Continued safety and long-term effectiveness of onasemnogene abeparvovec in Ohio

5q spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease caused by absence of the SMN1 gene with three FDA approved genetic therapies which significantly improve outcomes. The AAV9 mediated gene replacement therapy, onasemnogene abeparvovec, has the greatest potential for side effects. Here we report the safety and outcomes from 46 children treated with onasemnogene abeparvovec in the state of Ohio between December 2018 and January 2023. In our cohort, onasemnogene abeparvovec treatment remained safe and no child experienced any significant adverse events, including thrombotic microangiopathy, liver failure or death. All children experienced benefit, although the benefit in those with 2 copies of SMN2 was variable. 79 % of the children treated when symptomatic had a SMN2 modifying therapy added on. With careful screening and post treatment monitoring, onasemnogene abeparvovec is safe and effective for children with SMA in the state of Ohio, but more work needs to be done to ensure optimal outcomes for all children with 2 copies of SMN2.

Food Insecurity Increased During the COVID-19 Pandemic in a Pediatric Cystic Fibrosis Population but Was Not Associated With Weight or Pulmonary Function

Objectives

This study's purpose is to determine changes in household food security status and nutrition-related anthropometrics and pulmonary function of children with Cystic Fibrosis during the COVID-19 pandemic.

Methods

This retrospective study includede caregivers of children ages 2–18 years old with Cystic Fibrosis who had Ohio residency, a Forced Expiratory Volume in 1 second (FEV₁) above 30% and consumed at least half of nutrient needs by mouth. After contacting all eligible households by phone, 30 subjects (50% response) enrolled. The validated 18 item Food Security survey module along with several supplemental questions was used to assess household food security status before and after the onset of the COVID-19 pandemic. A medical chart review collected demographics as well as weight (kg) and FEV₁(%) for the visit closest to the start of the pandemic (Jan-Mar 2020) and the

most current visit (July-Dec 2020). Change in weight was categorized as desirable/undesirable based on clinic standards for using the fiftieth percentile as desirable. A paired t-test was used to determine change in FEV₁ since the pandemic. Changes in food security status in relation to change in weight and change in FEV₁ were determined using Fisher's test and Welch's t-test, respectively.

Results

Participants were caregivers of children who were 9.96 ± 5.02 years old, 56% female, and 83% Caucasian. Ten % of participants (n = 3) reported household food insecurity before the pandemic, which increased to thirty % (n = 9) after the pandemic. Fifty percent of participants (n = 15) experienced an undesirable weight gain (2.71 kg ± 6.32 kg; mean ± std dev). There was no change in FEV₁ during the pandemic (−0.6% ± 9.02; P = .74). Changes in weight and FEV₁ were not related to change in household food security status (P = 0.287 and P = .088 respectively).

Conclusions

Food insecurity increased during the COVID-19 pandemic; however, it was not related to undesirable weight change or decrease in FEV₁. The second part of this study will use semi-structured interviews to elucidate how families with children with cystic fibrosis coped with food insecurity during the pandemic.

Funding Sources

Pulmonary Division, Nationwide Children's Hospital, Columbus OH

The respiratory impact of novel therapies for spinal muscular atrophy

The phenotype of spinal muscular atrophy (SMA) has been changing with the recent availability of three FDA-approved treatments: intrathecal nusinersen, intravenous onasemnogene abeparvovec-xioi, and enteral risdiplam. The degree of improvement in muscle strength and respiratory health varies with SMA genotype, severity of baseline neuromuscular and pulmonary impairment, medication used, and timing of the first dose. A spectrum of pulmonary outcomes has been reported with these novel medications when used early and in conjunction with proactive multidisciplinary management of comorbidities. In this review, we summarize the reported impact of these novel therapies on pulmonary well-being and the improving trajectory of pulmonary morbidity, compared to the natural history of SMA. The importance of ongoing clinical monitoring albeit the improved phenotype is reiterated. We also discuss the limitations of the current SMA-therapy trials and offer suggestions for future clinical-outcome studies and long-term monitoring.

Health outcomes in spinal muscular atrophy type 1 following AVXS-101 gene replacement therapy

BACKGROUND

Spinal Muscular Atrophy type 1 (SMA1) is a rare genetic neuromuscular disease where 75% of SMA1 patients die/require permanent-ventilation by 13.6 months. This study assessed the health outcomes of SMA1 infants treated with AVXS-101 gene replacement therapy.

METHODS

Twelve genetically confirmed SMA1 infants with homozygous deletions of the SMN1 gene and two SMN2 gene copies received a one-time intravenous proposed therapeutic dose of AVXS-101 in an open label study conducted between December 2014 and 2017. Patients were followed for 2-years post-treatment for outcomes including (1) pulmonary interventions; (2) nutritional interventions; (3) swallow function; (4) hospitalization rates; and (5) motor function.

RESULTS

All 12 patients completed the study. Seven infants did not require noninvasive ventilation (NIV) by study completion. Eleven patients had stable or improved swallow function, demonstrated by the ability to feed orally; 11 patients were able to speak. The mean proportion of time hospitalized was 4.4%; the mean unadjusted annualized hospitalization rate was 2.1 (range = 0, 7.6), with a mean length of stay/hospitalization of 6.7 (range = 3, 12.1) days. Eleven patients achieved full head control and sitting unassisted and two patients were walking independently.

CONCLUSIONS

AVXS-101 treatment in SMA1 was associated with reduced pulmonary and nutritional support requirements, improved motor function, and decreased hospitalization rate over the follow-up period. This contrasts with the natural history of progressive respiratory failure and reduced survival. The reduced healthcare utilization could potentially alleviate patient and caregiver burden, suggesting an overall improved quality of life following gene replacement therapy.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT02122952.

Improved quality-of-life of caregivers of children with asthma through guideline-based management

OBJECTIVE

The quality of life (QOL) of caregivers of children with asthma may be related to children's responses to asthma management.

AIM

To evaluate change in QOL over time of caregivers of children with asthma through guideline-based management.

DESIGN

This was a 3-year prospective cohort study of children with asthma referred to our pediatric asthma center. Families completed Pediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ), the Asthma Control Test™ (ACT), and reported the number of days/month of albuterol use and wheezing at each clinic visit.

RESULTS

We enrolled 143 children, ages 7-17 years (mean = 10.6 ± 2.9), 56.6% male, 70.6% Caucasian. Patients were managed by the same MD (n = 65,45.5%) or APN (n = 78,54.5%) over time. The mean total PACQLQ significantly increased over the 3-year period (F = 67.418, p < .001). Total scores at the first visit were 4.8 ± 1.6, which improved to 6.1 ± 1 at the 3-month follow-up visit. This improvement was sustained at the 1, 2, and 3-year clinic visits. PACQLQ emotional function (F = 60.798, p < .001) and activity limitation (F = 41.517, p < .001) domains significantly improved as well. PACQLQ scores were significantly associated with improved ACT scores (r = .37 to .47, p < .05), fewer days/month of albuterol use (r = -.25 to -.36., p < .05), and wheezing (r = -.28 to -.33, p < .05). There were no significant differences in PACQLQ, or asthma clinical outcome measures between MD and APN providers.

CONCLUSION

Use of National Asthma Education and Prevention Program (NAEPP) guidelines significantly improved QOL of caregivers of children with asthma and in asthma-related symptoms. Improvements over time were independent of type of providers.

Concentration of fractional excretion of nitric oxide (FENO): A potential airway biomarker of restored CFTR function

BACKGROUND

Lower airway biomarkers of restored cystic fibrosis transmembrane conductance regulator (CFTR) function are limited. We hypothesized that fractional excretion of nitric oxide (FENO), typically low in CF patients, would demonstrate reproducibility during CFTR-independent therapies, and increase during CFTR-specific intervention (ivacaftor) in patients with CFTR gating mutations.

METHODS

Repeated FENO and spirometry measurements in children with CF (Cohort 1; n=29) were performed during hospital admission for acute pulmonary exacerbations and routine outpatient care. FENO measurements before and after one month of ivacaftor treatment (150 mg every 12h) were completed in CF patients with CFTR gating mutations (Cohort 2; n=5).

RESULTS

Cohort 1: Mean forced expiratory volume in 1s (FEV1 % predicted) at enrollment was 72.3% (range 25%-102%). Mean FENO measurements varied minimally over the two inpatient and two outpatient measurements (9.8-10.9 ppb). There were no clear changes related to treatment of pulmonary exacerbations, gender, genotype or microbiology, and weak correlation with inhaled corticosteroid use (P<0.05). Between the two inpatient measurements, FEV1 % predicted increased by 7.3% (P<0.03) and FENO did not change. In Cohort 2, mean FENO increased from 6.6 ppb (SD=2.19) to 11.8 ppb (SD=4.97) during ivacaftor treatment. Mean sweat chloride dropped by 58 mM and mean FEV1 % predicted increased by 10.2%.

CONCLUSIONS

Repeated FENO measurements were stable in CF patients, whereas FENO increased in all patients with CFTR gating mutations treated with ivacaftor. Acute changes in FENO may serve as a biomarker of restored CFTR function in the CF lower airway during CFTR modulator treatment.

Tgf-beta downregulation of distinct chloride channels in cystic fibrosis-affected epithelia

Rationale

The cystic fibrosis transmembrane conductance regulator (CFTR) and Calcium-activated Chloride Conductance (CaCC) each play critical roles in maintaining normal hydration of epithelial surfaces including the airways and colon. TGF-beta is a genetic modifier of cystic fibrosis (CF), but how it influences the CF phenotype is not understood.

Objectives

We tested the hypothesis that TGF-beta potently downregulates chloride-channel function and expression in two CF-affected epithelia (T84 colonocytes and primary human airway epithelia) compared with proteins known to be regulated by TGF-beta.

Measurements and Main Results

TGF-beta reduced CaCC and CFTR-dependent chloride currents in both epithelia accompanied by reduced levels of TMEM16A and CFTR protein and transcripts. TGF-beta treatment disrupted normal regulation of airway-surface liquid volume in polarized primary human airway epithelia, and reversed F508del CFTR correction produced by VX-809. TGF-beta effects on the expression and activity of TMEM16A, wtCFTR and corrected F508del CFTR were seen at 10-fold lower concentrations relative to TGF-beta effects on e-cadherin (epithelial marker) and vimentin (mesenchymal marker) expression. TGF-beta downregulation of TMEM16A and CFTR expression were partially reversed by Smad3 and p38 MAPK inhibition, respectively.

Conclusions

TGF-beta is sufficient to downregulate two critical chloride transporters in two CF-affected tissues that precedes expression changes of two distinct TGF-beta regulated proteins. Our results provide a plausible mechanism for CF-disease modification by TGF-beta through effects on CaCC.

Ivacaftor treatment of cystic fibrosis patients with the G551D mutation: a review of the evidence

Cystic fibrosis (CF) is a recessive disorder caused by mutations in the gene that encodes the CF transmembrane conductance regulator (CFTR) protein. CFTR protein is a chloride and bicarbonate channel that is critical for normal epithelial ion transport and hydration of epithelial surfaces. Current CF care is supportive, but recent breakthroughs have occurred with the advent of novel therapeutic strategies that assist the function of mutant CFTR proteins. The development and key clinical trial results of ivacaftor, a small molecule that targets gating defects in disease-causing CFTR mutations including G551D CFTR, are summarized in this review. The G551D mutation is reasonably common in the CF patient population and produces a CFTR protein that localizes normally to the plasma membrane, but fails to open in response to cellular cues. Ivacaftor treatment produces dramatic improvements in lung function, weight, lung disease stability, patient-reported outcomes, and CFTR biomarkers in patients with CF harboring the G551D CFTR mutation compared with placebo controls and patients with two copies of the common F508del CFTR mutation. The unprecedented success of ivacaftor treatment for the G551D CF patient population has generated excitement in the CF care community regarding the expansion of its use to other CF patient populations with primary or secondary gating defects.