Precision Medicine In Action: The Impact Of Ivacaftor On Cystic Fibrosis-Related Hospitalizations

Long-term impact of ivacaftor on mortality rate and health outcomes in people with cystic fibrosis

BACKGROUND

Ivacaftor (IVA) has been shown to improve lung function and other clinical outcomes in people with cystic fibrosis (CF). A decade of real-world IVA availability has enabled the examination of long-term outcomes with this treatment. This retrospective, longitudinal cohort study investigated the impact of IVA on mortality rate and health outcomes among people with CF in the US.

METHODS

Data from the US CF Foundation Patient Registry from January 2010 to December 2019 were analysed. The IVA-treated cohort included people with a CF transmembrane conductance regulator (CFTR) gating mutation (excluding R117H); age-matched comparator cohort included people with a F508del and a minimal function CFTR mutation who had no prior CFTR modulator treatment. Baseline characteristics were balanced between cohorts using standardised mortality ratio weighting generated from propensity scores. Outcomes of interest were overall survival, lung transplant, percent predicted forced expiratory volume in 1 s (ppFEV1), body mass index (BMI), pulmonary exacerbations (PEx), outpatient visits and hospitalisations.

FINDINGS

Over a maximum follow-up of 7.9 years, the IVA-treated cohort (N=736) had lower rates of mortality (hazard ratio [HR] (95% CI): 0.22 (0.09 to 0.45)), lung transplant (HR: 0.11 (95% CI 0.02 to 0.28)), PEx (rate ratio: 0.49 (95% CI 0.42 to 0.55)) and all-cause hospitalisations (rate ratio: 0.50 (95% CI 0.43 to 0.56)) as well as better lung function (mean difference in ppFEV1: 8.46 (95% CI 7.34 to 9.75)) and higher BMI/BMI z-scores (mean difference 1.20 (95% CI 0.92 to 1.71) kg/m2 and 0.27 (95% CI 0.25 to 0.40), respectively) than the comparator cohort (N=733).

INTERPRETATION

Our analysis suggests that IVA provides sustained clinical benefits in people with CF over a follow-up period of approximately 8 years. These findings reinforce the existing real-world evidence that IVA can slow disease progression and decrease the healthcare burden of CF over the long term.

Preventive service utilization among adults with cystic fibrosis covered by private insurance is comparable to the general population

BACKGROUND

As the life expectancy of the cystic fibrosis (CF) population is lengthening with modulator therapies, diligent age-appropriate screening and preventive care are increasingly vital for long-term health and wellbeing.

METHODS

We performed a retrospective analysis comparing rates of receiving age- and sex-appropriate preventive services by commercially insured adult people with CF (PwCF) and adults without CF from the general population (GP) via the Truven Health MarketScan database (2012-2018).

RESULTS

We captured 25,369 adults with CF and 488,534 adults from the GP in the United States. Comparing these groups, we found that 43% versus 39% received an annual preventive visit, 28% versus 28% were screened for chlamydia, 38% versus 37% received pap smears every 3 years (21-29-year-old females), 33% versus 31% received pap smears every 5 years (30-64-year-old females), 55% versus 44% received mammograms, 23% versus 21% received colonoscopies, and 21% versus 20% received dyslipidemia screening (all screening rates expressed per 100 person-years). In age-stratified analysis, 18-27-year-old PwCF had a lower rate of annual preventive visits compared to adults in the same age group of the GP (27% versus 42%).

CONCLUSIONS

We discovered a comparable-to-superior rate of preventive service utilization in adults with CF relative to the GP, except in young adulthood from 18-27 years. Our findings establish the importance of meeting the primary care needs of adults with CF and call for development of strategies to improve preventive service delivery to young adults.

Identification of Single Nucleotide Variants in SLC26A9 Gene in Patients with Cystic Fibrosis (p.Phe508del Homozygous) and its Association to Orkambi® (Lumacaftor and Ivacaftor) Response in vitro

BACKGROUND

Since patients with cystic fibrosis with different Cystic Fibrosis Transmembrane Regulator (CFTR) genotypes present a wide response variability for modulator drugs such as Orkambi®, it is important to screen variants in candidate genes with an impact on precision and personalized medicine, such as Solute Carrier Family 26, member 9 (SLC26A9) gene.

METHODS

Sanger sequencing for the exons and intron-exon boundary junctions of the SLC26A9 gene was employed in nine individuals with p.Phe508del homozygous genotype for the CFTR gene who were not under CFTR modulators therapy. The sequencing variants were evaluated by in silico prediction tools. The CFTR function was measured by cAMP-stimulated current (ΔIsc-eq-FSK) in polarized CFTR of human nasal epithelial cells cultured in micro-Ussing chambers with Orkambi®.

RESULTS

We found 24 intronic variants, three in the coding region (missense variants - rs74146719 and rs16856462 and synonymous - rs33943971), and three in the three prime untranslated region (3' UTR) region in the SLC26A9 gene. Twenty variants were considered benign according to American College of Medical Genetics and Genomics guidelines, and ten were classified as uncertain significance. Although some variants had deleterious predictions or possible alterations in splicing, the majority of predictions were benign or neutral. When we analyzed the ΔIsc-eq-FSK response to Orkambi®, there were no significant differences within the genotypes and alleles for all 30 variants in the SLC26A9 gene.

CONCLUSIONS

Among the nine individuals with p.Phe508del homozygous genotype for the CFTR gene, no pathogenic SLC26A9 variants were found, and we did not detect associations from the 30 SLC26A9 variants and the response to the Orkambi® in vitro.

The Rapid Reduction of Infection-Related Visits and Antibiotic Use Among People With Cystic Fibrosis After Starting Elexacaftor-Tezacaftor-Ivacaftor

BACKGROUND

People with cystic fibrosis (CF) routinely suffer from recurrent sinopulmonary infections. Such infections require frequent courses of antimicrobials and often involve multidrug-resistant organisms. The goal of this study was to identify real-world evidence for the effectiveness of elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA) in decreasing infection-related visits and antimicrobial use in people with CF.

METHODS

Using IBM MarketScan data, we identified 389 enrollees with CF who began taking ELX/TEZ/IVA before 1 December 2019 and were enrolled from 1 July 2019 to 14 March 2020. We also identified a comparison population who did not begin ELX/TEZ/IVA during the study period. We compared the following outcomes in the 15 weeks before and after medication initiation: total healthcare visits, inpatient visits, infection-related visits, and antimicrobial prescriptions. We analyzed outcomes using both a case-crossover analysis and a difference-in-differences analysis, to control for underlying trends.

RESULTS

For the case-crossover analysis, ELX/TEZ/IVA initiation was associated with the following changes over a 15-week period: change in overall healthcare visit dates, -2.5 (95% confidence interval, -3.31 to -1.7); change in inpatient admissions, -0.16 (-.22 to -.10); change in infection-related visit dates, -0.62 (-.93 to -.31); and change in antibiotic prescriptions, -0.78 (-1.03 to -.54). Results from the difference-in-differences approach were similar.

CONCLUSIONS

We show a rapid reduction in infection-related visits and antimicrobial use among people with CF after starting a therapy that was not explicitly designed to treat infections. Currently, there are >30 000 people living with CF in the United States alone. Given that this therapy is effective for approximately 90% of people with CF, the impact on respiratory infections and antimicrobial use may be substantial.

The IDeaS initiative: pilot study to assess the impact of rare diseases on patients and healthcare systems

Background

Rare diseases (RD) are a diverse collection of more than 7–10,000 different disorders, most of which affect a small number of people per disease. Because of their rarity and fragmentation of patients across thousands of different disorders, the medical needs of RD patients are not well recognized or quantified in healthcare systems (HCS).

Methodology

We performed a pilot IDeaS study, where we attempted to quantify the number of RD patients and the direct medical costs of 14 representative RD within 4 different HCS databases and performed a preliminary analysis of the diagnostic journey for selected RD patients.

Results

The overall findings were notable for: (1) RD patients are difficult to quantify in HCS using ICD coding search criteria, which likely results in under-counting and under-estimation of their true impact to HCS; (2) per patient direct medical costs of RD are high, estimated to be around three–fivefold higher than age-matched controls; and (3) preliminary evidence shows that diagnostic journeys are likely prolonged in many patients, and may result in progressive, irreversible, and costly complications of their disease

Conclusions

The results of this small pilot suggest that RD have high medical burdens to patients and HCS, and collectively represent a major impact to the public health. Machine-learning strategies applied to HCS databases and medical records using sentinel disease and patient characteristics may hold promise for faster and more accurate diagnosis for many RD patients and should be explored to help address the high unmet medical needs of RD patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02061-3.

A Review of Trikafta: Triple Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Modulator Therapy

Cystic fibrosis (CF) is a potentially fatal genetic disease that causes serious lung damage. With time, researchers have a more complete understanding of the molecular-biological defects that underlie CF. This knowledge is leading to alternative approaches regarding the treatment of this condition. Trikafta is the third FDA-approved drug that targets the F508del mutation of the CFTR gene. The drug is a combination of three individual drugs which are elexacaftor (ELX), tezacaftor (TEZ), and ivacaftor (IVA). This trio increases the activity of the cystic fibrosis transmembrane conductance regulator (CFTR) protein and reduces the mortality and morbidity rates in CF patients. The effectiveness of Trikafta, seen in clinical trials, outperforms currently available therapies in terms of lung function, quality of life, sweat chloride reduction, and pulmonary exacerbation reduction. The safety and efficacy of CFTR modulators in children with CF have also been studied. Continued evaluation of patient data is needed to confirm its long-term safety and efficacy. In this study, we will focus on reviewing data from clinical trials regarding the benefits of CFTR modulator therapy. We address the impact of Trikafta on lung function, pulmonary exacerbations, and quality of life. Adverse events of the different CFTR modulators are discussed.

An evaluation of healthcare utilization and clinical charges in children and adults with cystic fibrosis

BACKGROUND

Prior studies have estimated healthcare costs for cystic fibrosis (CF) of $8000-$131,000, but do not account for impacts of CF modulator therapy. This study aims to assess utilization patterns and cost of CF care in a center in the United States.

METHODS

Care utilization patterns and costs at a large pediatric-adult CF center were examined from November 2017 to November 2018. Subjects were stratified by age and cost (excluding pharmacy costs) were calculated based on hospital-derived utilization charges.

RESULTS

A total of 166 patients were reviewed with mean clinical charges of $28,755. Lower lung function ($23,032 normal lung function, $62,293 moderate reduction, $186,786 severe reduction; p = .05), hospitalizations ($85,452 yes, $6362 no; p = .0001), Pseudomonas positive culture ($48,660 positive, $22,013 negative, p = .0001), and CF-related diabetes ($161,892 CFRD, $22,153 no CFRD; p = .001) were associated with increased charges. Patients utilizing Ivacaftor had lower charges compared to lumacaftor-ivacaftor ($6633 vs. $33,039; p = .05) and tezacaftor-ivacaftor ($6633 vs. $64,434; p = .002).

CONCLUSION

Our study characterized utilization and care charges among a CF cohort. Lower lung function, hospitalizations, and CFRD were associated with increased charges.

Long-Term Impact of Ivacaftor on Healthcare Resource Utilization Among People with Cystic Fibrosis in the United States

INTRODUCTION

Ivacaftor was first approved in 2012 for the treatment of a select population of individuals with cystic fibrosis (CF), a rare, life-shortening genetic disease. Reductions in healthcare resource utilization (HCRU) associated with ivacaftor have been observed during limited follow-up and for selected outcomes in real-world studies. This study aimed to further describe the long-term impact of ivacaftor treatment on multiple measures of HCRU among people with CF (pwCF).

METHODS

This retrospective study used US commercial and Medicaid claims data from 2011-2018. We included pwCF ≥ 6 years of age with ≥ 1 claim for ivacaftor and 12 months of continuous health plan enrollment before ivacaftor initiation ("pre-ivacaftor" period) who also had 36 months of continuous enrollment and persistent ivacaftor use (i.e., no gap ≥ 90 days between refills) following initiation ("post-ivacaftor" period). We compared comorbidities occurring pre-ivacaftor versus the last 12 months post-ivacaftor. HCRU outcomes included medication use, inpatient admissions, and outpatient office visits. We compared medication use pre-ivacaftor versus the last 12 months post-ivacaftor and inpatient admissions and outpatient office visits pre-ivacaftor versus the post-ivacaftor period annualized across 36 months.

RESULTS

Seventy-nine pwCF met all criteria, including persistent ivacaftor use during the post-ivacaftor period. Ivacaftor treatment was associated with a significant reduction in pneumonia prevalence (10.1% vs. 26.6%; p < 0.001) and significantly fewer mean [SD] antibiotics claims (8.0 [7.3] vs. 12.3 [11.1]; p < 0.001) in the last 12 months post-ivacaftor versus pre-ivacaftor. In comparing the 36-month post-ivacaftor period to the pre-ivacaftor period, we also observed fewer mean [SD] annual inpatient admissions (0.2 [0.4] vs. 0.4 [0.7]), CF-related inpatient admissions (0.1 [0.2] vs. 0.2 [0.5]), and outpatient office visits (8.8 [4.9] vs. 9.9 [5.4]) (all, p < 0.05).

CONCLUSION

Long-term ivacaftor treatment reduced HCRU, consistent with trends observed in prior real-world studies. Our results support the sustained, long-term value of ivacaftor treatment in reducing CF burden.

Benzimidazoles in Drug Discovery: A Patent Review

Benzimidazole is a heterocyclic ring system that has been widely studied in the pharmaceutical field. For the past decade, numerous benzimidazole derivatives have been synthesized and evaluated for their wide range of pharmacological activities, which are beneficial for drug development. This article presents the biological effects of benzimidazole derivatives in each invention from 2015 to 2020. Two patent databases, Google Patents and Lens, were used to locate relevant granted patent applications. Specifically, this review delineates the role of patented benzimidazoles from a disease-centric perspective and examines the mechanisms of action of these compounds in related diseases. Most of the benzimidazoles have shown good activities against various target proteins. Whilst several of them have progressed into clinical trials, most patents presented novel therapeutic approaches for respective target diseases. Hence, their potential in being developed into clinical drugs are also discussed.

Real-World Outcomes of Ivacaftor Treatment in People with Cystic Fibrosis: A Systematic Review

Cystic fibrosis (CF) is a rare, progressive, multi-organ genetic disease. Ivacaftor, a small-molecule CF transmembrane conductance regulator modulator, was the first medication to treat the underlying cause of CF. Since its approval, real-world clinical experience on the use of ivacaftor has been documented in large registries and smaller studies. Here, we systematically review data from real-world observational studies of ivacaftor treatment in people with CF (pwCF). Searches of MEDLINE and Embase identified 368 publications reporting real-world studies that enrolled six or more pwCF treated with ivacaftor published between January 2012 and September 2019. Overall, 75 publications providing data from 57 unique studies met inclusion criteria and were reviewed. Studies reporting within-group change for pwCF treated with ivacaftor consistently showed improvements in lung function, nutritional parameters, and patient-reported respiratory and sino-nasal symptoms. Benefits were evident as early as 1 month following ivacaftor initiation and were sustained over long-term follow-up. Decreases in pulmonary exacerbations, Pseudomonas aeruginosa prevalence, and healthcare resource utilization also were reported for up to 66 months following ivacaftor initiation. In studies comparing ivacaftor treatment to modulator untreated comparator groups, clinical benefits similarly were reported as were decreases in mortality, organ-transplantation, and CF-related complications. The safety profile of ivacaftor observed in these real-world studies was consistent with the well-established safety profile based on clinical trial data. Our systematic review of real-world studies shows ivacaftor treatment in pwCF results in highly consistent and sustained clinical benefit in both pulmonary and non-pulmonary outcomes across various geographies, study designs, patient characteristics, and follow-up durations, confirming and expanding upon evidence from clinical trials.

Genomic, transcriptomic, and protein landscape profile of CFTR and cystic fibrosis

Cystic Fibrosis (CF) is caused most often by removal of amino acid 508 (Phe508del, deltaF508) within CFTR, yet dozens of additional CFTR variants are known to give rise to CF and many variants in the genome are known to contribute to CF pathology. To address CFTR coding variants, we developed a sequence-to-structure-to-dynamic matrix for all amino acids of CFTR using 233 vertebrate species, CFTR structure within a lipid membrane, and 20 ns of molecular dynamic simulation to assess known variants from the CFTR1, CFTR2, ClinVar, TOPmed, gnomAD, and COSMIC databases. Surprisingly, we identify 18 variants of uncertain significance within CFTR from diverse populations that are heritable and a likely cause of CF that have been understudied due to nonexistence in Caucasian populations. In addition, 15 sites within the genome are known to modulate CF pathology, where we have identified one genome region (chr11:34754985-34836401) that contributes to CF through modulation of expression of a noncoding RNA in epithelial cells. These 15 sites are just the beginning of understanding comodifiers of CF, where utilization of eQTLs suggests many additional genomics of CFTR expressing cells that can be influenced by genomic background of CFTR variants. This work highlights that many additional insights of CF genetics are needed, particularly as pharmaceutical interventions increase in the coming years.

Prognosis-Based Early Intervention Strategies to Resolve Exacerbation and Progressive Lung Function Decline in Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disease caused by a mutation(s) in the CF transmembrane regulator (CFTR), where progressive decline in lung function due to recurring exacerbations is a major cause of mortality. The initiation of chronic obstructive lung disease in CF involves inflammation and exacerbations, leading to mucus obstruction and lung function decline. Even though clinical management of CF lung disease has prolonged survival, exacerbation and age-related lung function decline remain a challenge for controlling the progressive lung disease. The key to the resolution of progressive lung disease is prognosis-based early therapeutic intervention; thus, the development of novel diagnostics and prognostic biomarkers for predicting exacerbation and lung function decline will allow optimal management of the lung disease. Hence, the development of real-time lung function diagnostics such as forced oscillation technique (FOT), impulse oscillometry system (IOS), and electrical impedance tomography (EIT), and novel prognosis-based intervention strategies for controlling the progression of chronic obstructive lung disease will fulfill a significant unmet need for CF patients. Early detection of CF lung inflammation and exacerbations with the timely resolution will not only prolong survival and reduce mortality but also improve quality of life while reducing significant health care costs due to recurring hospitalizations.

How Clinically Efficient Is Lumacaftor/Ivacaftor for Cystic Fibrosis Patients? An Updated Literature Review

Cystic fibrosis (CF) is an autosomal recessive illness caused by the defective cystic fibrosis transmembrane conductance regulator (CFTR) gene. These patients suffer from repeated chronic sinuses and lung infections, resulting in frequent hospital admissions and antibiotic (Abx) courses. These are the major contributing factors responsible for a low health-related quality of life (HRQoL) and increasing the disease burden. The introduction and approval of CFTR modulators-lumacaftor (LUM) and ivacaftor (IVA) in 2015 by the US Food and Drug Administration (FDA) reduced the mortality and morbidity rates associated with the disease. In 2018, the FDA approved these drugs from age two and five years with two copies of F5806 del. This literature review aims to present the studies centered on the clinical effects of LUM/IVA. We searched for the relevant articles, from 2016 to 2020, in PubMed Central (PMC), Google Scholars, and Journal of Cystic Fibrosis. LUM/IVA has a broader range of effects. They showed marked improvement in the reduction of pulmonary exacerbations (PEx), Hospitalization rates, Abx use, and modification in forced expiratory volume in one second (FEV1) status of pre-existing severe lung disease. Now, there is a need for an initiative to conduct more clinical trials and studies in the future to assess and evaluate the long-term clinical benefits and safety of LUM/IVA therapy in all age groups.

Long term clinical effectiveness of ivacaftor in people with the G551D CFTR mutation

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.

Practitioner Due Diligence: Real-World Lumacaftor/Ivacaftor Use

OBJECTIVE

Previous trials evaluated the efficacy of lumacaftor/ivacaftor in Phe508del homozygotes. These trials are limited by manufacturer sponsorship and were conducted under strict protocol. Additionally, this therapy is costly and does not allow for reduction in daily cystic fibrosis therapies. This study assessed the efficacy of lumacaftor/ivacaftor therapy and its effect on health care utilization in a real-world setting.

METHODS

Retrospective chart review comparing the first 12 months of therapy to the 24 months prior was conducted to evaluate the impact of lumacaftor/ivacaftor on pulmonary function following a streamlined process for therapy introduction. The impact on body mass index and healthcare utilization were also evaluated. The following measurements were assessed: percent predicted forced expiratory volume in 1 second, body mass index and z-scores, number of admissions, length of stay, number of emergency department visits.

RESULTS

Mean ppFEV₁ was improved for the first 12 months on lumacaftor/ivacaftor treatment when compared with the 24 months prior: 78.8 (95% CI: 72.6, 84.9) vs 76.2 (95% CI: 70.1, 82.3) (p = 0.03). Body mass index significantly improved (patients ≥20 years), but improvement in BMI z-score (patients <20 years) was not significant. Number of admissions and LOS were significantly decreased, but ED visits were not.

CONCLUSIONS

Lumacaftor/ivacaftor is effective for improving ppFEV1 and BMI and for reducing health care utilization. However, this small reduction does not overcome the financial cost of treatment. Long-term outcomes and use must be studied to determine the overall effect of this therapy on cystic fibrosis interventions and their costs.

Re-imagining cystic fibrosis care: next generation thinking

Cystic fibrosis (CF) is a common multi-system genetically inherited condition, predominately found in individuals of Caucasian decent. Since the identification of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene in 1989, and the subsequent improvement in understanding of CF pathophysiology, significant increases in life-expectancy have followed. Initially this was related to improvements in the management and systems of care for treating the various affected organ systems. These cornerstone treatments are still essential for CF patients born today. However, over the last decade, the major advance has been in therapies that target the resultant genetic defect: the dysfunctional CFTR protein. Small molecule agents that target this dysfunctional protein via a variety of mechanisms have led to lung function improvements, reductions in pulmonary exacerbation rates and increases in weight and quality-of-life indices. As more patients receive these agents earlier and earlier in life, it is likely that general CF care will increasingly pivot around these specific therapies, although it is also likely that effects other than those identified in the initial trials will be discovered and need to be managed. Despite great excitement for modulator therapies, they are unlikely to be suitable or available for all; whether this is due to a lack of availability for specific CFTR mutations, drug-reactions or the health economic set-up in certain countries. Nevertheless, the CF community must be applauded for its ongoing focus on research and development for this life-limiting disease. With time, personalised individualised therapy would ideally be the mainstay of CF care.

Longitudinal Trends in Real-World Outcomes after Initiation of Ivacaftor. A Cohort Study from the Cystic Fibrosis Registry of Ireland

RATIONALE

Patient registries have the potential to collect and analyze high-quality postauthorization data on new medicines.

OBJECTIVES

We used cystic fibrosis (CF) registry data to assess outcomes after the initiation of ivacaftor, a CF transmembrane conductance regulator (CFTR) potentiator approved for the treatment of CF with a defective gating CFTR mutation.

METHODS

Longitudinal trends were examined using mixed-effects regression analysis in 80 ivacaftor-treated patients with CF aged 6 to 56 years registered with the CF Registry of Ireland with at least 36 months of before and after commencement data. The effects of ivacaftor treatment on forced expiratory volume in 1 second (FEV₁) % predicted, body mass index (BMI), hospitalization for pulmonary exacerbation, and oral and intravenous antibiotic use were assessed.

RESULTS

In the 36 months after ivacaftor initiation, FEV₁% predicted improved by 2.26% per annum (95% confidence interval [CI], 0.2 to 4.3) for patients aged younger than 12 years, remained unchanged for 12- to younger than 18-year-olds (95% CI, -1.9 to 2.9), and declined in adults by 1.74% per annum (95% CI, -3.1 to -0.4). BMI in adults increased 0.28 kg/m² per annum (95% CI, 0.03 to 0.5), and there was no significant change in BMI z-score in children (95% CI, -0.01 to 0.1). In the year after ivacaftor initiation, intravenous antibiotic treatment reduced by 46% (95% CI, -62.5% to -23.3%, oral antibiotic treatment reduced by 49% (95% CI, -61.1% to -32.1%), and there was no significant reduction in hospitalization (95% CI, -59.2% to 9.7%).

CONCLUSIONS

In this study of real-world CF registry data, clinical outcomes improved and healthcare resource utilization decreased after commencing ivacaftor.

Two Unanticipated Pregnancies While on Cystic Fibrosis Gene-Specific Drug Therapy

Women with cystic fibrosis (CF) desire to become pregnant and accomplish the same life goals as women without CF. The underlying pathology of CF and medications used to treat this genetically transmitted disease can affect women’s reproductive potential. An interview with Ana (pseudonym), who became pregnant twice while taking the medication lumacaftor/ivacaftor (LUMA/IVA), was analyzed using thematic analysis. She described her experiences related to “Fertility and Pregnancy Surrounding LUMA/IVA,” the major theme that emerged from her narrative. While there are anecdotal reports of infants conceived by women on LUMA/IVA and other CF precision medications, pregnancy rates and outcomes are not systematically tracked. Education about risks and benefits of these medications should be provided as part of comprehensive clinical care.

Genetic Support for Longevity-Enhancing Drug Targets: Issues, Preliminary Data, and Future Directions

Interventions meant to promote longevity and healthy aging have often been designed or observed to modulate very specific gene or protein targets. If there are naturally occurring genetic variants in such a target that affect longevity as well as the molecular function of that target (eg, the variants influence the expression of the target, acting as "expression quantitative trait loci" or "eQTLs"), this could support a causal relationship between the pharmacologic modulation of the target and longevity and thereby validate the target at some level. We considered the gene targets of many pharmacologic interventions hypothesized to enhance human longevity and explored how many variants there are in those targets that affect gene function (eg, as expression quantitative trait loci). We also determined whether variants in genes associated with longevity-related phenotypes affect gene function or are in linkage disequilibrium with variants that do, and whether pharmacologic studies point to compounds exhibiting activity against those genes. Our results are somewhat ambiguous, suggesting that integrating genetic association study results with functional genomic and pharmacologic studies is necessary to shed light on genetically mediated targets for longevity-enhancing drugs. Such integration will require more sophisticated data sets, phenotypic definitions, and bioinformatics approaches to be useful.

In-vitro evaluation of a ciprofloxacin and azithromycin sinus stent for Pseudomonas aeruginosa biofilms

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease characterized by persistent inflammation and bacterial infection. Ciprofloxacin and azithromycin are commonly prescribed antibiotics for CRS, but the ability to provide targeted release in the sinuses could mitigate side effects and improve drug concentrations at the infected site. This study was aimed to evaluate the efficacy of the novel ciprofloxacin-azithromycin sinus stent (CASS) in vitro.

METHODS

The CASS was created by coating ciprofloxacin (hydrophilic, inner layer) and azithromycin (hydrophobic, outer layer) onto a biodegradable poly-l-lactic acid (PLLA) stent. In-vitro evaluation included: (1) assessment of drug-coating stability within the stent using scanning electron microscopy (SEM); (2) determination of ciprofloxacin and azithromycin release kinetics; and (3) assessment of anti-biofilm activities against Pseudomonas aeruginosa.

RESULTS

The ciprofloxacin nanoparticle suspension in the inner layer was confirmed by zeta potential. Both ciprofloxacin (60 µg) and azithromycin (3 mg) were uniformly coated on the surface of the PLLA stents. The CASS showed ciprofloxacin/azithromycin sustained release patterns, with 80.55 ± 11.61% of ciprofloxacin and 93.85 ± 6.9% of azithromycin released by 28 days. The CASS also significantly reduced P aeruginosa biofilm mass compared with bare stents and controls (relative optical density units at 590-nm optical density: CASS, 0.037 ± 0.006; bare stent, 0.911 ± 0.015; control, 1.000 ± 0.000; p < 0.001; n = 3).

CONCLUSION

The CASS maintains a uniform coating and sustained delivery of ciprofloxacin and azithromycin, providing anti-biofilm activities against P aeruginosa. Further studies evaluating the efficacy of CASS in a preclinical model are planned.

Sequencing as a first-line methodology for cystic fibrosis carrier screening

Purpose

Medical society guidelines recommend offering genotyping-based cystic fibrosis (CF) carrier screening to pregnant women or women considering pregnancy. We assessed the performance of sequencing-based CF screening relative to genotyping, in terms of analytical validity, clinical validity, clinical impact, and clinical utility.

Methods

Analytical validity was assessed using orthogonal confirmation and reference samples. Clinical validity was evaluated using the CFTR2 database. Clinical impact was assessed using ~100,000 screened patients. Three screening strategies were compared: genotyping 23 guideline-recommended variants (“CF23”), sequencing all coding bases in CFTR (“NGS”), and sequencing with large copy-number variant (CNV) identification (“NGS + CNV”). Clinical utility was determined via self-reported actions of at-risk couples (ARCs).

Results

Analytical accuracy of NGS + CNV was 100% for SNVs, indels, and CNVs; interpretive clinical specificity relative to CFTR2 was 99.5%. NGS + CNV detected 58 ARCs, 18 of whom would have gone undetected with CF23 alone. Most ARCs (89% screened preconceptionally, 56% prenatally) altered pregnancy management, and no significant differences were observed between ARCs with or without at least one non-CF23 variant.

Conclusion

Modern NGS and variant interpretation enable accurate sequencing-based CF screening. Limiting screening to 23 variants does not improve analytical validity, clinical validity, or clinical utility, but does fail to detect approximately 30% (18/58) of ARCs.

Use of ivacaftor in late diagnosed cystic fibrosis monozygotic twins heterozygous for F508del and R117H-7T - a case report

BACKGROUND

CFTR modulator therapy with ivacaftor is a treatment option for Cystic Fibrosis (CF) patients with at least one copy of a R117H-7T mutation in the CFTR gene. Desirable effects of this therapy are improvement of lung function, decrease in exacerbation rate, normalization or reduction of sweat chloride and weight gain. Monogenetic CF-twins carry identical genetic information, so therapy response and side effects are expected to be nearly identical under this specific therapy.

CASE PRESENTATION

In monozygotic twins, at the age of 55, two pathogenic variants in the CFTR gene (F508del and R117H-7T) were detected. Both patients presented with a borderline sweat test (30-59 mmol/L) and despite the same genetic information and similar life circumstances the disease proceeds completely different. While one patient has severe pulmonary involvement with chronic P. aeruginosa infection, her twin sister is almost unimpaired. Liver or pancreatic involvement was not seen in either patient. Due to the presence of one copy of a R117H-7T mutation, CFTR modulator therapy with ivacaftor was initiated in both. Response and side effects were significantly different. In the less affected patient, we observed an improvement in lung function and a normalization of sweat chloride. In the severely affected patient, no functional response to treatment was seen, but stabilization of the disease state with a decrease in exacerbation and hospitalization rate and weight gain as well as a normalization of sweat chloride. There was an increase in liver enzymes in the less affected patient, which normalized after halving the dose of ivacaftor, while the therapeutic effect was maintained.

CONCLUSIONS

Despite nearly identical genetic information, as in monogenetic twins, therapy response and onset of side effects of CFTR modulating therapy are very different. In patients with late diagnosis and severe pulmonary involvement, ivacaftor does not seem to improve lung function, whereas in patients with late diagnosis and low disease severity a relevant therapy response was obtained. In addition to lung function, additional clinical parameters such as reduction of exacerbation and hospitalization rate and weight gain should be used to assess therapy response, especially in severely affected patients.

Clinical impact and cost-effectiveness of a 176-condition expanded carrier screen

PURPOSE

Carrier screening identifies couples at high risk for conceiving offspring affected with serious heritable conditions. Minimal guidelines recommend offering testing for cystic fibrosis and spinal muscular atrophy, but expanded carrier screening (ECS) assesses hundreds of conditions simultaneously. Although medical societies consider ECS an acceptable practice, the health economics of ECS remain incompletely characterized.

METHODS

Preconception screening was modeled using a decision tree comparing minimal screening and a 176-condition ECS panel. Carrier rates from >60,000 patients, primarily with private insurance, informed disease incidence estimates, while cost and life-years-lost data were aggregated from the literature and a cost-of-care database. Model robustness was evaluated using one-way and probabilistic sensitivity analyses.

RESULTS

For every 100,000 pregnancies, 290 are predicted to be affected by ECS-panel conditions, which, on average, increase mortality by 26 undiscounted life-years and individually incur $1,100,000 in lifetime costs. Relative to minimal screening, preconception ECS reduces the affected birth rate and is estimated to be cost-effective (i.e.,<$50,000 incremental cost per life-year), findings robust to perturbation.

CONCLUSION

Based on screened patients predominantly with private coverage, preconception ECS is predicted to reduce the burden of Mendelian disease in a cost-effective manner compared with minimal screening. The data and framework herein may facilitate similar assessments in other cohorts.