BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is characterised by a severe hypersensitivity reaction to Aspergillus species. Current treatment relies on oral corticosteroids (OCS) and triazole antifungal therapy, but there is increasing evidence of the benefits of biologic therapies targeting type 2 inflammatory pathways. OBJECTIVE: To assess the real-world effectiveness of biologic therapies in patients with ABPA. METHODS: We performed a large retrospective single-centre analysis of patients with ABPA as defined by the modified ISHAM criteria between 2014 and 2022. Baseline characteristics were recorded. Clinical outcome was assessed at 12 months post commencement of a biologic including symptom scores, exacerbation frequency, corticosteroid use and multidisciplinary team (MDT) consensus of effectiveness. RESULTS: 74 patients received a biologic. 32% (n=24) received anti-immunoglobulin E therapy, 65% (n=48) anti-interleukin-5/5Rα therapy and 3% (n=2) anti-interleukin 4-Rα therapy. 65% (n=48) of patients were deemed to have a successful response at 12 months with a ≥50% reduction in OCS use. 35% (n=26) stopped or changed biologic during the follow-up period due to failed clinical response (n=21), side effects (n=4), or medical co-morbidities (n=1). There was a significant reduction in ACQ-6 score (p = <
0.0001), exacerbation rate over 12 months (p = <
0.0001) and maintenance OCS use (p = 0.0173). Univariate analysis revealed mucus plugging was associated with non-response to biologic therapy (p = 0.0189) CONCLUSION: Biologic therapies are effective in a number of patients with ABPA. However, further prospective clinical trials are required to determine the effectiveness and which phenotypes likely to respond. This data nevertheless increases the evidence-base for biologics in ABPA.