Background The monoclonal anti-IgE agent Omalizumab holds an established place in the management of severe allergic asthma patients (GINA Step 5). Fungal allergic asthma possesses added complexity as fungi are ubiquitous in our environment and are capable of not only triggering asthma, but may grow, colonise and infect host tissue. Current treatment approaches include: Allergen avoidance, mucus reduction, control of bacterial infection, control of inflammation, reducing fungal burden and recently blockade of allergy using Omalizumab.
Aims/purpose Investigate the response to Omalizumab in severe asthma patients who are sensitised to fungal allergens compared to those who are non-fungal allergic. Current literature describes the use of Omalizumab in fungal allergic airways disease, though published data takes the form of case reports/series with limited total population.
Methods Retrospective cohort study of severe asthma patients treated with Omalizumab (n = 168). Patients were grouped into fungal or non-fungal allergy status, followed by a comparison of the change in a variety of clinical and physiological outcomes at 16 weeks and 52 weeks from baseline between these two groups. The change in Asthma Quality of Life Questionnaire (AQLQ) between baseline and 16 weeks was utilised as the primary outcome. Groups will be compared using an unpaired t-test or Chi-squared test, as appropriate, to test for non-inferiority (threshold −0.25) in the fungal allergic group compared to the non-fungal allergic group.
Results The fungal allergic group (n = 76) was found to have a mean AQLQ difference between baseline and 16 weeks of +1.34 ( ± 1.25). When compared to the non-fungal allergic cohort, the fungal allergic group was found to have a statistically significant mean AQLQ difference between baseline and 16 weeks of −0.41 (95% CI: −0.14 – −0.81). See Figure 1.
Conclusion Fungal allergic patients have a less profound AQLQ response to Omalizumab than non-fungal allergic although the benefit is still clinically significant in the majority of cases. The reduced benefit is statistically different in terms of change, though it does not fulfil the a-priori threshold for non-inferiority.