Sustained clinical efficacy of sublingual immunotherapy with a high-dose grass pollen extract.

BACKGROUND: Sublingual immunotherapy (SLIT) with a high-dose 6-grass pollen SingleDose preparation was shown to be effective and safe in a 2-year randomized, double-blind, placebo-controlled trial. OBJECTIVE: We evaluated the effect of the third year of SLIT in comparison to the second year. METHODS: 46 grass pollen-allergic patients who had received active treatment for 3 consecutive years were included in the safety set. Diary data from 39 subjects were evaluated to calculate symptom and medication scores as well as 'well days'. RESULTS: Symptoms and medication intake further decreased in the third year of SLIT during the grass pollen season in comparison to the previous years and the number of 'well days' increased accordingly. No serious adverse events occurred during the three years of SLIT. CONCLUSION: The third year of SLIT with the high-dose 6-grass pollen preparation results in sustained and even further increased clinical efficacy.