Temperature-controlled Laminar Airflow (TLA) in symptomatic severe asthma – a post hoc analysis of severe exacerbations, quality of life and health economics

Purpose

Uncontrolled severe asthma constitutes a major economic burden to society. Add-ons to standard inhaled treatments include inexpensive oral corticosteroids and expensive biologics. Nocturnal treatment with Temperature-controlled Laminar Airflow (TLA; Airsonett®) could be an effective, safe and cheaper alternative. The potential of TLA in reducing severe asthma exacerbations was addressed in a recent randomised placebo-controlled trial (RCT) in patients with severe asthma (Global Initiative for Asthma (GINA) step 4/5), but the results were inconclusive. We re-analysed the RCT with severe exacerbations stratified by the level of baseline asthma symptoms and Quality of Life.

Methods

More uncontrolled patients, defined by Asthma Control Questionnaire 7 (ACQ7) > 3, EuroQoL 5-Dimension Questionnaire Visual Analogue Scale (EQ5D-VAS) ≤ 65 and Asthma Quality of Life Questionnaire (AQLQ) ≤ 4 were selected for re-analysis. The rates of severe asthma exacerbations, changes in QoL and health-economics were analysed and compared between TLA and placebo.

Results

The study population included 226 patients (113 TLA / 113 placebo.) The rates of severe asthma exacerbations were reduced by 33, 31 and 25% (p = 0.083, 0.073, 0.180) for TLA compared to placebo, dependent on selected control measures (ACQ7, EQ5D-VAS, AQLQ, respectively). For patients with less control defined by AQLQ≤4, the difference in mean AQLQ0-12M between TLA and placebo was 0.31, 0.33, 0.26 (p = 0.085, 0.034, 0.150), dependent on selected covariate (AQLQ, EQ5D-VAS, ACQ7, respectively). For patients with poor control defined by ACQ7 > 3, the difference in EQ5D-5 L utility scores between TLA and placebo was significant at 9 and 12 months with a cost-effective ICER. The results from the original study did not demonstrate these differences.

Conclusion

This post hoc analysis demonstrated an effect of TLA over placebo on severe exacerbations, asthma control and health economics in a subgroup of patients with more symptomatic severe allergic asthma. The results are consistent with the present recommendations for TLA. However, these differences were not demonstrated in the full study. Several explanations for the different outcomes have been outlined, which should be addressed in future studies.

Funding

NIHR Health Technology Assessment Programme and Portsmouth Hospitals NHS Trust.

Time to onset of improvements in Quality of Life from Temperature-controlled Laminar Airflow (TLA) in severe allergic asthma

BACKGROUND

Allergen avoidance is important in allergic asthma management. Nocturnal treatment with Temperature-controlled Laminar Airflow (TLA; Airsonett^®) has been shown to provide significant reduction of exposure to allergens in the breathing zone, leading to long-term reduction in airway inflammation and improvement in quality of life. Allergic asthma patients uncontrolled on GINA step 4 were found to benefit the most. A frequently asked question from clinicians and funders is related to time to onset (TTO) of improvements for patients using TLA.

METHODS

Asthma Quality of Life Questionnaire (AQLQ) scores were collected in a previous study. TTO of improvements in Quality of Life was analysed for difference (TLA-placebo) in Area-under-Curve using backwards deletion from 12, 9, 6, 3 down to 1 month for the AQLQ total score, the four individual domains and specifically the sleep question.

RESULTS

Patients with uncontrolled asthma on GINA step 4 (n = 87)) reported a statistically significant and clinically relevant (≥0.5 point) improvement in total AQLQ score (0.57; p = 0.009) after 3 months treatment for TLA over placebo. The shortest TTO was within 1 month for the environmental domain (0.68; p = 0.016) and the sleep question (0.771; p = 0.037). TTO for the emotional and symptom domains was 3 months (0.66; p = 0.020 and 0.64; p = 0.014 respectively) and for the activity domain 6 months (0.47; p = 0.036).

CONCLUSION

Nocturnal avoidance of allergens using TLA provided a statistically significant and clinically relevant improvement in total AQLQ score within 3 months in patients in the GINA 4 + ACT<18 group. Questions related to sleep quality may provide the first signal of response already within a month after commencing treatment.

Safety of formoterol in children and adolescents: experience from asthma clinical trials

BACKGROUND

The safety of long-acting β(2) agonist (LABA) therapy in asthma remains controversial but no large scale analyses have been published of LABA safety in children.

METHODS

The frequency of asthma-related deaths and hospitalisations following formoterol use in children (4-11 years) and adolescents (12-17 years), compared with non-LABA treatment, was assessed in all AstraZeneca-sponsored, randomised, controlled, parallel-group trials (≥3 months) where formoterol was used as maintenance and/or as reliever therapy.

RESULTS

11,849 children and adolescents under the age of 18 years from 41 trials were identified, 82% of whom used an inhaled corticosteroid (ICS) as concomitant medication. The number of asthma-related deaths (one 13-year-old boy among 7796 formoterol-treated patients, and none among 4053 non-LABA-treated patients) was too low to allow any between-group comparison. The frequency of patients with asthma-related hospitalisations was not different in formoterol-treated versus non-LABA-treated patients, either in children (1.16% (38/3263) vs 1.11% (24/2165)) or in adolescents (0.51% (23/4533) vs 0.85% (16/1888)). Asthma-related hospitalisations based on daily dose of formoterol were: (A) 4.5 or 9 µg: 1.9% (18/980); (B) 18 µg: 0.5% (14/2870); (C) 36 µg: 0% (0/67); and (D) variable dosing: 0.75% (29/3879). There was no difference between formoterol-treated and non-LABA-treated patients as regards ethnicity.

CONCLUSIONS

Formoterol use in children and adolescents (4-17 years) with asthma in this large study where the majority are prescribed concomitant ICS is not associated with any increased risk of asthma-related hospitalisations. The results are not influenced by dose or ethnicity.

Long-acting beta-agonists: a review of formoterol safety data from asthma clinical trials

The safety of long-acting beta(2)-agonist (LABA) treatment in asthma has been questioned following reported increased respiratory deaths when salmeterol was added to usual pharmacotherapy. The aim of this study was to examine whether asthma, cardiac or all-cause mortality and morbidity were increased with formoterol use. The analysis included all AstraZeneca randomised controlled parallel-group asthma trials of 3-12-months duration involving formoterol. Risks associated with formoterol use compared with non-LABA treatment, overall and in combination with inhaled corticosteroids (ICS), were assessed using an intention-to-treat analysis of the rates and rate ratios of deaths and serious adverse events (SAEs). The main objective of this study was to compare asthma-related mortality in patients using formoterol and those not using formoterol. There were eight asthma-related deaths (0.34 per 1,000 person-yrs) among 49,906 formoterol-randomised patients (92% using ICS), and two (0.22 per 1,000 person-yrs) among 18,098 patients (83% using ICS) not randomised to formoterol, which was nonsignificant. Asthma-related SAEs (>90% of which were hospitalisations) were significantly fewer among formoterol-randomised patients (0.75 versus 1.10%). There was no increase in asthma-related SAEs with increased daily doses of formoterol (9, 18 or 36 microg). There was no significant difference in cardiac mortality or noncardiac nonasthma-related mortality in formoterol-randomised compared to non-LABA-treated patients. All-cause mortality was similar. In the data set in which all subjects were prescribed ICS at baseline, there were seven asthma-related deaths (0.32 per 1,000 person-yrs) among 46,003 formoterol-randomised patients and one (0.14 per 1,000 person-yrs) among 13,905 patients not randomised to formoterol, which was also nonsignificant. There were few asthma-related or cardiac-related deaths among patients randomised to formoterol, and all differences were nonsignificant compared with non-long-acting beta(2)-agonist-randomised patients. However, despite data on >68,000 patients, the power was insufficient to conclude that there was no increased mortality with formoterol. Cardiac-related serious adverse events were not increased, and asthma-related serious adverse events were significantly reduced with formoterol.