Artemisia annua sublingual immunotherapy in pediatric patients with seasonal allergic rhinoconjunctivitis: Comparison to adult patients.

Background: Mounting evidence supports the efficacy of sublingual immunotherapy (SLIT) due to its favorable safety profile and convenience. However, there is limited research comparing the efficacy and safety of SLIT between adults and children.

Objective: The aim of this prospective study is to contribute additional corroborative findings by evaluating the efficacy and safety of a SLIT vaccine formulated with Artemisia annua extracts in children and adult patients with seasonal allergic rhinoconjunctivitis (SARC).

Methods: SARC patients (n = 75, SLIT group: 49, control group: 26) allergic to Artemisia were treated with a standardized SLIT or symptomatic drug following the end of the grass pollen season in 2022. Evaluation of the efficacy of SLIT during the peak pollen phase (PPP) in 2023 was based on combined scores of medication and rhinoconjunctivitis symptom (CSMRS) and visual analog scale (VAS). Tolerability assessment was based on the incidence of local or systemic reactions.

Results: Compared with the control group, the SLIT group showed significant improvement in CSMRS after 1 year of treatment with Artemisia annua-SLIT (P < 0.001). Besides, Artemisia annua-SLIT significantly reduced VAS to a greater level from baseline (P < 0.001) than pharmacotherapy (P < 0.01) at the PPP in 2023. Meanwhile, our observations revealed no significant differences in CSMRS or VAS between the monosensitized group (n = 14) and polysensitized group (n = 35), as well as between the <18 age group and ≥18 age group within the SLIT cohort in terms of clinical efficacy (P > 0.05). No severe systemic adverse events (AEs) were reported. Overall, 20/49 patients experienced mild to moderate treatment-related adverse events (TRAEs) following Artemisia annua-SLIT. In the <18 age group, 20% of patients (3/15) experienced TRAEs, while in the ≥18 age group, 50% of patients (17/34) experienced TRAEs.

Conclusion: For patients suffering from SARC, Artemisia annua-SLIT demonstrates significant therapeutic efficacy and an excellent safety profile. Notably, we have provided the first evidence that the efficacy of Artemisia annua-SLIT is consistent across both adult and pediatric populations.