Increasing long-term safety of seasonal grass pollen sublingual immunotherapy: the ECRIT study

The usual build-up phase of days or weeks in allergen-specific immunotherapy entails inconveniences for individuals with symptoms only during the pollen season. Additionally, affected individuals often appear for treatment shortly before the expected start of the season without enough time for titration. This double-blind, placebo-controlled study evaluated the safety of ultra-rush grass pollen immunotherapy with sublingual drops (Staloral)® in co-seasonal treatment over three consecutive seasons.

209 patients with grass pollen allergic rhinitis received ultra-rush titration (30, 90, 150 and 300 index of reactivity (IR)) of a five grass pollen mixture or placebo every 20 min at the start of the season, followed by 300 IR daily or placebo until the end of the respective season for three consecutive years. Adverse events were documented.

Mean treatment duration varied between seasons (81.8 - 92.7 days). No systemic or anaphylactic reactions were reported and no unexpected adverse events were observed. Adverse events included application site irritation, oedema, abdominal pain and diarrhoea. Fourteen patients discontinued treatment due to adverse events (placebo: four (6%) patients, verum: ten (7%) patients). Adverse events decreased in frequency over each consecutive year of treatment.

Seasonal sublingual immunotherapy with ultra-rush titration is well tolerated even when administered as co-seasonal treatment. It may be a valuable option for patients who present late.