Use of omalizumab in a severe asthma clinic

Real-World Effectiveness of Omalizumab in Severe Allergic Asthma: A Meta-Analysis of Observational Studies

BACKGROUND

Assessment of clinical outcomes in the real-world corroborates findings from randomized controlled trials (RCTs).

OBJECTIVE

This meta-analysis evaluated real-world data of omalizumab on treatment response, lung function, exacerbations, oral corticosteroid (OCS) use, patient-reported outcomes (PROs), health care resource utilization (HCRU), and school/work absenteeism at 4, 6, and 12 months after treatment.

METHODS

Observational studies in patients with severe allergic asthma (≥6 years) treated with omalizumab for ≥16 weeks, published from January 2005 to October 2018, were retrieved from PubMed, Embase, and Cochrane. A random-effects model was used to assess heterogeneity.

RESULTS

In total, 86 publications were included. Global evaluation of treatment effectiveness (GETE) was good/excellent in 77% patients at 16 weeks (risk difference: 0.77; 95% confidence interval [CI]: 0.70-0.84; I² = 96%) and in 82% patients at 12 months (0.82, 0.73-0.91; 97%). The mean improvement in forced expiratory volume in 1 second was 160, 220, and 250 mL at 16 weeks, 6 months, and 12 months, respectively. There was a decrease in Asthma Control Questionnaire score at 16 weeks (-1.14), 6 months (-1.56), and 12 months (-1.13) after omalizumab therapy. Omalizumab significantly reduced annualized rate of severe exacerbations (risk ratio [RR]: 0.41, 95% CI: 0.30-0.56; I² = 96%), proportion of patients receiving OCS (RR: 0.59, 95% CI: 0.47-0.75; I² = 96%), and number of unscheduled physician visits (mean difference: -2.34, 95% CI: -3.54 to -1.13; I² = 98%) at 12 months versus baseline.

CONCLUSION

The consistent improvements in GETE, lung function, and PROs, and reductions in asthma exacerbations, OCS use, and HCRU with add-on omalizumab in real-life confirm and complement the efficacy data of RCTs.

Omalizumab Treatment Response in a Population With Severe Allergic Asthma and Overlapping COPD

BACKGROUND

Asthma and COPD are common airway diseases. Individuals with overlapping asthma and COPD experience increased health impairment and severe disease exacerbations. Efficacious treatment options are required for this population. Omalizumab (anti-IgE) therapy is effective in patients with severe persistent asthma, but limited data are available on efficacy in populations with overlapping asthma and COPD.

METHODS

Data from the Australian Xolair Registry were used to compare treatment responses in individuals with asthma-COPD overlap with responses in patients with severe asthma alone. Participants were assessed at baseline and after 6 months of omalizumab treatment. We used several different definitions of asthma-COPD overlap. First, we compared participants with a previous physician diagnosis of COPD to participants with no COPD diagnosis. We then made comparisons based on baseline lung function, comparing participants with an FEV₁ < 80% predicted to those with an FEV₁ > 80% predicted after bronchodilator use. In the population with an FEV₁< 80%, analysis was further stratified based on smoking history.

RESULTS

Omalizumab treatment markedly improved asthma control and health-related quality of life in all populations assessed based on the Asthma Control Questionnaire and Asthma Quality of Life Questionnaire scores. Omalizumab treatment did not improve lung function (FEV₁, FVC, or FEV₁/FVC ratio) in populations that were enriched for asthma-COPD overlap (diagnosis of COPD or FEV₁ < 80%/ever smokers).

CONCLUSIONS

Our study suggests that omalizumab improves asthma control and health-related quality of life in individuals with severe allergic asthma and overlapping COPD. These findings provide real-world efficacy data for this patient population and suggest that omalizumab is useful in the management of severe asthma with COPD overlap.

Exacerbations of severe asthma

Exacerbations occur frequently in severe asthma. They result in significant morbidity and can lead to hospitalization and death. Severe exacerbations can also lead to an accelerated decline in lung function. Phenotyping severe asthma can aid with both prognostication of exacerbation risk and maintenance treatment selection to minimize future risks of exacerbations in severe asthma. The rate of exacerbations differs by phenotype, and is most frequent in refractory eosinophilic asthma and early onset allergic asthma. Phenotype specific therapy can reduce exacerbations in both these forms of severe asthma. Exacerbations are multi-component events. Each exacerbation represents an opportunity to assess and target treatment to the domains of airway pharmacotherapy, self-management behaviour, risk factors, and relevant co-morbidities.

How to set up a severe asthma service

Severe asthma affects 5-20% of the asthma population but is discordantly responsible for the major burden of illness and impairment to quality of life. Patients with severe asthma continue to experience ongoing symptoms despite maximal therapy. A severe asthma service provides a systematic approach to the management of the disease and aids in confirming the correct diagnosis, managing comorbid conditions that may mimic or aggravate asthma, and provides the environment to optimize treatment and asthma self-management skills and education. A severe asthma service is also the ideal environment for trialling add-on therapies and hence can improve patient outcomes and clinical practice. Within such a service there are many opportunities for training and research. In this article we describe the purpose of a severe asthma clinic, the necessary components of a service including staffing and facilities and the processes for trialling additional therapies used in the management of severe asthma.