Main idea: This study confirmed both the clinical efficacy and safety of a sublingual liquid birch pollen extract in adults with birch pollen allergy in a pivotal phase III trial.
Background: Sublingual allergen immunotherapy (SLIT) has been demonstrated to be both clinically efficacious and safe. However, in line with the current regulatory guidance from the European Medicines Agency, allergen immunotherapy (AIT) products must demonstrate their efficacy and safety in pivotal phase III trials for registration.
The objective of the study was to investigate the efficacy and safety of sublingual high-dose liquid birch pollen extract (40,000 allergy units native [AUN]/mL) in adults with birch pollen allergy.
A randomized, double-blind, placebo-controlled, parallel-group multi-center trial was conducted in 406 adult patients with moderate-to-severe birch pollen-induced allergic rhinoconjunctivitis with or without mild-to-moderate controlled asthma. Treatment was started 3 to 6 months before the birch pollen season and continued during the season in 40 clinical study centers in 5 European countries.
Results: Primary efficacy results demonstrated a significant and clinically relevant (32%) reduction in the combined symptom and medication scores compared with placebo after 3 to 6 months of sublingual allergen immunotherapy. Significantly better rhinoconjunctivitis quality-of-life scores and the patient’s own overall assessment of his or her health status, including the visual analog scale score (Euro Quality of Life Visual Analogue Scale), were also demonstrated. In total, a good safety profile of sublingual allergen immunotherapy was observed.