Catalytic Performance in Nitroarene Reduction of Nanocatalyst Based on Noble Metal Nanoparticles Supported on Polymer/s-Layer Protein Hybrids.

We present a novel bionanocatalyst fabricated by the adsorption-reduction of metal ions on a polyurethane/S-layer protein biotemplate. The bioinspired support was obtained by the adsorption of S-layer proteins (isolated from Lentilactobacillus kefiri) on polyurethane particles. Silver and platinum nanoparticles were well-loaded on the surface of the support after the combination with metallic salts and reduction with H2 at room temperature. Transmission electron microscopy analysis revealed the strawberry-like morphology of the bionanocatalysts with a particle size, dn, of 2.39 nm for platinum and 9.60 nm for silver. Both systems catalyzed the hydrogenation of p-nitrophenol to p-aminophenol with high efficiency in water at mild conditions in the presence of NaBH4. Three different amounts of bionanocatalyst were tested, and in all cases, conversions between 97 and 99% were observed. The catalysts displayed excellent recyclability over ten cycles, and no extensive damage in their nanostructure was noted after them. The bionanocatalysts were stable during their production, storage, and use, thanks to the fact that the biosupport provides an effective driving force in the formation and stabilization of the metallic nanoparticles. The successful bioinspired production strategy and the good catalytic ability of the systems are encouraging in the search for nontoxic, simple, clean, and eco-friendly procedures for the synthesis and exploitation of nanostructures.

Impact of CFTR modulator therapy on body composition as assessed by thoracic computed tomography: A follow-up study.

OBJECTIVE: Treatment with cystic fibrosis transmembrane conductance regulator (CFTR) modulators in individuals with cystic fibrosis (CF) has brought a significant change in forced expiratory volume in 1 second (FEV1) and clinical parameters. However, it also results in weight gain. The aim of our study is to evaluate the effect of CFTR modulator treatment on body composition, measured by computed tomography (CT). METHODS: Adult subjects with CF under follow-up at La Princesa University Hospital were recruited. All of them were on elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA) treatment. Body composition analysis was conducted using CT scans and an open-source software. The results were then compared with bioimpedance estimations, as well as other clinical and spirometry data. RESULTS: Our sample consisted of 26 adult subjects. The fat mass compartments on CT scans correlated with similar compartments on bioimpedance, and normal-density muscle mass exhibited a strong correlation with phase angle. Higher levels of very low-density muscle prior to treatment were associated with lower final FEV1 and less improvement in FEV1 after therapy. We observed an increase in total body area (P < 0.001), driven by increases in total fat mass (P < 0.001), subcutaneous fat (P < 0.001), visceral fat (P = 0.002), and intermuscular fat (P = 0.022). The only muscle compartment that showed an increase after treatment was very low-density muscle (P = 0.032). CONCLUSIONS: CT scans represent an opportunity to assess body composition on CF. Combination treatment with CFTR modulators, leads to an improvement in FEV1 and to an increase in body mass in all compartments primarily at the expense of fat mass.

Persistence and evolution of Pseudomonas aeruginosa following initiation of highly effective modulator therapy in cystic fibrosis.

Today, more than 90% of people with cystic fibrosis (pwCF) are eligible for the highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy called elexacaftor/tezacaftor/ivacaftor (ETI) and its use is widespread. Given the drastic respiratory symptom improvement experienced by many post-ETI, clinical studies are already underway to reduce the number of respiratory therapies, including antibiotic regimens, that pwCF historically relied on to combat lung disease progression. Early studies suggest that bacterial burden in the lungs is reduced post-ETI, yet it is unknown how chronic Pseudomonas aeruginosa populations are impacted by ETI. We found that pwCF remain infected throughout their upper and lower respiratory tract with their same strain of P. aeruginosa post-ETI, and these strains continue to evolve in response to the newly CFTR-corrected airway. Our work underscores the continued importance of CF airway microbiology in the new era of highly effective CFTR modulator therapy. IMPORTANCE: The highly effective cystic fibrosis transmembrane conductance regulator modulator therapy Elexakaftor/Tezacaftor/Ivacaftor (ETI) has changed cystic fibrosis (CF) disease for many people with cystic fibrosis. While respiratory symptoms are improved by ETI, we found that people with CF remain infected with Pseudomonas aeruginosa. How these persistent and evolving bacterial populations will impact the clinical manifestations of CF in the coming years remains to be seen, but the role and potentially changing face of infection in CF should not be discounted in the era of highly effective modulator therapy.

In utero and postnatal ivacaftor/lumacaftor therapy rescues multiorgan disease in CFTR-F508del ferrets.

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, with F508del being the most prevalent mutation. The combination of CFTR modulators (potentiator and correctors) has provided benefit to CF patients carrying the F508del mutation; however, the safety and effectiveness of in utero combination modulator therapy remains unclear. We created a F508del ferret model to test whether ivacaftor/lumacaftor (VX-770/VX-809) therapy can rescue in utero and postnatal pathologies associated with CF. Using primary intestinal organoids and air-liquid interface cultures of airway epithelia, we demonstrate that the F508del mutation in ferret CFTR results in a severe folding and trafficking defect, which can be partially restored by treatment with CFTR modulators. In utero treatment of pregnant jills with ivacaftor/lumacaftor prevented meconium ileus at birth in F508del kits and sustained postnatal treatment of CF offspring improved survival and partially protected from pancreatic insufficiency. Withdrawal of ivacaftor/lumacaftor treatment from juvenile CF ferrets reestablished pancreatic and lung diseases, with altered pulmonary mechanics. These findings suggest that in utero intervention with a combination of CFTR modulators may provide therapeutic benefits to individuals with F508del. This CFTR-F508del ferret model may be useful for testing therapies using clinically translatable endpoints.

Elexacaftor/tezacaftor/ivacaftor influences body composition in adults with cystic fibrosis: a fully automated CT-based analysis.

A poor nutritional status is associated with worse pulmonary function and survival in people with cystic fibrosis (pwCF). CF transmembrane conductance regulator modulators can improve pulmonary function and body weight, but more data is needed to evaluate its effects on body composition. In this retrospective study, a pre-trained deep-learning network was used to perform a fully automated body composition analysis on chest CTs from 66 adult pwCF before and after receiving elexacaftor/tezacaftor/ivacaftor (ETI) therapy. Muscle and adipose tissues were quantified and divided by bone volume to obtain body size-adjusted ratios. After receiving ETI therapy, marked increases were observed in all adipose tissue ratios among pwCF, including the total adipose tissue ratio (+ 46.21%, p < 0.001). In contrast, only small, but statistically significant increases of the muscle ratio were measured in the overall study population (+ 1.63%, p = 0.008). Study participants who were initially categorized as underweight experienced more pronounced effects on total adipose tissue ratio (p = 0.002), while gains in muscle ratio were equally distributed across BMI categories (p = 0.832). Our findings suggest that ETI therapy primarily affects adipose tissues, not muscle tissue, in adults with CF. These effects are primarily observed among pwCF who were initially underweight. Our findings may have implications for the future nutritional management of pwCF.

Predicting lung function decline in cystic fibrosis: the impact of initiating ivacaftor therapy.

BACKGROUND: Modulator therapies that seek to correct the underlying defect in cystic fibrosis (CF) have revolutionized the clinical landscape. Given the heterogeneous nature of lung disease progression in the post-modulator era, there is a need to develop prediction models that are robust to modulator uptake. METHODS: We conducted a retrospective longitudinal cohort study of the CF Foundation Patient Registry (N = 867 patients carrying the G551D mutation who were treated with ivacaftor from 2003 to 2018). The primary outcome was lung function (percent predicted forced expiratory volume in 1 s or FEV1pp). To characterize the association between ivacaftor initiation and lung function, we developed a dynamic prediction model through covariate selection of demographic and clinical characteristics. The ability of the selected model to predict a decline in lung function, clinically known as an FEV1-indicated exacerbation signal (FIES), was evaluated both at the population level and individual level. RESULTS: Based on the final model, the estimated improvement in FEV1pp after ivacaftor initiation was 4.89% predicted (95% confidence interval [CI]: 3.90 to 5.89). The rate of decline was reduced with ivacaftor initiation by 0.14% predicted/year (95% CI: 0.01 to 0.27). More frequent outpatient visits prior to study entry and being male corresponded to a higher overall FEV1pp. Pancreatic insufficiency, older age at study entry, a history of more frequent pulmonary exacerbations, lung infections, CF-related diabetes, and use of Medicaid insurance corresponded to lower FEV1pp. The model had excellent predictive accuracy for FIES events with an area under the receiver operating characteristic curve of 0.83 (95% CI: 0.83 to 0.84) for the independent testing cohort and 0.90 (95% CI: 0.89 to 0.90) for 6-month forecasting with the masked cohort. The root-mean-square errors of the FEV1pp predictions for these cohorts were 7.31% and 6.78% predicted, respectively, with standard deviations of 0.29 and 0.20. The predictive accuracy was robust across different covariate specifications. CONCLUSIONS: The methods and applications of dynamic prediction models developed using data prior to modulator uptake have the potential to inform post-modulator projections of lung function and enhance clinical surveillance in the new era of CF care.

PREFUL MRI for Monitoring Perfusion and Ventilation Changes after Elexacaftor-Tezacaftor-Ivacaftor Therapy for Cystic Fibrosis: A Feasibility Study.

Purpose To assess the feasibility of monitoring the effects of elexacaftor-tezacaftor-ivacaftor (ETI) therapy on lung ventilation and perfusion in people with cystic fibrosis (CF), using phase-resolved functional lung (PREFUL) MRI. Materials and Methods This secondary analysis of a multicenter prospective study was carried out between August 2020 and March 2021 and included participants 12 years or older with CF who underwent PREFUL MRI, spirometry, sweat chloride test, and lung clearance index assessment before and 8-16 weeks after ETI therapy. For PREFUL-derived ventilation and perfusion parameter extraction, two-dimensional coronal dynamic gradient-echo MR images were evaluated with an automated quantitative pipeline. T1- and T2-weighted MR images and PREFUL perfusion maps were visually assessed for semiquantitative Eichinger scores. Wilcoxon signed rank test compared clinical parameters and PREFUL values before and after ETI therapy. Correlation of parameters was calculated as Spearman ρ correlation coefficient. Results Twenty-three participants (median age, 18 years [IQR: 14-24.5 years]; 13 female) were included. Quantitative PREFUL parameters, Eichinger score, and clinical parameters (lung clearance index = 21) showed significant improvement after ETI therapy. Ventilation defect percentage of regional ventilation decreased from 18% (IQR: 14%-25%) to 9% (IQR: 6%-17%) (P = .003) and perfusion defect percentage from 26% (IQR: 18%-36%) to 19% (IQR: 13%-24%) (P = .002). Areas of matching normal (healthy) ventilation and perfusion increased from 52% (IQR: 47%-68%) to 73% (IQR: 61%-83%). Visually assessed perfusion scores did not correlate with PREFUL perfusion (P = .11) nor with ventilation-perfusion match values (P = .38). Conclusion The study demonstrates the feasibility of PREFUL MRI for semiautomated quantitative assessment of perfusion and ventilation changes in response to ETI therapy in people with CF. Keywords: Pediatrics, MR-Functional Imaging, Pulmonary, Lung, Comparative Studies, Cystic Fibrosis, Elexacaftor-Tezacaftor-Ivacaftor Therapy, Fourier Decomposition, PREFUL, Free-Breathing Proton MRI, Pulmonary MRI, Perfusion, Functional MRI, CFTR, Modulator Therapy, Kaftrio Clinical trial registration no. NCT04732910 Supplemental material is available for this article. © RSNA, 2024.

Circular economical approach of extracting nanocarbons from waste pea peel for sensing of p-nitrophenol and its conversion into paracetamol.

An important paradigm shift towards the circular economy is to prioritize waste prevention, reuse, recycling, and recovery before disposal is necessary. In this context, a sustainable protocol of converting waste pea peel (wPP) into low-cost carbon nanomaterials for sensing and conversion of p-nitrophenol (p-NP) into value-added paracetamol is being reported. Two fractions of the carbonaceous nanomaterials were obtained after the hydrothermal treatment (HT) of wPP, firstly an aqueous portion containing water-soluble carbon dots (wPP-CDs) and a solid residue, which was converted into carbonized biochar (wPP-BC). Blue-colored fluorescent wPP-CDs displayed excitation-dependent and pH-independent properties with a quantum yield (QY) of 8.82 %, which were exploited for the fluorescence sensing of p-NP with 4.20 µM limit of detection. Pyrolyzed biochar acting as an efficient catalyst effectively reduces p-NP to p-aminophenol (p-AP) in just 16 min with a 0.237 min-1 rate of conversion. Furthermore, the produced p-AP was converted into paracetamol, an analgesic and antipyretic drug, to achieve zero waste theory. Thus, this study provides the execution of sustainable approaches based on the integral valorization of biowaste that can be further recycled and reused, offering an effective way to attain a profitable circular economy.

Ivacaftor attenuates gentamicin-induced ototoxicity through the CFTR-Nrf2-HO1/NQO1 pathway.

OBJECTIVES: Gentamicin is one of the most common ototoxic drugs that can lower patients' quality of life. Oxidative stress is a key factors inducing sensory hair cell death during gentamicin administration. So far, there are no effective drugs to prevent or treat gentamicin- induced hearing loss. A recent study found cystic fibrosis transmembrane conductance regulator (CFTR) as a new target to modulate cellular oxidative balance. The objective of this study was to estimate the effect of the CFTR activator ivacaftor on gentamicin-induced ototoxicity and determine its mechanism. METHODS: The hair cell count was analyzed by Myosin 7a staining. Apoptosis was analyzed by TUNEL Apoptosis Kit. Cellular reactive oxygen species (ROS) level was detected by DCFH-DA probes. The Nrf2 related proteins expression levels were analyzed by western blot. RESULTS: An in vitro cochlear explant model showed that gentamicin caused ROS accumulation in sensory hair cells and induced apoptosis, and this effect was alleviated by pretreatment with ivacaftor. Western blotting showed that ivacaftor administration markedly increased the protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO1), and NAD(P)H:quinone oxidoreductase 1 (NQO1). The protective effect of ivacaftor was abolished by the Nrf2 inhibitor ML385. DISCUSSION: Our results indicate the protective role of the CFTR-Nrf2-HO1/NQO1 pathway in gentamicin-induced ototoxicity. Ivacaftor may be repositioned or repurposed towards aminoglycosides-induced hearing loss.

Perceived burden of respiratory physiotherapy in people with cystic fibrosis taking elexacaftor-tezacaftor-ivacaftor combination: a 1-year observational study.

BACKGROUND: To limit the progression of disease, people with cystic fibrosis (pwCF) perform daily respiratory physiotherapy, which is perceived as the most burdensome routine in managing their condition. The elexacaftor-tezacaftor-ivacaftor (ETI) combination has changed respiratory management. OBJECTIVE: To investigate how the perceived treatment burden changed in 1 year of treatment with ETI. DESIGN: Prospective observational study. METHODS: Ad hoc questionnaires for the pwCF and for the caregivers of pwCF < 18 years were administered before the initiation of ETI therapy and then at 6-12 months. The Cystic Fibrosis Questionnaire-Revised (CFQ-R) and the Sinonasal Outcome Test (SNOT-22) were administered to explore disease-related symptoms and social limitations. The International Physical Activity Questionnaire was used to determine levels of physical activity. Mixed-effect models were fitted to explore whether the time engaged in respiratory physiotherapy changed during 1 year. RESULTS: The study included 47/184 pwCF aged 21.4 (5.7) years, who completed 1 year of ETI therapy. At 6 months, time on aerosol therapy was decreased by 2.5 (95% CI -32.9 to 27.8) min/day, time on airway clearance therapies (ACTs) was decreased by 8.8 (95% CI -25.9 to 8.3) min/day, and time for cleaning and disinfecting respiratory equipment was decreased by 10.6 (95% CI -26.5 to 5.3) min/day. At 1 year, gains in time saved were nearly 15 min/day on average. At 1 year, 5/47 (10.6%) pwCF reported that they had discontinued positive expiratory pressure mask. CONCLUSION: PwCF on ETI may note less time engaged in their daily respiratory physiotherapy routine. Nonetheless, aerosol therapy, ACTs and maintaining respiratory equipment were still perceived as time-consuming daily activities.

Understanding the challenges of respiratory physiotherapy in individuals with cystic fibrosis using triple therapy: a one-year study.In order to slow down the progression of their disease, people with cystic fibrosis typically do daily respiratory physiotherapy, which they find to be the most challenging part of managing their condition. The elexacaftor-tezacaftor-ivacaftor combination has changed how they manage their respiratory health. We wanted to see how the perceived difficulty of the treatment changed over one year of using elexacaftor-tezacaftor-ivacaftor. We gave questionnaires to people with cystic fibrosis and to their caregivers before they started the triple therapy and again at 6-12 months. We also used two international questionnaires to learn about symptoms and social limitations related to the disease. The International Physical Activity Questionnaire helped us understand their physical activity levels. We used statistical models to see if the time spent on respiratory physiotherapy changed over the year. Our study involved 47 individuals with cystic fibrosis, with an average age of 21 years, who completed one year of elexacaftor-tezacaftor-ivacaftor therapy. After 6 months, time spent on aerosol therapy decreased by 2.5 minutes per day, time on airway clearance therapies decreased by 8.8 minutes per day, and time for cleaning respiratory equipment decreased by 10.6 minutes per day. By the end of the year, they were saving almost 15 minutes per day on average. At one year, 5 out of 47 said they had stopped using the positive expiratory pressure mask. People with cystic fibrosis using elexacaftor-tezacaftor-ivacaftor may find that they spend less time on their daily respiratory physiotherapy routine. However, activities like aerosol therapy, airway clearance therapies, and maintaining respiratory equipment were still seen as time-consuming.

Surgical and medical management of chronic rhinosinusitis in pediatric cystic fibrosis patients: Impact on olfactory symptoms.

BACKGROUND AND PURPOSE: Olfactory dysfunction (OD) commonly occurs in patients with sinonasal dysfunction, but the prevalence and severity of olfactory issues in adolescents with cystic fibrosis (AwCF) is unclear. OD may contribute to dietary deficiencies and exacerbate nutritional challenges. We sought to review literature on the effectiveness of medical and surgical management of sinonasal symptoms in AwCF and the associated impact on olfactory function. METHODS: We performed a systematic literature search of PubMed, Embase, Web of Science, and Ebsco CINAHL from 1980 to 2022 per PRISMA-ScR protocols to conduct a scoping review in an effort to compile data on study design, patient demographics, clinical characteristics and outcomes, along with risk of bias. RESULTS: Of 368 abstracts, 3 articles exclusively evaluated AwCF for a total of 34 patients. Two studies evaluated endoscopic sinus surgery (ESS) and dornase alfa. An additional 6 articles were included for mixed pediatric and adult CF populations totaling 313 patients. Interventions included ESS, elexacaftor-tezacaftor-ivacaftor (ETI), ivacaftor, saline, dornase alfa, hyaluronic acid, and hyaluronic acid-tobramycin combination. Outcome measures included subjective assessment of OD using non-validated (4/9) and validated (4/9) surveys, and psychophysical (1/9) smell testing. Studies evaluating ESS, FESS, dornase alfa, ivacaftor, and both hypertonic and isotonic saline reported statistically significant improvement in OD, whereas ETI failed to improve OD despite improvement in other quality of life measures. CONCLUSIONS: There is limited data regarding the impact of medical and surgical interventions on olfaction for AwCF. Assessment of olfaction was often limited to subjective and qualitative self-report. We suggest that tracking of olfactory outcomes with psychophysical testing is critical in this population with dietary challenges and weight management issues.

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.

Production of Biomass-Derived p-Hydroxybenzamide: Synthesis of p-Aminophenol and Paracetamol.

As we work to transition the modern society that is based on non-renewable chemical feedstocks to a post-modern society built around renewable sources of energy, fuels, and chemicals, there is a need to identify the renewable resources and processes for converting them to platform chemicals. Herein, we explore a strategy for utilizing the p-hydroxybenzoate in biomass feedstocks (e. g., poplar and palm trees) and converting it into a portfolio of commodity chemicals. The targeted bio-derived product in the first processing stage is p-hydroxybenzamide produced from p-hydroxybenzoate esters found in the plant. In the second stage a continuous reaction process converts the p-hydroxybenzamide to p-aminophenol via the Hofmann rearrangement and recovers the unreacted p-hydroxybenzamide. In the third stage the p-aminophenol can be acetylated to form paracetamol, which is readily isolated by liquid/liquid extraction at >95 % purity and an overall p-hydroxybenzamide-to-paracetamol process yield of ~90 %. We explore how utilization of protecting groups alters the challenges in this process and expands the portfolio of possible products to include p-(methoxymethoxy)aniline and N-acetyl-p-(methoxymethoxy)aniline. These target compounds could become value-added renewably-sourced platform chemicals that could be used to produce biodegradable plastics, pigments, and pharmaceuticals.

Use of CFTR Modulators for Cystic Fibrosis in a Patient with Liver Transplant and ESRD on Hemodialysis.

Cystic fibrosis is an autosomal recessive disorder caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most recent therapeutic approach to cystic fibrosis aims to correct structural and functional abnormalities of CFTR protein. CFTR modulators including ivacaftor-tezacaftor-elexacaftor are used in patients with F508del mutation, with clinical improvement. To date, there are no experiences of CFTR modulator therapy in cystic fibrosis patients with organ transplantation and severe renal impairment. We report the case of a patient diagnosed with cystic fibrosis with F508del mutation, who underwent liver transplantation at the age of 19 and started hemodialysis at the age of 24 due to end-stage renal disease secondary to membranous glomerulonephritis. She was treated with Kaftrio (ivacaftor-tezacaftor-elexacaftor) with clinical benefits on appetite, improvement of body mass index, and reduction of pulmonary exacerbations. A reduction of dosage to 75% of the standard dose was required due to alterations of the liver function. Conclusions. Use of CFTR modulators in patient with cystic fibrosis, liver transplant and end-stage renal disease could be considered safe but a clinical and laboratoristic monitoring of hepatic function is needed.

Comprehensive Assessment of CFTR Modulators' Therapeutic Efficiency for N1303K Variant.

p.Asn1303Lys (N1303K) is a common missense variant of the CFTR gene, causing cystic fibrosis (CF). In this study, we initially evaluated the influence of CFTR modulators on the restoration of N1303K-CFTR function using intestinal organoids derived from four CF patients expressing the N1303K variant. The forskolin-induced swelling assay in organoids offered valuable insights about the beneficial effects of VX-770 + VX-661 + VX-445 (Elexacaftor + Tezacaftor + Ivacaftor, ETI) on N1303K-CFTR function restoration and about discouraging the prescription of VX-770 + VX-809 (Ivacaftor + Lumacaftor) or VX-770 + VX-661 (Ivacaftor + Tezacaftor) therapy for N1303K/class I patients. Then, a comprehensive assessment was conducted on an example of one patient with the N1303K/class I genotype to examine the ETI effect on the restoration of N1303K-CFTR function using in vitro the patient's intestinal organoids, ex vivo the intestinal current measurements (ICM) method and assessment of the clinical status before and after targeted therapy. All obtained results are consistent with each other and have proven the effectiveness of ETI for the N1303K variant. ETI produced a significant positive effect on forskolin-induced swelling in N1303K/class I organoids indicating functional improvement of the CFTR protein; ICM demonstrated that ETI therapy restored CFTR function in the intestinal epithelium after three months of treatment, and the patient improved his clinical status and lung function, increased his body mass index (BMI) and reduced the lung pathogenic flora diversity, surprisingly without improving the sweat test results.

Lumacaftor/Ivacaftor Population Pharmacokinetics in Pediatric Patients with Cystic Fibrosis: A First Step Toward Personalized Therapy.

BACKGROUND: A major breakthrough in cystic fibrosis (CF) therapy was achievedAQ1 with CFTR modulators. The lumacaftor/ivacaftor combination is indicated for the treatment of CF in pediatric patients above 6 years old. Pharmacokinetic (PK) studies of lumacaftor/ivacaftor in these vulnerable pediatric populations are AQ2crucial to optimize treatment protocols. OBJECTIVES AND METHODS: The objectives of this study were to describe the population PK (PPK) of lumacaftor and ivacaftor in children with CF, and to identify factors associated with interindividual variability. The association between drug exposure and clinical response was also investigated. RESULTS: A total of 75 children were included in this PPK study, with 191 concentrations available for each compound and known metabolites (lumacaftor, ivacaftor, ivacaftor-M1, and ivacaftor-M6). PPK analysis was performed using Monolix software. A large interindividual variability was observed. The main sources of interpatient variability identified were patient bodyweight and hepatic function (aspartate aminotransferase). Forced expiratory volume in the first second (FEV1) was statistically associated with the level of exposure to ivacaftor after 48 weeks of treatment. CONCLUSIONS: This study is the first analysis of lumacaftor/ivacaftor PPK in children with CF. These data suggest that dose adjustment is required after identifying variability factors to optimize efficacy. The use of therapeutic drug monitoring as a basis for dose adjustment in children with CF may be useful.

Highly effective cystic fibrosis transmembrane conductance (regulator) modulator therapy: shifting the curve for most while leaving some further behind.

PURPOSE OF REVIEW: Traditional cystic fibrosis (CF) care had been focused on early intervention and symptom mitigation. With the advent of highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy (HEMT), in particular, the approval of elexacaftor/tezacaftor/ivacaftor in 2019, there has been a dramatic improvement in outcomes in CF. The purpose of this article is to review the benefits, limitations, and impact of HEMT as well as discuss the new implications, challenges, and hope that modulators bring to people with CF (pwCF). RECENT FINDINGS: HEMT has demonstrated sustained improvement in lung function, nutrition, quality of life, and survival for over 90% of pwCF. As HEMT has delivered such promise, there is a small but significant portion of pwCF who do not benefit from HEMT due to ineligible mutations, intolerance, or lack of accessibility to modulators. SUMMARY: HEMT has significantly improved outcomes, but continued research is needed to understand the new challenges and implications the era of HEMT will bring, as well as how to provide equitable care to those who are unable to benefit from HEMT.