Abstract:
BACKGROUND: This is an interim analysis of a randomized,
double-blind, placebo-controlled phase III trial with 3 years of
daily treatment with grass tablet immunotherapy (GRAZAX; ALK-Abelló
A/S, Hørsholm, Denmark) or placebo, followed by 2 years of follow-up
to assess the persistent efficacy.
OBJECTIVE: We sought to evaluate
the efficacy and safety of specific immunotherapy with grass
allergen tablets compared with placebo after treatment covering 2
consecutive grass pollen seasons.
METHODS: The interim analyses
included 351 adult participants with moderate-to-severe allergic
rhinoconjunctivitis caused by grass pollen. Participants were
treated with active (n = 189) or placebo (n = 162) tablets for an
average of 22 months. All participants were allowed to use
symptomatic rescue medication.
RESULTS: The primary efficacy
analysis showed highly significant mean reductions of 36% in rhinoconjunctivitis symptom score
(P < .0001; median reduction, 44%)
and 46% in rhinoconjunctivitis medication score (P < .0001; median
reduction, 73%) in the active group relative to the placebo group.
Mean rhinoconjunctivitis quality of life was 33% better (P < .0001;
median, 40%). Clinical improvements were paralleled by significant
changes in allergen-specific immunoglobulins.
The treatment was well
tolerated, and adverse events led to withdrawal in less than 1% of
participants. There were no serious adverse events related to
treatment.
CONCLUSION: Grass allergen tablet immunotherapy showed
progressive immunologic changes and highly significant efficacy over
2 years of continued treatment.
