Efficacy and safety of onasemnogene abeparvovec in children with spinal muscular atrophy type 1: real-world evidence from 6 infusion centres in the United Kingdom.

Background: Real-world data on the efficacy and safety of onasemnogene abeparvovec (OA) in spinal muscular atrophy (SMA) are needed, especially to overcome uncertainties around its use in older and heavier children. This study evaluated the efficacy and safety of OA in patients with SMA type 1 in the UK, including patients ≥2 years old and weighing ≥13.5 kg. Methods: This observational cohort study used data from patients with genetically confirmed SMA type 1 treated with OA between May 2021 and January 2023, at 6 infusion centres in the United Kingdom. Functional outcomes were assessed using age-appropriate functional scales. Safety analyses included review of liver function, platelet count, cardiac assessments, and steroid requirements. Findings: Ninety-nine patients (45 SMA therapy-naïve) were treated with OA (median age at infusion: 10 [range, 0.6-89] months; median weight: 7.86 [range, 3.2-20.2] kg; duration of follow-up: 3-22 months). After OA infusion, mean ± SD change in CHOP-INTEND score was 11.0 ± 10.3 with increased score in 66/78 patients (84.6%); patients aged <6 months had a 13.9 points higher gain in CHOP-INTEND score than patients ≥2 years (95% CI, 6.8-21.0; P < 0.001). Asymptomatic thrombocytopenia (71/99 patients; 71.7%), asymptomatic troponin-I elevation (30/89 patients; 33.7%) and transaminitis (87/99 patients; 87.9%) were reported. No thrombotic microangiopathy was observed. Median steroid treatment duration was 97 (range, 28-548) days with dose doubled in 35/99 patients (35.4%). There were 22.5-fold increased odds of having a transaminase peak >100 U/L (95% CI, 2.3-223.7; P = 0.008) and 21.2-fold increased odds of steroid doubling, as per treatment protocol (95% CI, 2.2-209.2; P = 0.009) in patients weighing ≥13.5 kg versus <8.5 kg. Weight at infusion was positively correlated with steroid treatment duration (r = 0.43; P < 0.001). Worsening transaminitis, despite doubling of oral prednisolone, led to treatment with intravenous methylprednisolone in 5 children. Steroid-sparing immunosuppressants were used in 5 children to enable steroid weaning. Two deaths apparently unrelated to OA were reported. Interpretation: OA led to functional improvements and was well tolerated with no persistent clinical complications, including in older and heavier patients. Funding: Novartis Innovative Therapies AG provided a grant for independent medical writing services.

Risdiplam for the treatment of adults with spinal muscular atrophy: Experience of the Northern Ireland neuromuscular service.

INTRODUCTION/AIMS: Risdiplam is the newest available treatment for patients with spinal muscular atrophy (SMA). There is little information on its use in adults. We present the clinical experience of adults with SMA treated with risdiplam through the Early Access to Medicines Scheme (EAMS) in Northern Ireland. METHODS: All adults with Type 2 SMA attending the regional neuromuscular clinic were offered risdiplam treatment. Patients had assessments of respiratory function, the Epworth Sleepiness Scale (ESS), Quality of Life Measure for People with Slowly Progressive and Genetic Neuromuscular Disease (QOLM), and Egen Klassifikation 2 (EK2) every 3 mo and the Revised Upper Limb Module for SMA (RULM) at baseline and 6 mo. All assessments other than the RULM were carried out virtually. RESULTS: Six of seven patients who were offered risdiplam consented to treatment through the EAMS (five female, one male, mean age 33.7 y). It was generally well tolerated other than skin photosensitivity in all patients. All patients remained on therapy at 9 mo. All reported meaningful improvements in overall strength, sense of wellbeing, and speech quality. There was no change in respiratory function, daytime hypersomnolence, or upper limb function (all p > .05). There was improvement in the QOLM (p = .027) and EK2 (p = .009). DISCUSSION: Our study raises hopes that risdiplam may be efficacious in adults; however, more systematic studies in larger cohorts are needed before drawing any definitive conclusions. This study also demonstrated the feasibility of virtual assessments.

In Vitro Modeling of RSV Infection and Cytopathogenesis in Well-Differentiated Human Primary Airway Epithelial Cells (WD-PAECs).

The choice of model used to study human respiratory syncytial virus (RSV) infection is extremely important. RSV is a human pathogen that is exquisitely adapted to infection of human hosts. Rodent models, such as mice and cotton rats, are semi-permissive to RSV infection and do not faithfully reproduce hallmarks of RSV disease in humans. Furthermore, immortalized airway-derived cell lines, such as HEp-2, BEAS-2B, and A549 cells, are poorly representative of the complexity of the respiratory epithelium. The development of a well-differentiated primary pediatric airway epithelial cell models (WD-PAECs) allows us to simulate several hallmarks of RSV infection of infant airways. They therefore represent important additions to RSV pathogenesis modeling in human-relevant tissues. The following protocols describe how to culture and differentiate both bronchial and nasal primary pediatric airway epithelial cells and how to use these cultures to study RSV cytopathogenesis.

Exhaled breath temperature measurement and asthma control in children prescribed inhaled corticosteroids: A cross sectional study.

BACKGROUND: Exhaled breath temperature (EBT) reflects airways (both eosinophilic and neutrophilic) inflammation in asthma and thus may aid the management of children with asthma that are treated with anti-inflammatory drugs. A new EBT monitor has become available that is cheap and easy to use and may be a suitable monitoring device for airways inflammation. Little is known about how EBT relates to asthma treatment decisions, disease control, lung function, or other non-invasive measures of airways inflammation, such as exhaled nitric oxide (ENO). OBJECTIVE: To determine the relationships between EBT and asthma treatment decision, current control, pulmonary function, and ENO. METHODS: Cross-sectional prospective study on 159 children aged 5-16 years attending a pediatric respiratory clinic. EBT was compared with the clinician's decision regarding treatment (decrease, no change, increase), asthma control assessment (controlled, partial, uncontrolled), level of current treatment (according to British Thoracic Society guideline, BTS step), ENO, and spirometry. RESULTS: EBT measurement was feasible in the majority of children (25 of 159 could not perform the test) and correlated weakly with age (R = 0.33, P = <0.01). EBT did not differ significantly between the three clinician decision groups (P = 0.42), the three asthma control assessment groups (P = 0.9), or the current asthma treatment BTS step (P = 0.57). CONCLUSIONS & CLINICAL IMPLICATIONS: EBT measurement was not related to measures of asthma control determined at the clinic. The routine intermittent monitoring of EBT in children prescribed inhaled corticosteroids who attend asthma clinics cannot be recommended for adjusting anti-inflammatory asthma therapy.

Induction and Antagonism of Antiviral Responses in Respiratory Syncytial Virus-Infected Pediatric Airway Epithelium.

UNLABELLED: Airway epithelium is the primary target of many respiratory viruses. However, virus induction and antagonism of host responses by human airway epithelium remains poorly understood. To address this, we developed a model of respiratory syncytial virus (RSV) infection based on well-differentiated pediatric primary bronchial epithelial cell cultures (WD-PBECs) that mimics hallmarks of RSV disease in infants. RSV is the most important respiratory viral pathogen in young infants worldwide. We found that RSV induces a potent antiviral state in WD-PBECs that was mediated in part by secreted factors, including interferon lambda 1 (IFN-λ1)/interleukin-29 (IL-29). In contrast, type I IFNs were not detected following RSV infection of WD-PBECs. IFN responses in RSV-infected WD-PBECs reflected those in lower airway samples from RSV-hospitalized infants. In view of the prominence of IL-29, we determined whether recombinant IL-29 treatment of WD-PBECs before or after infection abrogated RSV replication. Interestingly, IL-29 demonstrated prophylactic, but not therapeutic, potential against RSV. The absence of therapeutic potential reflected effective RSV antagonism of IFN-mediated antiviral responses in infected cells. Our data are consistent with RSV nonstructural proteins 1 and/or 2 perturbing the Jak-STAT signaling pathway, with concomitant reduced expression of antiviral effector molecules, such as MxA/B. Antagonism of Jak-STAT signaling was restricted to RSV-infected cells in WD-PBEC cultures. Importantly, our study provides the rationale to further explore IL-29 as a novel RSV prophylactic. IMPORTANCE: Most respiratory viruses target airway epithelium for infection and replication, which is central to causing disease. However, for most human viruses we have a poor understanding of their interactions with human airway epithelium. Respiratory syncytial virus (RSV) is the most important viral pathogen of young infants. To help understand RSV interactions with pediatric airway epithelium, we previously developed three-dimensional primary cell cultures from infant bronchial epithelium that reproduce several hallmarks of RSV infection in infants, indicating that they represent authentic surrogates of RSV infection in infants. We found that RSV induced a potent antiviral state in these cultures and that a type III interferon, interleukin IL-29 (IL-29), was involved. Indeed, our data suggest that IL-29 has potential to prevent RSV disease. However, we also demonstrated that RSV efficiently circumvents this antiviral immune response and identified mechanisms by which this may occur. Our study provides new insights into RSV interaction with pediatric airway epithelium.

Epidermal Growth Factor Removal or Tyrphostin AG1478 Treatment Reduces Goblet Cells & Mucus Secretion of Epithelial Cells from Asthmatic Children Using the Air-Liquid Interface Model.

RATIONALE: Epithelial remodelling in asthma is characterised by goblet cell hyperplasia and mucus hypersecretion for which no therapies exist. Differentiated bronchial air-liquid interface cultures from asthmatic children display high goblet cell numbers. Epidermal growth factor and its receptor have been implicated in goblet cell hyperplasia. OBJECTIVES: We hypothesised that EGF removal or tyrphostin AG1478 treatment of differentiating air-liquid interface cultures from asthmatic children would result in a reduction of epithelial goblet cells and mucus secretion. METHODS: In Aim 1 primary bronchial epithelial cells from non-asthmatic (n = 5) and asthmatic (n = 5) children were differentiated under EGF-positive (10 ng/ml EGF) and EGF-negative culture conditions for 28 days. In Aim 2, cultures from a further group of asthmatic children (n = 5) were grown under tyrphostin AG1478, a tyrosine kinase inhibitor, conditions. All cultures were analysed for epithelial resistance, markers of differentiation using immunocytochemistry, ELISA for MUC5AC mucin secretion and qPCR for MUC5AC mRNA. RESULTS: In cultures from asthmatic children the goblet cell number was reduced in the EGF negative group (p = 0.01). Tyrphostin AG1478 treatment of cultures from asthmatic children had significant reductions in goblet cells at 0.2 µg/ml (p = 0.03) and 2 µg/ml (p = 0.003) as well as mucus secretion at 2 µg/ml (p = 0.04). CONCLUSIONS: We have shown in this preliminary study that through EGF removal and tyrphostin AG1478 treatment the goblet cell number and mucus hypersecretion in differentiating air-liquid interface cultures from asthmatic children is significantly reduced. This further highlights the epidermal growth factor receptor as a potential therapeutic target to inhibit goblet cell hyperplasia and mucus hypersecretion in asthma.

Relative respiratory syncytial virus cytopathogenesis in upper and lower respiratory tract epithelium.

RATIONALE: Respiratory syncytial virus (RSV) is a major pathogen that primarily infects airway epithelium. Most infants suffer mild upper respiratory tract (URT) symptoms, whereas approximately one-third progress to lower respiratory tract (LRT) involvement. Despite the ubiquity of URT infection, little is known about the relative cytopathogenesis of RSV infection in infant URT and LRT. OBJECTIVES: This study aimed to compare RSV cytopathogenesis in nasal- and bronchial-derived epithelium from the same individuals using novel models derived from well-differentiated primary pediatric nasal (WD-PNECs) and bronchial epithelial cells (WD-PBECs). METHODS: WD-PNECs and WD-PBECs were generated from nasal and bronchial brushes, respectively, and mock-infected or infected with RSV BT2a. RSV tropism, infectivity, cytopathology, growth kinetics, cell sloughing, apoptosis, and cytokine and chemokine responses were determined. MEASUREMENTS AND MAIN RESULTS: RSV infection in both cultures was restricted to apical ciliated cells and occasional nonciliated cells but not goblet cells. It did not cause gross cytopathology. Infection resulted in apical release of progeny virus, increased apical cell sloughing, apoptosis, and occasional syncytia. RSV growth kinetics and peak titers were higher in WD-PBECs, coincident with higher ciliated cell contents, cell sloughing, and slightly compromised tight junctions. However, proinflammatory chemokine responses were similar for both cultures. Also, lambda IFNs, especially IL-29, were induced by RSV infection. CONCLUSIONS: RSV induced remarkably similar, albeit quantitatively lower, cytopathogenesis and proinflammatory responses in WD-PNECs compared with WD-PBECs that reproduce many hallmarks of RSV pathogenesis in infants. WD-PNECs may provide an authentic surrogate model with which to study RSV cytopathogenesis in infant airway epithelium.

In vitro modeling of respiratory syncytial virus infection of pediatric bronchial epithelium, the primary target of infection in vivo.

Respiratory syncytial virus (RSV) is the major viral cause of severe pulmonary disease in young infants worldwide. However, the mechanisms by which RSV causes disease in humans remain poorly understood. To help bridge this gap, we developed an ex vivo/in vitro model of RSV infection based on well-differentiated primary pediatric bronchial epithelial cells (WD-PBECs), the primary targets of RSV infection in vivo. Our RSV/WD-PBEC model demonstrated remarkable similarities to hallmarks of RSV infection in infant lungs. These hallmarks included restriction of infection to noncontiguous or small clumps of apical ciliated and occasional nonciliated epithelial cells, apoptosis and sloughing of apical epithelial cells, occasional syncytium formation, goblet cell hyperplasia/metaplasia, and mucus hypersecretion. RSV was shed exclusively from the apical surface at titers consistent with those in airway aspirates from hospitalized infants. Furthermore, secretion of proinflammatory chemokines such as CXCL10, CCL5, IL-6, and CXCL8 reflected those chemokines present in airway aspirates. Interestingly, a recent RSV clinical isolate induced more cytopathogenesis than the prototypic A2 strain. Our findings indicate that this RSV/WD-PBEC model provides an authentic surrogate for RSV infection of airway epithelium in vivo. As such, this model may provide insights into RSV pathogenesis in humans that ultimately lead to successful RSV vaccines or therapeutics.