately predicted a 2-fold (1.9, 2.3-fold) higher level of HCCFTR activity in subjects on ETI with two vs. one responsive mutation. Function A predicted a 4, 5.5-fold higher level. ConclusionsFunction B predicts that 60 mmol/L SCC, the cutoff for a CF diagnosis, is associated with 10 % HCCFTR activity. Comparing HEMT effects on subjects with one or two mutations provides an additional tool for calibrating SCC to CFTR activity.

Functional and radiological sinonasal outcomes of CFTR modulators for sinus disease in cystic fibrosis: A meta-analysis.

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators improve pulmonary outcomes in cystic fibrosis (CF) by stabilizing the CFTR protein on respiratory epithelial surfaces. To determine the efficacy of CFTR modulators on sinonasal outcomes in patients with CF, we performed a meta-analysis of clinical trials to date that include functional and radiographic evidence of sinus disease. English full-text articles were searched in PubMed, Embase, and Scopus databases. Two reviewers screened articles and a third reviewer resolved disagreements. Articles were included if they reported functional or radiological sinonasal outcomes in patients with CF before and after CFTR modulator therapies. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed, and the risk of bias in non-randomized studies of interventions tool was used for quality assessment. The generic inverse variance method with random effects model was used for meta-analysis. Standardized mean difference (SMD) and mean difference (MD) were used as effect measurements. Seven prospective and two retrospective studies representing 248 patients were included in this analysis. There was a significant improvement in sinonasal outcome test-22 scores on elexacaftor‒tezacaftor‒ivacaftor (MD=12.80, [95% confidence interval, CI: 10.46‒15.13], p<0.001, n=222), with no heterogeneity detected (I2=0%, p=0.820). There was also a significant improvement in Lund‒Mackay scores (SMD=1.25, [95% CI: 0.58‒1.91], p<0.001, n=88), with heterogeneity detected (I2=67%, p=0.030). CFTR modulators improve functional and radiologic sinonasal outcomes. Given the utility of CFTR modulators, the treatment paradigm for CF-related chronic rhinosinusitis promises to evolve.

Elexacaftor/Tezacaftor/Ivacaftor (ETI) Treatment Corrects the Salt-Losing Phenotype in People with Cystic Fibrosis

Elexacaftor/Tezacaftor/Ivacaftor (ETI) Treatment Corrects the Salt-Losing Phenotype in People with Cystic Fibrosis

Impact of Elexacaftor–Tezacaftor–Ivacaftor Therapy on Body Composition, Dietary Intake, Biomarkers, and Quality of Life in People with Cystic Fibrosis: A Prospective Observational Study

Background: The combination of elexacaftor–tezacaftor–ivacaftor modulators (ETI) has improved clinical outcomes for people with cystic fibrosis (pwCF). Objectives: This study aimed to evaluate changes in nutritional and morphofunctional assessments, as well as anxiety, depression symptoms, and quality of life, in pwCF after starting ETI therapy. Methods: This was a prospective observational study. We measured body composition (fat mass [FM] and fat-free mass [FFM]) using bioelectrical impedance analysis (BIA) and skinfold thickness measurements (SMs). We also assessed hand grip strength, dietary intake via surveys, blood and stool biomarkers, symptoms of anxiety and depression using the Hospital Anxiety and Depression Scale [HADS], and quality of life through the Cystic Fibrosis Questionnaire—Revised (CFQR). Results: A total of 31 pwCF were evaluated. Significant improvements were observed in respiratory function and quality of life, alongside an average weight increase of approximately 5 kg (60% FM and 40% FFM). The prevalence of malnutrition, based on BMI and the FFM index, decreased significantly, while the rate of overweight/obesity increased. Biomarker analysis indicated better nutrient absorption and reduced intestinal inflammation, as evidenced by significant changes in faecal calprotectin, nitrogen, and fat levels, as well as blood lipid and vitamin profiles. Conclusions: Despite a reduction in caloric intake, an increase in weight was observed one year after initiating ETI. This increase was attributed to gains in both FM and FFM, suggesting improved metabolic efficiency and nutrient absorption. Both SM and BIA were found to be useful assessment tools. These findings indicate the need to modify the nutritional approach, focusing on the quality rather than the quantity of intake, and aiming for an appropriate body composition (FFM) rather than solely focusing on BMI.

CFTR modulators response of S737F and T465N CFTR variants on patient-derived rectal organoids

BackgroundPredictions based on patient-derived materials of CFTR modulators efficacy have been performed lately in patient-derived cells, extending FDA-approved drugs for CF patients harboring rare variants. Here we developed intestinal organoids from subjects carrying S737F- and T465N-CFTR in trans with null alleles to evaluate their functional impact on CFTR protein function and their restoration upon CFTR modulator treatment. The characterization of S737F-CFTR was performed in two subjects recently assessed in nasal epithelial cells but not in colonoids.ResultsOur functional analysis (Ussing chamber) confirmed that S737F-CFTR is a mild variant with residual function as investigated in colonoids of patients with S737F/Dele22-24 and S737F/W1282X genotypes. An increase of current upon Elexacaftor/Tezacaftor/Ivacaftor (ETI) treatment was recorded for the former genotype. T465N is a poorly characterized missense variant that strongly impacts CFTR function, as almost no CFTR-mediated anion secretion was registered for T465N/Q39X colonoids. ETI treatment substantially improved CFTR-mediated anion secretion and increased the rescue of mature CFTR expression compared to either untreated colonoids or to dual CFTR modulator therapies.ConclusionsOur study confirms the presence of a residual function of the S737F variant and its limited response to CFTR modulators while predicting for the first time the potential clinical benefit of Trikafta® for patients carrying the rare T465N variant.

Impact of the expanded label for elexacaftor/tezacaftor/ivacaftor in people with cystic fibrosis with no F508del variant in the USA.

Elexacaftor/tezacaftor/ivacaftor (ETI), which is approved for people with cystic fibrosis (pwCF) with a F508del variant, was further approved based on in vitro data in the USA for those carrying at least one of 177 rare CFTR (cystic fibrosis transmembrane conductance regulator) variants. PwCF, aged ≥6 years, carrying no F508del variant but with at least one of these 177 rare variants, were identified within the US Cystic Fibrosis Foundation Patient Registry (CFFPR) between 2020 and 2022. The evolution of forced expiratory volume in 1 s (FEV1) percentage predicted and rates of pulmonary exacerbations were analysed over the first year following ETI initiation, using a linear regression with generalised estimating equations and a negative binomial model, respectively. A total of 1791 individuals aged ≥6 years with rare CFTR variants were eligible for ETI, corresponding to 5.2% of CFFPR participants. 815 individuals (45.5%), of which 57.9% were already treated with another CFTR modulator, initiated ETI within the first 2 years following approval. Individuals with more severe respiratory disease were more likely to initiate ETI, whereas those previously treated with another CFTR modulator or those with no private insurance coverage had less ETI initiation. ETI initiation was associated with an increase in mean FEV1 % pred by +3.39 (95% CI 2.14-4.64) and a decrease in the rates of pulmonary exacerbations (adjusted rate ratio 0.55, 95% CI 0.38-0.79). These effects were greater in individuals naïve of previous CFTR modulators. Extension of the ETI label to rare CFTR variants is associated with meaningful improvements in lung function and a marked reduction in pulmonary exacerbations.

Gene expression profile of intestinal organoids from people with cystic fibrosis upon exposure to elexacaftor/tezacaftor/ivacaftor

The forskolin-induced swelling assay (FIS) in patient-derived intestinal organoids (PDIOs), used to determine in vitro responsiveness to elexacaftor/tezacaftor/ivacaftor (ETI), showed variability in swelling among PDIOs obtained from people with CF (pwCF) carrying the same F508del/F508del CFTR genotype. We aimed to characterise the effect of ETI on the transcriptional activity of PDIOs-derived cells to understand the intracellular processes triggered by ETI and the differences in treatment response. Six high- and six low-responding PDIOs to ETI, derived from F508del/F508del pwCF, were incubated with or without ETI for 2 to 6 h. Gene expression was assessed using 3′-mRNA sequencing and modelled using negative binomial models. Incubation with ETI resulted in a significant upregulation of several biological processes: mostly related to chemokines and signalling, chemotaxis, and tissue development processes. No changes were observed in abundance of the CFTR transcripts or in CFTR-related gene sets and pathways. The genes and pathways associated with ETI did not overlap with those whose expression changed with time only. PDIOs with a high FIS response did not significantly differ in any interpretable gene from the FIS-low organoids. The changes in the PDIOs gene expression upon the exposure to ETI cannot explain differences in the magnitude of PDIOs FIS-measured response to ETI. In conclusion, on incubation with ETI, genes of the CFTR-related pathways do not change their transcriptional activity; instead, overexpression was observed in genes of inflammatory-like cytokine response and receptor activation pathways.

Elexacaftor/tezacaftor/ivacaftor in people with cystic fibrosis and rare mutations.

The triple combination of elexacaftor/tezacaftor/ivacaftor (ETI) has dramatically improved the outcome of people with Cystic Fibrosis (pwCF) with at least one F508del mutation. However, carriers of rare cystic fibrosis transmembrane conductance regulator (CFTR) variants are not candidates for this innovative treatment. In this observational study, we report the results of the compassionate use of ETI in 10 pwCF carriers of rare mutations after 2 months of treatment. Rectal organoids and short-term cultures of nasal epithelium obtained from rectal suction biopsies and nasal brushing were obtained from four subjects. After 2 months of ETI, all patients (4 males, mean age 30.1 ± 13.3 years) showed a significant increase of FEV1% predicted values [+8.0 (3.5-12.7) %, p < 0.010], body mass index [+0.85 (0-1.22) kg/m2, p < 0.020] and cystic fibrosis questionnaire-revised [+19.5 (6.3-29.2) points, p < 0.009]. A significant decrease of sweat chloride concentration [-11.2 (-1.7 to -34.0) mmol/L, p < 0.020] and exacerbations [-1.5 (-2 to -1), p < 0.008] was also recorded. Overall, 7 out of 10 participants were considered full responders. All patients reported cough disappearance (n = 3) or reduction (n = 7). Long-term oxygen was discontinued in two out of three patients and one also stopped noninvasive ventilation and was removed from the lung transplantation waiting list. Despite the limited number of cases, our results support the use of CFTR modulators in patients with rare CFTR variants that are not currently approved for ETI in Europe.