Cost-effectiveness of grass pollen subcutaneous immunotherapy (SCIT) compared to sublingual immunotherapy (SLIT) and symptomatic treatment in Austria, Spain, and Switzerland

Allergen immunotherapy (AIT) has been used to treat allergic disease since the early 1900s. Despite numerous clinical trials and meta-analyses proving AIT efficacious, it remains underused and is estimated to be used in less than 10% of patients with allergic rhinitis or asthma worldwide. In addition, there are large differences between regions, which are not only due to socioeconomic status. There is practically no controversy about the use of AIT in the treatment of allergic rhinitis and allergic asthma, but for atopic dermatitis or food allergy, the indications for AIT are not well defined. The elaboration of a wider consensus is of utmost importance because AIT is the only treatment that can change the course of allergic disease by preventing the development of asthma and new allergen sensitizations and by inducing allergen-specific immune tolerance. Safer and more effective AIT strategies are being continuously developed both through elaboration of new allergen preparations and adjuvants and alternate routes of administration. A number of guidelines, consensus documents, or both are available on both the international and national levels. The international community of allergy specialists recognizes the need to develop a comprehensive consensus report to harmonize, disseminate, and implement the best AIT practice. Consequently, the International Collaboration in Asthma, Allergy and Immunology, formed by the European Academy of Allergy and Clinical Immunology; the American Academy of Allergy, Asthma & Immunology; the American College of Allergy, Asthma & Immunology; and the World Allergy Organization, has decided to issue an international consensus on AIT.

Sublingual immunotherapy is well tolerated and data suggest its effectiveness for the treatment of allergic rhinitis in adults, but it lacks optimum dose definition. To assess the efficacy, safety, and optimal dose of grass pollen tablets for immunotherapy of patients with allergic rhinoconjunctivitis. In this multinational, randomized, double-blind, placebo-controlled study, 628 adults with grass pollen rhinoconjunctivitis (confirmed by positive skin prick test and serum-specific IgE) received 1 of 3 doses of a standardized 5-grass pollen extract, or placebo, administered sublingually using a once-daily tablet formulation. The treatment was initiated 4 months before the estimated pollen season and continued throughout the season. The primary outcome was Rhinoconjunctivitis Total Symptom Score; secondary outcomes included 6 individual symptom scores, rescue medication use, quality of life, and safety assessments. Both the 300-index of reactivity (IR) and 500-IR doses significantly reduced mean Rhinoconjunctivitis Total Symptom Score (3.58 +/- 3.0, P = .0001; and 3.74 +/- 3.1, P = .0006, respectively) compared with placebo (4.93 +/- 3.2) in the intent-to-treat and per-protocol analyses. The 100-IR group (4.70 +/- 3.1) score was not significantly different from placebo. Analysis of all secondary efficacy variables (sneezing, runny nose, itchy nose, nasal congestion, watery eyes, itchy eyes, rescue medication usage, and quality of life) confirmed the efficacy of the 300-IR and 500-IR doses. No serious side effects were reported. In the first pollen season, the efficacy and safety of sublingual immunotherapy with grass tablets was confirmed. The 300-IR and 500-IR doses both demonstrated significant efficacy compared with placebo. The risk-benefit ratio favors the use of 300-IR tablets for clinical practice.

Children with allergic rhinitis are likely to develop asthma.