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Background: Acrolein, an aldehyde in smoke from tobacco products, inhibits CFTR function in vitro. Ivacaftor is an FDA-approved potentiator that improves mutant CFTR function. This human clinical study investigated the relationship between two urinary markers of tobacco smoke exposure - the acrolein metabolite 3-HPMA and the nicotine metabolite NNAL - and sweat chloride response to ivacaftor in the G551D Observational Trial (GOAL)., Methods: 3-HPMA (low: <50th centile; moderate: 50-75th centile; high: >75th centile) and NNAL (detectable/undetectable) in GOAL samples was quantified with LC-MS/MS. Self-report of tobacco smoke exposure (Y/N) served as a subjective measure. Change in sweat chloride from pre- to 6 months post-ivacaftor treatment (ΔSC) was the primary CFTR-dependent readout., Results: The sample included 151 individuals, mean age 20.7 (SD 11.4) years, range 6-59 years. Smoke exposure prevalence was 15 % per self-reports but 27 % based on detectable NNAL. 3-HPMA was increased in those reporting tobacco smoke exposure (607 vs 354 ng/ml, p = 0.008), with a higher proportion of smoke-exposed in the high- vs low-acrolein group (31 % vs 9 %, p=0.040). Compared to low-acrolein counterparts, high-acrolein participants experienced less decrease in sweat chloride (-35.2 vs -48.2 mmol/L; p = 0.020) and had higher sweat chloride values (50.6 vs 37.6 mmol/L; p = 0.020) 6 months post-ivacaftor. The odds of ivacaftor-mediated potentiation to near normative CFTR function (defined as SC 6mo <40 mmol/L) was more than twice as high in the low-acrolein cohort (OR: 2.51, p = 0.026)., Conclusions: Increased urinary 3-HPMA, an acrolein metabolite of tobacco smoke, is associated with a diminished sweat chloride response to ivacaftor potentiation of CFTR function., Competing Interests: Declaration of competing interest None., (Copyright © 2024 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Many people with CF (pwCF) desire a reduction in inhaled treatment burden after initiation of elexacaftor/tezacaftor/ivacaftor. The randomized, open-label SIMPLIFY study showed that discontinuing hypertonic saline (HS) or dornase alfa (DA) was non-inferior to continuation of each treatment with respect to change in lung function over a 6-week period. In this SIMPLIFY substudy, we used gamma scintigraphy to determine whether discontinuation of either HS or DA was associated with deterioration in the rate of in vivo mucociliary clearance (MCC) in participants ≥12 years of age. While no significant differences in MCC endpoints were associated with HS discontinuation, significant improvement in whole and peripheral lung MCC was observed after discontinuing DA. These results suggest that pwCF on ETI with mild lung disease do not experience a subclinical deterioration in MCC that could later impact health outcomes after discontinuing HS, and in fact may benefit from improved MCC after stopping DA treatment., Competing Interests: Declaration of competing interest Unrelated to the submitted work, SHD reports research funding from Chiesi USA, Vertex Pharmaceuticals, Calithera Biosciences, and 4D Molecular Therapeutics, and consulting income from Boehringer Ingelheim and Abbvie. PJM reports grant funding from Vertex Pharmaceuticals and Eloxx. SMR reports grant funding from Vertex Pharmaceuticals, Galapagos/Abbvie, Eloxx, Synspira, Translate Bio, Arcturus, Astra-Zenica, and Ionis, and consulting income from Vertex Pharmaceuticals, Synspira, Renovion, Cystetic Medicines, and Arcturus; all personal conflicts to SMR were resolved or ended in 2022 or before. AHG has clinical trial agreements with AbbVie, 4D Molecular Therapeutics, and Insmed. TEC reports research funding from NIH, Astra Zeneca, Regeneron, Pieris, and the CF Foundation through a Research Development Program award. NMH reports grants from CFF, NIH, and FDA, and DSMB membership for the NIH., (Copyright © 2024. Published by Elsevier B.V.)

Background: Cystic fibrosis associated liver disease (CFLD) carries a significant disease burden with no effective preventive therapies. According to the gut-liver axis hypothesis for CFLD pathogenesis, dysbiosis and increased intestinal inflammation and permeability permit pathogenic bacterial translocation into the portal circulation, leading to hepatic inflammation and fibrosis. Evaluating the effect of CFTR (cystic fibrosis transmembrane conductance regulator) modulation with elexacaftor/tezacaftor/ivacaftor (ETI) may help determine the role of CFTR in CFLD and increase understanding of CFLD pathogenesis, which is critical for developing therapies. We aimed to characterize the fecal microbiota in participants with CF with and without advanced CFLD (aCFLD) before and after ETI., Methods: This is an ancillary analysis of stool samples from participants ages ≥12 y/o enrolled in PROMISE (NCT04038047). Included participants had aCFLD (cirrhosis with or without portal hypertension, or non-cirrhotic portal hypertension) or CF without liver disease (CFnoLD). Fecal microbiota were defined by shotgun metagenomic sequencing at baseline and 1 and 6 months post-ETI., Results: We analyzed 93 samples from 34 participants (11 aCFLD and 23 CFnoLD). Compared to CFnoLD, aCFLD had significantly higher baseline relative abundances of potential pathogens Streptococcus salivarius and Veillonella parvula. Four of 11 aCFLD participants had an initially abnormal fecal calprotectin that normalized 6 months post-ETI, correlating with a significant decrease in S. salivarius and a trend towards decreasing V. parvula., Conclusions: These results support an association between dysbiosis and intestinal inflammation in CFLD with improvements in both post-ETI, lending further support to the gut-liver axis in aCFLD., Competing Interests: Declaration of competing interest JTD – Grant funding from CFF SJS – Grant funding from Vertex, CFF, NIH SMR – Consultant for Vertex; Grant funding from Vertex, CFF, NIH GMS – Consultant for GSK, Genentech, Electromed; Grant funding from Vertex, CFF, NIH DPN – Consultant for Vertex, Genentech; Grant funding from Vertex, CFF, NIH LRH – Grant funding from CFF, NIH MRN – Consultant for UpToDate, Vertex: Grant funding from Gilead, AbbVie, CFF, NIH NG – Grant funding from SCRI-CRSP, (Copyright © 2024. Published by Elsevier B.V.)

Background: The cystic fibrosis transmembrane conductance regulator (CFTR) modulator elexacaftor/tezacaftor/ivacaftor (E/T/I) is highly effective clinically for those with at least one F508del-CFTR allele. The effects of E/T/I on mucociliary clearance (MCC) and sputum properties are unknown. We, therefore, sought to characterize the effects of E/T/I on in vivo MCC and sputum characteristics hypothesized to impact mucus transport., Methods: Forty-four participants ≥12 years of age were enrolled into this prospective, observational trial prior to initiation of E/T/I and had baseline measurement of MCC and characterization of induced sputum and exhaled breath condensate (EBC) samples. Study procedures were repeated after 1 month of E/T/I treatment., Results: Average age was 27.7 years with baseline forced expiratory volume in 1 second (FEV 1 ) of 78.2 % predicted. 52 % of subjects had previously been treated with a 2-drug CFTR modulator combination. The average whole lung MCC rate measured over 60 min (WLAveClr60) significantly improved from baseline to post-E/T/I (14.8 vs. 22.8 %; p = 0.0002), as did other MCC indices. Sputum% solids also improved (modeled mean 3.4 vs. 2.2 %; p<0.0001), whereas non-significant reductions in sputum macrorheology (G', G") were observed. No meaningful changes in exhaled breath condensate endpoints (sialic acid:urea ratio, pH) were observed., Conclusions: E/T/I improved the hydration of respiratory secretions (% solids) and markedly accelerated MCC. These data confirm the link between CFTR function, mucus solid content, and MCC and help to define the utility of MCC and mucus-related bioassays in future efforts to restore CFTR function in all people with CF., Competing Interests: Declaration of Competing Interest All authors received research support from the Cystic Fibrosis Foundation for the conduct of this study. In addition, SHD declares research funding from Vertex Pharmaceuticals, Astra Zeneca, Calithera Biosciences, Chiesi, and 4D Molecular Therapeutics, as well as consulting or advisory fees from Boehringer Ingleheim, Abbvie Pharmaceuticals, and Enterprise Therapeutics; PM reports research support from Eloxx Pharmaceuticals, Vertex Pharmaceuticals; CRE declares research funding Tavanta Therapeutics and the NIDDK; DPN reports consulting fees from Vertex Pharmaceuticals, Respirion, and Kither Biotechnology; WDB reports research funding from Vertex Pharmaceuticals; and SMR reports research funding and non-financial support from Vertex Pharmaceuticals. TEC, JMP, BLL, ERB, ESH, AC, LJE, KZ and JW declare no other relevant conflicts of interest., (Copyright © 2023. Published by Elsevier B.V.)

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation, respiratory symptoms, inflammation of the airways, and systemic manifestations of the disease. Genetic susceptibility and environmental factors are important in the development of the disease, particularly exposure to cigarette smoke which is the most notable risk factor. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are the cause of cystic fibrosis (CF), which shares several pathophysiological pulmonary features with COPD, including airway obstruction, chronic airway inflammation and bacterial colonization; in addition, both diseases also present systemic defects leading to comorbidities such as pancreatic, gastrointestinal, and bone-related diseases. In patients with COPD, systemic CFTR dysfunction can be acquired by cigarette smoking, inflammation, and infection. This dysfunction is, on average, about half of that found in CF. Herein we review the literature focusing on acquired CFTR dysfunction and the potential role in the pathogenesis of comorbidities associated with COPD and chronic bronchitis., Competing Interests: Declaration of competing interest In the past 36 months, M. Miravitlles has received consulting fees from AstraZeneca, Atriva Therapeutics, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, CSL Behring, Inhibrx, Mereo Biopharma, Verona Pharma, Spin Therapeutics, ONO Pharma, Palobiofarma SL, Takeda, Novartis, Novo Nordisk, Sanofi and Grifols, speaker fees from AstraZeneca, GlaxoSmithKline, Boehringer Ingelheim, Chiesi, Cipla, Janssen, Kamada, Menarini, Takeda, Speciality Therapeutics, Zambon, CSL Behring, Grifols and Novartis, support for attending meetings/travel from Novartis, Boehringer Ingelheim and Menarini, research grants from Grifols, and has participated on a data safety monitoring board for Mereo. G.J. Criner has no declarations. M.A. Mall declares editorial support from Novartis Pharma AG since the initial planning of the work, and declares grants from German Ministry for Education and Research and the German Research Foundation, consulting fees from Abbvie, Antabio, Boehringer Ingelheim, Enterprise Therapeutics, Kither Biotech, Pieris Pharmaceuticals, Santhera, Sterna Biologicals and Vertex Paharmaceuticals, lecture fees from Arrowhead Pharmaceuticals, Boehringer Ingelheim and Vertex Pharmaceuticals, travel reimbursement from Boehringer Ingelheim and Vertex Pharmaceuticals, and personal fees for participation on advisory boards from Boehringer Ingelheim, Arrowhead Pharmaceuticals, Vertex Pharmaceuticals, Santhera, Enterprise Therapeutics, Antabio, Kither Biotech, Pari and Abbvie; an elected unpaid member of the ECFS board. S.M. Rowe declares grant support for clinical trials conducted through university grants/contracts from Novartis, TranslateBio, Galapagos/Abbvie, Vertex Pharmaceuticals, research grant through University grants/contracts from Synedgen/Synspira, Eloxx, Ionis and AstraZeneca, consulting fees services on the design and conduct of clinical trials from Arcturus, Cystetic Medicines, Galapagos/Abbvie, Ionis, Novartis, Renovion, Synedgen/Synspira, Vertex Pharmaceuticals, support for travel to attend meetings from Vertex Pharmaceuticals; co-chair of the Next Generation Steering Committee with Vertex Pharmaceuticals, research product for investigator initiated research provided from Synedgen/Synspira and Renovion, consulting services on the design and conduct of clinical trials including stock options for Synedgen/Synspira and Renovion within the past 36 months; MTAs for investigator-initiated and externally funded research efforts from Ionis, Galapagos/Abbvie and Synedgen/Synspira, all in the past 36 months; and declares six patents. C.F. Vogelmeier declares institution grants from German Ministry of Education and Science (BMBF), AstraZeneca, Boehringer Ingelheim, Chiesi, CSL Behring, GlaxoSmithKline, Grifols and Novartis, consulting fees from Aerogen, AstraZeneca, Boehringer Ingelheim, CSL Behring, Chiesi, GlaxoSmithKline, Insmed, Menarini, Novartis and Nuvaira, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Aerogen, AstraZeneca, Boehringer Ingelheim, CSL Behring, Chiesi, GlaxoSmithKline, Insmed, Menarini and Novartis, in the past 36 months. B. Hederer was an employee of Novartis Pharma AG at the timing of writing this manuscript. M. Schoenberger is a full-time employee of Novartis Pharma AG and retains Novartis stock. P. Altman was an employee of Novartis Pharmaceutical Corporation at time of writing this manuscript., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: We previously discovered that Korean red ginseng aqueous extract (RGAE) potentiates the TMEM16A channel, improved mucociliary transport (MCT) parameters in CF nasal epithelia in vitro, and thus could serve as a therapeutic strategy to rescue the MCT defect in cystic fibrosis (CF) airways. The hypothesis of this study is that RGAE can improve epithelial Cl - secretion, MCT, and histopathology in an in-vivo CF rat model., Methods: Seventeen 4-month old CFTR -/- rats were randomly assigned to receive daily oral control (saline, n = 9) or RGAE (Ginsenosides 0.4mg/kg/daily, n = 8) for 4 weeks. Outcomes included nasal Cl - secretion measured with the nasal potential difference (NPD), functional microanatomy of the trachea using micro-optical coherence tomography, histopathology, and immunohistochemical staining for TMEM16a., Results: RGAE-treated CF rats had greater mean NPD polarization with UTP (control = -5.48 +/- 2.87 mV, RGAE = -9.49 +/- 2.99 mV, p < 0.05), indicating, at least in part, potentiation of UTP-mediated Cl - secretion through TMEM16A. All measured tracheal MCT parameters (airway surface liquid, periciliary liquid, ciliary beat frequency, MCT) were significantly increased in RGAE-treated CF rats with MCT exhibiting a 3-fold increase (control, 0.45+/-0.31 vs. RGAE, 1.45+/-0.66 mm/min, p < 0.01). Maxillary mucosa histopathology was markedly improved in RGAE-treated cohort (reduced intracellular mucus, goblet cells with no distention, and shorter epithelial height). TMEM16A expression was similar between groups., Conclusion: RGAE improves TMEM16A-mediated transepithelial Cl - secretion, functional microanatomy, and histopathology in CF rats. Therapeutic strategies utilizing TMEM16A potentiators to treat CF airway disease are appropriate and provide a new avenue for mutation-independent therapies., Competing Interests: Declaration of Competing Interest Bradford A. Woodworth, M.D. is a consultant for Cook Medical, Smith and Nephew, and Medtronic. All other authors have no conflicts of interest to report., (Copyright © 2023. Published by Elsevier B.V.)

Background: Mucus stasis, a hallmark of muco-obstructive disease, results from impaired mucociliary transport and leads to lung function decline and chronic infection. Although therapeutics that target mucus stasis in the airway, such as hypertonic saline or rhDNAse, show some therapeutic benefit, they do not address the underlying electrostatic defect apparent in mucins in CF and related conditions. We have previously shown poly (acetyl, arginyl) glucosamine (PAAG, developed as SNSP113), a soluble, cationic polymer, significantly improves mucociliary transport in a rat model of CF by normalizing the charge defects of CF mucin. Here, we report efficacy in the CFTR-sufficient, ENaC hyperactive, Scnn1b-Tg mouse model that develops airway muco-obstruction due to sodium hyperabsorption and airway dehydration., Methods: Scnn1b-Tg mice were treated with either 250 µg/mL SNSP113 or vehicle control (1.38% glycerol in PBS) via nebulization once daily for 7 days and then euthanized for analysis. Micro-Optical Coherence Tomography-based evaluation of excised mouse trachea was used to determine the effect on the functional microanatomy. Tissue analysis was performed by routine histopathology., Results: Nebulized treatment of SNSP113 significantly improved mucociliary transport in the airways of Scnn1b-Tg mice, without altering the airway surface or periciliary liquid layer. In addition, SNSP113 significantly reversed epithelial hypertrophy and goblet cell metaplasia. Finally, SNSP113 significantly ameliorated eosinophilic crystalline pneumonia and lung consolidation in addition to inflammatory macrophage influx in this model., Conclusion: Overall, this study extends the efficacy of SNSP113 as a potential therapeutic to alleviate mucus stasis in muco-obstructive diseases in CF and potentially in related conditions., Competing Interests: Declaration of Competing Interest Steven M. Rowe received grant funding and consulting fees from Synspira and Synedgen that ended in 2022. Shenda M. Baker provided SNSP113 (PAAG) used in study. Elex S. Harris, Lea Novak, Courtney M. Fernandez-Petty, and Susan E. Birket have no conflicts of interest to report., (Copyright © 2023. Published by Elsevier B.V.)

The growing use of modulator therapies aimed at restoring cystic fibrosis transmembrane conductance regulator (CFTR) protein function in people with cystic fibrosis has fundamentally altered clinical trial strategies needed to advance new therapeutics across an orphan disease population that is now divided by CFTR modulator eligibility. The development of a robust pipeline of nucleic acid-based therapies (NABTs)-initially directed towards the estimated 10% of the cystic fibrosis population who are genetically ineligible for, or intolerant of, CFTR modulators-is dependent on the optimisation of restricted trial participant resources across multiple development programmes, a challenge that will preclude the use of gold standard placebo-controlled trials. Advancement of a full pipeline of symptomatic therapies across the entire cystic fibrosis population will be challenged by smaller effect sizes and uncertainty regarding their clinical importance in a growing modulator-treated population with more mild and stable pulmonary disease. In this Series paper, we aim to lay the foundation for clinical trial strategy and community partnership that must deviate from established and familiar precedent to advance the future pipeline of cystic fibrosis therapeutics., Competing Interests: Declaration of interests NM-H reports grants from the Cystic Fibrosis Foundation (CFF), the National Institutes of Health (NIH; P30 DK 089507 and UL1 TR002319), and the Food and Drug Administration (FDA); consulting fees from Enterprise Therapeutics; and data safety monitoring board (DSMB) membership for the NIH. JPC is an employee of CFF. RJ reports grants from CFF; consulting fees from Boehringer Ingelheim and Recode Therapeutics; honoraria from Vertex Pharmaceuticals; and travel support from CFF. SHD reports contracts from Calithera, CFF, NIH (P30 DK065988), Vertex Pharmaceuticals, 4D Molecular Therapeutics, and Chiesi USA; consulting fees from Polarean, 501 Ventures, Enterprise Therapeutics, and Boehringer Ingelheim; fees for participation on advisory boards for Innova Healthcare and Boehringer Ingleheim; travel fees from Enterprise Therapeutics and CFF; and participation on a board for Abbvie. IF reports grants from AbbVie, Bayer, Boehringer Ingelheim, Insmed, GSK, and Vertex Pharmaceuticals; honoraria from Vertex Pharmaceuticals; board participation for AbbVie, Boehringer Ingelheim, Kither Biotech, and Vertex Pharmaceuticals; and support to her institution from the European Cystic Fibrosis Society (ECFS). CHG reports grants and contracts from CFF, NIH (P30 DK 089507 and UL1 TR000423), and FDA; consulting fees from Enterprise Therapeutics; honoraria from Gilead Sciences and Vertex Pharmaceuticals; travel support from Vertex Pharmaceuticals and Enterprise Therapeutics; participation on the board for Novartis; stock options for Air Therapeutics; and leadership roles for the American Thoracic Society (ATS). DP reports grants from CFF (002805121), NIH, and Aclaris Pharmaceuticals; travel support from CFF; and board participation for Vertex Pharmaceuticals and Translate Bio. FR reports grants from Vertex Pharmaceuticals and consulting fees from Vertex Pharmaceuticals and Calithera. BSQ reports grants from CFF, Cystic Fibrosis Canada, Vertex Pharmaceuticals, and Gilead Sciences; honoraria from Vertex Pharmaceuticals; and travel support from CFF. ETZ reports grants from NIH, Vertex Pharmaceuticals, and CFF (002884121); consulting fees from CFF; travel support from CFF, Vertex Pharmaceuticals, and ECFS; and participation on boards for CFF and Vertex Pharmaceuticals. SCB reports grants from the National Health and Medical Research Council Australia (APP1102494), the Medical Research Futures Fund Australia, and CFF (BELL1480 and BELL19A0); and honoraria from Vertex Pharmaceuticals. JCD reports grants from the UK Cystic Fibrosis Trust (as part of their Clinical Trials Accelerator Platform), CFF, Cystic Fibrosis Ireland, the Engineering and Physical Sciences Research Council, and the National Institute for Health and Care Research; and honoraria from Vertex Pharmaceuticals, Boehringer Ingelheim, Eloxx, Algipharma, Abbvie, Arcturus, Enterprise Therapeutics, Recode, LifeArc, Genentech, and Tavanta. JCD serves as Deputy Editor for the Journal of Cystic Fibrosis. MWK reports grants from NIH (P01HL128192 and UL1TR002548) and CFF; consulting fees from AbbVie, AzurRx, Cystetic Medicines, EnBiotix, First Wave Biopharma, Insmed, Laurent Pharmaceuticals, Mylan, and PBM BC Holdings; board participation for AbbVie, CFF, First Wave Biopharma, Insmed, Laurent Pharmaceuticals, Sionna, and Vertex; and committee membership for CFF. MAM reports grants from the German Research Foundation (CRC 1449 project #431232613), the German Ministry for Education and Research (82DZL009B1), the German Innovation Fund, and Vertex Pharmaceuticals; consulting fees from Abbvie, Antabio, Arrowhead, Boehringer Ingelheim, Enterprise Therapeutics, Kither Biotec, Prieris, Recode, Santhera, Splisense, and Vertex Pharmaceuticals; honoraria from Vertex Pharmaceuticals; travel support from Boehringer Ingelheim and Vertex Pharmaceuticals; and participation on boards for Abbvie, Antabio, Arrowhead, Boehringer Ingelheim, Enterprise Therapeutics, Kither Biotec, Pari, and Vertex Pharmaceuticals. EM reports grants from Vertex Pharmaceuticals; honoraria from Vertex Phamaceuticals; travel support from Menarini; and board participation for the Cystic Fibrosis Storm Clinical Trial, Vertex Pharmaceuticals, Janssen, Abbvie, and Insmed. JHR reports grants from Cystic Fibrosis Canada, CFF, Vertex Phamaceuticals, the Canada Foundation for Innovation, and the Canadian Institutes of Health Research; consulting fees from Sanofi; and travel support from Vertex Pharmaceuticals. SMR reports grant funding from CFF (P30DK072482), NIH (UL1TR003096), Vertex Pharmaceuticals, Galapagos/Abbvie, Eloxx, Synspira, Translate Bio, Arcturus, Astra-Zenica, and Ionis; and consulting fees from Vertex Pharmaceuticals, Synspira (including stock options), Renovion (including stock options), Cystetic Medicines, and Arcturus. SMR's potential competing interests were resolved or ended in 2022 or earlier. JLT-C reports grants and contracts from CFF, Vertex Pharmaceutics, Eloxx, and 4DMT; consulting fees from Vertex Phamaceuticals, Insmed, and 4DMT; participation on a DSMB for Abbvie; and participation on advisory boards for CFF, ATS, Journal of Cystic Fibrosis, The Lancet Respiratory Medicine, and Emily's Entourage. GR-B reports grants and contracts from Vertex Pharmaceuticals and CFF. DGD reports grants from Chiesi Farmaceutici and CFF; consulting fees from Vertex and Insmed; honoraria from Chiesi and Gilead; travel support from ECFS and CFF; board participation for Momab and CSL Behring; and support from ECFS as director of the Clinical Trials Network. MJ, NRK, TL, KP, JMP, and LQ declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: MRT5005, a codon-optimized CFTR mRNA, delivered by aerosol in lipid nanoparticles, was designed as a genotype-agnostic treatment for CF lung disease., Methods: This was a randomized, double-blind, placebo-controlled Phase 1/2 study performed in the US. Adults with 2 severe class I and/or II CFTR mutations and baseline ppFEV1 values between 50 and 90% were randomized 3:1 (MRT5005: placebo). Six dose levels of MRT5005 (4, 8, 12, 16, 20, and 24 mg) or placebo (0.9% Sodium Chloride) were administered by nebulization. The single ascending dose cohort was treated over a range from 8 to 24 mg; the multiple ascending dose cohort received five weekly doses (range 8-20 mg); and the daily dosing cohort received five daily doses (4 mg)., Results: A total of 42 subjects were assigned to MRT5005 [31] or placebo [11]. A total of 14 febrile reactions were observed in 10 MRT5005-treated participants, which were mild [3] or moderate [11] in severity; two subjects discontinued related to these events. Additionally, two MRT5005-treated patients experienced hypersensitivity reactions, which were managed conservatively. The most common treatment emergent adverse events were cough and headache. No consistent effects on FEV1 were noted., Conclusions: MRT5005 was generally safe and well tolerated through 28 days of follow-up after the last dose, though febrile and hypersensitivity reactions were noted. The majority of these reactions resolved within 1-2 days with supportive care allowing continued treatment with MRT5005 and careful monitoring. In this small first-in-human study, FEV1 remained stable after treatment, but no beneficial effects on FEV1 were observed., Competing Interests: Declaration of Competing Interest The authors have completed ICMJE disclosure of interest forms. MJ, JL, KDM, and SZN report no competing interests. JBZ, CB, JCC, DD, NL, SL, SMR, KAM, KSM, and MSS report clinical trial funding from Translate Bio to their institution for this study. MSS, EBM, KAM, and JCC report support for the current manuscript from Emily's Entourage. DD reports research contracts with Insmed, Inc., Aridis Pharmaceuticals, Armata Pharmaceuticals, and 4D Molecular Therapeutics and fees from the CFF for his role on the Data Safety Monitoring Board (DSMB). DD is a member of the DSMB at the University of Pennsylvania. KSM reports research grants to her institution from the CFF in partnership with 4D Molecular Therapeutics, Abbvie, Aridis Pharmaceuticals, Armata Pharmaceuticals, Boeringer-Ingelheim, Corbus, Insmed, Laurent Pharmaceuticals, Novartis, Eloxx, Vertex Pharmaceuticals, Savara, and Proteostasis for unrelated research. SMR reports research grants to his institution from the CFF in partnership with Novartis, Galapagos/Abbvie, Synedgen/Synspira, Eloxx, Vertex Pharmaceuticals, Ionis, and Astra Zenica for unrelated research. SMR reports consulting fees for clinical trial design and conduct from Novartis, Galapagos/Abbvie, Synedgen/Synspira, Vertex Pharmaceuticals, Renovion, Ionis, Cystetic Medicines, and Arcturus. JBZ reports fees from the CFF for his role on the DSMB and research grants from the CFF in partnership with Laurent Pharmaceuticals, Savara, AzureRx Biopharma, Aridis Pharmaceuticals, and Vertex Pharmaceuticals for unrelated research but no personal payments. AB, EBM and MV were full-time employees of Translate Bio during the conduct of the study. MV was an employee of Rho, Inc. and is currently an employee of Krystal Biotech. MV reports stock options provided to employees of Translate Bio and Krystal Biotech. MV is former board member of the CFF Central Carolinas Chapter. AB is currently on the Board of Directors for Pieris Pharmaceuticals. CB reports research grants from the CFF and CFF Therapeutic Development Network (CFFTDN) in partnership with Vertex pharmaceuticals for unrelated research but no personal payments. MSS reports research grants to his institution from the CFF in partnership with Vertex Pharmaceuticals and consulting fees from Vertex Pharmaceuticals. MVI reports research grants from the CFF and CFFTDN. To advance drug development and a search for a cure, the CFF has contracts with several companies to help fund the development of potential treatments and/or cures for CF. Pursuant to these contracts, CFF may receive milestone-based payments, equity interests, royalties on the net sales of therapies, and/or other forms of consideration. Resulting revenue received by CFF is used in support of their mission., (Copyright © 2023 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Elexacaftor-tezacaftor-ivacaftor has been shown to be safe and efficacious in people with cystic fibrosis and at least one F508del allele. Our aim was to identify a novel cystic fibrosis transmembrane conductance regulator (CFTR) modulator combination capable of further increasing CFTR-mediated chloride transport, with the potential for once-daily dosing., Methods: We conducted two phase 2 clinical trials to assess the safety and efficacy of a once-daily combination of vanzacaftor-tezacaftor-deutivacaftor in participants with cystic fibrosis who were aged 18 years or older. A phase 2 randomised, double-blind, active-controlled study (VX18-561-101; April 17, 2019, to Aug 20, 2020) was carried out to compare deutivacaftor monotherapy with ivacaftor monotherapy in participants with CFTR gating mutations, following a 4-week ivacaftor monotherapy run-in period. Participants were randomly assigned to receive either ivacaftor 150 mg every 12 h, deutivacaftor 25 mg once daily, deutivacaftor 50 mg once daily, deutivacaftor 150 mg once daily, or deutivacaftor 250 mg once daily in a 1:1:2:2:2 ratio. The primary endpoint was absolute change in ppFEV 1 from baseline at week 12. A phase 2 randomised, double-blind, controlled, proof-of-concept study of vanzacaftor-tezacaftor-deutivacaftor (VX18-121-101; April 30, 2019, to Dec 10, 2019) was conducted in participants with cystic fibrosis and heterozygous for F508del and a minimal function mutation (F/MF genotypes) or homozygous for F508del (F/F genotype). Participants with F/MF genotypes were randomly assigned 1:2:2:1 to receive either 5 mg, 10 mg, or 20 mg of vanzacaftor in combination with tezacaftor-deutivacaftor or a triple placebo for 4 weeks, and participants with the F/F genotype were randomly assigned 2:1 to receive either vanzacaftor (20 mg)-tezacaftor-deutivacaftor or tezacaftor-ivacaftor active control for 4 weeks, following a 4-week tezacaftor-ivacaftor run-in period. Primary endpoints for part 1 and part 2 were safety and tolerability and absolute change in ppFEV 1 from baseline to day 29. Secondary efficacy endpoints were absolute change from baseline at day 29 in sweat chloride concentrations and Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain score. These clinical trials are registered with ClinicalTrials.gov, NCT03911713 and NCT03912233, and are complete., Findings: In study VX18-561-101, participants treated with deutivacaftor 150 mg once daily (n=23) or deutivacaftor 250 mg once daily (n=24) had mean absolute changes in ppFEV 1 of 3·1 percentage points (95% CI -0·8 to 7·0) and 2·7 percentage points (-1·0 to 6·5) from baseline at week 12, respectively, versus -0·8 percentage points (-6·2 to 4·7) with ivacaftor 150 mg every 12 h (n=11); the deutivacaftor safety profile was consistent with the established safety profile of ivacaftor 150 mg every 12 h. In study VX18-121-101, participants with F/MF genotypes treated with vanzacaftor (5 mg)-tezacaftor-deutivacaftor (n=9), vanzacaftor (10 mg)-tezacaftor-deutivacaftor (n=19), vanzacaftor (20 mg)-tezacaftor-deutivacaftor (n=20), and placebo (n=10) had mean changes relative to baseline at day 29 in ppFEV 1 of 4·6 percentage points (-1·3 to 10·6), 14·2 percentage points (10·0 to 18·4), 9·8 percentage points (5·7 to 13·8), and 1·9 percentage points (-4·1 to 8·0), respectively, in sweat chloride concentration of -42·8 mmol/L (-51·7 to -34·0), -45·8 mmol/L (95% CI -51·9 to -39·7), -49·5 mmol/L (-55·9 to -43·1), and 2·3 mmol/L (-7·0 to 11·6), respectively, and in CFQ-R respiratory domain score of 17·6 points (3·5 to 31·6), 21·2 points (11·9 to 30·6), 29·8 points (21·0 to 38·7), and 3·3 points (-10·1 to 16·6), respectively. Participants with the F/F genotype treated with vanzacaftor (20 mg)-tezacaftor-deutivacaftor (n=18) and tezacaftor-ivacaftor (n=10) had mean changes relative to baseline (taking tezacaftor-ivacaftor) at day 29 in ppFEV 1 of 15·9 percentage points (11·3 to 20·6) and -0·1 percentage points (-6·4 to 6·1), respectively, in sweat chloride concentration of -45·5 mmol/L (-49·7 to -41·3) and -2·6 mmol/L (-8·2 to 3·1), respectively, and in CFQ-R respiratory domain score of 19·4 points (95% CI 10·5 to 28·3) and -5·0 points (-16·9 to 7·0), respectively. The most common adverse events overall were cough, increased sputum, and headache. One participant in the vanzacaftor-tezacaftor-deutivacaftor group had a serious adverse event of infective pulmonary exacerbation and another participant had a serious rash event that led to treatment discontinuation. For most participants, adverse events were mild or moderate in severity., Interpretation: Once-daily dosing with vanzacaftor-tezacaftor-deutivacaftor was safe and well tolerated and improved lung function, respiratory symptoms, and CFTR function. These results support the continued investigation of vanzacaftor-tezacaftor-deutivacaftor in phase 3 clinical trials compared with elexacaftor-tezacaftor-ivacaftor., Funding: Vertex Pharmaceuticals., Competing Interests: Declaration of interests AZU received grants from the Cystic Fibrosis Foundation and the CFF-Therapeutic Development Network for the present work; received payment or honoraria from Vertex Pharmaceuticals for presentations at CF Centers in UK; and participated in advisory boards for Vertex and Eloxx. VI received grant support from CF TDN for the present work; consulting fees from Mylan for CF—TOBI podhaler advisory board; and grant support from CFF for meeting attendance. PA received support from Vertex Pharmaceuticals for lectures, presentations, and materials; meeting attendance; and participation on data safety monitoring boards or advisory boards. MAM received payment from Vertex for the current work and personal fees for serving on an advisory board; grants from Vertex and from the German Ministry for Education and Research; consulting fees from Boehringer Ingelheim, Arrowhead Pharmaceuticals, Vertex Pharmaceuticals, Santhera, Sterna Biologicals, Enterprise Therapeutics, Antabio, and Abbvie; lecture fees from Boehringer Ingelheim, Arrowhead Pharmaceuticals, and Vertex Pharmaceuticals; travel reimbursement from Boehringer Ingelheim and Vertex Pharmaceuticals; personal fees for participation in an advisory board from Boehringer Ingelheim, Arrowhead Pharmaceuticals, Vertex Pharmaceuticals, Santhera, Enterprise Therapeutics, Antabio, Kither Biotech, Abbvie, and Pari; and serves as an ECFS Board member. EFM received grants and other payments or honoraria from Vertex; and support for meetings or travel from Menarini. BWR received payments from Vertex for the present work, and payments for a presentation in Vancouver, BC, Canada in 2019; and participated on data safety monitoring boards or advisory boards for CF Storm Clinical Trial, Vertex Pharmaceuticals, Janssen, Abbvie, and Insmed. SMR received support for a clinical trial; consulting fees on the design and conduct of clinical trials; support for meeting attendance and for his role as Co-Chair of the Next Generation Steering Committee; received grants or contracts from Novartis, TranslateBio, Galapagos–Abbvie, Synedgen–Synspira, Eloxx, Vertex Pharmaceuticals, and Ionis Astra Zenica; consulting fees from Novartis, Galapagos–Abbvie, Synedgen–Synspira, Vertex Pharmaceuticals, Renovion, Ionis, Cystetic Medicines, and Arcturus; support for meeting attendance from Vertex; has patents planned, issued or pending; serves as a Co-Chair of the Next Generation Steering Committee; and owns stock or stock options with Synedgen–Synspira and Renovion. RCR received clinical trial support and consulting fees from Vertex for the present work; grants from CFF, NIDDK, NHLBI, NICHD, and NIDCD; received consulting fees from Guidepoint Global, Gerson Lehrman Group, and Cystic Fibrosis Foundation; participated on a data safety monitoring or advisory board for NHLBI DSMB. JLT-C received personal consulting fees from Vertex for the present work; received grants from Vertex, Eloxx, and 4DMT for the conduct of a research trial; personal fees from Vertex, Insmed, and 4DMT for trial design consulting; personal fees from Vertex for non-branded speaking; and personal fees from AbbVie for her role as DMC Chair; served as the adult patient care representative to the CFF Board of Trustees, on the CF Foundation's Clinical Research Executive Committee, Clinical Research Advisory Board, and Racial Justice Working Group; as immediate past chair of the CF TDN's Sexual Health, Reproduction and Gender Research Working Group; on the scientific advisory board for Emily's Entourage; on the ATS Respiratory Health Awards Working Group; on the ATS Scientific Grant Review and Clinical Problems Assembly Programming Committees; and served as an associate editor for the Journal of Cystic Fibrosis. ET received payment for the present work and grants for doing clinical trials from Vertex Pharmaceuticals; received payment and reimbursement from Vertex for her role on a steering committee and for presentations at educational events. JB received funding from Vertex Pharmaceuticals for the present work. AH received funding from Vertex Pharmaceuticals for the present work; grant support from NIHR, CF Trust, CF Foundation, and Medical Research Council; payments for educational lectures from Vertex Pharmaceuticals and for an advisory board from Mylan; medical writing support from Vertex; served as Chair of the UK CF Clinical Trials Accelerator Platform and as a board member of the UK CF Medical Association. LMY received salary support from mgH TDN for clinical research activity for the present work. DW has patents planned, issued or pending. DW, LTW, CC, APM, NN, PRS, ST, FVG, and YX are Vertex employees and might own stocks or stock options. GM and CK have nothing to disclose. LV was a clinical pharmacology lead at Vertex during the conduct of this study and conducted PK data analysis for the present study., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Elexacaftor/tezacaftor/ivacaftor (ETI) improves pulmonary disease in people with cystic fibrosis (PwCF), but its effect on gastrointestinal symptoms, which also affect quality of life, is not clear., Methods: PROMISE is a 56-center prospective, observational study of ETI in PwCF >12 years and at least one F508del allele. Gastrointestinal symptoms, evaluated by validated questionnaires: Patient Assessment of Upper Gastrointestinal Disorders-Symptom (PAGI-SYM), Patient Assessment of Constipation-Symptom (PAC-SYM), Patient Assessment of Constipation-Quality of Life (PAC-QOL)), fecal calprotectin, steatocrit and elastase-1 were measured before and 6 months after ETI initiation. Mean difference and 95% confidence intervals were obtained from linear regression with adjustment for age and sex., Results: 438 participants fully completed at least 1 questionnaire. Mean (SD) for baseline PAGI-SYM, PAC-SYM, and PAC-QOL total scores were 0.56 (0.59), 0.47 (0.45), and 0.69 (0.53) out of maximum 5, 4, and 5, respectively (higher score indicates greater severity). Corresponding age- and sex-adjusted 6 months mean changes (95% CI) in total scores were -0.15 (-0.21, -0.09) for PAGI-SYM, -0.14 (-0.19, -0.09) for PAC-SYM, and -0.15 (-0.21, -0.10) for PAC-QOL. While statistically significant, changes were small and unlikely to be of clinical importance. Fecal calprotectin showed a change (95% CI) from baseline of -66.2 µg/g (-86.1, -46.2) at 6 months, while fecal elastase and steatocrit did not meaningfully change., Conclusions: After 6 months of ETI, fecal markers of inflammation decreased. Gastrointestinal symptoms improved, but the effect size was small. Pancreatic insufficiency did not improve., Competing Interests: Declaration of Competing Interest SJS-Consultant for UpToDate, Abbvie, Mirium, Nestle; Grant funding from Gilead, Cystic Fibrosis Foundation, NIH. SDF – Consultant for UpToDate, Abbvie, Nestle, Synspira; Grant funding from NIH, Cystic Fibrosis Foundation, Amagma Therapeutics. MRN – Consultant for UpToDate, Vertex: Grant funding from Gilead, AbbVie, Cystic Fibrosis Foundation, NIH SMR: Consultant for Vertex; Grant funding from Vertex, Cystic Fibrosis Foundation, NIH DPN: Consultant for Vertex, Genentech; Grant funding from Vertex, Cystic Fibrosis Foundation, NIH GMS: Consultant for Genentech, Electromed; Grant Funding from Vertex, Cystic Fibrosis Foundation, NIH DG: Consultant for Vertex, Abbvie, Chiesi USA, Eli Lilly AK: Grant funding from NIH, Cystic Fibrosis Foundation, SDS – Grant funding from Cystic Fibrosis Foundation and NIH MSS—Grant funding from Cystic Fibrosis Foundation, (Copyright © 2022. Published by Elsevier B.V.)

Cystic fibrosis (CF), first described in 1938, is a common, life-limiting monogenetic disease. The discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 1989 was crucial in advancing our understanding of disease pathogenesis and paving the road for treatment aimed at the fundamental molecular defect. With the delineation of over 2000 variations in the CFTR gene, a sound understanding of the individual variations in cell biology, and electrophysiological abnormalities conferred by the most common defects propelled the advent of targeted disease-modifying therapeutics beginning in 2012. Since then, CF care has transformed beyond just symptomatic treatment to include a variety of small-molecule therapies that address the basic electrophysiologic defect and cause profound improvements in physiology, clinical manifestations, and long-term outcomes, designed to differentially address six genetic/molecular subtypes. This chapter illustrates the progress made toward how fundamental science and translational initiatives enabled personalized, mutation specific treatment. We highlight the importance of preclinical assays and mechanistically-driven development strategies that were coupled with sensitive biomarkers and a clinical trial cooperative to provide a platform for successful drug development. This convergence of academic and private partnerships, and formation of multidisciplinary care teams directed by evidence-based initiatives provide a seminal example of addressing the needs of individuals with a rare, but fatal genetic disease., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: CHEC-SC is an ongoing epidemiologic study characterizing modulator-induced sweat chloride (SC) responses across the CF population, with interim results available prior to the availability of triple combination modulator therapy., Methods: Eligible participants had been prescribed a modulator for ≥90 days with re-enrollment allowed upon establishment of a new modulator. Pre-modulator SC values were obtained from chart review; post-modulator sweat was collected and analyzed locally. SC changes were descriptively summarized with biologic sex effects adjusted for age, weight, and CFTR genotype. Heterogeneity in ivacaftor SC response was characterized in relation to published CFTR functional responses., Results: 1848 participants provided 2004 SC measurements, 26.2% on ivacaftor, 39.1% on lumacaftor/ivacaftor, and 34.7% on tezacaftor/ivacaftor. Average SC changes for all modulators were consistent with those reported in previous clinical studies, with greater variation in SC response observed among rarer mutations and notable shifts in the proportion with SC <60mmol/L independent of the magnitude of SC change. Ivacaftor induced in vitro CFTR functional change was significantly correlated with ivacaftor-modulated SC response (Pearson correlation= ‒0.52, 95% CI: ‒0.773, ‒0.129). Average SC change from ivacaftor to tezacaftor/ivacaftor was ‒4.9 mmol/L (n=17,95% CI:‒9.3, ‒0.5) and differed from those switching from lumacaftor/ivacaftor (10.0 mmol/L, n=139, 95% CI:7.8,12.3). Sex at birth was not associated with SC response., Conclusions: CHEC-SC is the largest study characterizing modulator-induced SC changes across the CF population. There was a strong association between ivacaftor induced in vitro CFTR function and SC response across a genotypically heterogenous cohort. Biological sex was not associated with SC response., Competing Interests: Conflict of Interest Statement NMH serves as a consultant through her institution in her role as Executive Director of the CF Therapeutics Development Network Coordinating Center (CF TDNCC) and has received personal consulting fees from Vertex Pharmaceuticals. She has received grant funding from the Cystic Fibrosis Foundation (CFF) and National Institutes of Health (NIH). DRV has received personal consulting fees from AbbVie, Albumedix, AN2, Aradigm, Armata, Arrevus, Calithera, Chiesi USA, Cipla, Corbus, CFF, Eloxx, Enbiotix, Eveo, Galephar, Horizon, IBF, ICON clinical sciences, Ionis, Kala, Merck, Microbion, NDA, Protalix, PTC, Pulmocide, Recida, Savara, Vast, and VRTX. MWK has received personal consulting fees for advisory board participation, grant support to his institution for clinical trial participation, and non-financial support from VRTX, Savara, Laurent, Corbus Pharmaceuticals, PTC, and AzurRx. He has received personal consulting fees and non-financial support from Chiesi, Celtaxsys, Merck, and Kala. Personal consulting fees were received from Albumedix, Paranta, Protalix, Santhera, pH Pharma, Novartis, Ionis, the Italian Cystic Fibrosis Foundation, and the Food and Drug Administration. SMR reports grants and personal fees from Vertex Pharmaceuticals Inc, during the conduct of the study; grants and personal fees from Novartis, grants and personal fees from Bayer, grants from Translate Bio, grants and non-financial support from Proteostasis, grants, personal fees and non-financial support from Galapagos/Abbvie, grants, personal fees and non-financial support from Synedgen/Synspira, grants from Eloxx, grants from Celtaxsys, grants, personal fees and non-financial support from Vertex Pharmaceuticals Inc, personal fees and non-financial support from Renovion, grants and personal fees from Arrowhead, grants, personal fees and non-financial support from Ionis, grants from Astra Zenica, personal fees from Cystetic Medicines, outside the submitted work. ETZ reports grants and personal consulting fees from Vertex Pharmaceuticals and the Cystic Fibrosis Foundation during the conduct of the study., (Copyright © 2022. Published by Elsevier B.V.)

The spectrum of disorders involving CFTR (cystic fibrosis transmembrane conductance regulator) dysfunction correlates with a continuous gradient of CFTR function defined by the combination of two allelic CFTR variants. CFTR-related disorders are clinical entities with features of cystic fibrosis (CF) and evidence for presence of CFTR dysfunction but not meeting criteria for diagnosis of CF. Individuals with CFTR-RDs demonstrate a wide range of CFTR activity and are still under-recognized or misclassified. The level of CFTR dysfunction may be measured in vivo (sweat testing, nasal potential difference measurements) and/or by ex vivo tests (intestinal current measurement), or indirectly indicated by CFTR variants, as alteration in sequence of the CFTR gene translates into CFTR dysfunction. CFTR bioassays can aid in the diagnosis of individuals with CF, but we lack parameters to differentiate CF from CFTR-RD. In the era of the CFTR modulators and their potential clinical benefit, it is of utmost importance to diagnose CFTR-RD as unambiguously as possible. We therefore propose the following to define compatible CFTR dysfunction in a person with a suspected diagnosis of CFTR-RD : (1) evidence of CFTR dysfunction in vivo or ex vivo in at least two different CFTR functional test types, or (2) One CFTR variant known to reduce CFTR function and evidence of CFTR dysfunction in vivo or ex vivo in at least two different CFTR functional test types, or (3) Two CFTR variants shown to reduce CFTR function, with at most one CF-causing variant., Competing Interests: Declaration of Competing Interest All the authors have declared their conflict of interests., (Copyright © 2022. Published by Elsevier B.V.)

Background: Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator for people with CF and the G551D mutation. We aimed to investigate the biology of CFTR modulation and systemic effects of CFTR restoration by examining changes in circulating measurements of inflammation and growth and novel proteins with ivacaftor treatment., Methods: Blood samples from 64 CF subjects with G551D-CFTR were analyzed for inflammatory and growth-related proteins at baseline, 1 and 6 months after ivacaftor initiation. In 30 subjects, plasma was assayed for 1,322 proteins using the SomaScan proteomic platform at baseline and 6 months post-ivacaftor. Correlations with clinical outcomes were assessed., Measurements and Main Results: Significant reductions in high mobility group box-1 protein (HMGB-1), calprotectin, serum amyloid A, and granulocyte colony-stimulating factor (G-CSF), and an increase in insulin-like growth factor (IGF-1) occurred 1 month after ivacaftor. This treatment effect was sustained at 6 months for HMGB-1 and calprotectin. Correcting for multiple comparisons in the proteomic analysis, 9 proteins (albumin, afamin, leptin, trypsin, pancreatic stone protein [PSP], pituitary adenylate cyclase-activating polypeptide-38, repulsive guidance molecule A [RGMA], calreticulin, GTPase KRas) changed significantly with ivacaftor. Proteins changing with treatment are involved in lipid digestion and transport and extracellular matrix organization biological processes. Reductions in calprotectin and G-CSF and increases in calreticulin, and RGMA correlated with improved lung function, while increasing IGF-1, leptin and afamin and decreasing PSP correlated with increased weight., Conclusions: Ivacaftor led to changes in inflammatory, lipid digestion, and extracellular matrix proteins, lending insights into the extrapulmonary effects of CFTR modulation., Competing Interests: Conflict of interest statement JEH reports grants from Cystic Fibrosis Foundation, outside the submitted work, SMR reports grants, personal fees, non-financial support and other from Vertex Pharmaceuticals Inc., during the conduct of the study; grants and personal fees from Novartis, grants and personal fees from Bayer, grants from Translate Bio, non-financial support from Proteostasis, grants, personal fees and non-financial support from Galapagos/Abbvie, grants, personal fees and other from Synedgen/Synspira, grants from Eloxx, grants and personal fees from Celtaxsys, grants, personal fees, non-financial support and other from Vertex Pharmaceuticals Inc, personal fees from Renovion, grants and personal fees from Arrowhead, grants and other from Ionis, grants from Astra Zenica, personal fees from Cystetic Medicines, personal fees from Arcturus, outside the submitted work; EMD reports other from EvoEndoscopy (formerly Triple Endoscopy), outside the submitted work and is a consultant for Boehringer Ingelheim, not related to this work. SDS reports grants from the Cystic Fibrosis Foundation that funds the work under consideration, and grants from the Cystic Fibrosis Foundation and National Institutes of Health funding activities outside the submitted work. BDW, JKH and SLH have nothing to disclose., (Copyright © 2022 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

CFTR function is required for normal mucociliary clearance (MCC) and cough-assisted clearance (CC). Lumacaftor-ivacaftor is approved for use in people with cystic fibrosis (CF) carrying two copies of F508del-CFTR. In this observational study performed at four study sites, we characterized the effect of lumacaftor-ivacaftor on mucociliary and cough clearance and related this to other clinical and research endpoints after one month of treatment. Twenty-five adolescents and adults were enrolled. No effect on whole lung MCC was observed, but CC was significantly increased. Sweat chloride improved by 18 mEq/L in this group, indicating a modest restoration of CFTR activity, but no demonstrable change in FEV 1 or lung clearance index was observed. We speculate that the modest effect of lumacaftor-ivacaftor on CFTR function was insufficient to yield an improvement in MCC., (Copyright © 2021 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: The Characterizing CFTR Modulated Changes in Sweat Chloride and their Association with Clinical Outcomes (CHEC-SC) study is a large epidemiologic study designed to determine the relationship between sweat chloride response and clinical outcomes in people with cystic fibrosis (CF) on commercially approved CFTR modulators. A challenge to study feasibility was capturing sweat chloride measurements before modulator initiation. We tested the hypothesis that historic sweat chloride approximated contemporary pre-modulator values to estimate CFTR modulator-induced changes, allowing a single-visit study design., Methods: GOAL and PROSPECT were multi-center prospective studies of individuals initiating ivacaftor or lumacaftor-ivacaftor. At enrollment, pre-modulator sweat chloride was measured and historic results recorded. Post-modulator sweat chloride was measured at 1, 3 and 6 months. For this analysis, differences between historic and pre-modulator sweat chloride were estimated. CFTR modulator-induced sweat chloride mean changes were compared using historic and pre-modulator sweat chloride., Results: Paired historic and pre-modulator sweat chloride (n=406 participants) revealed a non-significant mean change of -1.0 mmol/L (95% CI: -2.71, 0.66) over an average of 17.2 years. Calculating sweat response to ivacaftor or lumacaftor-ivacaftor using historic or pre-modulator values resulted in similar estimates of modulator response. Based on these results, the CHEC-SC study was designed with a single, post-modulator sweat chloride measurement., Conclusions: Historic sweat chloride values provide a reliable estimate of pre-modulator sweat chloride for people starting on modulator therapy. The CHEC-SC study anticipates capturing approximately 5,000 sweat chloride values, providing an unprecedented understanding of sweat chloride across the CF population in the era of CFTR modulators., Competing Interests: Declaration of Competing Interest ETZ, NMH, DRV, SMR, MWK: grants or consulting CFF; DRV consults for aMoon, Arrevus, Eloxx, Enbiotix, Felix, Ionis, Matinas, Merck, Polyphor, Respirion, Savara; SMR consults for Vertex; MWK consults for Anthera, AzurRx, Celtaxsys, Chiesi, Ionis, Kala, Laurent, Merck, Paranta, pH Pharma, Santhera, Vertex; JPC, KOD and MS: none., (Copyright © 2021. Published by Elsevier B.V.)

Background: Riociguat is a first-in-class soluble guanylate cyclase stimulator for which preclinical data suggested improvements in cystic fibrosis transmembrane conductance regulator (CFTR) function., Methods: This international, multicenter, two-part, Phase II study of riociguat enrolled adults with cystic fibrosis (CF) homozygous for Phe508del CFTR. Part 1 was a 28-day, randomized, double-blind, placebo-controlled study in participants not receiving CFTR modulator therapy. Twenty-one participants were randomized 1:2 to placebo or oral riociguat (0.5 mg three times daily [tid] for 14 days, increased to 1.0 mg tid for the subsequent 14 days). The primary and secondary efficacy endpoints were change in sweat chloride concentration and percent predicted forced expiratory volume in 1 second (ppFEV 1 ), respectively, from baseline to Day 14 and Day 28 with riociguat compared with placebo., Results: Riociguat did not alter CFTR activity (change in sweat chloride) or lung function (change in ppFEV 1 ) at doses up to 1.0 mg tid after 28 days. The most common drug-related adverse event (AE) was headache occurring in three participants (21%); serious AEs occurred in one participant receiving riociguat (7%) and one participant receiving placebo (14%). This safety profile was consistent with the underlying disease and the known safety of riociguat for its approved indications., Conclusions: The Rio-CF study was terminated due to lack of efficacy and the changing landscape of CF therapeutic development. The current study⁠, within its limits of a small sample size, did not provide evidence that riociguat could be a valid treatment option for CF., Clinical Trial Registration Number: NCT02170025., Competing Interests: Declaration of Competing Interest N. Derichs received a speaker honorarium from Vertex Pharmaceuticals, Inc. for participation in a symposium, and served as a consultant for Vertex Pharmaceuticals, Inc. at educational activities and advisory boards. J.L. Taylor-Cousar reports grants paid to her institution from the Cystic Fibrosis Foundation; grants paid to her institution and consulting and speaking fees from Vertex Pharmaceuticals, Inc.; grants paid to her institution from Bayer; grants, consulting, and speaking fees from Celtaxys; grants paid to her institution and consulting fees from Proteostasis Therapeutics, Inc.; consulting fees from Santhera, 4DMT, AbbVie, and Polarean; and grants paid to her institution from Eloxx Pharmaceuticals. J.C. Davies reports grants from the CF Trust and other funding from Algipharma AS, Bayer AG, Boehringer Ingelheim Pharma GmbH & Co. KG, Galapagos NV, ImevaX GmbH, Nivalis Therapeutics, Inc., ProQR Therapeutics III B.V., Proteostasis Therapeutics, Inc., Raptor Pharmaceuticals, Inc., Vertex Pharmaceuticals, Inc., Enterprise, Novartis, Pulmocide, Flatley, Nivalis Therapeutics, Inc., and Teva. I. Fajac received speaker honoraria from Vertex Pharmaceuticals, Inc. for participation in symposia and served as a consultant for Novartis, Proteostasis Therapeutics, Inc., and Vertex Pharmaceuticals, Inc. E. Tullis reports grants paid to her institution from Vertex Pharmaceuticals, Inc., Proteostasis Therapeutics, Bayer AG, Boehringer Ingelheim, AbbVie, Celtaxis, Corbus, and Spyryx, and consultancy fees and honoraria from Vertex Pharmaceuticals, Proteostasis Therapeutics, Astra Zeneca and Horizon. D. Nazareth has nothing to disclose. D.G. Downey reports grants from Vertex Pharmaceuticals, Inc., Proteostasis Therapeutics, Inc., Gilead, and Chiesi; and honoraria or speaker fees from Vertex Pharmaceuticals, Inc., Proteostasis Therapeutics, Inc., and Chiesi. D. Rosenbluth has nothing to disclose. A. Malfroot has nothing to disclose. C. Saunders has nothing to disclose. R. Jensen has nothing to disclose. G.M. Solomon reports work on advisory boards for Bayer and Electromed. F. Vermeulen has nothing to disclose. A. Kaiser is an employee of Bayer AG. S. Willmann is an employee of Bayer AG. S. Saleh is an employee of Bayer AG. K. Droebner is an employee of Bayer AG. P. Sandner is an employee of Bayer AG. C.E. Bear has nothing to disclose. A. Hoffmann is an employee of Bayer AG. F. Ratjen reports other consultancy fees from Vertex Pharmaceuticals, Inc., Bayer, Talecris, CSL Behring, Roche, and Gilead; grants and consultancy from Novartis; and developed speaker bureau for Genentech outside the submitted work. S.M. Rowe reports grants and consulting fees from Arrowhead, Bayer, Celtaxsys, Galapagos/AbbVie, Novartis, Renovion, Synedgen/Synspira, andVertex Pharmaceuticals Inc.; consulting fees from Arcturus, and Cysteic Medicines; and grants from AstraZeneca, Eloxx, N30 Pharmaceuticals, PTC Therapeutics, Translate Bio, and Proteostasis Therapeutics, Inc., (Copyright © 2021. Published by Elsevier B.V.)

Background: Cystic fibrosis (CF) is characterized by neutrophilic inflammation in the airways. Leukotriene B4 (LTB 4 ) is a neutrophil chemoattractant and has been implicated in CF pathogenesis. Acebilustat, a novel, synthetic, small-molecule leukotriene A4 hydrolase inhibitor, reduces LTB 4 production. We report findings from a randomized placebo-controlled trial of acebilustat in adult subjects with mild-to-moderate lung disease., Methods: Subjects were randomized (1:1:1) to once-daily acebilustat 50 mg, 100 mg or placebo for 48 weeks, concomitantly with their current therapeutic regimen. Subjects were stratified by use of concomitant CF transmembrane conductance regulator (CFTR) modulators, baseline percent predicted forced expiratory volume in 1 second (ppFEV 1 ) 50-75 and >75, and number of pulmonary exacerbations in the past year (1 or >1). Primary endpoints were the change from baseline in ppFEV 1 and safety. Secondary endpoints included the rate of pulmonary exacerbations., Results: Overall, 199 subjects were randomized and dosed (acebilustat 50 mg, n=67; acebilustat 100 mg, n=66; placebo, n=66). Baseline demographics and disease profile were well balanced among treatment groups. Acebilustat had no statistically significant effect on the primary endpoint of change in ppFEV 1 at week 48 or the secondary endpoint pulmonary exacerbations. There was a trend towards reduced pulmonary exacerbations in subjects receiving acebilustat in pre-specified populations with ppFEV 1 >75 (35% rate reduction) and those on concomitant CFTR modulator therapy (20% rate reduction). Acebilustat was well tolerated., Conclusions: Acebilustat did not improve lung function. A trend towards reduced pulmonary exacerbations in subjects with an earlier stage of lung disease suggests a potential effect in this population., Competing Interests: Declaration of Competing Interest Dr. Aaron has nothing to disclose. Dr. Ahuja reports personal fees from Celtaxsys, Inc., during the conduct of the study; In addition, Dr. Ahuja has a patent PCT/US19/034810 pending, and a patent US16/427,571 pending. Dr. Daines has nothing to disclose. Dr. Downey reports and Honoraria from Vertex, Proteostasis and Chiesi. Dr. Elborn reports other from Celtaxsys, during the conduct of the study; grants and other from Corbus, grants from Novartis, grants from polyphor, outside the submitted work. Dr. Fajac reports grants from Celtaxsys, during the conduct of the study; grants and personal fees from Boehringer Ingelheim, grants and personal fees from Proteostasis Therapeutics, grants and personal fees from Vertex Pharmaceuticals, outside the submitted work. Mr. Grosswald reports personal fees from Celtaxsys, Inc., during the conduct of the study; In addition, Dr. Grosswald has a patent PCT/US19/034810 pending, and a patent US16/427,571 pending. Dr. Horsley reports other from Celtaxys pharmaceuticals, during the conduct of the study; grants from NIHR, grants from CF Trust, grants from CF Foundation, personal fees from Vertex pharmaceuticals, personal fees from Mylan, outside the submitted work. Dr. Konstan reports personal fees from Celtaxsys, during the conduct of the study; grants and personal fees from Vertex Pharmaceuticals, personal fees from Chiesi, personal fees from Ionis Pharmaceuticals, grants and personal fees from Laurent Pharmaceuticals, grants and personal fees from Anthera, personal fees from Merck, personal fees from Paranta Biosciences, personal fees from Santhera, personal fees from pH Pharma, grants and personal fees from Cystic Fibrosis Foundation, grants from National Institutes of Health, grants and personal fees from AzurRx, personal fees from Kala Pharmaceuticals, outside the submitted work. John Mershon has nothing to disclose. Dr. Rowe reports grants from Celtaxsys, during the conduct of the study; grants and personal fees from Novartis, grants and personal fees from Bayer, grants from Translate Bio, non-financial support from Proteostasis, grants, personal fees and non-financial support from Galapagos/Abbvie, grants, personal fees and other from Synedgen/Synspira, grants from Eloxx, grants from Celtaxsys, grants, personal fees, non-financial support and other from Vertex Pharmaceuticals Inc, personal fees from Renovion, grants and personal fees from Arrowhead, grants and other from Ionis, grants from Astra Zenica, outside the submitted work. Dr. Springman reports personal fees from Celtaxsys, Inc., during the conduct of the study; In addition, Dr. Springman has a patent PCT/US19/034810 pending, and a patent US16/427,571 pending. Dr. Sutharsan reports personal fees personal Proteostasis Therapeutics, personal fees from Novartis Pharma GmbH, personal fees from Vertex Pharmaceuticals Incorporated, personal fees from Teva GmbH, personal fees from Chiesi GmbH, outside the submitted work; . SS has served as an investigator in clinical trials for Galapagos NV, Proteostasis, Celtaxsys, Flatley Discovery Lab, Novartis and Vertex. Dr. Taylor-Cousar reports grants and personal fees from Celtaxys, during the conduct of the study; grants and personal fees from Gilead, grants from N30, grants and personal fees from Vertex, grants and personal fees from Proteostasis, grants from Bayer, personal fees from Novartis, personal fees from Genentech, personal fees from Protalix, personal fees from Santhera, personal fees from 4DMT, personal fees from Polarean Imaging, personal fees from Insmed, personal fees from Abbvie, outside the submitted work; and Service on the CF TDN Clinical Research Executive CommitteeÐervice as the Chair of the ATS Clinical Problems Assembly Program Committee. Dr. Uluer has served in an advisory capacity with Vertex and Eloxx but these relationships are in no way associated with the work submitted in this manuscript, (Crown Copyright © 2021. Published by Elsevier B.V. All rights reserved.)

Background: Antisense oligonucleotide (ASO)-based drugs for splicing modulation were recently approved for various genetic diseases with unmet need. Here we aimed to develop an ASO-based splicing modulation therapy for Cystic Fibrosis (CF) patients carrying the 3849+10 kb C-to-T splicing mutation in the CFTR gene., Methods: We have screened, in FRT cells expressing the 3849+10 kb C-to-T splicing mutation, ~30 2'-O-Methyl-modified phosphorothioate ASOs, targeted to prevent the recognition and inclusion of a cryptic exon generated due to the mutation. The effect of highly potent ASO candidates on the splicing pattern, protein maturation and CFTR function was further analyzed in well differentiated primary human nasal and bronchial epithelial cells, derived from patients carrying at least one 3849+10 kb C-to-T allele., Results: A highly potent lead ASO, efficiently delivered by free uptake, was able to significantly increase the level of correctly spliced mRNA and completely restore the CFTR function to wild type levels in cells from a homozygote patient. This ASO led to CFTR function with an average of 43% of wild type levels in cells from various heterozygote patients. Optimized efficiency of the lead ASO was further obtained with 2'-Methoxy Ethyl modification (2'MOE)., Conclusion: The highly efficient splicing modulation and functional correction, achieved by free uptake of the selected lead ASO in various patients, demonstrate the ASO therapeutic potential benefit for CF patients carrying splicing mutations and is aimed to serve as the basis for our current clinical development., Competing Interests: Declaration of Competing Interest Batsheva Kerem has equity in SpliSense and is paid for consultancy. All other authors have no financial conflict of interest., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Tobacco smoke exposure is a major risk factor for the health of children and adolescents with CF. In this study, we assess whether cessation of smoke exposure is associated with improved outcomes in this population., Methods: We used annualized and encounter-based data from the U.S. CF Foundation Patient Registry (2006-2018) on all individuals born 1998-2010. The analytical sample included those who ever reported second-hand smoke exposure (daily or weekly), ever lived with a smoker, or ever reported smoking themselves. We used non-linear mixed models for pulmonary exacerbations and linear mixed models for ppFEV 1 and BMI as a function of ceased exposure., Results: The sample included 3,633 individuals contributing 19,629 person-years. Cessation of smoke exposure reduced the odds of a pulmonary exacerbation in 12 months by 17% (OR 0.83, p < 0.001) in the first year of cessation, with an additional 6% decrease (OR 0.94, p = 0.003) for each additional year of cessation. Cessation was associated with improvements in ppFEV 1 and BMI: 0.7% ppFEV 1 increase (p < 0.001) in the first year of cessation and 0.4% increase (p = 0.001) for each additional year of cessation; 1% increase in BMI percentile (p < 0.001) in the first year of cessation plus 0.4% increase (p = 0.009) for each additional year. Three years of cessation reduce the predicted probability of a pulmonary exacerbation in 12 months by 8% and improve ppFEV 1 and BMI by 2%., Conclusion: Eliminating smoke exposure may reduce pulmonary exacerbations and improve respiratory and nutritional outcomes in children and adolescents with CF. Both smoking cessation and exposure prevention should be prioritized in pediatric CF care., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Objectives: Tobacco smoke exposure reduces CFTR functional expression in vitro and contributes to acquired CFTR dysfunction. We investigated whether it also inhibits the clinical benefit of CFTR modulators, focusing on tezacaftor/ivacaftor, approved in February 2018 for individuals with CF age ≥12 years., Methods: A retrospective longitudinal analysis of encounter-based data from the CF Foundation Patient Registry (2016-2018) compared the slope of change in lung function (GLI FEV 1 % predicted) before and after tezacaftor/ivacaftor initiation in smoke-exposed vs unexposed age-eligible pediatric patients. Tobacco smoke exposure (Ever/Never) was determined from caregiver self-report. Statistical analyses used hierarchical linear mixed modeling and fixed effects regression modeling., Results: The sample included 6,653 individuals with a total of 105,539 person-period observations. Tezacaftor/ivacaftor was prescribed to 19% (1,251) of individuals, mean age 17 years, mean baseline ppFEV 1 83%, 28% smoke-exposed. Tezacaftor/ivacaftor users who were smoke-exposed had a lower baseline ppFEV 1 and experienced a greater lung function decline. Over two years, the difference in ppFEV 1 by smoke exposure among tezacaftor/ivacaftor users increased by 1.2% (7.6% to 8.8%, p<0.001). In both mixed effects and fixed effects regression models, tezacaftor/ivacaftor use was associated with improved ppFEV 1 among unexposed individuals (1.2% and 1.7%, respectively; p<0.001 for both) but provided no benefit among smoke-exposed counterparts (0.3%, p = 0.5 and 0.6%, p = 0.07, respectively)., Conclusion: Tobacco smoke exposure nullifies the therapeutic benefit of tezacaftor/ivacaftor among individuals with CF aged 12-20 years old. To maximize the therapeutic opportunity of CFTR modulators, every effort must be taken to eliminate smoke exposure in CF., Competing Interests: Declaration of Competing Interest WTH and SMR have received support through their institution (UAB) from Vertex Pharmaceuticals to conduct and oversee CFTR modulator clinical trials., (Copyright © 2020 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Infertility and subfertility are commonly faced by females with cystic fibrosis (FwCF) and resulting in decreased contraceptive use and increased utilization of reproductive technologies. Elexacaftor-tezacaftor-ivacaftor (ETI) is a CFTR modulator that affects common causes of subfertility. Two CF centers conducted a retrospective chart review on females with CF who were receiving ETI and became pregnant. We analyzed obstetrical-gynecological history, genotype, and clinical response to ETI therapy. Fourteen FwCF on ETI became pregnant. Half (7) of the FwCFs were previously attempting to conceive, but only three were using contraceptives. Four FwCF had a history of infertility; two were reconsidering use of reproductive technologies (IUI). Patients achieved conception at mean 8 weeks after initiating ETI. ETI may lessen CF-associated factors that affect fertility; however, its exact mechanism is unknown. This warrants counseling on contraceptive use and family planning prior to initiation of therapy and at routine intervals while utilizing ETI., Competing Interests: Declarations of Competing Interest None, (Copyright © 2020. Published by Elsevier B.V.)

Background: This is the first-in-human study of icenticaftor, an oral potentiator of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) channel. Restoration of CFTR activity has shown significant clinical benefits, but more studies are needed to address all CFTR mutations., Methods: Safety, pharmacodynamics/pharmacokinetics of icenticaftor were evaluated in a randomized, double-blind, placebo-controlled study in healthy volunteers. Efficacy was assessed in adult CF patients with ≥1 pre-specified CFTR Class III or IV mutation (150 and 450 mg bid), or homozygous for F508del mutation (450 mg bid). Primary efficacy endpoint was change from baseline in lung clearance index (LCI 2.5 ). Secondary endpoints included %predicted FEV 1 and sweat chloride level., Results: Class IV mutations were present in 22 patients, Class III in 2 (both S549N), and 25 were homozygous for F508del. Icenticaftor was well-tolerated in healthy and CF subjects with no unexpected events or discontinuations in the CF groups. The most frequent study-drug related adverse events in CF patients were nausea (12.2%), headache (10.2%), and fatigue (6.1%). Icenticaftor 450 mg bid for 14 days showed significant improvements in all endpoints versus placebo in patients with Class III and IV mutations; mean %predicted FEV 1 increased by 6.46%, LCI 2.5 decreased by 1.13 points and sweat chloride decreased by 8.36 mmol/L. No significant efficacy was observed in patients homozygous for a single F508del., Conclusions: Icenticaftor was safe and well-tolerated in healthy volunteers and CF patients, and demonstrated clinically meaningful changes in lung function and sweat chloride level in CF patients with Class III and IV CFTR mutations. ClinicalTrials.gov: NCT02190604., Competing Interests: Declaration of Competing Interest IB, JM, BS, DR, IJ, KK, SM, LM, IMN, RV, JV, PSA, MSI are employees of Novartis. SK, JA, HD, MG and RS are past employees of Novartis. SMR reports grants, personal fees and non-financial support from Novartis, during the conduct of the study; grants, personal fees, non-financial support and other from Vertex Pharmaceuticals Inc., grants and personal fees from Bayer, grants from Translate Bio, non-financial support from Proteostasis, grants, personal fees and non-financial support from Galapagos/Abbvie, grants and personal fees from Synedgen/Synspira, grants from Eloxx, grants and personal fees from Celtaxsys, grants from Ionis, grants, personal fees and other from Renovion, outside the submitted work; in addition, SMR has a patent regarding the use of CFTR-directed therapies for diseases of mucus in which CFTR is not dysfunctional issued. NJS reports personal fees from Vertex, personal fees from Chiesi, personal fees from Raptor, personal fees from Pulmocide, personal fees from Novartis Pharmaceuticals Corporation, personal fees from Roche, personal fees from Teva, personal fees from Mylan, personal fees from Gilead, personal fees from Zambon, outside the submitted work. All other authors declare no competing interests., (Copyright © 2020. Published by Elsevier B.V.)

Background: The cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, ivacaftor, was first approved for people with CF and the G551D CFTR mutation. This study describes the long-term clinical effectiveness of ivacaftor in this population., Methods: We conducted a multicenter, prospective, longitudinal, observational study of people with CF ages ≥6 years with at least one copy of the G551D CFTR mutation. Measurements of lung function, growth, quality of life, and sweat chloride were performed after ivacaftor initiation (baseline, 1 month, 3 months, 6 months, and annually thereafter until 5.5 years)., Results: Ninety-six participants were enrolled, with 81% completing all study measures through 5.5 years. This cohort experienced significant improvements in percent predicted forced expiratory volume in 1 second (ppFEV1) of 4.8 [2.6, 7.1] (p < 0.001) at 1.5 years, that diminished to 0.8 [-2.0, 3.6] (p = 0.57) at 5.5 years. Adults experienced larger improvements in ppFEV1 (7.4 [3.6, 11.3], p < 0.001 at 1.5 years and 4.3 [0.6, 8.1], p = 0.02 at 5.5 years) than children (2.8 [0.1, 5.6], p = 0.04 at 1.5 years and -2.0 [-5.9, 2.0], p = 0.32 at 5.5 years). Rate of lung function decline for the overall study cohort from 1 month after ivacaftor initiation through 5.5 years was estimated to be -1.22 pp/year [-1.70, -0.73]. Significant improvements in growth, quality of life measures, sweat chloride, Pseudomonas aeruginosa detection, and pulmonary exacerbation rates requiring antimicrobial therapy persisted through five years of therapy., Conclusions: These findings demonstrate the long-term benefits and disease modifying effects of ivacaftor in children and adults with CF and the G551D mutation., Competing Interests: Declaration of Competing Interest SMR and MJ serve as investigators and/or consultants on the design and conduct of CF clinical trials to Vertex Pharmaceuticals, the manufacturer of ivacaftor. A.P. declares a previous (within 36 months) equity interest in AbbVie, Inc. All other authors declare no conflicts of interest., (Copyright © 2020. Published by Elsevier B.V.)

Background: Glucose tolerance abnormalities including cystic fibrosis related diabetes (CFRD) are common in patients with cystic fibrosis (CF). The underlying pathophysiology is not fully understood. Emerging evidence suggests that CFTR dysfunction may directly or indirectly impact β-cell function, offering the potential for improvement with CFTR modulator therapy. In small pilot studies, treatment with ivacaftor improved insulin secretion in patients with the G551D CFTR mutation. In the current study, we examined the impact of lumacaftor/ivacaftor therapy on glucose tolerance and insulin secretion in patients with CF who were homozygous for the F508del mutation., Methods: 39 subjects from the PROSPECT Part B study who had been prescribed lumacaftor/ivacaftor by their CF care team at a CF Foundation's Therapeutic Development Network center were recruited. Subjects underwent 2-hour oral glucose tolerance tests (OGTTs) at baseline prior to first dose of lumacaftor/ivacaftor, and at 3, 6 and 12 months on therapy. OGTT glucose, insulin and c-peptide parameters were compared., Results: Compared to baseline, OGTT fasting and 2 hour glucose levels, glucose area under the curve, insulin area under the curve and time to peak insulin level were not significantly different at 3, 6 and 12 months on lumacaftor/ivacaftor therapy. Similarly, C-peptide levels were no different., Conclusions: Lumacaftor/ivacaftor therapy did not improve insulin secretion or glucose tolerance in patients with CF who were homozygous for the F508del mutation., Competing Interests: Declaration of Competing Interest Amir Moheet has no declarations of interest. Daniel Beisang has no declarations of interest. Lin Zhang has no declarations of interest. Scott D. Sagel received grant funding from the CFF to conduct this study. Jill M. VanDalfsen has no declarations of interest. Sonya L. Heltshe has no declarations of interest. Carla Frederick has no declarations of interest. Michelle Mann has no declarations of interest. Nicholas Antos has no declarations of interest. Joanne Billings has no declarations of interest. Steven M. Rowe provided consulting services for Vertex Pharmaceuticals, and received research product for investigator initiated research and trial support from that company. Antoinette Moran served on a medical advisory board for Vertex Pharmaceuticals. She received grant funding from the CFF to conduct this study., (Copyright © 2020. Published by Elsevier B.V.)

Background: Increased rates of respiratory adverse events have been observed in people ≥12 years of age with cystic fibrosis homozygous for the Phe508del-CFTR mutation treated with lumacaftor/ivacaftor, particularly in those with percent predicted forced expiratory volume in 1 s (ppFEV 1 ) of <40%. We evaluated the safety, tolerability, and efficacy of tezacaftor/ivacaftor in people with cystic fibrosis homozygous for Phe508del-CFTR who discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms., Methods: Participants ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV 1 of ≥25% and ≤90% were randomized 1:1 and treated with tezacaftor/ivacaftor or placebo for 56 days., Results: Of 97 participants, 94 (96.9%) completed the study. The primary endpoint was incidence of predefined respiratory adverse events of special interest (chest discomfort, dyspnea, respiration abnormal, asthma, bronchial hyperreactivity, bronchospasm, and wheezing): tezacaftor/ivacaftor, 14.0%; placebo, 21.3%. The adverse events were mild or moderate in severity. None were serious or led to treatment interruption or discontinuation. Overall, the discontinuation rate was similar between groups. The mean (SD) ppFEV 1 at baseline was 44.6% (16.1%) with tezacaftor/ivacaftor and 48.0% (18.1%) with placebo. The posterior mean difference in absolute change in ppFEV 1 from baseline to the average value of days 28 and 56 was 2.7 percentage points with tezacaftor/ivacaftor vs placebo., Conclusions: Tezacaftor/ivacaftor was generally safe, well tolerated, and efficacious in people ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV 1 of ≥25% and ≤90% who previously discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms., Competing Interests: Declaration of Competing Interests All authors received nonfinancial support (assistance with manuscript preparation) from ArticulateScience LLC, which received funding from Vertex. Additional disclosures are as follows. BGB, MED, and NA are employees of Vertex and may own stock or stock options in Vertex. PKA, TJF and XY are former employees of Vertex and may own stock or stock options in Vertex. CS received a grant from Vertex and personal fees from Vertex, PTI, Chiesi, and Teva outside the submitted work. RF received an honorarium from Vertex during the conduct of the study. SMR received grants, personal fees, and nonfinancial support from Vertex during the conduct of the study; grants from Bayer, Forest Research Institute, AstraZeneca, Nivalis, Novartis, Galapagos/AbbVie, Proteostasis, Eloxx, Celtaxsys, PTC, and Vertex; personal fees from Bayer, Celtaxsys, Novartis, and Vertex; and nonfinancial support from Vertex outside the submitted work. SS received personal fees from Proteostasis, Novartis and Vertex outside the submitted work; has served as an investigator in clinical trials for Galapagos, Proteostasis, Celtaxsys, Flatley, Novartis, and Vertex; and has consulted for Proteostasis and Vertex. RCK and RE have no additional disclosures., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Highly effective CFTR modulator drug therapy is increasingly available to those with cystic fibrosis. Multiple observational research studies are now being conducted to better understand the impacts of this important therapeutic milestone on long-term outcomes, patient care needs, and future research priorities. PROMISE is a large, multi-disciplinary academic study focused on the broad impacts of starting elexacaftor/tezacaftor/ivacaftor in the US population age 6 years and older. The many areas of investigation and rationale for each are discussed by organ systems, along with recognition of remaining important questions that will not be addressed by this study alone. Knowledge gained through this and multiple complementary studies around the world will help to understand important health outcomes, clinical care priorities, and research needs for a large majority of people treated with these or similarly effective medications targeting the primary cellular impairment in cystic fibrosis., Competing Interests: Declaration of Competing Interest The primary author declares no conflict of interest with the content of this manuscript. Any potential conflicts of interest among all authors related to funding or other financial agreements will be collected and updated during the review process., (Copyright © 2021. Published by Elsevier B.V.)

The PROSPECT study, a post-approval observational study in the U.S., showed no significant changes in lung function as measured by spirometry with clinical initiation of lumacaftor/ivacaftor. A sub-study within the PROSPECT study assessed the lung clearance index (LCI), as measured by multiple breath washout (MBW), a measure of lung function demonstrated to be sensitive among people with normal spirometry. Participants performed MBW prior to clinically initiating lumacaftor/ivacaftor therapy and for one year of follow-up. Similar to the whole PROSPECT study, this sub-study cohort (N = 49) had no significant absolute or relative changes in FEV 1 % predicted at any time point. LCI, however, decreased (improved) by 0.81 units or 5.3% (95% CI -9.7, -0.9%) at 1 month, 0.77 units or 5.9% at 3 months, 0.67 units or 5.9% at 6 months, and 0.55 units or 4.3% at 12 months. These results demonstrate the utility of the LCI in assessing treatment effects of relatively modest size in a heterogenous study population., Competing Interests: Declaration of Competing Interest MS has nothing to disclose. UK reports grants from Cystic Fibrosis Foundation, during the conduct of the study and outside the submitted work. JPC reports grants from Cystic Fibrosis Foundation, during the conduct of the study. SHD reports grants from Cystic Fibrosis Foundation, during the conduct of the study. SDS reports a grant from the Cystic Fibrosis Foundation that funds the work under consideration, and grants from the Cystic Fibrosis Foundation and National Institutes of Health funding activities outside the submitted work. SMR reports grants, contracts, and consulting services from Vertex Pharmaceuticals related to the conduct of clinical trials. FR reports grants and personal fees from Vertex, personal fees from Novartis, personal fees from Bayer, personal fees from Roche, personal fees from Genetech, outside the submitted work., (Copyright © 2020. Published by Elsevier B.V.)

Background: Pulmonary decline in CF is heterogeneous, with socio-environmental factors contributing to this variability. Few studies have attempted to disentangle the effects of tobacco smoke exposure and socioeconomic factors on lung function deterioration in pediatric CF. The current study evaluates their contributions longitudinally across the entire U.S. CF care network population., Methods: Data from the CF Foundation Patient Registry were obtained on all individuals who at the end of 2016 were 6-18 years old. Lung function measures (ppFEV 1 ) for each person were calculated at each attained age. Multivariable analyses used mixed modeling to assess the impact of smoke exposure and socioeconomic factors on initial lung function and change over time., Results: The sample included 10,895 individuals contributing 65,581 person years. At age 6, ppFEV 1 of smoke-exposed children was 4.7% lower than among unexposed. The deficit persisted through age 18. In adjusted mixed models, smoke exposure and socioeconomic factors had independent, additive associations with lung function. Median ppFEV 1 declined 2.4% with smoke exposure, 4.9% with lower paternal education, 0.3% with public insurance, and increased 0.2% with each $10,000 annual household income. The effect of smoke exposure on ppFEV 1 was larger in disadvantaged children compared to privileged counterparts (3.2% vs 1.2%)., Conclusions: Smoke exposure and socioeconomic factors are independent risk factors for decreased ppFEV 1 in pediatric CF. Smoking cessation strategies should be emphasized at the time of CF diagnosis and reiterated during infancy and early childhood. Interventions may be prioritized in disadvantaged families, where the exposure has a disproportionately large effect., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The development of CFTR modulators has transformed the care of patients with cystic fibrosis (CF). Although the clinical efficacy of modulators depends on their concentrations in target tissues, the pharmacokinetic properties of these drugs in epithelia are not utilized to guide patient care. We developed assays to quantitate ivacaftor in cells and plasma from patients on modulator therapy, and our analyses revealed that cellular ivacaftor concentrations differ from plasma concentrations measured concurrently, with evidence of in vivo accumulation of ivacaftor in the cells of patients. While the nature of this study is exploratory and limited by a small number of patients, these findings suggest that techniques to measure modulator concentrations in vivo will be essential to interpreting their clinical impact, particularly given the evidence that ivacaftor concentrations influence the activity and stability of restored CFTR protein., Competing Interests: Declaration of Competing Interest S.M.R. serves as investigator and consultant to Vertex Pharmaceuticals, the manufacturer of ivacaftor, ivacaftor/lumacaftor, and ivacaftor/tezacaftor on CF clinical trials. J.S.G. and E.P.A. participated in clinical studies independent of Vertex Pharmaceuticals to evaluate the CFTR modulators described here. All other authors declare no conflicts of interest., (Copyright © 2020. Published by Elsevier B.V.)

Background: Ataluren was developed for potential treatment of nonsense-mutation cystic fibrosis (CF). A previous phase 3 ataluren study failed to meet its primary efficacy endpoint, but post-hoc analyses suggested that aminoglycosides may have interfered with ataluren's action. Thus, this subsequent trial (NCT02139306) was designed to assess the efficacy and safety of ataluren in patients with nonsense-mutation CF not receiving aminoglycosides., Methods: Eligible subjects with nonsense-mutation CF (aged ≥6 years; percent predicted (pp) FEV 1 ≥40 and ≤90) from 75 sites in 16 countries were randomly assigned in double-blinded fashion to receive oral ataluren or matching placebo thrice daily for 48 weeks. The primary endpoint was absolute change in average ppFEV 1 from baseline to the average of Weeks 40 and 48., Findings: 279 subjects were enrolled; 138 subjects in the ataluren arm and 136 in the placebo arm were evaluable for efficacy. Absolute ppFEV 1 change from baseline did not differ significantly between the ataluren and placebo groups at Week 40 (-0.8 vs -1.8) or Week 48 (-1.7 vs -2.4). Average ppFEV 1 treatment difference from baseline to Weeks 40 and 48 was 0.6 (95% CI -1.3, 2.5; p = 0.54). Pulmonary exacerbation rate per 48 weeks was not significantly different (ataluren 0.95 vs placebo 1.13; rate ratio p = 0.40). Safety was similar between groups. No life-threatening adverse events or deaths were reported., Interpretation: Neither ppFEV 1 change nor pulmonary exacerbation rate over 48 weeks were statistically different between ataluren and placebo groups. Development of a nonsense-mutation CF therapy remains elusive., Competing Interests: Declaration of Competing Interest JM is an employee of PTC Therapeutics, the funder of this clinical trial, and holds financial interests in the company. MWK, SMR, and DRV received compensation for consultant services from PTC Therapeutics prior to and/or during this study. EK, MW, IS-G, and KDB received compensation for travel expenses for meetings related to the study. All other authors declare no competing interests., (Copyright © 2020. Published by Elsevier B.V.)

The past six decades have seen remarkable improvements in health outcomes for people with cystic fibrosis, which was once a fatal disease of infants and young children. However, although life expectancy for people with cystic fibrosis has increased substantially, the disease continues to limit survival and quality of life, and results in a large burden of care for people with cystic fibrosis and their families. Furthermore, epidemiological studies in the past two decades have shown that cystic fibrosis occurs and is more frequent than was previously thought in populations of non-European descent, and the disease is now recognised in many regions of the world. The Lancet Respiratory Medicine Commission on the future of cystic fibrosis care was established at a time of great change in the clinical care of people with the disease, with a growing population of adult patients, widespread genetic testing supporting the diagnosis of cystic fibrosis, and the development of therapies targeting defects in the cystic fibrosis transmembrane conductance regulator (CFTR), which are likely to affect the natural trajectory of the disease. The aim of the Commission was to bring to the attention of patients, health-care professionals, researchers, funders, service providers, and policy makers the various challenges associated with the changing landscape of cystic fibrosis care and the opportunities available for progress, providing a blueprint for the future of cystic fibrosis care. The discovery of the CFTR gene in the late 1980s triggered a surge of basic research that enhanced understanding of the pathophysiology and the genotype-phenotype relationships of this clinically variable disease. Until recently, available treatments could only control symptoms and restrict the complications of cystic fibrosis, but advances in CFTR modulator therapies to address the basic defect of cystic fibrosis have been remarkable and the field is evolving rapidly. However, CFTR modulators approved for use to date are highly expensive, which has prompted questions about the affordability of new treatments and served to emphasise the considerable gap in health outcomes for patients with cystic fibrosis between high-income countries, and low-income and middle-income countries (LMICs). Advances in clinical care have been multifaceted and include earlier diagnosis through the implementation of newborn screening programmes, formalised airway clearance therapy, and reduced malnutrition through the use of effective pancreatic enzyme replacement and a high-energy, high-protein diet. Centre-based care has become the norm in high-income countries, allowing patients to benefit from the skills of expert members of multidisciplinary teams. Pharmacological interventions to address respiratory manifestations now include drugs that target airway mucus and airway surface liquid hydration, and antimicrobial therapies such as antibiotic eradication treatment in early-stage infections and protocols for maintenance therapy of chronic infections. Despite the recent breakthrough with CFTR modulators for cystic fibrosis, the development of novel mucolytic, anti-inflammatory, and anti-infective therapies is likely to remain important, especially for patients with more advanced stages of lung disease. As the median age of patients with cystic fibrosis increases, with a rapid increase in the population of adults living with the disease, complications of cystic fibrosis are becoming increasingly common. Steps need to be taken to ensure that enough highly qualified professionals are present in cystic fibrosis centres to meet the needs of ageing patients, and new technologies need to be adopted to support communication between patients and health-care providers. In considering the future of cystic fibrosis care, the Commission focused on five key areas, which are discussed in this report: the changing epidemiology of cystic fibrosis (section 1); future challenges of clinical care and its delivery (section 2); the building of cystic fibrosis care globally (section 3); novel therapeutics (section 4); and patient engagement (section 5). In panel 1, we summarise key messages of the Commission. The challenges faced by all stakeholders in building and developing cystic fibrosis care globally are substantial, but many opportunities exist for improved care and health outcomes for patients in countries with established cystic fibrosis care programmes, and in LMICs where integrated multidisciplinary care is not available and resources are lacking at present. A concerted effort is needed to ensure that all patients with cystic fibrosis have access to high-quality health care in the future., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators correct the basic defect caused by CFTR mutations. Improvements in health outcomes have been achieved with the combination of a CFTR corrector and potentiator in people with cystic fibrosis homozygous for the F508del mutation. The addition of elexacaftor (VX-445), a next-generation CFTR corrector, to tezacaftor plus ivacaftor further improved F508del-CFTR function and clinical outcomes in a phase 2 study in people with cystic fibrosis homozygous for the F508del mutation., Methods: This phase 3, multicentre, randomised, double-blind, active-controlled trial of elexacaftor in combination with tezacaftor plus ivacaftor was done at 44 sites in four countries. Eligible participants were those with cystic fibrosis homozygous for the F508del mutation, aged 12 years or older with stable disease, and with a percentage predicted forced expiratory volume in 1 s (ppFEV 1 ) of 40-90%, inclusive. After a 4-week tezacaftor plus ivacaftor run-in period, participants were randomly assigned (1:1) to 4 weeks of elexacaftor 200 mg orally once daily plus tezacaftor 100 mg orally once daily plus ivacaftor 150 mg orally every 12 h versus tezacaftor 100 mg orally once daily plus ivacaftor 150 mg orally every 12 h alone. The primary outcome was the absolute change from baseline (measured at the end of the tezacaftor plus ivacaftor run-in) in ppFEV 1 at week 4. Key secondary outcomes were absolute change in sweat chloride and Cystic Fibrosis Questionnaire-Revised respiratory domain (CFQ-R RD) score. This study is registered with ClinicalTrials.gov, NCT03525548., Findings: Between Aug 3 and Dec 28, 2018, 113 participants were enrolled. Following the run-in, 107 participants were randomly assigned (55 in the elexacaftor plus tezacaftor plus ivacaftor group and 52 in the tezacaftor plus ivacaftor group) and completed the 4-week treatment period. The elexacaftor plus tezacaftor plus ivacaftor group had improvements in the primary outcome of ppFEV 1 (least squares mean [LSM] treatment difference of 10·0 percentage points [95% CI 7·4 to 12·6], p<0·0001) and the key secondary outcomes of sweat chloride concentration (LSM treatment difference -45·1 mmol/L [95% CI -50·1 to -40·1], p<0·0001), and CFQ-R RD score (LSM treatment difference 17·4 points [95% CI 11·8 to 23·0], p<0·0001) compared with the tezacaftor plus ivacaftor group. The triple combination regimen was well tolerated, with no discontinuations. Most adverse events were mild or moderate; serious adverse events occurred in two (4%) participants receiving elexacaftor plus tezacaftor plus ivacaftor and in one (2%) receiving tezacaftor plus ivacaftor., Interpretation: Elexacaftor plus tezacaftor plus ivacaftor provided clinically robust benefit compared with tezacaftor plus ivacaftor alone, with a favourable safety profile, and shows the potential to lead to transformative improvements in the lives of people with cystic fibrosis who are homozygous for the F508del mutation., Funding: Vertex Pharmaceuticals., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. In this study we assessed the effect of antisense oligonucleotide eluforsen on CFTR biological activity measured by Nasal Potential Difference (NPD) in patients with the most common mutation, F508del-CFTR., Methods: This multi-centre, exploratory, open-label study recruited adults with CF homozygous or compound heterozygous for the F508del-CFTR mutation. Subjects received intranasal eluforsen three times weekly for 4 weeks. The primary endpoint was the within-subject change from baseline in total chloride transport (Cl-free+iso), as assessed by NPD. Secondary endpoints included within-subject change from baseline in sodium transport., Results: In the homozygous cohort (n = 7; per-protocol population), mean change (90% confidence interval) in Cl-free+iso was -3.0 mV (-6.6; 0.6) at day 15, -4.1 mV (-7.8; -0.4, p = .04) at day 26 (end of treatment) and - 3.7 mV (-8.0; 0.6) at day 47. This was supported by improved sodium transport as assessed by an increase in average basal potential difference at day 26 of +9.4 mV (1.1; 17.7, p = .04). The compound heterozygous cohort (n = 7) did not show improved chloride or sodium transport NPD values. Eluforsen was well tolerated with a favourable safety profile., Conclusions: In F508del-CFTR homozygous subjects, repeated intranasal administration of eluforsen improved CFTR activity as measured by NPD, an encouraging indicator of biological activity., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: To raise awareness of colocolonic intussusception as a gastrointestinal complication of CF mimicking distal intestinal obstruction syndrome (DIOS) and discuss risk of recurrence., Case Summary: A 33-year-old Caucasian male with cystic fibrosis presented with an acute abdomen diagnosed via imaging as colocolonic intussusception. He was managed with fluid replacement therapy and polyethylene glycol. He was re-admitted due to recurrence likely secondary to recurrent constipation and development of a fecalith. Surgery was contraindicated due to absence of tissue ischemia or necrosis., Discussion: Several possible etiological factors have been described, especially some that tend to occur within the context of CF disease, such as DIOS and PERT, and symptoms of colocolonic intussusception are similar to those of other causes of an acute abdomen but distinguishable by advanced imaging modalities. Due to risk of recurrence, an etiology of intussusception should be sought., Conclusion: Colo-colonic intussusception is a rare cause of an acute abdomen in the adult Cystic Fibrosis (CF) patient and may be associated with underlying constipation or presence of a fecalith., (Copyright © 2018. Published by Elsevier B.V.)

This study evaluated the effect of equine chorionic gonadotropin (eCG) on reproductive performance, when incorporated into the first Ovsynch + P4 synchronization following planned start mating (PSM) in pasture-based lactating dairy cows. Two synchrony programs were compared in a randomized controlled trial in Queensland, Australia. Lactating cows from a single dairy herd (n = 782) were randomly allocated to Control and eCG groups. Control cows had their estrous cycles synchronized by treatment with 100 μg gonadotropin releasing hormone (GnRH; im) and insertion of a progesterone (P4) releasing intravaginal device that contained 1.0 g of P4 on Day 0; removal of P4 device and administration of 500 μg of an analogue of PGF2α on Day 7 (cloprostenol; im); 100 μg im of GnRH on Day 9, and fixed-time artificial insemination (FTAI) on Day 10. The eCG group were treated the same as the Control group except for the addition of 400 IU of eCG, im on Day 7 of the first synchronized estrous cycle. Following the first insemination, non-pregnant cows from both groups had their estrous cycles synchronized with the same treatment protocol without using eCG. The effects of eCG on 42d cumulative incidence of pregnancy and pregnancy per AI (P/AI) were determined using logistic regression models. The effect of eCG on time to pregnancy was determined using Kaplan-Meier survival analysis and Cox proportional hazards models. Adjusted 42 d cumulative incidence of pregnancy for eCG and control groups were 47.2 and 39.3% respectively (Odds ratio [OR] = 1.38, 95% CI: 1.01-1.88). Hazard of pregnancy tended to be higher in eCG cows overall (Hazard ratio [HR] = 1.18, 95% CI: 0.99-1.41) and was significantly higher when restricting to the first 42 days after PSM (HR = 1.31, 95% CI: 1.04-1.64). Hazards of pregnancy were not different between groups when restricting to > Day 42 post PSM (HR = 1.00, 95% CI: 0.77-1.31). P/AI tended to be higher in eCG treated cows at the first AI (44.0 vs 37.7%, OR = 1.30, 95% CI: 0.94-1.78). P/AI for second and third AIs were not significantly different between groups. In this herd, a single treatment of eCG at the first synchronized estrus after PSM improved reproductive performance in the short term, but not at subsequent inseminations., (Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.)

This study utilizes morphological and mechanistic endpoints to characterize the onset of bilateral atresia of the vas deferens in a recently derived cystic fibrosis (CF) rat model. Embryonic reproductive structures, including Wolffian (mesonephric) duct, Mullerian (paramesonephric) duct, mesonephric tubules, and gonad, were shown to mature normally through late embryogenesis, with involution of the vas deferens and/or epididymis typically occurring between birth and postnatal day 4 (P4), although timing and degree of atresia varied. No evidence of mucus obstruction, which is associated with pathology in other CF-affected tissues, was observed at any embryological or postnatal time point. Reduced epididymal coiling was noted post-partum and appeared to coincide with, or predate, loss of more distal vas deferens structure. Remarkably, α smooth muscle actin expression in cells surrounding duct epithelia was markedly diminished in CF animals by P2.5 when compared to wild type counterparts, indicating reduced muscle development. RNA-seq and immunohistochemical analysis of affected tissues showed disruption of developmental signaling by Wnt and related pathways. The findings have relevance to vas deferens loss in humans with CF, where timing of ductular damage is not well characterized and underlying mechanisms are not understood. If vas deferens atresia in humans begins in late gestation and continues through early postnatal life, emerging modulator therapies given perinatally might preserve and enhance integrity of the reproductive tract, which is otherwise absent or deficient in 97% of males with cystic fibrosis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: The cystic fibrosis transmembrane conductance regulator (CFTR) potentiator ivacaftor is approved for patients with CF with gating and residual function CFTR mutations. We report the results of an observational study investigating its effects in CF patients with non-G551D gating mutations., Methods: Patients with non-G551D gating mutations were recruited to an open-label study evaluating ivacaftor. Primary outcomes included: lung function, sweat chloride, weight gain, and quality of life scores., Results: Twenty-one subjects were enrolled and completed 6 months follow-up on ivacaftor; mean age was 25.6 years with 52% <18. Baseline ppFEV 1 was 68% and mean sweat chloride 89.6 mEq/L. Participants experienced significant improvements in ppFEV 1 (mean absolute increase of 10.9% 95% CI = [2.6,19.3], p = 0.0134), sweat chloride (-48.6 95% CI = [-67.4,-29.9], p < 0.0001), and weight (5.1 kg, 95% CI = [2.8, 7.3], p = 0.0002)., Conclusions: Patients with non-G551D gating mutations experienced improved lung function, nutritional status, and quality of life. This study supports ongoing use of ivacaftor for patients with these mutations., (Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Inflammation causes irreparable damage in the cystic fibrosis (CF) lung. Despite high standards of care and the advent of new therapies, inflammation continues to cause significant loss of lung function and morbidity. Acebilustat is a once-daily, oral molecule with anti-inflammatory activity through the inhibition of LTA4 hydrolase and modulation of LTB4. It has potential to reduce lung function decline and pulmonary exacerbations in patients with CF and is currently being tested in a Phase II multicenter, randomized, double-blind, placebo-controlled, parallel-group study (EMPIRE-CF). Strict inclusion criteria based on modeling of the Cystic Fibrosis Foundation Patient Registry data were selected to enrich the trial with patients most likely to benefit from chronic anti-inflammatory therapy that reduces lung function decline. 200 patients between 18 and 30 years of age, with an FEV 1 percent predicted (pp) ≥50%, and ≥1 exacerbation in the past year have been enrolled. Patients are randomized 1:1:1 to placebo, acebilustat 50 mg or 100 mg for 48 weeks, taken concomitantly with their current standard of care, and stratified based on concomitant CFTR modulator use, baseline FEV 1 pp (50% to 75% and >75%), and number of exacerbations in the past year (1 or >1). The primary endpoints are absolute change from baseline in FEV 1 pp and safety outcomes. Secondary endpoints include rate of pulmonary exacerbations and time to first pulmonary exacerbation. Biomarkers of inflammation will also be assessed. EMPIRE-CF is expected to identify the optimal patient population, dose, duration and endpoints for future acebilustat trials, and widen understanding of the drug's efficacy in patients with CF., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Nasal Potential Difference (NPD) is a biomarker of CFTR activity used to diagnose CF and monitor experimental therapies. Limited studies have been performed to assess agreement between expert readers of NPD interpretation using a scoring algorithm., Methods: We developed a standardized scoring algorithm for "interpretability" and "confidence" for PD (potential difference) measures, and sought to determine the degree of agreement on NPD parameters between trained readers., Results: There was excellent agreement for interpretability between NPD readers for CF and fair agreement for normal tracings but slight agreement of interpretability in indeterminate tracings. Amongst interpretable tracings, excellent correlation of mean scores for Ringer's Baseline PD, Δ amiloride , and Δ Cl-free+Isoproterenol was observed. There was slight agreement regarding confidence of the interpretable PD tracings, resulting in divergence of the Ringers and Δ amiloride , and ΔCl -free+Isoproterenol PDs between "high" and "low" confidence CF tracings., Conclusion: A multi-reader process with adjudication is important for scoring NPDs for diagnosis and in monitoring of CF clinical trials., (Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

New therapeutics, such as ivacaftor, and the combination drug lumacaftor/ivacaftor that target the underlying genetic cause of cystic fibrosis are being hailed as game-changers in this era of personalized medicine. Although these drugs improve lung function, their effects on female fertility have not been studied. In this case report we describe one woman's experience with ivacaftor and her unanticipated pregnancy. Implications related to comprehensive sexual and reproductive health care for women with cystic fibrosis are presented., (Copyright © 2017 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.)

Premature termination codons (PTCs) in cystic fibrosis transmembrane conductance regulator (CFTR) gene result in nonfunctional CFTR protein and are the proximate cause of ~11% of CF causing alleles. Aminoglycosides and other novel agents are known to induce translational readthrough of PTCs, a potential therapeutic approach. Among PTCs, W1282X CFTR is unique, as it is a C-terminal CFTR mutation that can exhibit partial activity, even in the truncated state. The potentiator ivacaftor (VX-770) is approved for treating CF patients with G551D and other gating mutations. Based on previous studies demonstrating the beneficial effect of ivacaftor for PTC mutations following readthrough in vitro, we hypothesized that ivacaftor may enhance CFTR activity in CF patients expressing W1282X CFTR, and could be further enhanced by readthrough. Ivacaftor significantly increased CFTR activity in W1282X-expressing cells compared to R1162X CFTR cells, and was further enhanced by readthrough with the aminoglycoside G418. Primary nasal epithelial cells from a W1282X homozygous patient showed improved CFTR function in the presence of ivacaftor. Upon ivacaftor administration to the same patient, there was significant improvement in pulmonary exacerbation frequency, BMI, and insulin requirement, whereas FEV 1 remained stable over 3years. These studies suggest that ivacaftor may have moderate clinical benefit in patients with preserved expression of the W1282X CFTR mutation by stimulating residual activity of the truncated protein, suggesting the need for further studies including the addition of efficacious readthrough agents., (Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Acute pulmonary exacerbations are associated with progressive lung function decline and increased mortality in cystic fibrosis. The role of pulmonary vascular disease in pulmonary exacerbations is unknown. We aimed to assess the association between pulmonary artery enlargement (defined as pulmonary artery diameter to ascending aorta diameter [PA:A] ratio >1), a marker of pulmonary vascular disease, and exacerbations., Methods: In this cohort study, we used clinical, CT imaging, and prospective exacerbation data from a previous prospective clinical trial (derivation cohort) and from The Prince Charles Hospital (TPCH; Brisbane, QLD, Australia) cystic fibrosis registry (validation cohort). In our derivation cohort, we included adults aged 18 years or older with cystic fibrosis and at least one CFTR nonsense mutation, who were enrolled in the trial between Sept 8, 2009, and Nov 30, 2010, randomly assigned to receive placebo, and had baseline CT imaging. Our validation cohort included adult patients with cystic fibrosis who had CT imaging performed between Jan 1, 2002, and Dec 31, 2014. We measured the PA:A ratio at the level of the pulmonary artery bifurcation on CT scans. Patients in each cohort were separated into two groups on the basis of PA:A ratio (>1 or ≤1) and were followed up for 1 year in the derivation cohort and 2 years in the validation cohort. The primary endpoint was the development of one or more acute pulmonary exacerbations during follow-up. We used linear and logistic regression models to determine associations between clinical factors, the PA:A ratio, and pulmonary exacerbations. We used Cox regression to determine the time to first exacerbation in the validation cohort., Findings: 37 (50%) of 74 patients in the derivation cohort and 89 (47%) of 190 patients in the validation cohort had enlarged pulmonary arteries (PA:A>1). 50 (68%) patients in the derivation cohort had one or more exacerbations at 1 year and 133 (70%) patients in the validation cohort had one or more exacerbations at 2 years. At baseline, patients with pulmonary artery enlargement were younger than those without enlargement in both cohorts and had elevated sweat chloride concentrations in the derivation cohort (100·5 mmol/L [SD 10·9] vs 90·4 mmol/L [19·9]; difference 10·1 mmol/L [95% CI 2·5-17·7], p=0·017). Pulmonary artery enlargement was associated with exacerbations in the derivation cohort (odds ratio 3·49 [95% CI 1·18-10·3], p=0·023) when adjusted for sex, body-mass index (BMI), forced expiratory volume in 1 s (FEV1), and PA:A greater than 1, and in the validation cohort (2·41 [1·06-5·52], p=0·037) when adjusted for sex, BMI, chronic Pseudomonas aeruginosa infection, FEV1/FVC (forced vital capacity), PA:A greater than 1, and previous exacerbation. The time to first exacerbation was shorter in patients with enlarged pulmonary arteries than in those with normal-sized pulmonary arteries in the validation cohort (hazard ratio 1·66 [95% CI 1·18-2·34], p=0·0038) in unadjusted analysis, but not when adjusted for sex, BMI, exacerbations within 1 year before index CT scan, FEV1/FVC, and chronic P aeruginosa infection (1·14 [0·80-1·62], p=0·82)., Interpretation: Pulmonary artery enlargement is prevalent in adult patients with cystic fibrosis and was associated with acute pulmonary exacerbation risk in two well characterised cohorts. The PA:A ratio could be a predictive marker in cystic fibrosis., Funding: US National Heart, Lung, and Blood Institute/National Institutes of Health, Cystic Fibrosis Foundation, the University of Alabama at Birmingham, and the Queensland Health Fellowship., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Ivacaftor improves clinical outcome by potentiation of mutant G551D CFTR. Due to the presence of CFTR in monocytes and polymorphonuclear neutrophils (PMNs), we hypothesized that ivacaftor may impact leukocyte activation., Methods: We examined blood leukocytes from G551D CF subjects prior to and at one and six months after receiving ivacaftor. Blood leukocytes from ivacaftor-naïve G551D, F508del, and healthy controls were also treated with ivacaftor ex vivo to assess mutation-specific effects., Results: Compared to healthy controls, G551D CF subjects had significantly higher expression of active CD11b on PMNs and of CD63 on monocytes, which were normalized by in vivo ivacaftor treatment. Ex vivo exposure to ivacaftor of blood cells from G551D, but not F508del and healthy subjects, resulted in changes in CXCR2 and CD16 expression on PMNs., Conclusions: In vivo and ex vivo exposure of G551D CF leukocytes to ivacaftor resulted in an altered activation profile, suggesting mutation-specific leukocyte modulation., (Published by Elsevier B.V.)

Rationale: Despite the demonstrated advantageous systemic changes in response to regular exercise for individuals with cystic fibrosis (CF), exercise is still viewed as an elective rather than a vital component of therapy, and it is likely that these benefits extend to and are partially mediated by exercise-induced changes in ion regulation., Objective: We sought to determine if exercise could provide comparable improvements in ion regulation in the CF lung as albuterol, measured using exhaled breath condensate (EBC) collection and nasal potential difference (NPD)., Methods: Fourteen CF (13-42 yrs.) and sixteen healthy (18-42 yrs.) subjects completed a randomized crossover study of albuterol and submaximal exercise. EBC was collected at baseline, 30- and 60-min post-albuterol administration, and at baseline and during three separate 15 min cycling exercise bouts at low, moderate, and vigorous intensity (25, 50 and 65% of the maximum workload, respectively). NPD was performed at 30- and 80-min post albuterol or following moderate and vigorous intensity exercise., Results: CF subjects had lower EBC Cl(-), but no difference in EBC Na(+) at baseline when compared to healthy subjects. EBC Cl(-) increased four-fold with moderate exercise which was similar to that seen 60-min post albuterol administration for CF subjects. Neither exercise nor albuterol altered EBC Na(+). The change in NPD voltage with amiloride (ΔAmil) was greater and there was minimal Cl(-) secretion (ΔTCC) seen at baseline in the CF compared to the healthy subjects. ΔAmil was greater with both albuterol and exercise when compared to baseline within both CF and healthy groups, but there was no significant difference in the ΔTCC response with either treatment., Conclusion: Both exercise and albuterol can alter ion regulation increasing Cl(-) secretion to a significant and similar degree in individuals with CF., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Ivacaftor has been previously assessed in patients with cystic fibrosis with Gly551Asp-CFTR or other gating mutations. We assessed ivacaftor in patients with Arg117His-CFTR, a residual function mutation., Methods: We did a 24-week, placebo-controlled, double-blind, randomised clinical trial, which enrolled 69 patients with cystic fibrosis aged 6 years and older with Arg117His-CFTR and percentage of predicted forced expiratory volume in 1 s (% predicted FEV1) of at least 40. We randomly assigned eligible patients (1:1) to receive placebo or ivacaftor 150 mg every 12 h for 24 weeks. Randomisation was stratified by age (6-11, 12-17, and ≥18 years) and % predicted FEV1 (<70, ≥70 to ≤90, and >90). The primary outcome was the absolute change from baseline in % predicted FEV1 through week 24. Secondary outcomes included safety and changes in sweat chloride concentrations and Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain scores. An open-label extension enrolled 65 of the patients after washout; after 12 weeks, we did an interim analysis., Findings: After 24 weeks, the treatment difference in mean absolute change in % predicted FEV1 between ivacaftor (n=34) and placebo (n=35) was 2·1 percentage points (95% CI -1·13 to 5·35; p=0·20). Ivacaftor treatment resulted in significant treatment differences in sweat chloride (-24·0 mmol/L, 95% CI -28·01 to -19·93; p<0·0001) and CFQ-R respiratory domain (8·4, 2·17 to 14·61; p=0·009). In prespecified subgroup analyses, % predicted FEV1 significantly improved with ivacaftor in patients aged 18 years or older (treatment difference vs placebo: 5·0 percentage points, 95% CI 1·15 to 8·78; p=0·01), but not in patients aged 6-11 years (-6·3 percentage points, -11·96 to -0·71; p=0·03). In the extension study, both placebo-to-ivacaftor and ivacaftor-to-ivacaftor groups showed % predicted FEV1 improvement (absolute change from post-washout baseline at week 12: placebo-to-ivacaftor, 5·0 percentage points [p=0·0005]; ivacaftor-to-ivacaftor, 6·0 percentage points [p=0·006]). We did not identify any new safety concerns. The studies are registered with ClinicalTrials.gov (the randomised, placebo-controlled study, number NCT01614457; the open-label extension study, number NCT01707290)., Interpretation: Although this study did not show a significant improvement in % predicted FEV1, ivacaftor did significantly improve sweat chloride and CFQ-R respiratory domain scores and lung function in adult patients with Arg117His-CFTR, indicating that ivacaftor might benefit patients with Arg117His-CFTR who have established disease., Funding: Vertex Pharmaceuticals Incorporated., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The underlying cause of cystic fibrosis (CF) is the loss of epithelial chloride and bicarbonate transport due to mutations in the CF transmembrane conductance regulator (CFTR) gene encoding the CFTR protein. Ivacaftor is a gene-specific CFTR potentiator that augments in vivo chloride transport in CFTR mutations affecting channel gating. Originally approved for the G511D CFTR mutation, ivacaftor is now approved for eight additional alleles exhibiting gating defects and has also been tested in R117H, a CFTR mutation with residual function that exhibits abnormal gating. P67L is a class 4 conductance (nongating) mutation exhibiting residual CFTR function. We report marked clinical improvement, normalization of spirometry, and dramatic reduction in radiographic structural airway changes after > 1 year of treatment with ivacaftor in a young adult with the compound heterozygous genotype P67L/F508del CFTR. The case suggests that ivacaftor may have a potential benefit for patients with CF with nongating mutations.