Fuente: PubMed "pollen" Allergy Asthma Clin Immunol. 2026 Jul 11. doi: 10.1186/s13223-026-01054-w. Online ahead of print.ABSTRACTBACKGROUND: Pollen from birch and other trees in the birch homologous group (e.g., oak) is a common trigger of allergic rhinitis and/or conjunctivitis (AR/C) in Canada. The efficacy and safety of the tree sublingual immunotherapy (SLIT)-tablet in children with AR/C was evaluated post hoc in the Canadian subpopulation of a phase III, double-blind trial (EudraCT2020-004372-17).METHODS: Children and adolescents aged 5-17 years with moderate-to-severe tree AR/C were randomized to either daily tree SLIT-tablet or placebo for up to 52 weeks. Participants had free access to symptom-relieving medication. The primary endpoint was the average total combined score (TCS; sum of rhinoconjunctivitis daily symptom score [DSS] and daily medication score [DMS]) during birch pollen season (BPS). Average TCS during tree pollen season (TPS, consisting of birch, alder, hazel, and oak pollen seasons), oak pollen season (OPS), and pure OPS (excluding days from birch, alder, or hazel pollen seasons) were also analyzed.RESULTS: In the Canadian subpopulation (n = 87), treatment with the tree SLIT-tablet reduced the average TCS by 26.8% versus placebo during BPS (absolute difference [95% CI] = 1.89 [-0.71, 4.49], p = 0.138), 32.0% during TPS (absolute difference = 2.14 [-0.03, 4.32], p = 0.042), 46.6% during OPS (absolute difference = 3.70 [0.98, 6.42], p = 0.004), and 50.6% during pure OPS (absolute difference = 4.20 [1.12, 7.27], p = 0.005). Reductions in DSS and DMS with tree SLIT-tablet versus placebo were also observed. In the total trial population (N = 952), tree SLIT-tablet treatment reduced the average TCS by 19.2% versus placebo during BPS (absolute difference = 1.13 [0.42, 1.84], p = 0.002), 16.8% during TPS (absolute difference = 0.76 [0.26, 1.26], p = 0.003), 23.4% during OPS (absolute difference = 1.32 [0.60, 2.05], p < 0.001), and 19.9% during pure OPS (absolute difference = 1.03 [0.27, 1.80], p = 0.009). The tree SLIT-tablet was well tolerated in the total trial and Canadian subgroup populations.CONCLUSIONS: The tree SLIT-tablet demonstrated favorable efficacy and was well tolerated in Canadian children and adolescents with AR/C.CLINICAL TRIAL REGISTRATION: EudraCT 2020-004372-17 and NCT04878354.PMID:42432760 | DOI:10.1186/s13223-026-01054-w