Efficacy and Safety of Ragweed SLIT-Tablet in Children with Allergic Rhinoconjunctivitis in a Randomized, Placebo-Controlled Trial.

Background: Ragweed sublingual immunotherapy (SLIT) tablet reduces symptoms and symptom-relieving medication use in adults with allergic rhinitis with or without conjunctivitis (AR/C) but has not been evaluated in children.

Objective: This international, multicenter, double-blind, placebo-controlled trial evaluated the efficacy and safety of ragweed SLIT-tablet in children with AR/C.

Methods: Children (N = 1025; 77.7% polysensitized) aged 5 to 17 years with ragweed pollen-induced AR/C with or without asthma (FEV ≥80% predicted) were randomized 1:1 to daily ragweed SLIT-tablet (12 Amb a 1-Unit) or placebo for up to 28 weeks (NCT02478398). The primary end point was the average total combined score (TCS; sum of rhinoconjunctivitis daily symptom score [DSS] and daily medication score [DMS]) during peak ragweed pollen season (RPS). Key secondary end points were TCS during the entire RPS, and DSS and DMS during the peak RPS.

Results: Relative TCS (95% CI) improvements with ragweed SLIT-tablet versus placebo were -38.3% (-46.0% to -29.7%; least square [LS] mean difference, -2.73; P < .001) during peak RPS and -32.4% (-40.7% to -23.3%; LS mean difference, -1.86; P < .001) during the entire RPS. DSS and DMS during peak RPS improved with SLIT-tablet versus placebo by -35.4% (-43.2% to -26.1%; LS mean difference, -1.40; P < .001) and -47.7% (-59.8% to -32.5%; LS mean difference, -1.84; P < .001), respectively. Asthma DSS, short-acting β-agonist use, and nocturnal awakenings during peak RPS improved with SLIT-tablet versus placebo by -30.7%, -68.1%, and -75.1%, respectively (all nominal P ≤ .02). No events of anaphylaxis, airway compromise, or severe treatment-related systemic allergic reactions were reported.

Conclusions: Ragweed SLIT-tablet significantly improved symptoms and decreased symptom-relieving medication use in children with ragweed pollen-induced AR/C and was well tolerated.