Sublingual-swallow immunotherapy (SLIT) with a standardized five-grass-pollen extract (drops and sublingual tablets) versus placebo in seasonal rhinitis

Abstract

Background: Recent studies have demonstrated the efficacy of sublingual-swallow immunotherapy (SLIT) in seasonal and perennial rhinitis. Sublingual administration of solutions is not convenient for all patients. The aim of the study was to evaluate the efficacy and safety of immunotherapy administered sublingually, initially as drops, and then as tablets during maintenance therapy.

Methods: A total of 126 patients with grass-pollen seasonal rhinitis were included in this double-blind, randomized, placebo-controlled trial. During the progression of doses phase, the five-grass extract was given as sublingual drops from 1 to 100 IR/ml. Once the 100 IR dose was reached, the drops were replaced by a single 100-IR sublingual tablet per day.

Results: Throughout the grass-pollen season, patients in the active treatment group had significantly lower (P < 0.05) total conjunctivitis and ocular redness scores. Rhinitis symptoms were not significantly different between the two groups. Patients given the active treatment were significantly (P < O.02) less likely to have asthma symptoms. The global medication score showed no significant difference between the two groups. A highly significant difference in favor of the active treatment group was seen in inhaled salbutamol use (P < 0.01).

Conclusions: Clinical benefits achieved during the present study included significant improvements in conjunctivitis symptoms and prevention of asthma symptoms. The overall safety profile of the active treatment (drops or tablets) was good.