The expanded French compassionate programme for elexacaftor-tezacaftor-ivacaftor use in people with cystic fibrosis without a F508del CFTR variant: a real-world study.

BACKGROUND: Elexacaftor-tezacaftor-ivacaftor has been approved in Europe for people with cystic fibrosis with at least one F508del CFTR variant. Additionally, it is approved by the US Food and Drug Administration (FDA) for people with cystic fibrosis with at least one of 177 rare variants. The aims of this study were to describe the clinical response to elexacaftor-tezacaftor-ivacaftor for people with cystic fibrosis without a F508del CFTR variant in France and to determine CFTR variant responsiveness to elexacaftor-tezacaftor-ivacaftor based on the observed clinical response. METHODS: The French compassionate programme expanded access to elexacaftor-tezacaftor-ivacaftor to people with cystic fibrosis, aged 6 years and older, without a F508del variant, excluding those with two variants previously characterised as non-responsive. Participants at France's 47 cystic fibrosis centres were given a 4-6 week trial of elexacaftor-tezacaftor-ivacaftor and response was determined by a centralised committee based on evolution of clinical data, lung function, and sweat chloride concentration. Responsiveness of individual CFTR variants was derived from observed clinical responses. FINDINGS: The first compassionnate programme was launched on May 19, 2022; by March 8, 2024, 516 people with cystic fibrosis had been identified for inclusion in this real-word study: 37 were not included due to the presence of two variants previously characterised as non-responsive to elexacaftor-tezacaftor-ivacaftor, and 479 (229 females [48%] and 250 males [52%]) received elexacaftor-tezacaftor-ivacaftor for 4-6 weeks. Among 443 participants who received no CFTR modulator before elexacaftor-tezacaftor-ivacaftor, 83 had at least one FDA-approved variant, of whom 81 (98%) were responders and continued elexacaftor-tezacaftor-ivacaftor; in responders, mean absolute change in sweat chloride was -44·5 mmol/L (95% CI -39·1 to -49·8) and percentage of predicted FEV1 (ppFEV1) was 11·1 percentage points (95% CI 8·4 to 13·7; both comparisons p<0·0001). Among 360 participants with no FDA-approved variant and no previous CFTR modulator, 177 (49%) were responders; in responders, mean absolute change in sweat chloride was -20·5 mmol/L (-17·2 to -23·8) and ppFEV1 was 13·2 percentage points (11·4 to 15·0; both comparisons p<0·0001). Among 36 participants who were receiving ivacaftor before elexacaftor-tezacaftor-ivacaftor, 32 (89%) continued elexacaftor-tezacaftor-ivacaftor. Of 251 individual CFTR variants, 64 (28 FDA-approved) were classified as responsive or possibly responsive to elexacaftor-tezacaftor-ivacaftor, and 123 (two FDA-approved) as non-responsive or possibly non-responsive to elexacaftor-tezacaftor-ivacaftor. INTERPRETATION: In France, over half of the population with cystic fibrosis without a F508del variant responded to elexacaftor-tezacaftor-ivacaftor, with most responders having no FDA-approved variant. The treatment period was relatively short and further research is warranted to describe the long-term safety and effectiveness of elexacaftor-tezacaftor-ivacaftor in this population. FUNDING: Association Vaincre la Mucoviscidose, Société Française de la Mucoviscidose, and Filière Maladies Rares MUCO-CFTR.

Local Receptor-interacting Protein Kinase 2 inhibition mitigates HDM-induced asthma.

House dust mite (HDM) is the most frequent trigger of allergic asthma with innate and adaptive immune mechanisms playing critical roles in outcomes. We recently identified the NOD1/RIPK2 signalling pathway as a relevant contributor to murine HDM-induced asthma. This study aimed to evaluate the effectiveness of a pharmacological RIPK2 inhibitor administered locally as a preventive and therapeutic approach using an HDM-induced asthma model in Wild-type (WT) and humanized (h)NOD1 mice harbouring an asthma associated risk allele, and its relevance using airway liquid interface (ALI) epithelial cultures from asthmatics.A RIPK2 inhibitor was administered intra-nasally either preventively or therapeutically in a murine HDM-induced asthma model. Airway hyperresponsiveness (AHR), bronchoalveolar lavage composition, cytokine/chemokines expression and mucus production were evaluated, as well as the effect of the inhibitor on precision-cut lung slices (PCLS). Furthermore, the inhibitor was tested on ALI cultures from asthmatics and controls.While local preventive administration of the RIPK2 inhibitor reduced AHR, eosinophilia, mucus production, Th2 cytokines and IL-33 in WT mice, its therapeutic administration failed to reduce the above parameters, except IL-33. By contrast, therapeutic RIPK2 inhibition mitigated all asthma features in hNOD1 mice. Results of PCLS emphasized an early role of TSLP and IL-33 in the NOD1-dependent response to HDM, and a late effect of NOD1 signalling on IL-13 effector response. RIPK2 inhibitor down-regulated TSLP and chemokines in HDM-stimulated ALI epithelial cultures from asthma patients.These data support that local interference of the NOD1 signalling pathway through RIPK2 inhibition may represent a new therapeutic approach in HDM-induced asthma.

Mucus plugs in the airways of asthmatic subjects and smoking status.

BACKGROUND: Mucus plugs have been described in the airways of asthmatic subjects, particularly those with associated with type 2 inflammation and sputum eosinophilia. In the current study we addressed the question of whether smoking, neutrophilic inflammation and airway dimensions affected the prevalence of mucus plugs. METHODS: In a cohort of moderate to severe asthmatics (n = 50), including a group of ex-smokers and current smokers, the prevalence of mucus plugs was quantified using a semi-quantitative score based on thoracic computerized tomography. The relationships between mucus score, sputum inflammatory profile and airway architecture were tested according to patient's smoking status. RESULTS: Among the asthmatics (37% former or active smokers), 74% had at least one mucus plug. The median score was 3 and was unrelated to smoking status. A significant but weak correlation was found between mucus score, FEV1 and FEV1/FVC. Mucus score was significantly correlated with sputum eosinophils. Among former and active smokers, mucus score was correlated with sputum neutrophils. Mucus score was positively associated with FeNO in non-smoking subjects. The lumen dimensions of the main and lobar bronchi were significantly inversely correlated with mucus score. CONCLUSION: Airway mucus plugs could define an asthma phenotype with altered airway architecture and can occur in asthmatic subjects with either neutrophilic or eosinophilic sputum according to their smoking status.

Allergic bronchopulmonary aspergillosis: A multidisciplinary review.

Allergic bronchopulmonary aspergillosis (ABPA) is a rare disease characterized by a complex allergic inflammatory reaction of airways against Aspergillus affecting patients with chronic respiratory diseases (asthma, cystic fibrosis). Exacerbation is often the way to diagnose ABPA and marks its evolution by its recurrent character leading to cortico-requirement or long-term antifungal treatment. Early diagnosis allows treatment of ABPA at an initial stage, preventing recurrence of exacerbations and long-term complications, mainly represented by bronchiectasis. This review of the literature aims to present the current state of the art in terms of diagnosis and treatment of ABPA from a multidisciplinary perspective. As there is no clinical, biological nor radiological specific sign, diagnostic criteria are regularly revised. They are mainly based on the elevation of total and specific IgE against Aspergillus fumigatus and the presence of suggestive CT abnormalities such as mucoid impaction and consolidations. ABPA management includes eviction of mold and pharmacological therapy. Exacerbations are treated in first line with a moderate dose of oral corticosteroids. Azole antifungal agents represent an alternative for the treatment of exacerbations and are the preferential strategy to reduce the future risk of exacerbations and for corticosteroids sparing. Asthma biologics may be of interest; however, their place remains to be determined. Avoiding complications of ABPA while limiting the side effects of systemic drugs remains a major challenge of ABPA management. Several drugs, including new antifungals and asthma biologics, are currently being tested and may be useful in the future.

NOD-like receptors in asthma.

Asthma is an extremely prevalent chronic inflammatory disease of the airway where innate and adaptive immune systems participate collectively with epithelial and other structural cells to cause airway hyperresponsiveness, mucus overproduction, airway narrowing, and remodeling. The nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are a family of intracellular innate immune sensors that detect microbe-associated molecular patterns and damage-associated molecular patterns, well-recognized for their central roles in the maintenance of tissue homeostasis and host defense against bacteria, viruses and fungi. In recent times, NLRs have been increasingly acknowledged as much more than innate sensors and have emerged also as relevant players in diseases classically defined by their adaptive immune responses such as asthma. In this review article, we discuss the current knowledge and recent developments about NLR expression, activation and function in relation to asthma and examine the potential interventions in NLR signaling as asthma immunomodulatory therapies.

Role of Nrf2 in Disease: Novel Molecular Mechanisms and Therapeutic Approaches - Pulmonary Disease/Asthma.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a major transcription factor involved in redox homeostasis and in the response induced by oxidative injury. Nrf2 is present in an inactive state in the cytoplasm of cells. Its activation by internal or external stimuli, such as infections or pollution, leads to the transcription of more than 500 elements through its binding to the antioxidant response element. The lungs are particularly susceptible to factors that generate oxidative stress such as infections, allergens and hyperoxia. Nrf2 has a crucial protective role against these ROS. Oxidative stress and subsequent activation of Nrf2 have been demonstrated in many human respiratory diseases affecting the airways, including asthma and chronic obstructive pulmonary disease (COPD), or the pulmonary parenchyma such as acute respiratory distress syndrome (ARDS) and pulmonary fibrosis. Several compounds, both naturally occurring and synthetic, have been identified as Nrf2 inducers and enhance the activation of Nrf2 and expression of Nrf2-dependent genes. These inducers have proven particularly effective at reducing the severity of the oxidative stress-driven lung injury in various animal models. In humans, these compounds offer promise as potential therapeutic strategies for the management of respiratory pathologies associated with oxidative stress but there is thus far little evidence of efficacy through human trials. The purpose of this review is to summarize the involvement of Nrf2 and its inducers in ARDS, COPD, asthma and lung fibrosis in both human and in experimental models.

NOD1 sensing of house dust mite-derived microbiota promotes allergic experimental asthma.

BACKGROUND: Asthma severity has been linked to exposure to gram-negative bacteria from the environment that are recognized by NOD1 receptor and are present in house dust mite (HDM) extracts. NOD1 polymorphism has been associated with asthma. OBJECTIVE: We sought to evaluate whether either host or HDM-derived microbiota may contribute to NOD1-dependent disease severity. METHODS: A model of HDM-induced experimental asthma was used and the effect of NOD1 deficiency was evaluated. Contribution of host microbiota was evaluated by fecal transplantation. Contribution of HDM-derived microbiota was assessed by 16S ribosomal RNA sequencing, mass spectrometry analysis, and peptidoglycan depletion of the extracts. RESULTS: In this model, loss of the bacterial sensor NOD1 and its adaptor RIPK2 improved asthma features. Such inhibitory effect was not related to dysbiosis caused by NOD1 deficiency, as shown by fecal transplantation of Nod1-deficient microbiota to wild-type germ-free mice. The 16S ribosomal RNA gene sequencing and mass spectrometry analysis of HDM allergen, revealed the presence of some muropeptides from gram-negative bacteria that belong to the Bartonellaceae family. While such HDM-associated muropeptides were found to activate NOD1 signaling in epithelial cells, peptidoglycan-depleted HDM had a decreased ability to instigate asthma in vivo. CONCLUSIONS: These data show that NOD1-dependent sensing of HDM-associated gram-negative bacteria aggravates the severity of experimental asthma, suggesting that inhibiting the NOD1 signaling pathway may be a therapeutic approach to treating asthma.

Innate lymphoid cells at the interface between obesity and asthma.

Obesity and asthma prevalence has dramatically and concomitantly increased over the last 25 years, and many epidemiological studies have highlighted obesity as an important risk factor for asthma. Although many studies have been performed, the underlying mechanisms remain poorly understood. Innate mechanisms have been involved in both diseases, in particular through the recently described innate lymphoid cells (ILCs). ILCs are subdivided into three groups that are defined by their cytokine production and by their master transcription factor expression, in sharp correlation with their T helper counterparts. However, unlike T helper cells, ILCs do not express antigen-specific receptors, but respond to damage-induced signals. ILCs have been found in target tissues of both diseases, and data have implicated these cells in the pathogenesis of both diseases. In particular group 2 ILCs (ILC2) are activated in both the adipose and lung tissues under the effect of interleukin-33 and interleukin-25 expression. However, counter-intuitively to the well-known association between obesity and asthma, ILC2 are beneficial for obesity but deleterious for asthma. This review will examine the roles of ILCs in each disease and recent data highlighting ILCs as a putative link between obesity and asthma.