Abstract
BACKGROUND: In the realm of allergen immunotherapy (AIT), the quality of evidence varies across different products, making it unjustifiable to extend overall conclusions to all AIT products, as highlighted by WAO and EAACI. OBJECTIVE: To confirm the efficacy of the 300 IR 5-grass pollen sublingual AIT (SLIT)-tablet through a specific meta-analysis of randomized controlled trials (RCTs) involving patients with allergic rhino-conjunctivitis (ARC) with/without mild/intermittent asthma. METHODS: Data from published RCTs on the 300 IR 5-grass SLIT-tablet were gathered from electronic databases (MEDLINE, ISI Web of Science, LILACS, the Cochrane Library and ClinicalTrial.gov) and manual searches up to November 2023. Populations, treatments, and outcome data were combined. Efficacy was assessed based on symptom score (SS) and medication score (MS), measured as standardized mean difference (SMD) or mean difference (MD). RESULTS: Results from 5 RCTs comprising 1468 patients revealed a significant reduction in SS (SMD, -0.36; 95%confidence interval [CI], -0.52 to -0.19; P < 0.05) and MS (SMD, -0.29; 95%CI, -0.40 to -0.19; P < 0.05) compared to placebo. The difference of -0.36 SMD for SS corresponds to a MD of -1.26 SS points, greater than the minimal important difference. Subgroup analysis did not show differences in efficacy according to age, asthma status, and geographic location of the study (USA, Canada, Europe, Russia). No safety issues were reported. CONCLUSION: This product-specific meta-analysis reinforces the evidence of clinical benefits associated with the 300 IR 5-grass SLIT-tablet, suggesting its appropriateness as a therapeutic choice for patients with ARC, irrespective of concurrent asthma, and exhibiting a favorable safety profile.