D1.186 - Three years treatment with HDM injection allergen immunotherapy, omalizumab, or combination therapy in allergic asthma

Allergen immunotherapy (AIT) and biologics such as omalizumab are established treatment options for allergic asthma. Their combined efficacy in long-term disease control and potential remission remains under investigation.

In this prospective, randomized, controlled, parallel-group trial, 56 patients with mild-to-moderate house dust mite (HDM)-driven asthma were assigned to one of four treatment arms: omalizumab (A), omalizumab + subcutaneous immunotherapy (SCIT-HDM) (B), SCIT-HDM (C), or placebo (D). Patients were followed for 36 months. The primary outcomes were changes in daily inhaled corticosteroid (ICS) dose and annual asthma exacerbations. Secondary outcomes included the total asthma symptom score (TASS), total medication score (TMS), Asthma Control Test (ACT) score, asthma quality of life (AQLQ), spirometry, remission rates, and biomarker profiles.

After 36 months, all groups demonstrated significant reductions in ICS use, with the greatest reductions in Groups A (−455 µg) and B (−465 µg) (p<0.05 vs. C and D). Combination therapy (B) achieved the lowest rates of exacerbations and oral corticosteroid use, along with the highest remission rate (47%), compared with 31% (A), 29% (C), and 14% (D). Improvements in ACT scores, the FEV₁, and AQLQ scores were observed across all groups, with the most pronounced effects in Groups A and B. Biomarker analysis revealed significant decreases in IL-4, IL-5, and IgE levels in Groups A–C; an increase in IgG4 in the immunotherapy arms (B, C); and the greatest reductions in FeNO in Groups A and B (p<0.05).

Omalizumab and SCIT-HDM improved asthma control, reduced the use of ICSs, and improved quality of life over 36 months. Combination therapy provided the most consistent benefits, including the highest clinical remission rates and favorable biomarker changes, supporting its potential as an effective strategy for long-term disease modification in HDM-driven asthma.