Safety of Timothy Grass Sublingual Immunotherapy Tablet in Children: Pooled Analyses of Clinical Trials

Abstract Background Timothy grass sublingual immunotherapy (SLIT)-tablets are indicated for children with allergic rhinitis with or without conjunctivitis (AR/C). Objectives To use pooled analyses to assess the short- and long-term tolerability and safety of timothy grass SLIT-tablet in children. Methods Data from 9 double-blinded, randomized European or North American trials that included children with AR/C treated up to 3 years with once-daily timothy grass SLIT-tablet or placebo were pooled. Results In all, 1818 (SLIT-tablet=923; placebo=895) subjects were included in the analysis. The frequency of treatment-emergent adverse events (AEs) was 86% in the SLIT-tablet and 83% in the placebo groups and of treatment-related AEs (TRAEs) was 59% and 23%, respectively. Most (98%) TRAEs were mild-to-moderate in severity. The two most common TRAEs with SLIT-tablet were oral pruritus (33%) and throat irritation (19%), which had a median onset of 1 day and recurrence of 14.5 and 5 days, respectively. In all, 8% of subjects in the SLIT-tablet and 2% in the placebo groups discontinued due to AEs. There were 7 serious AEs assessed as related to SLIT-tablet, 1 systemic allergic reaction (severe with a drop in blood pressure), 3 epinephrine administrations, no eosinophilic esophagitis events, and no serious airway obstructions. The safety profile was similar in subjects across geographic regions and with and without asthma. Conclusions Pooled data indicate that short- and long-term timothy grass SLIT-tablet is well tolerated in children, regardless of geographic region. AEs were generally local, mild, and transient allergic reactions.