Safety of specific sublingual immunotherapy with SQ standardized grass allergen tablets in children

The aim of the study was to confirm the safety of an orodispersible grass allergen tablet 75,000 SQ-T (Grazax, ALK-Abelló A/S, Hørsholm, Denmark) in children aged 5-12 yr. The study was randomized, double-blinded and placebo-controlled. Sixty children aged 5-12 yr suffering from grass pollen-induced rhinoconjunctivitis (with or without asthma) from five centres in two countries (three in Germany and two in Spain) participated in the study. They were randomized at the ratio of 3:1 as receiving either Grazax or placebo tablet given sublingually once daily for 28 days outside the grass pollen season. A total of 810 treatment-related adverse events were reported in the Grazax group. The majority of these were local reactions in the mouth or throat and were mostly mild (71%) to moderate (27%) in severity and resolved within days. Thirty-five (78%) subjects treated with Grazax and five (33%) treated with placebo reported at least one treatment-related adverse event. Oral pruritus, throat irritation, mouth oedema and ear pruritus appeared as the most frequently reported treatment-related adverse events. 62% (28 of 45) of the actively treated subjects reported oral pruritus, 36% (16 of 45) throat irritation, 31% (14 of 45) mouth oedema and 22% (10 of 45) ear pruritus. Two actively treated subjects withdrew from the study: one subject due to four adverse events (moderate eye pruritus, moderate pharyngolaryngeal pain, moderate non-cardiac chest pain and moderate dysphagia) and one subject due to a serious adverse event (asthmatic attack). The subjects recovered completely from the events. In conclusion, in the present study, Grazax was in general tolerated in a paediatric population and considered suitable for further clinical investigations in children.