Safety of 300IR 5-Grass Tablet in Children with Grass Pollen-Induced Allergic Rhinoconjunctivitis: Results of an Observational, Post-Marketing Safety Study

Rationale: We report safety data of 300IR 5-grass pollen tablet* from a post-marketing study conducted in grass pollen-allergic children in Europe. Methods: This multicenter, observational study included allergy immunotherapy-naïve children 5 to 9 years old with grass pollen-induced allergic rhinitis (AR) with/without conjunctivitis prescribed with 300IR tablet daily. Patients whose parent/legal guardian provided written consent were followed for safety and tolerability during the first 30 treatment days. Adverse reactions (ADRs) were analyzed descriptively. Results: 307 children (mean age: 7.1 years, SD: 1.42) were enrolled in 2015-2016: 71% were males, 70% polysensitized. The mean duration of their AR was 2 years. 76% had conjunctivitis, 36% had asthma. Over the first treatment month, 173 (56%) patients reported ADRs, most frequently application-site reactions (e.g., throat irritation, oral pruritus, oral paresthesia), mild in 73% of ADRs, moderate in 24%. ADRs occurred in 20% patients on Day 1, 14% on Day 2, 34% within Day 3-Day 10. 16 (5.2%) patients discontinued due to ADRs: application-site reactions in 3.3%. Two patients reported serious reactions. One experienced oral pruritus, mild urticaria and asthmatic attack (grade II anaphylaxis, Day 5), received oral antihistamine/inhaled salbutamol and resumed treatment. The other developed severe lip and eye swelling (angioedema, Day 26) resolved within six hours with IV antihistamine/corticosteroid. She was hospitalized overnight. No epinephrine use nor ICU was reported. Conclusions: Over the first treatment month, the safety profile of the 300IR tablet in 5 to 9-year-old children was consistent with that previously observed in pre- and post-marketing settings. *The US indication is for patients 10-65.