SQ® grass tablet for subligual immunotherapy: Current evidence and results of clinical trials conducted in Europe and North America

Allergic rhinoconjunctivitis is one of the most frequent chronic diseases with a prevalence in Germany of 13 - 24%. In similar to 50% of patients in Central Europe it is triggered by allergens from grass pollen. Allergy immunotherapy is currently considered to be the only treatment option with a long-lasting and potentially disease-modifying effect. For the SQ grass SLIT-tablet that has been authorized for marketing in Germany by the Paul-Ehrlich-Institut in 2006, a large number of clinical trials has been conducted in Europe and North America demonstrating the efficacy already in the first grass pollen season as well as long-term trials with adults, children and adolescents over the complete treatment period of 3 years and a 2-year follow-up period after the end of treatment. The current review describes the actual evidence available for the efficacy of the SQ grass SLIT-tablet based on the trials conducted in Europe and North America. Two long-term trials have demonstrated long-term efficacy and disease-modifying effect both in children and adults. The long-term trial with children is currently the only available trial with allergy immunotherapy investigating the preventive effect with respect to progression of the allergic disease to asthma versus placebo and is, thus, giving direction for future allergy immunotherapy trials. In children between 5 and 12 years of age with clinically relevant grass pollen-induced allergic rhinoconjunctivitis but without asthma the risk to develop asthma symptoms or to need asthma medication was statistically significantly lower compared with placebo over the entire trial period of 5 years (odds ratio OR = 0.66, p = 0.036 at end of study). With more than 5,700 patients in clinical trials and more than 25 peer-reviewed publications the trial results with the SQ grass SLIT-tablet comprise an essential part of the currently available body of evidence for allergy immunotherapy.