Safety Review of 5-Grass Pollen Tablet from Pooled Data of Clinical Trials

Abstract

Background: The 5-grass pollen sublingual tablet has been approved for the treatment of grass pollen-induced allergic rhinoconjunctivitis in subjects with or without intermittent asthma.

Objective: To provide a comprehensive analysis of the safety profile of the 5-grass tablet on the basis of pooled data from 8 clinical trials.

Methods: Subjects (5-65 years old) with medically confirmed grass pollen-induced allergic rhinoconjunctivitis were included in the double-blind studies. Those with intermittent asthma not requiring treatment other than inhaled beta-2 agonists could participate. Randomized subjects received a 5-grass or placebo tablet daily 2 or 4 months preseasonally and coseasonally (5 single-season studies, over 3 years in a long-term study) or outside the season (phase I studies). Adverse events were pooled and analyzed descriptively.

Results: Among 2,512 subjects enrolled, 1,514 received the 5-grass tablet. A total of 1,038 adults and 154 pediatric (5-17 years old) subjects were treated with the 300 Index of Reactivity dose (vs 840 and 158 placebo recipients, respectively); 17% had intermittent asthma, and 62% were polysensitized. Adverse reactions (ADRs) reported in more than 10% of actively treated subjects were mild or moderate application-site reactions, for example, oral pruritus 25% (placebo 4%) and throat irritation 21% (placebo 3%). These generally occurred during the first week of treatment and decreased over time. They led to discontinuation in less than 2.5% of subjects. None of the 3 serious ADRs were reports of anaphylaxis. No notable differences were detected in terms of incidence, nature, and severity of ADRs between adult and pediatric populations, nor between subjects with or without asthma.

Conclusions: The pooled analysis in 1,514 subjects from 8 clinical studies demonstrates that the 5-grass pollen sublingual tablet has a similar good safety profile in adult and pediatric patients with or without mild, intermittent asthma.

Keywords: 5-Grass pollen tablet; Allergen-specific immunotherapy; Allergic rhinoconjunctivitis; Allergy immunotherapy; Asthma; Clinical trial; Grass pollen; Safety; Sensitization; Sublingual immunotherapy.