Pharmacotherapy is widely used to manage allergic rhinitis (AR), but often does not adequately control symptoms. Allergy immunotherapy (AIT) should be considered for patients who are not adequately controlled on symptomatic treatment. AIT is gaining attention because of its potential to improve symptom relief and quality of life, and to provide sustained effect after the end of treatment by modifying the course of disease. However, evidence of efficacy needs to be shown for each individual AIT product, based on stateof-the-art studies. The majority of products cannot truly claim efficacy and disease-modifying potential, as evidence of such an effect from robust randomized double-blind, placebo -controlled long-term trials is lacking. The potential of a specific immunotherapy product should be evaluated against four levels of benefit defined by the European Medicines Agency (EMA) guideline on clinical development of AIT products. These clearly distinguish between efficacy of symptom relief in the first year, efficacy over 2-3 treatment years, sustained efficacy and disease modification treatment ends, and sustained absence of allergic symptoms in posttreatment years. The clinician's choice of a specific AIT product should take the level of evidence and risk/benefit into account, as the patient's quality of life and the product's potential long-term effect are important components of its overall cost-effectiveness. Without evidence of maintained clinical benefit and disease modification after the end of treatment, claims of long-term economic benefit of specific AIT products cannot be justified. This paper discusses the evidence that is essential for critical evaluation of product claims in health economic analysis comparing AIT products. (C) 2016 S. Karger AG, Basel
