Severe asthma with fungal sensitization (SAFS) and allergic bronchopulmonary aspergillosis (ABPA) are important complications of severe asthma. The evidence for treating them with omalizumab is limited.

To determine the effectiveness of treatment with omalizumab in patients with severe allergic asthma comparing those with and without evidence of fungal sensitization using data recorded in the Australian Xolair Registry.

Data from 205 patients who received omalizumab and recorded in the Australian Xolair Registry were analyzed to determine change in the Juniper 5-item Asthma Control Questionnaire (ACQ-5) score, exacerbation frequency, and oral corticosteroid dose over a 24-month period of omalizumab treatment. Patients were grouped into cohorts on the basis of fungal sensitization, and an analysis of improvement in outcomes between baseline and 24 months was conducted within each group. A further subgroup analysis of patients with ABPA was also conducted.

Patients with SAFS (n = 62), including those with ABPA (ASAFS), were as likely to demonstrate significant improvements in ACQ-5 score and exacerbations and reduced regular oral corticosteroid dose over 24 months as those with severe asthma without sensitization to fungi (n = 156). After adjusting for age, sex, body mass index, smoking history, and baseline FEV%, the effects still remained. A subgroup analysis of 11 patients with ABPA similarly demonstrated a significant improvement on omalizumab.

Omalizumab is an effective therapy in ASAFS, leading to sustained improvements in symptoms and exacerbations for 24 months. The benefit for ABPA is less clear because of the small sample size.