Once daily sublingual immunotherapy without updosing--A new treatment schedule.

Background: Treatment regimens with specific immunotherapy include updosing. Due to excellent tolerance of sublingual immunotherapy (SLIT), it was hypothesized that administration of once-daily SLIT could be initiated safely without updosing. The objective was to evaluate tolerability of SLIT administered once daily without updosing.

Methods: 135 patients suffering from allergic rhinitis with/without asthma were included in a double-blind, placebo-controlled, parallel-group study. Patients were randomized into two groups. Group 1 (n = 69) received active treatment throughout the study, including 10 days updosing (T1), 20 days maintenance treatment (T2), and 2 consecutive months on maintenance treatment (T3 and T4). Group 2 (n = 66) obtained placebo updosing (T1), placebo maintenance (T2), initiated active treatment (maintenance) at T3, and continued active treatment until the end of the study (T4). Adverse events (AEs) were assessed at T1-T4. 66 grass- and 69 mite-allergic patients were evenly distributed between groups.

Results: 229 AEs were reported, 157 AEs were related to treatment. The most frequently reported AEs (>5% of patients in any group) related to treatment were oral itching, ocular itching, rhinitis, and sublingual edema. For group 1 at T2, the rate of all AEs related to treatment per dose administered was 1.79%, and for group 2 at T3 the rate was 1.33% (p = 0.37). For the most frequently reported AE, oral itching, the rate per dose administered was 1.01% for group 1 at T2, and 0.74% for group 2 at T3 (p = 0.53).

Conclusions: Once daily SLIT was well tolerated and can be safely initiated without updosing.