Three years treatment with HDM allergen immunotherapy, omalizumab, or combination therapy in allergic asthma: clinical outcomes and biomarkers.

Abstract

Background: Allergen immunotherapy (AIT) and biologics such as omalizumab are established treatments for allergic asthma, but long-term data on their combined use are limited.

Objective: To compare long-term clinical and immunological outcomes of omalizumab, subcutaneous AIT for house dust mite (SCIT-HDM), and their combination in mild-to-moderate allergic asthma.

Methods: In this prospective, randomized, controlled study, 79 patients with HDM-driven allergic asthma were assigned to omalizumab (A), omalizumab plus SCIT-HDM (B), SCIT-HDM (C), or standard therapy (D). Patients were followed for 36 months. Primary outcomes were changes in inhaled corticosteroid (ICS) dose and annual exacerbations. Secondary outcomes included symptom and medication scores, Asthma Control Test (ACT), asthma quality of life (AQLQ), lung function, remission rates, and biomarkers.

Results: All groups showed significant reductions in ICS use, with greater reductions in groups A and B than in C and D (p < 0.05). Combination therapy (B) resulted in lower exacerbation rates and reduced oral corticosteroid use compared to other groups. Improvements in ACT, FEV₁, and AQLQ were observed across all groups, with more consistent benefits in A and B. Clinical remission occurred most often in group B (47%), followed by A (31%), C (29%), and D (14%). Biomarker changes indicated reduced type 2 inflammation and immunological responses to therapy. No serious adverse events or systemic hypersensitivity reactions were observed.

Conclusions: Omalizumab, SCIT-HDM, and their combination improved outcomes over 36 months. Combination therapy showed the most consistent benefits, but results should be interpreted cautiously due to the small sample size. Further studies are needed.