Durham SR, Yang WH, Pedersen MR, Johansen N, Rak S. J Allergy Clin Immunol. 2006;117:802–809
PURPOSE OF THE STUDY. To examine the efficacy and safety of sublingual immunotherapy (SLIT) in seasonal allergic rhinoconjunctivitis using timothy-grass–allergen tablets.
STUDY POPULATION. The study included 855 patients aged 18 to 65 from 55 centers in Canada and Europe with seasonal allergic rhinoconjunctivitis induced by grass pollen.
METHODS. A double-blind, randomized, parallel-group, placebo-controlled trial was conducted during 2002–2003. Patients had a history of allergic rhinoconjunctivitis during grass-pollen season for at least 2 years with a positive skin-prick–test result and serum-specific immunoglobulin E (IgE) to Phleum pratense. Individuals were randomly assigned to receive placebo or 2500, 25 000, or 75 000 SQ-T sublingual tablets administered daily. Daily diaries of symptoms (0–3) and rescue-medication use from pre–through post–grass-pollen season were kept, and a rhinoconjunctivitis quality-of-life (QoL) questionnaire was completed. Well days were calculated as those with a symptom score of ≤2 and no rescue-medication use.
RESULTS. A total of 790 (92%) participants completed the trial that included a mean duration of treatment of 18 weeks. Treatment with 75 000 SQ-T tabs revealed an improvement in symptom score (16%; P = .0710) and medication score (28%; P = .0470) when compared with placebo. The QoL score and number of well days also revealed improvement of 17% (P = .006) and 18% (P = .041), respectively. The 2 lower doses did not demonstrate significant change from placebo. Preseason treatment for 8 weeks with the 75 000 SQ-T dose showed an increased improvement of symptom score (21%; P = .002) and medication score (29%; P = .012) compared with placebo. In the 75 000 SQ-T group, specific IgG to P pratense was increased after 8 weeks of treatment and tripled posttreatment. Specific IgE levels increased after treatment initialized but remained unchanged thereafter. Therapy was well tolerated with only mild-to-moderate symptoms (consisting of primarily oral pruritis and throat irritation) noted in 53% of the patients.
CONCLUSIONS. Grass-pollen SLIT has a dose-dependent efficacy, is well tolerated, and provides improved QoL for patients with seasonal allergic rhinoconjunctivitis.
REVIEWER COMMENTS. SLIT for grass-pollen allergy holds promise as an alternative future therapy to subcutaneous immunotherapy that is attractive on many levels. Grass-pollen SLIT may have broader coverage range because of improved accessibility and more convenient administration, less discomfort than injections, and decreased risk of IgE-mediated severe systemic reactions. Preseason coverage with SLIT may improve symptoms and reduce medication requirements for treatment of seasonal allergic rhinoconjunctivitis.
- Copyright © 2007 by the American Academy of Pediatrics