Advancing the pipeline of cystic fibrosis clinical trials: a new roadmap with a global trial network perspective

Comparative Efficacy of CFTR Modulators: A Network Meta-analysis

PURPOSE

The objective was to study comparative efficacies of cystic fibrosis transmembrane conductance regulator (CFTR) modulators, vanzacaftor-tezacaftor-deutivacaftor (VTD), elexacaftor-tezacaftor-ivacaftor (ETI), tezacaftor-ivacaftor (Tez-Iva), and lumacaftor-ivacaftor (Lum-Iva) in people with cystic fibrosis (pwCF), aged ≥ 12 years, carrying at least one F508del-CFTR-allele.

METHODS

Data from randomized controlled or randomized active comparator trials were included in this network meta-analysis which used frequentist approach for comparing the efficacy of drugs and ranking based on P-scores. Outcomes of interest were mean differences in percentage-predicted forced expiratory volume in one second (ppFEV1), CF questionnaire-revised respiratory domain (CFQ-R) scores, sweat chloride (SwCl) levels, and odds ratios (OR) for serious adverse events (SAE).

RESULTS

Data from 13 studies were analyzed. Compared to placebo, the effects of VTD and ETI on ppFEV1 were almost quadruple of Tez-Iva and Lum-Iva (VTD: 12.78 [95% confidence intervals: 6.41; 19.15] and ETI: 11.95 [7.40; 16.50]) and almost seven times of Tez-Iva and Lum-Iva for CFQ-R (VTD: 21.23 [- 28.72; 71.18] and ETI: 19.27 [10.56; 27.98]). A statistically significant difference was noted between VTD and ETI in SwCl reduction (mean difference: - 8.59 [- 15.53; - 1.65]). There were no statistically significant ORs for SAEs for any CFTR modulators but VTD, ETI, and Tez-Iva were least associated with SAEs (ORs were 0.15 [0.01; 1.79], 0.49 [0.31; 0.78], and 0.74 [0.50; 1.09], respectively, as compared to placebo). Overall, P-score ranking ranked VTD as first and ETI as second, followed by others.

CONCLUSION

VTD and ETI were more efficacious than Tez-Iva and Lum-Iva in pwCF with at least one F508del-CFTR-allele.

Strategies used to access CFTR modulators in countries without reimbursement agreements

CFTR modulators represent the international standard of care for the treatment of cystic fibrosis (CF). Yet due to prices of over $250,000 per year they are functionally inaccessible for people with CF (pwCF) unless reimbursed by healthcare systems. Current prices are unaffordable for payors in almost all low- and middle-income countries (LMICs) worldwide, and resulting disparities in access are widening existing global health inequities. In comparable situations in other therapeutic areas, patients have successfully developed strategies to bypass national reimbursement systems and gain access to treatment. We therefore undertook an international survey of CF clinicians in 15 countries where CFTR modulators are not reimbursed, to characterise alternative means of accessing modulator therapy. Successful methods were identified in 11 countries, and could broadly be categorised into legal challenges to access originator modulators, use of generic formulations, and access via donations. Aside from domestically produced generics used in Argentina and an originator-led donation program in Ukraine, these methods were only able to provide treatment to limited proportions of the local CF population due to significant associated financial costs. Accordingly, they are generally not sustainable or widely applicable, and fail to address the underlying structural issues driving international disparities in access. Twelve years after the initial marketing of CFTR modulators, pwCF in LMICs are being forced to take extraordinary measures to access disease-modifying treatment. Corrective measures are urgently required to overcome barriers posed by restrictive patents and prohibitively high prices, and to promote global health equity for pwCF.

The future of cystic fibrosis: A global perspective

The severity of lung disease as well as other disease manifestations have dramatically improved in those patients with cystic fibrosis (CF) that both have mutations responsive to small molecule- based therapies with CF transmembrane regulator (CFTR) modulators and do have access to these drugs. Unfortunately, these medications are not available to many patients with CF across the globe with access largely limited to high income countries. For those eligible to CFTR modulators new questions have arisen regarding the ongoing need for other medications addressing CF lung disease as well current care models with tight monitoring. This article aims to summarize how CF care may change in the future making a plea to expand the availability of highly effective medications to every child with CF that could benefit from treatment.

Heterogeneity in Pancreatitis: Recognizing Heterogeneity and Its Role in the Management of Pancreatitis Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

ABSTRACT

Both the clinical management and study of recurrent acute pancreatitis and chronic pancreatitis are complicated by significant heterogeneity in the etiology, mechanisms, symptoms, and complications of pancreatitis. The National Institutes of Diabetes and Digestive and Kidney Disease recently convened a workshop to address current knowledge and knowledge gaps in the field. Preclinical models that better replicate human disease are important for development of new therapies. Pain is often the most common and most difficult symptom to treat, as the causes are multifactorial and effective treatment may vary depending on whether pain is neuropathic or nociceptive in origin, and the placebo effect can complicate evaluation of the efficacy of medical and procedural interventions. Novel technologies like functional magnetic resonance imaging and virtual reality may offer novel means for assessing and treating pain, respectively. Clinical trial designs will need to consider best approaches to addressing the heterogeneity of chronic pancreatitis, including careful attention to designing eligibility criteria, and establishing accepted and validated core outcomes criteria for the field. The latter may be informed by consensus in pain research. Recruitment of participants into clinical trials has been challenging, often requiring multiple centers. Establishment of a clinical trials network would facilitate greater opportunities for therapeutic trials in pancreatitis.

Antibiotic treatment of bacterial lung infections in cystic fibrosis

Bacterial infections of the lower airways are the main cause of mortality and morbidity in cystic fibrosis. The most frequently isolated pathogens are S. aureus and P. aeruginosa; bacterial co-infections are frequently observed. The aim of this review is to provide, in the current context, the indications regarding the best antibiotic strategy to adopt in subjects affected by CF infected with the most common pathogens. We selected relevant publications (guidelines, systematic reviews and clinical studies published so far on these topics) and we analysed the sampling methods used and antibiotic strategies adopted. Oropharyngeal sampling methods are considered less sensitive for pathogen detection than sputum. In non-expectorating people, induced sputum is considered equivalent to two-lobe bronchoalveolar lavage, which is considered invasive. Antibiotic treatment against the main pathogens can consist in eradication treatment in the early stages of infection, chronic suppressive therapy and treatment of the pulmonary exacerbations. This scheme is valid for P. aeruginosa but remains to be demonstrated for the other pathogens. For S. aureus, no evidence-based therapeutic strategies on how to treat the different stages of bacterial infection have been established with certainty. With regard to the treatment of the other classic pathogens (B. cepacia complex, A. xylosoxidans and S. maltophilia), no evidence-based indications exist and decision is left to the clinician. The recent introduction of highly effective modulators on the CFTR protein, in addition to the favourable effects described in regulatory trials, has led to a reduction in bacterial isolations; the real effect of which in clinical practice has still to be assessed on the basis of scientific data. CONCLUSIONS: The reliability of culture examination depends on sampling methods, and expectorated sputum continues to be the best method as it is simple and non-invasive. P. aeruginosa is the pathogen for which antibiotic strategies for the various stages of infection appear best established, and the efficacy of early eradication treatment and chronic suppressive therapy have been underlined in clinical trials and systematic reviews. The recent introduction of modulators into clinical practice, despite their widely described efficacy, has not yet led to suggestions for changes in antibiotic strategies against the pathogens most frequently isolated.

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

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

The continuing need for dornase alfa for extracellular airway DNA hydrolysis in the era of CFTR modulators

INTRODUCTION

The availability of cystic fibrosis transmembrane conductance regulator (CFTR) modulators opens the possibility of discontinuing some chronic pulmonary therapies to decrease cystic fibrosis (CF) treatment burden. However, CFTR modulators may not adequately address neutrophilic inflammation, which contributes to a self-perpetual cycle of viscous CF sputum, airway obstruction, inflammation, and lung function decline.

AREAS COVERED

This review discusses the emerging role of neutrophil extracellular traps in CF and its role in CF sputum viscosity, airway obstruction, and inflammation, based on a literature search of PubMed (1990-present). We summarize clinical trials and real-world studies that support the efficacy of dornase alfa (Pulmozyme) in improving lung function and reducing pulmonary exacerbation in people with CF (PwCF), and we discuss the potential role of dornase alfa in reducing airway inflammation. We also examine the findings of short-term trials evaluating the discontinuation of mucoactive therapy in PwCF receiving CFTR modulators.

EXPERT OPINION

Long-term studies are needed to assess the impact of discontinuing mucoactive therapy in PwCF who are clinically stable while receiving CFTR modulatory therapy. Treatment decisions should take into account the severity of underlying lung disease. People with advanced CF will likely require ongoing mucoactive therapy.

Cystic fibrosis

Cystic fibrosis is a rare genetic disease caused by mutations in CFTR, the gene encoding cystic fibrosis transmembrane conductance regulator (CFTR). The discovery of CFTR in 1989 has enabled the unravelling of disease mechanisms and, more recently, the development of CFTR-directed therapeutics that target the underlying molecular defect. The CFTR protein functions as an ion channel that is crucial for correct ion and fluid transport across epithelial cells lining the airways and other organs. Consequently, CFTR dysfunction causes a complex multi-organ disease but, to date, most of the morbidity and mortality in people with cystic fibrosis is due to muco-obstructive lung disease. Cystic fibrosis care has long been limited to treating symptoms using nutritional support, airway clearance techniques and antibiotics to suppress airway infection. The widespread implementation of newborn screening for cystic fibrosis and the introduction of a highly effective triple combination CFTR modulator therapy that has unprecedented clinical benefits in up to 90% of genetically eligible people with cystic fibrosis has fundamentally changed the therapeutic landscape and improved prognosis. However, people with cystic fibrosis who are not eligible based on their CFTR genotype or who live in countries where they do not have access to this breakthrough therapy remain with a high unmet medical need.

Wellness in the modulator era: An observational study of the impact of CFTR modulator therapy on the well-being of people with cystic fibrosis

BACKGROUND

People with cystic fibrosis (PwCF) have experienced substantial improvements in health following use of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies. However, less is known about how modulator therapies impact well-being.

METHODS

We used a cross-sectional observational study to identify relationships between CFTR modulator therapies, health-related quality of life (HRQoL), and well-being. Adult PwCF and caregivers of children with CF completed the Wellness in the Modulator Era (Well-ME) survey between June 22 and July 31, 2022. HRQoL was measured with PROMIS Global 10/Global 7 + 2 Parent Proxy. We used a mixed methods analysis to compare experiences and concerns of PwCF who currently (n = 665), no longer (n = 51), or never (n = 184) took modulator therapy.

RESULTS

Adult PwCF taking a modulator (n = 416) reported better PROMIS global physical health than those who no longer (n = 37) or never took a modulator (n = 94) and better PROMIS global mental health than those who never took a modulator. Caregiver-reported HRQoL was similar across children with CF who currently, no longer, or never took a modulator. PwCF taking a modulator reported larger improvements in physical health, quality of life, social well-being, and treatment burden than those who no longer or never took a modulator. Nearly one-quarter (23 %) of PwCF taking modulator therapy reported worsening of mental well-being.

CONCLUSIONS

This study expands our knowledge of well-being among PwCF in the CFTR modulator era as reported by patients and parents. Findings lay the groundwork for establishing future research priorities, policy efforts, and communications in areas that improve well-being for PwCF.

The biogenesis of potassium transporters: implications of disease-associated mutations

The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.

International disparities in diagnosis and treatment access for cystic fibrosis

BACKGROUND

Elexacaftor/tezacaftor/ivacaftor (ETI) has revolutionized cystic fibrosis (CF) treatment. However, previous research has demonstrated profound global disparities in diagnosis and treatment access. If unaddressed, these threaten to widen existing health inequities. Therefore, in this analysis we aimed to reappraise gaps and evaluate progress in diagnosis and treatment equity in high-income (HIC) versus low- and middle-income countries (LMICs).

METHODS

Estimates of the global CF population were made in 158 countries using patient registries, systematic literature searches, and an international survey of 14 CF experts. Estimates of the global burden of undiagnosed CF were made using epidemiological studies identified in literature searches and registry coverage data. The proportion of people receiving ETI was estimated using publicly available revenue data and a survey of 23 national drug pricing databases.

RESULTS

188,336 (163,421-209,204) people are estimated to have CF in 96 countries. Of these, 111,767 (59%) were diagnosed and 51,322 (27%) received ETI. The undiagnosed patient burden is estimated to be 76,569 people, with 82% in LMICs. ETI is reimbursed in 35 HICs, but only one LMIC. Four years after approval, there are 13,723 people diagnosed with CF who live in a country where ETI is inaccessible. This increases to 76,199 when including the estimated undiagnosed population.

CONCLUSIONS

Equitable access to CFTR modulators must become a top priority for the international CF community. ETI costs up to $322,000 per year but could be manufactured for $5000 to allow access under a voluntary license. Given the extent of disparities, other mechanisms to improve access that circumvent the manufacturer should also be considered.

Update on advances in cystic fibrosis towards a cure and implications for primary care clinicians

During the past quarter century, the diagnosis and treatment of cystic fibrosis (CF) have been transformed by molecular sciences that initiated a new era with discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The knowledge gained from that breakthrough has had dramatic clinical impact. Although once a diagnostic dilemma with long delays, preventable deaths, and irreversible pathology, CF can now be routinely diagnosed shortly after birth through newborn screening programs. This strategy of pre-symptomatic identification has eliminated the common diagnostic "odyssey" that was a failure of the healthcare delivery system causing psychologically traumatic experiences for parents. Therapeutic advances of many kinds have culminated in CFTR modulator treatment that can reduce the effects of or even correct the molecular defect in the chloride channel -the basic cause of CF. This astonishing advance has transformed CF care as described fully herein. Despite this impressive progress, there are challenges and controversies in the delivery of care. Issues include how best to achieve high sensitivity newborn screening with acceptable specificity; what course of action is appropriate for children who are identified through the unavoidable incidental findings of screening tests (CFSPID/CRMS cases and heterozygote carriers); how best to ensure genetic counseling; when to initiate the very expensive but life-saving CFTR modulator drugs; how to identify new CFTR modulator drugs for patients with non-responsive CFTR variants; how to adjust other therapeutic modalities; and how to best partner with primary care clinicians. Progress always brings new challenges, and this has been evident worldwide for CF. Consequently, this article summarizes the major advances of recent years along with controversies and describes their implications with an international perspective.

The impact of switching to race-neutral reference equations on FEV1 percent predicted among people with cystic fibrosis. J Cyst Fibros 2024;23:443-449. [PMID: 38556415 DOI: 10.1016/j.jcf.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

RATIONALE

The American Thoracic Society recommended switching to race-neutral spirometry reference equations, as race is a social construct and to avoid normalizing disparities in lung function due to structural racism. Understanding the impact of the race-neutral equations on percent predicted forced expiratory volume in one second (ppFEV1) in people with cystic fibrosis (PwCF) will help prepare patients and providers to interpret pulmonary function test results.

OBJECTIVE(S)

To quantify the impact of switching from Global Lung Initiative (GLI) 2012 race-specific to GLI 2022 Global race-neutral reference equations on the distribution of ppFEV1 among PwCF of different races.

METHODS

Cross-sectional analysis of FEV1 among PwCF ages ≥6 years in the 2021 U.S. Cystic Fibrosis Foundation Patient Registry. We describe the absolute difference in ppFEV1 between the two reference equations by reported race and the effect of age and height on this difference.

RESULTS

With the switch to GLI Global, ppFEV1 will increase for White (median increase 4.7, (IQR: 3.1; 6.4)) and Asian (2.6 (IQR: 1.6; 3.7)) individuals and decrease for Black individuals (-7.7, (IQR: -10.9; -5.2)). Other race categories will see minimal changes in median ppFEV1. Individuals with higher baseline ppFEV1 and younger age will see a greater change in ppFEV1 (i.e., a greater improvement among White and Asian individuals and a greater decline among Black individuals).

CONCLUSIONS

Switching from GLI 2012 race-specific reference equations to GLI 2022 Global race-neutral equations will result in larger reductions in ppFEV1 among Black individuals with CF than increases among White and Asian people with CF.

Standards for the care of people with cystic fibrosis (CF); Planning for a longer life

This is the final of four papers updating standards for the care of people with CF. That this paper "Planning a longer life" was considered necessary, highlights how much CF care has progressed over the past decade. Several factors underpin this progress, notably increased numbers of people with CF with access to CFTR modulator therapy. As the landscape for CF changes, so do the hopes and aspirations of people with CF and their families. This paper reflects the need to consider people with CF not as a "problem" to be solved, but as a success, a potential and a voice to be heard. People with CF and the wider CF community have driven this approach, reflecting many of the topics in this paper. This exercise involved wide stakeholder engagement. People with CF are keen to contribute to research priorities and be involved in all stages of research. People with CF want healthcare professionals to respect them as individuals and consider the impact of our actions on the world around us. Navigating life presents challenges to all, but for people with CF these challenges are heightened and complex. In this paper we highlight the concerns and life moments that impact people with CF, and events that the CF team should aim to support, including the challenges around having a family. People with CF and their care teams must embrace the updated standards outlined in these four papers to enjoy the full potential for a healthier life.

Microbiology of cystic fibrosis persons not chronically infected with P. aeruginosa: A quasi-experimental study on two different upper airways' sampling methods

Background

The upper airways of cystic fibrosis (CF) persons are an evolutionary niche where genetically adapted bacterial strains are selected for lung infection. The microbiological studies conducted up to now on the upper airways are not easily comparable.

Methods

Using classical culture methods, we simultaneously studied the microbiological status of upper and lower airways in persons not chronically infected with P. aeruginosa. Each person had a single upper airways sampling and a concomitant lower airways sampling. Lower airways sampling was performed by oropharyngeal swab or sputum collection. Using a quasi-experimental design of study, we evaluated the performance of 2 different upper airways' sampling methods, nasal lavage according to method described by Mainz or nasal lavage with a rhino-set. Pain was measured with appropriate scales.

Results

A total of 194 persons were enrolled in this study. Pathogenic flora was found in 128 (6.6%) of 194 upper airways samples and in 164 (84.6%) lower airways samples. A statistically significant difference between the upper airways and the lower airways was found in the isolation of S. aureus and non-fermenter gram negatives. Nasal lavage according to Mainz resulted in the isolation of more non-fermenter gramnegatives than the rhino-set (p < 0.05). No differences were found in the pain caused bythe two methods.

Conclusions

In our study population, cultures of the upper airway and lower airway differ in CF persons. In people sampled with nasal lavage according to Mainz more non-fermenter gram negatives were detected than with rhino-set. The two sampling methods were comparable with regard to the caused pain, nasal lavage according to Mainz method being quicker to perform.

The future of cystic fibrosis treatment: from disease mechanisms to novel therapeutic approaches

With the 2019 breakthrough in the development of highly effective modulator therapy providing unprecedented clinical benefits for over 90% of patients with cystic fibrosis who are genetically eligible for treatment, this rare disease has become a front runner of transformative molecular therapy. This success is based on fundamental research, which led to the identification of the disease-causing CFTR gene and our subsequent understanding of the disease mechanisms underlying the pathogenesis of cystic fibrosis, working together with a continuously evolving clinical research and drug development pipeline. In this Series paper, we focus on advances since 2018, and remaining knowledge gaps in our understanding of the molecular mechanisms of CFTR dysfunction in the airway epithelium and their links to mucus dysfunction, impaired host defences, airway infection, and chronic inflammation of the lungs of people with cystic fibrosis. We review progress in (and the remaining obstacles to) pharmacological approaches to rescue CFTR function, and novel strategies for improved symptomatic therapies for cystic fibrosis, including how these might be applicable to common lung diseases, such as bronchiectasis and chronic obstructive pulmonary disease. Finally, we discuss the promise of genetic therapies and gene editing approaches to restore CFTR function in the lungs of all patients with cystic fibrosis independent of their CFTR genotype, and the unprecedented opportunities to transform cystic fibrosis from a fatal disease to a treatable and potentially curable one.