Sustained effects of grass pollen AIT

Abstract

We report the sustained efficacy of the SQ-standardized grass allergy immunotherapy tablet Grazax® (Phleum pratense 75000 SQ-T/2,800 BAU, ALK, Denmark) from a 5-year randomized, double-blind, placebo-controlled phase III trial. Adults with moderate-to-severe grass pollen allergy inadequately controlled by symptomatic medications were followed for 2 years after the completion of 3 years of treatment. The active group demonstrated a 31% reduction in median rhinoconjunctivitis symptom score over the season compared with placebo. Individual symptom scores favoured active treatment. Combined symptom and medication scores demonstrated a 33% reduction in medians with active treatment. Persistent clinical efficacy was accompanied by prolonged increases in allergen-specific IgG(4) antibodies and IgE-blocking factor, confirming clinical and immunological tolerance for at least 2 years after the treatment completion. No safety issues were identified during follow-up.