Clinical Effectiveness of Elexacaftor/Tezacaftor/Ivacaftor in People with Cystic Fibrosis: A Clinical Trial.

Rationale: The cystic fibrosis (CF) modulator drug, elexacaftor/tezacaftor/ivacaftor (ETI), proved highly effective in controlled clinical trials for individuals with at least one F508del allele, which occurs in at least 85% of people with CF. Objectives: PROMISE is a postapproval study to understand the broad effects of ETI through 30 months' clinical use in a more diverse U.S. patient population with planned analyses after 6 months. Methods: Prospective, observational study in 487 people with CF age 12 years or older with at least one F508del allele starting ETI for the first time. Assessments occurred before and 1, 3, and 6 months into ETI therapy. Outcomes included change in percent predicted FEV1 (ppFEV1), sweat chloride concentration, body mass index (BMI), and self-reported respiratory symptoms. Measurements and Main Results: Average age was 25.1 years, and 44.1% entered the study using tezacaftor/ivacaftor or lumacaftor/ivacaftor, whereas 6.7% were using ivacaftor, consistent with F508del homozygosity and G551D allele, respectively. At 6 months into ETI therapy, ppFEV1 improved 9.76 percentage points (95% confidence interval [CI], 8.76 to 10.76) from baseline, cystic fibrosis questionnaire-revised respiratory domain score improved 20.4 points (95% CI, 18.3 to 22.5), and sweat chloride decreased -41.7 mmol/L (95% CI, -43.8 to -39.6). BMI also significantly increased. Changes were larger in those naive to modulators but substantial in all groups, including those treated with ivacaftor at baseline. Conclusions: ETI by clinical prescription provided large improvements in lung function, respiratory symptoms, and BMI in a diverse population naive to modulator drug therapy, using existing two-drug combinations, or using ivacaftor alone. Each group also experienced significant reductions in sweat chloride concentration, which correlated with improved ppFEV1 in the overall study population. Clinical trial registered with www.clinicaltrials.gov (NCT NCT04038047).

Comparative Effectiveness of Vancomycin Versus Linezolid for the Treatment of Acute Pulmonary Exacerbations of Cystic Fibrosis.

Background: Data are limited regarding the preferred antibiotics for treatment of acute pulmonary exacerbations (APEs) of cystic fibrosis (CF), when methicillin-resistant Staphylococcus aureus (MRSA) is suspected. Objective: To compare the rate of return to baseline lung function among individuals with APEs of CF treated with either vancomycin or linezolid. Methods: This retrospective study included individuals hospitalized for APEs of CF from May 1, 2015, to April 30, 2017 who were infected with MRSA and treated with vancomycin or linezolid. The primary outcome was the return to baseline lung function, as measured by forced expiratory volume in 1 s (FEV1). Descriptive and inferential statistics were used. All tests were 2-tailed with α set at 0.05. Results: A total of 122 encounters were included (vancomycin: n = 66; linezolid: n = 66). No difference existed in return to baseline FEV1 between vancomycin (53 [80.3%]) and linezolid (50 [75.8%]; P = 0.53); nor was there a difference in median percentage change in FEV1 from admission to follow-up between vancomycin (24.7%) and linezolid (20.7%; P = 0.61). Adverse drug events occurred more frequently in patient encounters treated with vancomycin (10 [15.2%]) compared with linezolid (2 [3%]; P = 0.002). Conclusion and Relevance: Our study observed no difference in the effectiveness of vancomycin compared with linezolid in terms of change in lung function for APEs of CF. The rate of adverse drug events was low. In individuals with CF infected with MRSA who are experiencing an APE, either vancomycin or linezolid appear to be viable treatment options.

Development and preliminary validation of the personalized cystic fibrosis medication questionnaire (PCF-MQ).

BACKGROUND: A personalized approach to assessing medication knowledge may identify opportunities for education to support self-management of cystic fibrosis (CF). This project describes the development, scoring, and preliminary validity of the Personalized CF Medication Questionnaire (PCF-MQ), designed to assess knowledge of prescribed CF medication purpose, administration, and dose and frequency. METHODS: Participants completed the PCF-MQ, the Knowledge of Disease Management (KDM-CF), and the Cystic Fibrosis-Medication Beliefs Questionnaire (CF-MBQ). Prescribed regimens were abstracted from medical records. Eligibility criteria were age 12 years and older, diagnosed with CF, and prescribed a CF medication. Statistical analyses were conducted using R software. Spearman rho was used to test correlations between measures. RESULTS: Sixty people with CF (pwCF) were enrolled; three people reported a regimen that substantially deviated from the medical record and were excluded from the analyses. The mean (SD) age was 20.2 (7.3) years, 54 % were female, and 74 % had a FEV1pp ≥70 %. The mean (SD) PCF-MQ total score was 77.8 (12.3) and knowledge scores ranged from a low of 58.3 for levalbuterol to 100 for ivacaftor. The PCF-MQ total score correlated with the KDM total score and subscales (Spearman Rho= 0.32-0.59, p < 0.05) and was not correlated with the CF-MBQ subscales (p > 0.05)). CONCLUSIONS: The PCF-MQ was correlated with another measure of general CF knowledge, but not health beliefs; because of the small sample size, this should be considered preliminary evidence of its validity. Advantages over existing CF knowledge measures include its practicality for use to help assess pwCF's knowledge about their prescribed regimen.

Airway clearance after highly effective CFTR modulators: Normalizing life and reducing treatment burden.

OBJECTIVES: Airway clearance therapy (ACT) is an important component of therapy for cystic fibrosis (CF) but is associated with significant treatment burden. Highly effective CFTR modulator therapy (HEMT) has improved pulmonary function for many people with CF (pwCF). We sought to understand changes in attitudes and practices about ACT in the post-HEMT era. STUDY DESIGN: Surveys of CF community members and CF care team members. METHODOLOGY: Separate surveys were created for the CF community and CF care providers to evaluate attitudes towards ACT and exercise in the post-HEMT era. We solicited answers from pwCF via the CF Foundation's Community Voice and from CF care providers via CF Foundation listservs. Surveys were available between July 20 and August 3, 2021. RESULTS: Surveys were completed by 153 community members (parents of children and pwCF) and 192 CF care providers. Belief that exercise can substitute partially for ACT was endorsed similarly by community members (59%) and providers (68%). After starting HEMT, 36% of parents of children and 51% of adults did fewer ACT treatments including 13% who stopped ACT. Adults reported altering their ACT regimen more than parents of children, though the sample size was limited. Half of providers had changed their ACT recommendations for those on HEMT. Fifty-three percent of respondents had discussed changing ACT with their care team (36% of parents, 58% of pwCF). CONCLUSIONS: Providers should be aware that ACT management changes may have been undertaken by pwCF who have pulmonary benefits of HEMT. Treatment burden should be considered in co-management decisions regarding ACT and exercise.

Partners in research: The success with therapies research consortium and the CF community unite to improve self-management.

BACKGROUND: The daily treatment regimen for an individual with cystic fibrosis (CF) can take more than 2 h to complete, and chronic treatment adherence rates are low. Developing partnerships between CF clinical researchers and the CF community is essential in developing acceptable, feasible, and effective strategies to improve self-management and adherence. METHODS: The Success with Therapies Research Consortium (STRC) was formed as a multi-center US collaborative to conduct rigorous research studies of adherence to CF treatments. A multidisciplinary team of researchers from 15 sites, collaborating with members of the CF community, is charged with developing, implementing, and disseminating real-world, patient-centered interventions for people living with CF. RESULTS: Since 2014, the STRC has conducted 8 studies. The CF community, people with CF (pwCF), and caregivers have come to serve in multiple valuable capacities on the STRC, including as members of the Steering Committee and Co-Principal Investigators. Additionally, while people with CF are irreplaceable participants in STRC studies, their influence, and that of their families and healthcare professionals, extends beyond the traditional research participant role. CONCLUSIONS: Engaging broadly with the CF community is the optimal model for developing interventions to support those living with CF in sustaining daily care. Input and direct involvement from people with CF, their families, and their caregivers has enabled the STRC to advance its mission through innovative clinical research approaches.

Elexacaftor/tezacaftor/ivacaftor and gastrointestinal outcomes in cystic fibrosis: Report of promise-GI.

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.

Systematic depression and anxiety screening for patients and caregivers: implementation and process improvement in a cystic fibrosis clinic.

INTRODUCTION: Depression and anxiety are common. Rates are significantly higher in cystic fibrosis (CF), and impact health outcomes. Screening is recommended, but is difficult to implement/sustain annually in a busy CF centre. The aim was to develop an acceptable model for depression and anxiety screening in adolescents/adults with CF and their caregivers that could be sustained and shared. METHODS: Quality improvement methodology with plan-do-study-act cycles, flow diagrams, review of data monthly with our designated 'Mental Health Team' and caregiver satisfaction surveys, were used to begin screening in clinics and to improve the process. We then piloted our process at a larger paediatric CF centre. RESULTS: Prior to 2013, screening was not performed at our CF centre. After the first quarter of depression screening, 88% of adolescents and 69% of adults with CF were screened. The process was refined. By the second year, 99% of patients were screened. Anxiety screening began in year three; 97%-99% of patients were screened for both anxiety and depression in years 3-5. Annual caregiver screening rates were >95%. Screening was changed from Patient Health Questionnaire-2 (PHQ-2) to PHQ-9 due to better sensitivity in caregivers, and expanded to patients. Anxiety screening began in year 3 with the Generalised Anxiety Disorder-7 questionnaire. Patients and caregivers reported acceptance of screening. At the larger paediatric centre used as a pilot, 89.6% of patients were screened in year 1. Feedback included recommendations to improve tracking/follow-up of positive screens. CONCLUSIONS: Development and implementation of a stepwise process for depression and anxiety screening was successful in a paediatric/adult CF clinic, due to constant re-evaluation by an engaged team with feedback from patients via survey. A systematic approach at a busy CF centre can serve as a model to implement screening in a clinic.

Lumacaftor/ivacaftor therapy fails to increase insulin secretion in F508del/F508del CF patients.

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 ß-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.

PROMISE: Working with the CF community to understand emerging clinical and research needs for those treated with highly effective CFTR modulator therapy.

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.

RNA sequencing data from neutrophils of patients with cystic fibrosis reveals potential for developing biomarkers for pulmonary exacerbations.

BACKGROUND: There is no effective way to predict cystic fibrosis (CF) pulmonary exacerbations (CFPE) before they become symptomatic or to assess satisfactory treatment responses. METHODS: RNA sequencing of peripheral blood neutrophils from CF patients before and after therapy for CFPE was used to create transcriptome profiles. Transcripts with an average transcripts per million (TPM) level > 1.0 and a false discovery rate (FDR) < 0.05 were used in a cosine K-nearest neighbor (KNN) model. Real time PCR was used to corroborate RNA sequencing expression differences in both neutrophils and whole blood samples from an independent cohort of CF patients. Furthermore, sandwich ELISA was conducted to assess plasma levels of MRP8/14 complexes in CF patients before and after therapy. RESULTS: We found differential expression of 136 transcripts and 83 isoforms when we compared neutrophils from CF patients before and after therapy (>1.5 fold change, FDR-adjusted P < 0.05). The model was able to successfully separate CF flare samples from those taken from the same patients in convalescence with an accuracy of 0.75 in both the training and testing cohorts. Six differently expressed genes were confirmed by real time PCR using both isolated neutrophils and whole blood from an independent cohort of CF patients before and after therapy, even though levels of myeloid related protein MRP8/14 dimers in plasma of CF patients were essentially unchanged by therapy. CONCLUSIONS: Our findings demonstrate the potential of machine learning approaches for classifying disease states and thus developing sensitive biomarkers that can be used to monitor pulmonary disease activity in CF.

Vancomycin Versus Vancomycin Plus Rifampin for the Treatment of Acute Pulmonary Exacerbations of Cystic Fibrosis.

OBJECTIVES: This study aimed to compare the change in pulmonary function in children and adolescents with cystic fibrosis (CF) who were infected with methicillin-resistant Staphylococcus aureus (MRSA) treated with either vancomycin (VAN) alone or vancomycin plus rifampin (VAN-RIF). METHODS: Included patients were ages 6 to 20 years; hospitalized for an acute pulmonary exacerbation (APE) of CF from May 1, 2012, to April 30, 2014; had a respiratory tract culture positive for MRSA within 1 month of index hospital admission; received at least 48 consecutive hours of VAN or VAN-RIF; and had admission and discharge pulmonary function tests. The primary end point was change in percent predicted forced expiratory volume in 1 second (FEV1). RESULTS: A total of 39 encounters met inclusion criteria: 24 in the VAN group (mean age 15.1 years) and 15 in the VAN-RIF group (mean age 13.7 years). There were no between-group differences in mean percent change in FEV1 (32.6% ± 28.8% vs. 21.1% ± 12.1%; p = 0.091), mean percent change in forced vital capacity (22.6% ± 25.8% vs. 14% ± 9.4%; p = 0.127), or return to baseline FEV1 (20 [83.3%] vs. 14 [93.3%] patients; p = 0.631). Median (IQR) length of stay (13 days [11-14 days] vs. 13 days [9-14 days]; p = 0.6) and median (IQR) time to readmission (82 days [43-129 days] vs. 147 days [78-219 days]; p = 0.2) were similar between the VAN and VAN-RIF groups, respectively. CONCLUSIONS: Vancomycin monotherapy appears to be adequate when treating APEs of CF in children and adolescents with moderate lung disease and high MRSA VAN minimum inhibitory concentrations. Therefore, the addition of RIF may be unnecessary; however, larger studies are needed to confirm these findings.

Association of Vancomycin Trough Concentration With Response to Treatment for Acute Pulmonary Exacerbation of Cystic Fibrosis.

BACKGROUND: Our goal was to determine the relationship between serum vancomycin trough concentrations (VTCs) and changes in pulmonary function among individuals with an acute pulmonary exacerbation (APE) of cystic fibrosis (CF). METHODS: We included subjects who were ≥6 years of age, were hospitalized for an APE of CF between May 1, 2012, and April 30, 2014, were administered vancomycin for ≥48 hours, and had a history of airway infection with methicillin-resistant Staphylococcus aureus. Pearson correlations were performed to characterize the relationship between VTC and pulmonary function. RESULTS: The mean final VTC (± standard deviation) was 12.6 ± 3.3 µg/mL; 40 (81.6%) of 49 final VTCs were in the range of 10 to <15 µg/mL. The mean change in forced expiratory volume in 1 second (FEV1) between admission and discharge was 24.5% ± 24.4% (P < .001) of predicted values. Forty-two (85.7%) patients returned to their baseline FEV1. No correlation between the change in FEV1 and VTC (Pearson r = -0.10; P = .49) was identified. Similarly, VTC, daily weight-adjusted vancomycin dose, and vancomycin area under the concentration-time curve normalized to the minimum inhibitory concentration (AUC/MIC) were not significant predictors of change in FEV1 or return to baseline FEV1 on multivariate analysis. One (2%) subject experienced acute kidney injury. CONCLUSIONS: The majority of patients experienced improvement in pulmonary function and a return to their baseline FEV1 while achieving a VTC in the range of 10 to <15 µg/mL. We were unable to identify a correlation between markers of vancomycin exposure and change in pulmonary function test results. Additional studies are needed to reinforce the efficacy of VTCs of 10 to 15 µg/mL for treating APEs of CF.

Impact of CFTR Modulation on Intestinal pH, Motility, and Clinical Outcomes in Patients With Cystic Fibrosis and the G551D Mutation.

OBJECTIVES: A defect in bicarbonate secretion contributes to the pathophysiology of gastrointestinal complications in patients with cystic fibrosis (CF). We measured gastrointestinal pH, clinical outcomes, and intestinal transit profiles in patients with the G551D mutation before and after treatment with ivacaftor, a CF transmembrane regulator channel (CFTR) potentiator. METHODS: Observational studies of ivacaftor effectiveness were conducted in the United States and Canada. A subset of subjects ingested a wireless motility capsule (n=10) that measures in vivo pH, both before therapy with ivacaftor and 1 month after treatment; values obtained were compared for mean pH and area under the pH curve, and regional intestinal motility. We also queried subjects about abdominal pain and recorded body weight before and after treatment. RESULTS: One month after administering ivacaftor, a significant increase in mean pH was observed after gastric emptying (P<0.05). Area under the pH curve analyses indicate increased bicarbonate mass (P<0.05 for select 5 min intervals and all segments >30 min); mean weight gain was 1.1 kg (P=0.08). No difference in abdominal pain or regional transit times was seen. CONCLUSIONS: CFTR modulation improves the proximal small intestinal pH profile in patients with the G551D CFTR mutation and we observed clinically relevant, contemporaneous weight gain, although it did not reach statistical significance. These data provide in vivo evidence that CFTR is an important regulator of bicarbonate secretion, which may be a translational link between CFTR function and clinical improvement.

Psychosocial Challenges/Transition to Adulthood.

Advances in the health care of individuals with cystic fibrosis have resulted in more than half of the population older than the age of 18 living longer, fuller lives. This success brings about the need for new areas of improvement and development including the mastery of transitioning from pediatric to adult health care and attention to psychosocial needs. This article reviews key components of the process of transitioning to adult care and some important psychosocial considerations.

IP-10 is a potential biomarker of cystic fibrosis acute pulmonary exacerbations.

BACKGROUND: Cystic fibrosis (CF) is characterized by acute pulmonary exacerbations (APE). The CF nasal airway exhibits a similar ion transport defect as the lung, and colonization, infection, and inflammation within the nasal passages are common among CF patients. Nasal lavage fluid (NLF) is a minimally invasive means to collect upper airway samples. METHODS: We collected NLF at the onset and resolution of CF APE and compared a 27-plex cytokine profile to stable CF outpatients and normal controls. We also tested IP-10 levels in the bronchoalveolar lavage fluid (BALF) of CF patients. Well-differentiated murine sinonasal monolayers were exposed to bacterial stimulus, and IP-10 levels were measured to test epithelial secretion. RESULTS: Subjects hospitalized for APE had elevated IP-10 (2582 pg/mL [95% CL of mean: 818,8165], N=13) which significantly decreased (647 pg/mL [357,1174], P<0.05, N =13) following antimicrobial therapy. Stable CF outpatients exhibited intermediately elevated levels (680 pg/mL [281,1644], N=13) that were less than CF inpatients upon admission (P=0.056) but not significantly different than normal controls (342 pg/mL [110,1061]; P=0.3, N=10). IP-10 was significantly increased in CF BALF (2673 pg/mL [1306,5458], N=10) compared to healthy post-lung transplant patients (8.4 pg/mL [0.03,2172], N=5, P<0.001). IP-10 levels from well-differentiated CF murine nasal epithelial monolayers exposed to Pseudomonas PAO-1 bacteria-free prep or LPS (100 nM) apically for 24 hours were significantly elevated (1159 ± 147, P<0.001 for PAO-1; 1373 ± 191, P<0.001 for LPS vs. 305 ± 68 for vehicle controls). Human sino-nasal epithelial cells derived from CF patients had a similar response to LPS (34% increase, P<0.05, N=6). CONCLUSIONS: IP-10 is elevated in the nasal lavage of CF patients with APE and responds to antimicrobial therapy. IP-10 is induced by airway epithelia following stimulation with bacterial pathogens in a murine model. Additional research regarding IP-10 as a potential biomarker is warranted.

Clinical and molecular characterization of S1118F-CFTR.

BACKGROUND: Cystic fibrosis is a lethal autosomal recessive disorder usually associated with lung disease, pancreatic insufficiency and high sweat chloride levels. CLINICAL CASE: A patient admitted to Le Bonheur Children's Medical Center (LBCMC, Memphis, TN) showed symptoms of meconium ileus which required exploratory laparotomy, bowel resection and ileostomy. Genotyping showed DeltaF508/I1027T on one chromosome and S1118F on the other. Sweat testing on three different occasions gave negative and intermediate results (22.7, 24.6 mmol/L; 55.1, 58.6 mmol/L and 55.1, 58 mmol/L) and pancreatic elastase testing showed normal levels. OBJECTIVE: To characterize S1118F-CFTR mutation at a molecular level to help understand the associated CF-phenotype. METHODS: Molecular characterization of S1118F-CFTR mutant was studied in HEK-293 cells at 37 degrees C. Various biochemical methods such as Western blotting, real-time PCR, Pulse chase labeling and iodide efflux assay were employed. RESULTS: S1118F-CFTR makes less than 10-15% of mature CFTR (band C) compared to WT-CFTR. The mRNA levels of S1118F-CFTR and WT-CFTR are comparable. S1118F-CFTR is functional but shows about 10-15% of WT-CFTR activity. S1118F-CFTR shows impaired maturation and CF-correctors can increase the amount of mature and functional CFTR by three- to fourfold. CONCLUSION: S1118F-CFTR shows impaired maturation and an individual with S1118F-CFTR paired with DeltaF508-CFTR exhibits atypical CF symptoms with intermediate sweat chloride level and meconium ileus despite documented pancreatic sufficiency.