Sublingual grass allergen tablet immunotherapy provides sustained clinical benefit with progressive immunologic changes over 2 years.
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.


CONCLUSIONS
Grass allergen tablet immunotherapy showed progressive immunologic changes and highly significant efficacy over 2 years of continued treatment.
D000286:Administration, Sublingual; D000328:Adult; D052179:Antigens, Plant / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D003231:Conjunctivitis / Q000188:drug therapy* / Q000209:etiology; D003888:Desensitization, Immunologic / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006967:Hypersensitivity / Q000150:complications*; D008297:Male; D008875:Middle Aged; D006109:Poaceae / Q000276:immunology*; D012220:Rhinitis / Q000188:drug therapy* / Q000209:etiology; D013607:Tablets; D016896:Treatment Outcome
D052179:Antigens, Plant; D013607:Tablets